Imperial Journal of Interdisciplinary Research (IJIR) Vol-2, Issue-6, 2016 ISSN: 2454-1362, http://www.onlinejournal.in

Effective Disposal of Sewage Sludge by Composting Method

Mahath. C. S Pursuing Master’s degree, Department of Civil Engineering, UKFCET, Kollam, Kerala, India.

Abstract: Sewage sludge is formed during which 30% is covered by a piped sewage system, mechanical, biological and chemical sewage which serves the core city area. treatment. Composition of the sewage sludge is very complicated; it is rich in micro- and macro elements, but the sludge can contain toxic compounds and pathogenic organisms. There exist a large variety of methods of neutralization of the sewage sludge. The present work describes the sewage sludge treatment methods and pays special attention to non-industrial methods of neutralization of the sewage sludge. There exists a large variety of methods of neutralization of sewage sludge; however, their cost is a serious limitation in practice. Further development of the methods of waste material removal is necessary to limit the investment and exploitation costs. Sludge management should be developed towards great environmental utilization and this is possible with a gradual decrease of the storage on municipal dumping sites. Composting is an effective method to convert the sewage sludge to an effective fertilizer. Composting mainly due to the presence of microorganisms present in sample. There exists a large variety of methods of neutralization of sewage sludge; however, their cost is a serious limitation in practice. In this work effective sludge disposal by composting method is used. Various analytical and chemical methods are adopted for finding the heavy metal content, pathogenic content, nitrogen-phosphorous and Fig.1 Location of the pump house carbon content and compare the results before composting and after composting. More over The raw sewage from different parts of the city is germination test, field study, solubility tests are first received at the pumping stations, from lifting carried out for analysing the sample in before and stations, located in the city. The pumping stations are after composting to analyse the components. located at Kuriathy, Kannammoola, pattoor and Enjakkal. The location of the pump houses is shown Introduction in the figure provided above. Earlier the sewage collected from the city was pumped into open ground The aim of the study was to find a suitable and was used for cultivation of fodder for cattle. This solution for a major problem that the Trivandrum was known as sewage fodder farm and was installed city now facing due to sewage sludge. One of the in 1945 at Valiathura in Thiruvanthapuram.[2] largest sewage treatment plant in India 107 MLD Fodder farm is on the south bank of the Parvathy sewage treatment plant, Muttathara, located at Puthanar Canal. The partially treated effluent from Trivandrum is facing the sludge disposal problem, the fodder farm used to infiltrate into Parvathy after the treatment of waste water from the city[1]. Puthanar. In this process, no effective treatment was Thiruvananthapuram Municipal Corporation taking place and virtually raw sewage was directly presently comprises an area of 141.74 sq. km. of getting access to Parvathy Puthanar. There was direct

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Imperial Journal of Interdisciplinary Research (IJIR) Vol-2, Issue-6, 2016 ISSN: 2454-1362, http://www.onlinejournal.in discharge of sewage to Parvathy Puthanar from after composting to analyze the households also. Thus Parvathy Puthanar became an components.[8,9,10,11] open channