THE LIVING PLANT A building that purifies air and water and at the same time grows food THE LIVING PLANT Ruben Smits - 1324276 [email protected] AR3Ae011 - LAB09 - Msc3 tutors: ir. A. Snijders & ir. T. Homans All rights reserved. No part of this second mentor: A. van Timmeren publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, first published: photocopying, recording or otherwise, without January 15th 2013, Delft, the Netherlands the written permission of Ruben Smits. Table of contents

1. Motivation 5 2. Challenge 7 3. Context 9 4. Research 13 4.1 Abstract 13 4.2 Research approach; methods and techniques 13 4.3 Air treatment with plants 14 4.4 Water treatment with plants 17 4.5 Growing food on waste streams 21 4.6 Conclusions and end products 25 5. List of references 29

3 MOTIVATION “… unlike simple physico-chemical systems that can be ade- blossom to sapling to magnificent old age, the cherry tree’s quately studied using a linear train of thought, biological sys- growth is regenerative. We could say its life cycle is cradle- tems, when viewed at a long enough time scale, are recursive, to-cradle: after each useful life it provides nourishment for … If the loop was not complete, the structures that comprise something new. In a cradle-to-cradle world - a world of natu- it would not exist.” (Passioura, 1999) ral cycles powered by the sun - growth is good, waste nutri- tious, and ’s diverse responses to place are the source As human beings, like all other animals, we are very depen- of intelligent design.” (McDonough & Braungart, 2001) dent for our survival on the services provided by plants. On the other hand, plants depend on other organisms, like human So, according to McDonough and Braungart we should design beings, for nutrients, seed dispersal and pollination. Plants are buildings that turns solar energy into food, sequesters car- the only organisms that are able to directly use the energy of bon, produces oxygen and filter water. The building should the sun to turn water and carbon dioxide into carbohydrates play a role in the local ecosystem and after its life it should and oxygen. The oxygen we breathe and the carbohydrates be a source of nutrients for next generations. The picture of a we either eat directly or feed to our animals. Carbohydrates building that functions like a cherry tree is a very striking im- are also used for a lot of other things like building materials, age. But why do we not look at this from another perspective. fibres, fuel, etc. Besides that, plants purify water by taking out Apparently these plants provide a lot of services to animals nutrients with their roots and by evapotranspiration through (and humans alike). So, why would we not use these services the leaves. Human beings are thus dependent on plants for in buildings? Can we grow plants in buildings to provide the oxygen, sugars and clean water. In the built environment, this building with oxygen, filter the water and make food? And interrelationship is hardly visible. Food is grown outside the if so, what would the consequences be for the design of the city, air is treated mechanically and water is processed in large building? As we are now introducing another living organism purification plants. to design for, we probably have to deal with different de- mands. Do these demands conflict with the human demands? “How is it possible for industry and nature to fruitfully co- exist? Well, consider the cherry tree. Each spring it produces thousands of blossoms, only a few of which germinate, take root and grow. Who would see cherry blossoms piling up on the ground and think, “How inefficient and wasteful”? The tree’s abundance is useful and safe. After falling to the ground, the blossoms return to the soil and become nutrients for the surrounding environment. Every last particle contributes in some way to the health of a thriving ecosystem. Waste that List of references stays waste does not exist. Instead, waste nourishes; waste McDonough, W., & Braungart, M. (2001). The Extravagant equals food. Gesture: Nature, Design and the Transformation of Human Industry. In J. Schor (Ed.), Sustainable Planet: As a cherry tree grows, it enriches far more than the soil. Solutions for the Twenty-first Century. Boston, Unit- Through photosynthesis it makes food from the sun, provid- ed States of America: Beacon Press. ing nourishment for animals, birds and microorganisms. It se- Passioura, J. (1999). A plant science manifesto. In B. J. Atwell, questers carbon, produces oxygen and filters water. The tree’s Kriedemann, P.E. and Turnbull, C.G.N. (Ed.), Plants in limbs and leaves harbour a great diversity of microbes and Action: Adaptation in Nature, Performance in Culti- insects, all of which play a role within a local system of natu- vation. Melbourne, Australia: Macmillan Education ral cycles. Even in death the tree provides nourishment as it Australia Pty Ltd. decomposes and releases minerals that fuel new life. From 5 CHALLENGE Looking at an urban ‘ecosystem’, one can see that it is very building syndrome (Nelson & Wolverton, 2011). In a natural linear on the local scale. There is a clear distinction between ecosystem however, waste produced in one process is food input and output. When the first cities appeared, food for the for another. In this way resources are produced locally and CO2 citizens was produced in close proximity or even within the waste is processed locally. CLEAN WATER city. With increasing globalization and trade, cities became more and more dependent for their resources from a larger This research explores the possibilities of closing the cycles of area. Modern cities are highly dependent from global sup- water, carbon and nutrients in an urban environment by the plies. All resources are in one way or another imported to the use of plants. At the building systems level there is an input city. Whether it is the rather local supplies of drinking water, of energy (electricity and gas for the building and food for the for example from the dunes and the Amsterdam-Rijnkanaal people), drinking water and fresh air; the output consists of in Amsterdam, or the global dependence for food and min- wastewater, waste air (high amounts of CO2, VOCs and PM10) erals. When these resources have been used, they become and solid waste. To start closing the cycles, the neighbouring waste. This waste has to be dealt with locally or exported to buildings’ output will be the input for the design. WASTE WATER a place where it can be processed. So actually all kinds of re- O2 sources are imported to the city, where they are being pro- In this research the Teleport area, a business area around Am- cessed, after which they are being exported again. The pro- sterdam Sloterdijk station, is used as a case study. The before cessing causes a huge stress on the local environment, which mentioned ‘building’s output’ are in this case the output of a FOOD is reflected in high levels of carbon dioxide, nitrogen oxides group of buildings in the Teleport area. This case study is used and particulate matter in the air. Also the solid waste, if not to show the amount of space needed to deal with the output SOLID WASTE exported, forms a problem for soil and water quality. Not only of these buildings. As it is just a case study of in a more generic the ‘’ suffers from low air, water and soil research, the basics could also be applied to other scales, for quality, it also has its effects on human beings. Poor indoor air example the scale of a single building or a complete neigh- quality for example, is considered to be the main cause of sick bourhood. closing the cycles of water, air and solid waste in a building using plants

FOOD WASTE WATER WASTEWATER MATERIALS POLLUTION ENERGY List of references Nelson, M., & Wolverton, B. C. (2011). Plants + soil/wetland microbes: Food crop systems that also clean air and water. Advances in Space Research, 47(4), 582-590. inputs and outputs of an urban ecosystem 7 CONTEXT The Teleport area around Amsterdam Sloterdijk train station is a very monofunctional office district. Besides offices and premises there are a hotel and a few educational facilities. -Be cause of the lack of housing, shopping and cultural facilities, the area is only lively on very specific moments of the day. Except for rush hours and, to a lesser extent, lunchtime, the area is mainly abandoned. Also during weekends the streets are empty.

Being located around the Amsterdam Sloterdijk train station, the area could be very interesting for businesses. This train station is the ninth busiest in the Netherlands when it comes to the amount of travellers with 50,000 people passing every day. There are good connections to Amsterdam Central sta- tion (5 minutes) and Schiphol (10 minutes) as well as regu- lar trains to Haarlem (10 minutes), Leiden (30 minutes), the Hague (45 minutes) and Rotterdam (1h05). The area is also well connected to the ring (A10 highway) around Amsterdam. Schiphol is close by as mentioned before and the Westpoort harbour area lies just north of the Teleport area. So all modes of transport, both public and private, on land and water as well as in the air are well represented.

The result of this abundance of transport connections as well as the proximity of the harbour is a rather bad air quality, es- pecially around the major highway. The background concen- tration of particulate matter (PM10) in the area is on average 27-31 µg/m3 with peak concentrations around the highways exceeding 35 µg/m3. Research done by Ragas, Oldenkamp, Preeker, Wernicke, and Schlink (2011) shows the mean con- centrations of PM10, benzene, toluene, naphthalene and nonane in a fictitious city (Urbania) for both outdoors as well as office environments as shown on the next page. Comparing the values of PM10 from this study and from the situation in the Teleport shows that the location has slightly higher con- centrations in general and is very polluted around the high- ways, where the annual average is higher than the EU thresh- old of 28 µg/m3, which is 70 per cent of the limit value (EU directive 2008/50/EG).

For nitrogen dioxide (NO2) the background concentration in the area is 30-38 µg/m3 with concentrations higher than 45 µg/m3 close to the highways. These concentrations exceed aerial view of the Teleport area towards Haarlem from the book ‘Tussen Haarlemmerpoort en Halfweg’ (Abrahamse, Kosian, & Schmitz, 2010) 9 drinking water consumption data of offices as published at (last checked January 14th 2013) and of child daycare (used for the schools) published at mi- (last checked January 14th 2013). For the hotel, the amount of rooms is multiplied by the average amount of water a Dutch person used per day in 2010, based on information in the Drinkwaterstatistieken concentrations of VOCs and PM10 in the air (Ragas et al., 2011) 2012 (Drinking water statistics 2012) (Geudens, 2012). This the annual threshold for the protection of human health of 32 volatile organic compounds (VOCs), particulate matter, germs information shows that the total daily use of water by the of- 3 µg/m3, which is 80 per cent of the limit value according to EU or allergens (Bergs, 2004). fices alone is about 460 m ; together with the schools and ho- 3 legislation (EU directive 2008/50/EG). tel this grows to about 570 m of drinking water. The premises Besides being a rather polluted area, the Teleport also cuts are left out because it differs a lot per industry what amount Benzene concentrations outdoors are even lower than the right through an important piece of the main green infrastruc- and kind of wastewater they produce. The assumption is lower threshold of EU regulations of 2 µg/m3, which is 40 per ture (Hoofdgroenstructuur) as depicted by the municipality made that the input of drinking water is more or less equal cent of the annual limit value (EU directive 2008/50/EG). In of Amsterdam. This part of the green infrastructure is called to the output of wastewater, as the water is mainly used for offices however, the median is a lot higher than the upper the Brettenzone and is an interesting mix of different types of toilet flushing and drinking. threshold of 3,5 µg/m3 and even higher than the limit value of green, from ‘wild’ nature (ruigtegebied/struinnatuur) to city 5 µg/m3 (EU directive 2008/50/EG). (Ragas et al., 2011) parks to sports fields to allotment gardens. Within this patch- In the same way as described for the water use, the need for work of green infrastructure, the Teleport area is a barren ventilation air is calculated. Data of the municipality for gross floor area were combined with data of the amount of users CO2 concentrations are about 700 ppm in cities, compared to land that could play an important role in connecting the differ- the earth’s average of 400 ppm. In offices these concentrations ent green areas. Interestingly, because of the building crisis, per square meter. The amount of users is then combined are often even higher, between 800 and 1000 ppm, due to bad there are some wastelands in the core of the area that will not with the legal ventilation air rate according toNEN 8088:1+C1 3 3 ventilation. When concentrations exceed 1200 ppm it is -nec be developed in the near future (Wageningen, ?). This offers (2012); which is 6,5 dm /s per person for offices, 8,5 dm /s 3 essary to have your system checked (Raue, 2010). Although opportunities for the realization of a stepping stone kind of per person for education and 12 dm /s per person for accom- CO concentrations as high as 5000 and even 8000 ppm do structure on the neighbourhood scale. modation functions (logiesfunctie). These data show that all 2 3 not produce stress on the human body (Schaefer, 1961), they the offices together need 376442 m /h of ventilation air; to- are being used as indicator for indoor air quality and therefore To get an idea what the amount of wastewater is that is being gether with the schools and the hotel this amount increases 3 they should not exceed the 1200 ppm mark. However, as the produced in the Teleport area, an assumption has been made to 470725 m /h.

CO2 concentration is an indicator of ‘freshness’ of the air, it is using information of the municipality for the gross floor area not really a good indicator for concentrations of for example of the buildings in the Teleport area, combined with average

high to low natural value according to municipality 10 high to low concentration of particulate matter in the air

high to low concentration of nitrogen dioxide in the air

List of references Bergs, J. A. (2004). Planten in gebouwen: luchtverbeteraars en stresskillers Praktijkboek Duurzaam Bouwen. Geudens, P. J. J. G. (2012). Drinkwaterstatistieken 2012. Ri- jswijk, the Netherlands: VEWIN. Ragas, A. M. J., Oldenkamp, R., Preeker, N. L., Wernicke, J., & Schlink, U. (2011). Cumulative risk assessment of chemical exposures in urban environments. Environ- ment International, 37(5), 872-881. doi: 10.1016/j. envint.2011.02.015 Raue, A. (2010, March 2010). Frisse lucht, gezond kantoor. Arbo Magazine, 20-21. Schaefer, K. E. (1961). A concept of triple tolerance limits based on chronic carbon dioxide toxicity studies. Aerospace Medicine, 32, 197-204. Wageningen, D. v. (?). De vrije velden van Amsterdam Tele- port. Amsterdam: Ontwikkelingsbedrijf Amsterdam. water use in the teleport area per building 11 RESEARCH This review focuses on available literature in the field of bio- Abstract plants Todd has done a lot of pioneering (Feinbaum, 2008) logical treatment systems. The goal was to figure out whether As human beings, like all other animals, we are very depen- and Lohan, Muñoz, Salthouse, Fisher, and Black (2011) have it is possible to make a building that turns local waste streams dent for our survival on the services provided by plants. Plants researched the performance of these kinds of systems. About (wastewater and polluted air) into food streams (clean air, are the only organisms that are able to directly use the energy food production there is a lot of knowledge in the horticul- water and food) and if so, how to design such a building. A of the sun to turn water and carbon dioxide into carbohydrates ture sector. This sector is in the Netherlands also working on distinction has been made between water treatment systems and oxygen. The oxygen we breathe and the carbohydrates integration of greenhouses with other functions, an example and air treatment systems, because these are usually sepa- we either eat directly or feed to our animals. Carbohydrates of such a project is ‘Polydome’ (Bosschaert & Gladek, 2011). rated in the common building industry and research. A third are also used for a lot of other things like building materials, field of research is added, which is the growing of crops in fibres, fuel, etc. Besides that, plants purify water by taking out In the end the research aims to come up with an overview of buildings. This has to do with the fact that plants grow, while nutrients with their roots and by evapotranspiration through what plants are most suitable for using in a system that com- purifying air and water. Edible plants can thus be grown on the leaves. Human beings are thus dependent on plants for bines these three cycles. Also an insight in quantities will be waste air and water. Due to the vast amount of research on oxygen, sugars and clean water. In the built environment, this given, these will not aim to be very precise numbers, but rath- growing food, the focus was on research that already com- interrelationship is hardly visible. Food is grown outside the er indications of how much space certain systems take and bined the growing of food with (one of) the other topics. The city, air is treated mechanically and water is processed in large what they can handle. Eventual systems that are mentioned in research will focus on the abilities of (edible) plants to clean purification plants. literature about the combination of some or all of these cycles air and water as well as the possibilities to grow them in an will be discussed. indoor climate. Out of these three fields, together with the This research focuses on alternative systems that benefit from water and air pollution data from the Teleport area, an indica- plants by using their ability to treat air, treat water and/or pro- Keywords: living machine, biowall, hydroponics, water treat- tion will be given about the scale and possibilities in terms of duce food. Through literature review the existing knowledge ment, air treatment, crops treatment as well as function of the ‘Living Plant’. on using plants for these purposes will be explored. For case studies the techniques behind the living machine, biowall and Research approach; methods and techniques hydroponics will be described. The different fields of treating The research conducted was mainly literature review comple- air, purifying water and growing food will be touched upon mented with case studies. For the combination of the differ- after which the overlap between these fields will be shown. ent fields of interest (air, water and food), the Teleport area For each of the fields, different literature is being used. The in Amsterdam was used as a case study location. Information basic literature on air treatment is by Wolverton, Johnson, from the literature was combined with data from the area to and Bounds (1989) who did research on the air purifying qual- provide an image about the possible impact of such an inte- ities of plants for NASA. On the water filtering properties of grated system.

Living Machine at the Northern Zoo, Emmen (Jean-Luc Toilet, 13 Air treatment with plants gets not only polluted from industries and cars, but also from According to Quanjel et al. (2011) NASA research by Wolver- Poor air quality is a serious problem in most urban environ- the buildings itself. ton in 1974 states that the advantages of green on the indoor ments. Outdoor air often contains high amounts of particulate environment could be explained by the natural processes of matter, carbon dioxide, nitrogen oxides and sulphuric oxides Photosynthesis is the very well generally understood concept plants. It shows that plants are part of a complex ecosystem among others. These elements are for a large part byproducts of the process of turning water and carbon dioxide into oxy- in which leaves, roots, soil and microorganisms have a sym- of (incomplete) combustion in for example car engines and gen and carbohydrates under the influence of sunlight. Ac- biotic relationship. Chemicals are taken up through pores in industrial processes. Indoor air is not much better as it is often cording to Atwell, Kriedemann, and Turnbull (1999), plants the underside of the leaves and microorganisms living around contaminated with high levels of carbon dioxide and volatile that are adapted to an environment with a high light intensity the roots turn the chemicals into food for themselves and for

organic compounds (VOCs). VOCs are organic chemicals that have greater CO2 assimilation capacities than plants adapted the plant. Research has shown that this system for example occur in the air as gases and that are off-gassed by petro- to shady environments. The exact rate however is strongly re- is able to take formaldehyde, xylene and ammonia out of the chemical based materials like paints, carpets and plastics as lated to other variables like availability of water and nutrients. air (Wolverton & Wolverton, 1993). Other NASA research by

well as car exhaust (Quanjel et al., 2011). When talking about Leaves with a high CO2 assimilation capacity have the disad- Wolverton et al. (1989) has shown that plants do have air-pu- VOCs in indoor air, normally harmful VOCs are meant like ben- vantage of also having a higher respiration rate. To deal with rifying properties if kept in an airtight container. In this case zene, toluene, xylene and formaldehyde. Indoor air pollution this, ‘sun leaves’ have different properties to prevent drying plants were able to remove pathogenic levels of VOCs (ben- and urban air quality are considered two of the ten world out such as waxes and hairs on the surface or thicker leaves. zene, formaldehyde and trichloroethylene) from the air. Also worst pollution problems in the Blacksmith Institute’s World Plants in arid conditions can also close the stomata, small leaf research by Kwang et al. (2008) show the ability of Japanese Worst Polluted Places Report 2009 (Block & Hanrahan, 2009). pores, to reduce evapotranspiration at the expense of photo- aralia (Fatsia japonica) and weeping fig (Ficus benjamina) to synthesis. Although these properties reduce photosynthesis, reduce a high amount of formaldehyde to 50 per cent in re-

Although air quality is taken serious and regulations exist for plants adapted to sunny conditions still have higher CO2 as- spectively 96 and 123 minutes. Several other studies suggest all kinds of exhaust, there is still a lot of pollution in cities. To similation rates. Even the most sun-hardy plants reach their the decrease of indoor pollutants and chemicals in the air as deal with the polluted air, a lot of buildings have some kind of maximum photosynthesis rate compared to light intensity at a direct relation to plants (Burchett, Torpy, & Tarran, 2008; air treatment for their ventilation system. The air treatment more or less half of full sun intensity. (Atwell et al., 1999) So A. B. Darlington, Dat, & Dixon, 2001). Nonetheless there is filters out particles like soot, heats or cools the incoming air in general one can say that shade plants use light more ef- a lot of scepticism about whether this would also work out- and eventually adds or removes moisture. In the building all fectively for photosynthesis, but they reach their maximum side lab environments, as the amount of plants as well as the kinds of petrol based materials like paints, carpets and plas- rate faster and are more susceptible to leaf burns in high light concentrations of VOCs were higher than you would normally tics off gas VOCs into the air. The users of the building add intensity. Sun plants are less efficient in using solar energy, encounter in an indoor environment. Besides that, the room

carbon dioxide as well as things like perfumes, which are also but better adapted to high light levels and have a higher CO2 was not ventilated, so it is hard to translate the results directly VOCs, and body odours. Through ventilation the waste air is assimilation capacity in the right light levels. to a real situation. exhausted and returns to the city air. In this way, the urban air

Japanese aralia (ecos de pedra, weeping fig yew (mutolisp, 14 Although plants are sometimes held responsible for high cally ventilated rooms, but a positive effect in naturally ven- A way to improve the ability of plants to purify air seems to be amounts of molds and fungal spores, research has shown that tilated rooms. The effects were however only measurable in by exposing the root system to the airflow. This effect is based they are actually able to reduce the amount of airborne micro- concentrations higher than allowed by Dutch laws according on the idea that microorganisms living at the roots of plants organisms (A. Darlington, Dixon, & Pilger, 1998; Rautiala et al., to (Bergs, 2004). do a great deal of processing all kinds of substances. In normal 1999). Swedish research on the Levande Filter® (living filter) potted plants the exposure of the microorganisms to the air is also shows that plants seem to be able to reduce the amount Despite the scepticism, Wolverton has continued his research only at the soil surface. By exposing the roots to airflow, the of dust. Research at the Botanical Garden of Delft University of on the air-purifying properties of plants and published a book purifying area is greatly increased and thus should be a lot Technology has shown that some plants, like pine species such about the most effective houseplants to remove indoor air more effective. Several products are being made, based on as yew, are able to attract particulate matter to their leaves pollutants: How to grow fresh air: 50 houseplants that purify this principle. For example the Plant Air Purifier®, developed using electrical static fields (Muller, 2007). The findings from your home or office. According to this book, the Boston fern together with Wolverton, is a potted plant grown in porous this research resulted in a patented product (Ursem, Marijnis- (Nephrolepsis exaltata ‘Bostoniensis’) is most effective at re- growing media mixed with activated carbon. Airflow is di- sen, & Roos, 2007). Another study suggests that plants, espe- moving formaldehyde, the Areca palm (Chrysalidocarpus lu- rected past the root system with a fan. The company that has cially hairy plants, affect the amount of dust on surfaces in the tescens) and Dwarf date palm (Phoenix roebelenii) are most developed this system claims that one Plant Air Purifier® has room (Lohr & Pearson-mims, 1996). This corresponds with the effective at removing xylene and toluene and the Lady palm the same cleaning power as 100 to 200 standard houseplants study in Delft that an increased surface area, for example be- (Rhapis excelsa) is most effective at removing ammonia from (Wolverton, 2012). ( cause of hairs or needles instead of leaves, is more effective in the air (Wolverton, 2008). details-how-plant-air-purifier-works) dust control. Also a study by Zimmerman (2002) suggests that plants with a lot of leaf surface are more effective in cleaning the air, so plants with a lot of small leaves are preferred above plants with a few large leaves. Although most of these stud- ies have been done under lab conditions, a Norwegian study shows that health problems related to indoor air quality could be reduced by 23 per cent through the introduction of plants (Fjeld, 2002). A Dutch study did not find a direct relationship between plants in the office and a reduction of health prob- lems (Dortmont & Bergs, 2001), but this could have to do with the amount and distribution of the plants in the space (Bergs, 2004). Also the type of ventilation could have an influence, as a study by Wood (2004) shows hardly any effect in mechani-

Tillandsia tectorum, typical hairy plant (Eric Hunt, Plant Air Purifier ( ANDREA ( 15 The ANDREA, a product of the collaboration between the green plants to the indoor environment has the advantage of Nedlaw Living Walls is the company of Darlington that builds

French designer Mathieu Lehanneur and Harvard scientist their capacity to sequester CO2 (A. B. Darlington et al., 2001). and collects data from green walls that purify air. ‘The largest David Edwards, works more or less in the same way. ANDREA The main conclusions from this research are that higher plants living wall in the United States – a 1,570 square foot (146 m2, has a capacity of 180 m3/h, which is sufficient for a room of hardly remove VOCs with their leaves, that “the greatest re- red.) structure at Drexel University in Philadelphia, Pennsylva- 40 m2. This device is claimed to have a formaldehyde removal duction in concentrations per pass was under the slowest nia – is capable of generating up to 30,000 cubic feet (849.5 efficiency of 360 per cent compared to plants alone and 4400 influent air flux (0.025 m/s); however, the maximum amount m3, red.) of ‘virtual’ outside air per minute.’ (A. Darlington, per cent compared to normal HEPA and carbon filters, accord- removed per unit time occurred under the most rapid flux (0.2 2012) This comes down to approximately 350 m3/h of fresh air ing to their website ( This state- m/s)” (A. B. Darlington et al., 2001) and that the optimal tem- per m2 of living wall. Translating this information to the data ment was based on research conducted by Chen, Zang, Zhang, perature was less than 20 °C at the most rapid flux. from the Teleport area shows that a wall of 1345 m2 is needed and Smith (2004) comparing different available air treatment to treat the amount of air needed for ventilation of the build- systems. ings (470725 m3/h). That is quite a lot of space, but, as soil Another, more humble, claim is made by the developers of organisms do most of the work, would it be maybe possible to the Active Phytoremediation Wall System as described in the lead the air through soil, or, as Nelson and Wolverton (2011) magazine ARCHITECT (Gerfen, 2009). They claim that their put it: “Such systems might also be used for improvement of system increases the plants ability to filter harmful compo- urban air quality through incorporation of air-pumping under nents out of the air with 200 to 300 per cent efficiency com- portions of existing parks or in future urban greening efforts, pared to plants in normal potting soil. e.g. rooftop gardens.” Lars Thofelt and Börje Östlund developed the ‘Levande Fil- ter®’ (living filter) in Sweden. This is a small greenhouse that acts as an air treatment system. Air is pumped through the greenhouse to purify it. Research conducted on the perfor- mance of this system in a kindergarten show that it is capable

of removing 9.42 g/h CO2 and 7.5 µg/h formaldehyde as well as reducing soaring dust by 25 per cent (Zimmerman, 2002).

Darlington has conducted a lot of research on the possibili- ties of air treatment through the use of green walls. His main reasoning is that indoor air treatment largely reduces the need for ventilation with outdoor air and thus saves a lot of energy used for cooling or heating the outdoor air. Darlington opts for a phytoremediation approach, rather than a biofil- tration approach, which is becoming increasingly common to treat large amounts of industrial air or water contaminated with low levels of VOCs. Biofiltration is the use of microbes to remove contaminants from air or water. In this system the microbial population is highly adapted to the contaminant as this is the main organic support of the population (Swanson & Loehr, 1997). Phytoremediation is a way of soil recovery using plants to deal with a range of contaminants. This would be more convenient for indoor air treatment, as the VOC concen- trations are generally very low (below 200 µg/m3) and consist of a broad range of VOCs, which make it very hard to develop a highly specialized microbial population. Next to that, adding living wall system living wall at Drexel University (A. Darlington, 2012) 16 Water treatment with plants Although the use of constructed wetlands is gaining popular- This literature review will focus on the technology and theory Wastewater is in the Netherlands generally treated in large ity in the Netherlands, indoor water treatment systems using behind biological water treatment as described by Todd and wastewater treatment plants (rioolwaterzuiveringsinstallat- plants are very rare. Outdoors constructed wetlands are be- Josephson (1996). Although the before mentioned ‘vloeikas’ ies (rwzi)) at the outskirts of cities. At these locations large ing used for treatment of sewage water, runoff water from concept already connects the water and food cycles in the quantities of water (domestic wastewater and rainwater) are roads and rarely for use around buildings. In the latter case, same way as this research aims to connect, there is not much being cleaned of large debris and treated in several aerobic the clean water could be used for flushing toilets, washing and (scientific) literature and data available. It is thus more useful and anaerobic settling tanks. After the process the water has sometimes even for drinking water, although the latter is not as inspiration than as a basis for design. Another thing is that the quality of surface water and is discharged on a canal, lake allowed by Dutch laws. In the neighbourhood Eva-Lanxmeer the before mentioned research also links water treatment or river. The sludge that forms in the settling tanks is used in a in Culemborg, a system was planned where greywater would with growing of food crops and even fish as well as biofuels bio-digester for the production of electricity. There are how- be treated in constructed wetlands to be reused in the homes (Todd & Josephson, 1996). “Posner (operations manager, red.) ever alternatives to this system, that are considered a more for flushing toilets and washing. Unfortunately this was not describes harvesting bananas, grown with the treated waste- sustainable option according to Teeuw and Luising (2008), as allowed by the Dutch government, because of the risk of mis- water, in the middle of a Massachusetts winter.” (Feinbaum, in the large wastewater treatment plants water, energy and taking this water for drinking water. In the Watertoren in Bus- 2008) The system is based on the earth, the ‘most complete nutrients are being wasted and large infrastructure is needed. sum however, the water is treated in a constructed wetland living system of which we are aware’ (Todd & Josephson, As an alternative they opt for decentralized wastewater treat- on the roof of the parking garage and reused for toilet flush- 1996) and generally exists of three or maybe four treatment ment, for example through constructed wetlands, sand filters, ing. steps, although more are preferable. Twelve key factors are trickling filters (oxidatiebed), septic tanks, Living Machines being described as having an important impact on the func- or purification by algae. Another interesting alternative- de Research on constructed wetlands for water treatment has tioning of the system. The discussed factors are mineral diver- scribed by Teeuw and Luising (2008) is the so-called ‘vloeikas’ shown that plants are involved in almost every step of the sity, nutrient reservoirs, steep gradients, high exchange rates, (flow greenhouse) as developed by De Twaalf Ambachten in treatment process. Aquatic plants act as physical filters, take periodic and random pulses, cellular design and mesocosm Boxtel (NL). In this system wastewater (greywater only) flows up nutrients, provide a substrate for other lifeforms and cre- structure, subecosystems, microbial communities, photosyn- through a greenhouse where it is used to water the plants. ate aerobic and anaerobic zones for nitrification and denitri- thetic bases, animal diversity, biological exchanges beyond The plants take out the nutrients and the heat of the water fication (Thullen, Sartoris, & Nelson, 2005). Other research the mesocosm, and mesocosm/macrocosm relationships. The also warms the greenhouse. In the greenhouse food crops suggests that water treatment systems containing vegetation described factors have largely been discovered through trial could be grown if the incoming wastewater does not contain have a higher efficiency compared to systems without plants and error in building the systems. Species to incorporate in contaminants that could be stored in the plant and are harm- (Matheson, Nguyen, Cooper, Burt, & Bull, 2002; Tanner, 1996; the systems were chosen based on the similarities between ful for people. Tanner & Sukias, 1995). their natural environment and the proposed living technol-

constructed wetland at the Watertoren in Bussum pecan tree with nuts, a wet tolerant species (fvaldes) lotus, an edible tropical wetland plant (Xevi V, 17 ogy. Another key aspect in the choice for a certain species was system it is recommended to use a cellular design, because In the report, data of BOD5 (biochemical oxygen demand), whether or not it could turn into a threat for the local eco- then cells can be added and removed dependent on the sys- COD (chemical oxygen demand), TSS (total suspended sol- system. Therefore species were chosen that were either com- tems input, without having to redesign the whole system. It is ids), nitrification, phosphorus uptake, metal sequestration, mon in the region or that could not survive outside the living also easier to replace cells. Although the focus of this review coliform reduction are presented of a living machine that is machine. In temperate regions like New England for example, is on the use of plants, an interesting conclusion of Todd and operational since 1989 and produces high quality water inde- tropical plants and animals might be used to make the system Josephson (1996) is that it is very important to design a com- pendent of season or input variation. The living machine was economically viable. The complete description of the twelve plete ecosystem including micro-organisms, bacteria, algae built by Ocean Arks International (OAI) and is situated in Prov- key factors can be found in the report by Todd and Josephson and fungi as well as higher organisms like snails, invertebrates idence, Rhode Island, and sits next to the city’s main sewage (1996), but is beyond the scope of this review. and fish to name a few. Other than a nice addition, they are works, which processes an average amount of 150 000 m3 of considered a crucial part of the system. With this reason they wastewater daily to secondary standards. The living machine Some conclusions however, might be useful in the rest of the suggest it might be interesting to incorporate for example also itself processes an average of 34 m3/day with a maximum flow document, so they are shortly explained here. Although min- acid soil-based cells for the growth of fungi. Treatment cells of 61 m3/day. With maximum flow it takes 2.5 days for the eral deposits are very important for providing nutrients on the covered in pennywort (Hydrocotyle umbellata) and water water to complete the process, while on average this is 4.5 long-term, there is also a need for nutrients in available form hyacinth (Eichhornia crassipes) have shown increased nitrifi- days. The maximum flow rate does not affect the quality of for the plants. In this respect NPK (nitrogen (N), phosphorus cation. There are also plants that sequester metals, such as the effluent. (P), potassium (K)) ratios should be in balance. “Nutrient defi- mustard greens or Indian/Chinese mustard (Brassica juncea), ciencies are particularly common in biological systems treating which has been found to remove metals from flowing waste The system is made up of four rows; each row contains the food and industrial wastes. These waste streams need to be streams, resulting in a lead content of up to 60% of its dry whole treatment process divided into six treatment steps. The blended with other types of waste or the imbalances should weight, based on research by Nanda Kumar, Dushenkov, Mot- first step consists of five aerated reactors connected in series. be corrected with fertilizers.” (Todd & Josephson, 1996) High to, and Raskin (1995). It is not stated whether or not this is These tanks are rich in algal and microbial live and are covered exchange rates can be achieved through increasing surface still edible with such a high lead content. Water mint (Mentha with water hyacinths (Eichhornia crassipes). The second step area, for example in ecological fluidized beds, a system one aquatica) is known to produce compounds that can kill certain is a tank the same size as the first five (with a working volume step beyond trickling filters. A wide variety of plants can be human pathogens (Seidel, 1971). Several species of (edible) of 4.54 m3). The difference is that this tank is not aerated and planted on ecological fluidized beds, for example wet toler- fish can play a great role in controlling algae and plant growth, functions to settle the solids. The solids are recycled to the ant trees and emergent aquatic and semi-aquatic plants. The shredding woody materials and controlling sludge build up first tank and periodically returned to the main sewage facil- root zones of these plants provide extra surface area for gas while at the same time providing a food source. ity. The supernatant (liquid without solids) flows into the next and nutrient exchange. For the resilience and flexibility of the stage of the treatment process. Step three consists of a set of

pennywort (mkhairill, mustard greens (SolanoSnapper, water mint (Cosper Wosper, 18 engineered ‘tidal’ marshes. The marshes are planted with a in the first 1.5 years (of 3 years) of data collection. In those set of wetland species, mainly bulrushes (Scirpus spp.). Each cases the system did not even meet the secondary standards marsh is filled for 12 h and then drained and dried for 12 h of 30 mg/L. Most of the TSS is filtered out in the tidal marsh to simulate the tides. After the marsh the water is pumped at step three. into a new series of six aerated tanks planted with a diverse Alkalinity is the ability of water to neutralize acids, a reduc- combination of racked and floating temperate and tropical tion shows that bacterial nitrification of ammonia to nitrates plants. Also animals like fish of the carp family (Cyprinidae is happening. There is a gradual reduction in alkalinity mea- family), snails, mollusks and zooplankton live in the tanks. sured throughout the process, going from 80-270 mg/L in the This is the fourth step. The fifth step is a biofilter filled with influent to about 40-50 mg/L in the effluent. recycled plastic floating media. The sixth and last step consists Ammonia is a very important indicator as the un-ionized form of a marsh planted with a variety of tropical and temperate of ammonia (NH3) is highly toxic. Ammonia is reduced through wetland plants. nitrification; therefore the decrease of ammonia matches the data shown for alkalinity. Influent had values between 7-15 The data from the system show great performance of the mg/L with one exception of 28 mg/L, effluent values were different measured values. The biochemical oxygen demand generally lower than 1 mg/L with three cases exceeding this. (BOD5) shows the biochemical oxidation of organic matter Phosphorus uptake in the system was on average about 50% and reflects the strength of the organic loading. Values for and effluent values did not exceed 2 mg/L on average. hardstem bulrush (andrey_zharkikh, BOD5 in the influent (50-290 mg/L) were reduced to less than Despite of the high metal content in the influent due to the 10 mg/L in the effluent. This means it was way below second- large electroplating industry in Providence, the metal levels in the effluent was below 200 counts, except for two cases, and ary standards and even below advanced standards. the effluent were better than the US Food and Drug Admin- even below 15 counts for over 60% of the time. So this means Chemical oxygen demand (COD) shows the chemical oxidation istration’s standards for bottled water (Title 21-U.S. Code of the water is definitely safe for surface water, but it is not rec- of organic material in wastewater. The values of the influent Regulations, 1983). Cadmium, chromium, copper, silver and ommended to drink without testing. ranged from 100-800 mg/L, which were brought down to less zinc levels were even an order of magnitude below the stan- than 40 mg/L in the effluent. Most of the reduction happened dard levels, which shows that the system is an interesting al- For dimensioning the system one should completely dive into in the first five tanks of the treatment line. ternative to common technologies. the chemical composition of the influent. On the other hand, Total suspended solids (TSS) are an indicator for the clarity of Coliform, and especially fecal coliform (E. coli), is an important as also explained in the chapter about air, the diversity of ele- the water related to suspended matter. The influent showed indicator for water quality and food contamination. US swim- ments is so large that one can hardly design for each com- values between 40 mg/L and 1000 mg/L, although it was most ming water standards allow for a maximum of 200 counts per ponent apart and should design a system that more or less of the time between 100 mg/L and 500 mg/L. The values of 100 ml and a value higher than 15 colonies per 100 ml means regulates itself, hereby creating also a larger resilience of the the effluent were generally below 10 mg/L (advanced stan- food contamination. In the living machine in Providence, the system. The next example gives a nice idea about how resil- dards) although there are a few outliers as high as 50 mg/L influent had values of 10000 to 2000000 colonies, whereas ient a well-functioning system can be.

raw sewage

clean water return sludge

step 1: step 2: step 3: step 4: step 5: step 6: aerated reactors strati er mid-stage marsh aerated reactors bio lter nal marsh scheme of the different stages of the living system in Providence, Rhode Island 19 techniques, the Living Machine system needs less than 4 m2 to area as presented by Living Machine® Systems, L3C, however, ““That’s what’s so amazing,” said Olena Welhasch, a senior in treat one m3 of wastewater daily. In the same graph it shows in this number also the circulation space is included, which English. does the work for us. She reminded me of the that the footprint for an aerated wetland is about 10 m2 per might not be included in the graph of Living Machine® Sys- situation we learned about at the South Burlington, Vermont, m3 daily. This does not say anything about the type of waste- tems, L3C. Besides that, Todd and Josephson (1996) also say Living Machine, which treats ten percent of the town’s sew- water. Teeuw and Luising (2008) therefore use ‘inwonerequiv- that the newer living systems have a smaller footprint and a age. “All this gasoline came through and killed the plants in alent’ (the amount of wastewater produced by one person) smaller energy use per cubic meter of treated wastewater. A the first tank, Welhasch said. The operators were really wor- as a way to define the space needed per system. According to water treatment plant of constructed wetlands designed by ried, but they had to keep the experiment running. The plants them 3-5 m2 of constructed wetland or 3-4 m2 of sand filter Wolverton Environmental Services treats 15000 m3 of sewage ended up regenerating after the gas passed through, and the is needed per person. Assumed that a ‘inwonerequivalent’ is a day on an area of 8.8 hectares to serve a town of 14000 peo- following tanks were not affected. Nature has such a huge po- about 120 l (average water use of a Dutch person (Geudens, ple (Nelson & Wolverton, 2011). That is more than 13 times tential to self-organize and self-repair.”” (Wolovitz, 2000) 2012)), this would mean that 24-40 m2 of constructed wetland the amount of sewage of Teleport. would be needed to treat 1 m3 of wastewater. This large size Translating the data to the Teleport area would mean that a In dimensioning the system for the Teleport area, general data however has to do with the fact that it has to be designed size between 2300 m2 (Living Machine® Systems, L3C), 6400 from the company that build the Living Machine at the North- for a winter situation when it reaches only about 10 per cent m2 (Todd & Josephson, 1996) and 6700 m2 (Nelson & Wolver- ern Zoo in Emmen were used. The system in Emmen is the of its full efficiency. The living machine in Providence built ton, 2011) is needed for treating the daily amount of 570 m3 only Living Machine in the Netherlands and one of the largest by Ocean Arks International was situated in a 380 m2 green- of wastewater produced in the area. facilities realized by Living Machine® Systems, L3C. Also the house structure and processes on average 34 m3/day with a data from the Providence living machine as described by Todd maximum of 61 m3/day (Todd & Josephson, 1996). This would and Josephson (1996) could prove itself useful. mean that 11.2 m2 (greenhouse structure) is needed on aver- According to a graph shown in the brochure of Living Ma- age (or 6.2 m2 with maximum flow) for the purification of 1 chine® Systems, L3C, comparing different water treatment m3 of wastewater a day. This is almost three times the surface

site vs. energy comparison onsite wastewater treatment (brochure L3C) water hyacinth (Luiz Leite, Living Machine at the Northern Zoo, Emmen ( 20 Growing food on waste streams centration and nutrients are adapted to the crop. In the case but might be interesting to develop. Although it is a theoreti- Although the chapters on air and water focus on cleaning, of a purification facility, there is no choice about the amount cal case study, it is based on data from horticulture and gives this chapter deals in a way with a byproduct of that clean- of nutrients, carbon dioxide or heat, so the system should be at least an insight in the level of magnitude of yields com- ing. As pointed out in the previous chapters, the elements we adapted the other way around and show a larger flexibility pared to NPK inputs for example. The main design goals for consider pollution in water and air, are often considered food towards a change in these factors. this system were closed cycles and financial viability. One of or fertilizers in agriculture. Looking at the natural ecosystem, the conclusions is that it is very difficult to close the nutrient this completely makes sense, because what is waste from the Research by Bosschaert and Gladek (2011) shows some inter- loops, as the main source of nutrients (produce) is exported animal point of view; is food from the plant point of view. So esting insights in the possibilities of combining different plants out of the system. Therefore a nutrient input is important, in by treating waste air and wastewater with plants, the plants and optimising for a polyculture system (a system with mul- the case study this input is chicken feed, the chicken waste will grow. By choosing these plants to be useful plants, for ex- tiple crops). It gives a theoretical view on inputs and outputs is used as fertilizer, although they imagine other sources are ample plants that provide food (although one could also think in chemical components as well as food, waste and energy, al- also possible, for example green waste from parks, manure of construction materials, biofuel, fibres, etc.), the benefits though they clearly state that the system should be optimized from farms, food waste from restaurants or residential sew- will double. As also described in the previous chapters, it is for every specific location. The document provides useful in- age. Water use is relatively high due to the choice for cultiva- very important for resilience and a thorough cleaning of water formation about inputs and outputs of a case study system. tion in soil rather than hydroponics for example. That does and air to come up with different species of plants. Within It also gives a lot of basic information, like size and age till not mean that hydroponics are not included, they are used horticulture however, the focus is usually on optimizing a sys- maturity, about major food crops including tropical crops that for greens, herbs and strawberries, fast growing crops with tem for one crop. In that case ventilation, heating, CO2 con- are not (yet) popular in greenhouses, due to for example size, high yields, as the system is more expensive. As input water the wastewater of the fish is used, supplemented with liquid nutrients from the compost if necessary. The soil-based pro- duction is used for perennials such as fruit trees, berries and vegetables like artichoke and asparagus. These plants take several years to grow to full maturity. The presented scheme is based on a design for a polyculture greenhouse. It shows some nice insights about possible combinations of plants that have similar needs and maybe even have a positive impact on each other, like enhanced flavour, greater yield and pest depression among others. The exact details are too extensive to be described here, but could be very useful for the design of an integrated system. The report claims that one hectare of polydome greenhouse could provide 80% of the food of a population of 2000 people. It would however not be economi- cally viable if it were just a production facility, so Bosschaert and Gladek (2011) suggest to combine it with, for example, a restaurant, beer garden or shop/supermarket. Another option would be a co-development with either ‘normal’ agriculture or industry for exchange of materials and energy. The main benefits of a polyculture system compared to monocultures are the high diversity that causes a high resilience in both eco- nomic and environmental sense. It is also easier adaptable to market demands. Not all crops are considered suitable for the system. Criteria used by Bosschaert and Gladek (2011) for the selection of crops are excessive height, long maturation pe- riod, allelopathy (influence on other plants), basic crop value impression of the polydome with hanging hydroponics systems above the soil based groundfloor crops (Bosschaert and Gladek, 2011) 21 diagram of different material flows in polydome (Bosschaert and Gladek, 2011) 22 and yield potential, general labour requirements, prioritizing stock is also improved.” (13.4.2 Vegetables and fruit crops) ety of crops is then grown on the remaining nutrients in the for perennial plants, beneficial companion plants and ele- (Atwell et al., 1999) This effect applies to tomatoes, cucum- wastewater after step two. One should however keep in mind ments that provide required functions or material flows (for bers, mandarin oranges, lettuce and celery. In all of the crops, that these crops might need extra fertilizers because of nutri- the system). Stacked production allows for higher yields on a the yields were greatly increased due to CO2 enrichment. ent deficiencies that are particularly common in biological sys- small area. tems treating food and industrial wastes (Todd & Josephson, Research by Nelson and Wolverton (2011) comes even a step 1996). Other interesting research has been done on the reaction of closer towards the focus of this review as they did research plants to high CO2-levels. On the one hand plants grow faster, on the possibilities of growing food, fodder and other useful Although it is hard to combine the different data, because they which is of course why CO2-levels are increased in greenhous- crops to treat wastewater. They propose a system that con- are not very compatible, it would still be nice to have an idea es. However, research shows that plants also become less nu- sists of three main stages. The first step consists of a septic about the order of magnitude we are talking about in rela- tritious, because more energy goes to defence mechanisms. tank and sedimentation tank for anaerobic reactions and fil- tion to yields. According to Teeuw and Luising (2008) based on Based on research by Gleadow, Foley, and Woodrow (1998) tering the sediment out. The next step is made up of so-called the conclusion is drawn that: “If these controlled-environ- ‘wastewater gardens’, constructed wetlands where food can ment experiments are good predictors of what will happen in grow. It is not recommended to grow any crop here, as there more complex, natural ecosystems then the balance between is no disinfection step included. Crops that are better left out plants and herbivores in the next century could be different. are root crops and uncooked greens like lettuce. Crops like While this is good news for plants, it is bad news for herbi- bananas, papaya, rice, dwarf coconut and several species of vores. In a future high-CO2 world plants are likely to be less berries however, have ben successfully grown in subsurface nutritious and also contain increased concentrations of toxins flow wetlands. An extra advantage of subsurface flow- wet and defence compounds. Plants will be able to grow faster lands compared to open water is the absence of bad smell and be more resistant to herbivores.” (CASE STUDY 13.1) (At- and there is no risk of accidental contact with the wastewater. well et al., 1999) Also fodder for livestock could be grown here. In Biosphere 2 What actually is being said; is that, although plants grow faster Canna edulis, water hyacinth and wetland reeds were grown in high CO2 environments, they might as well become less nu- for this purpose. The last step in the system is subsoil irriga- tritious. That is an interesting statement considering the fact tion of treated water. In this step all kinds of crops can be that quite a lot of vegetables in the Netherlands are grown in grown, and the choice is not limited to wetland species, ex- greenhouses. On the other hand, the addition of CO2 also of- cept for root crops, unless a disinfection step is included. A fers some benefits, as stated by the same authors. UV light disinfection system could be installed for this purpose

“CO2 enrichment increases quantum yield of photosynthesis (Nelson & Wolverton, 2011). This last step could for example for C3 species and lowers the light compensation point. This be designed as the before mentioned polydome. A large vari- effect is particularly advantageous in high-latitude environ- ments for winter/spring glasshouse cropping when light levels are low. CO2 enrichment also raises the temperature optimum for photosynthesis and growth and this may permit less fre- quent venting of enclosures to control temperature. Respira- tion is often suppressed by CO2, although variable responses are reported.” (13.4.1 Greenhouse cropping) (Atwell et al., 1999)

“CO2 enrichment stimulates vegetative growth of tomato by increasing both net assimilation rate and expansion of leaf area. This is particularly important in winter when large num- bers of plants are propagated commercially and CO2 enrich- ment can substitute for limiting light. The quality of planting three step diagram for integrated system (Nelson & Wolverton, 2011) Canna edulis (Powell Gardens, Kansas City’s botanical garden, 23 data from Henze, Harremoës, la Cour Jansen, and Arvin (1997) staggering 17.6 million kg yield per year. From a wastewater (208050 m3) would be enough for 9 ha of polydome (23000 domestic wastewater contains yearly about 4-5 kg of nitrogen treatment point of view this looks like a lot of space to treat m3/ha), but the nutrients (12434 kg) would only be enough (N), 0.75 kg of phosphorus (P) and 1.8 kg of potassium (K), the wastewater of its nutrients, but as tomatoes are usually for 3.6 ha of polydome (3446 kg/ha) and comparing the sup- they do not state if this is per person or per household. As- grown as an annual and take about 6 months to bear fruit, ply and demand of phosphorus, the Teleport area (1423 kg) sumed that this is per household and a household consists of it would be possible to grow two cycles of tomatoes on the would only be sufficient for 1.2 ha of polydome (1165 kg/ha). 2.5 persons using 120.1 l per person daily (Geudens, 2012), same area, reducing it to almost 12 hectares. This is however This calculation shows the complexity that has to be dealt this would mean that 109.6 m3 of wastewater contains 6.55- completely theoretical, as all the other growing conditions, with in optimizing such a system for water and air treatment, 7.55 kg of nutrients per year. Translating this to the Teleport like light, temperature and other nutrients should also be as well as food production, not even taken into account the area, with an average daily wastewater production of 570 m3 right. Looking at the total scheme for the polydome, a less fluctuations of within the supply and demand chains. as explained in chapter 3, would mean a yearly production extreme image appears. The amount of water of the Teleport of 208050 m3 of wastewater. Considering this contains about the same amount of nutrients as household wastewater, that would add up to 12434-14332 kg of nutrients, consisting of 7593-9491 kg of nitrogen, 1423 kg of phosphorus and 3417 kg of potassium. To get an idea about the yield this amount of nutrients could give, data for tomato are used, as this crop gives high yields and has a high nutrient demand per square meter. According to Bosschaert and Gladek (2011) tomatoes have a yield of up to 75 kg/m2 with a nutrient demand of 53 g/m2. This means that 12434 kg of nutrients is enough to grow 234603 m2 (or 23.5 hectares) of tomatoes resulting in a

nutrient diagram (Bosschaert and Gladek, 2011) schematic greenhouse layout polydome (Bosschaert and Gladek, 2011) 24 Conclusions and end products ties. A water treatment system of 2300 m2 could now double tem of constructed wetlands, which will cause a pretty high The main aim of this literature review is to get an idea about as an air treatment system of the same size producing food humidity in the space, unless it is actively dehumidified. For the possibilities of combining different purification systems on a part of that area. That would mean that almost twice plants this is ideal, especially in combination with high tem- with food production, which has been illustrated by relating the amount of air could be treated. The other benefit from peratures. On the contrary human beings and electronic ap- the data from the literature with the data from the Teleport combining the systems is that the polluted air offers extra pliances usually do not enjoy it very much, as everything gets area in Amsterdam. It has turned out that the different exist- nutrients and carbon dioxide to the plants, at the same time damp. It is thus important to understand the influence of each ing systems combine very well. The most important research supplying oxygen to the roots and releasing carbon dioxide part of the system on the climate when adding an extra func- on this complete integration of systems was done quite re- trapped in the soil (Nelson & Wolverton, 2011). So combining tion to a space. In general the influence on humidity decreas- cently by Nelson and Wolverton (2011). This offers a lot of the different systems eliminates the need for external input es with a decrease in surface area of open water and with a reasons to introduce green in the built environment other other than the waste streams. Streams that are traditionally decrease in plants relative to the volume of the space. than the usual ‘passive’ park related functions. Although the seen as costly waste streams become free supply chains hit- goal was to end up with a set of data to estimate the size of a ting two birds with one stone. The diversity of plants is very large and as the goal is to design system and to come up with a catalogue of design solutions, with plants as an active element, it is important to understand this turned out to be more difficult than expected. The dif- During the studying of the literature it became clear that it that plants are living organisms and only function under the ficulty is not a lack of data, but rather such a large variety of is not really the plants that do the hard work in the case of right conditions. One of the main factors on the health of possibilities that not one right answer can be given. This has air and water treatment. This was different from the first as- plants is (day)light, as this is an essential part of photosyn- to do with optimizing for a complex system and therefore with sumptions and resulted in a lot less restrictions in the plant thesis. The minimal light intensity is 700 lux, although most the choice of the architect. Optimizing for air treatment in the choice. In the end it became clear that there might be a design houseplants prefer a light intensity between 1000 and 2500 Teleport area would in this case lead to a living wall of 1345 solution for almost every plant you wish to grow, so maybe lux and a cactus can cope with an intensity of more than 8000 m2. Water treatment on the other hand would be possible that should be the starting point of the design. What do you lux. Compared to outside situations: on a sunny summer day on an area between 2300 m2 and 6700 m2. Food production want to grow? Food or fodder, fibres or biofuel? Another rea- the outside light intensity is between 100000 to 130000 lux, shows an even larger range between 1.2 ha and 12 ha. The son for choosing certain plants could be their shape; do you on a cloudy winter day only 1000 to 5000 lux. Also tempera- size of each system is closely related with the type of system want trees or ground cover? Dense or open vegetation? Also ture plays an important role. For tropical plants for example, that has been chosen. Also the fact that these systems could climate should play an important role in the final design. The the minimum temperature is 16-20 °C with an optimum of be completely integrated offers some interesting possibili- first visible part of the living plant in general requires a sys- 35-45 °C. For subtropical plants this is respectively 10-16 °C

proposed integrated system based on hydroponics proposed integrated system based on aeroponics proposed integrated system based on soil culture 25 and 15-35 °C. (Quanjel et al., 2011) In a building where wa- place in the treatment process. It is for example wise to plant example). On the other hand it would be totally arguable to ter and air are being cleaned using plants, maintenance of metal sequestering plants in a step prior to edible plants, as grow tropical fruit, as this has added value to the experience the plants is needed, just as maintenance of installations are the other way around might cause edible plants contaminated and the energy needed for this could be harvested from a bio- needed. The maintenance consists of pruning, weeding, feed- with heavy metals. digester as well as from excessive summer heat stored in the ing and monitoring. More information on introducing plants ground. However, the energy problem is, although very inter- in buildings can be found in Interior Plants in Large Buildings It is almost impossible to give one solution, as explained be- esting, beyond the scope of this particular document. (Scrivens, 1980) and in the SBR publication groen in gebou- fore. Nonetheless one option is further expanded for more wen (SBR, Bergs, Pötz, & Seitz, 2009)(in Dutch). detailed understanding. On the next page is a diagram for the material flows in the Living Plant. It is very important though, For a greater understanding of the roles plants can play in an to understand that this is just one possibility of many. The pro- integrated living system it is highly recommended to read bo- posed system is also not finished and with new developments tanical literature, as a lot of information is available on plant changes could be made to the diagram. It is very important properties, such as size, growing requirements, edibility/ though, to understand that this is just one possibility of many. toxicity, etc. The same is true for literature on other possible Also exact details are dependent on both exact composition organisms that can play a role in the process. “Research into of influent and the demand in the neighbourhood. These the aquarium and ichthyological literature will be valuable to data were not always available, so assumptions have been ecological engineers.” (Todd & Josephson, 1996) It is impos- made. Changes in these data can be applied to the diagram sible to say what plants are generally good, except maybe that and to further elaborate on the details. If there appears to they should be quite water tolerant. On the other hand, if you be for example a great demand for bell peppers and a very really want to grow crops that are less water tolerant, there small demand for tomatoes, the system could be adjusted a is most probably a way around, as long as it is known in an bit towards focusing more on bell peppers and less on toma- early stage of the design. The choice for a certain plant should toes. This example is just illustrative and there might not be depend on climate and lighting conditions as well as on char- a one to one possibility of replacing tomatoes with peppers, acteristics like edibility, metal sequestration, (de-)nitrification, without affecting the amounts of other crop species. Also one etc. These characteristics also have to do with the role and should realize that this kind of optimization is easier with an- nual crops than with perennials, as the latter take time to ma- ture and are thus less flexible to change. In the end you will have to try to optimize a complex system, which might mean that you cannot optimize for each individual aspect.

One possibility for this system could be a set of multilevel indoor parks planted with edible plants where possible. The parks could range in size from a small urban backyard to a neighbourhood park (or even larger, dependant on the space available). The small parks could be rented as green meeting rooms, meditation spaces or hotel rooms, whereas the larger spaces could serve as terraces for restaurants, public meet- ing spaces, beer gardens or events grounds. Fresh herbs and fruits could be grown next to the tables or a part could even serve as an alternative greengrocer. Also the climate could range from hot and humid to temperate or even having a winter dormancy period, as some temperate perennials need this to bear fruit (temperate fruit trees and berry bushes for design proposal urban air purifier design proposal stacked living machine 26 WASTEWATER ANAEROBIC WASTE AIR REACTOR AERATED REACTORS






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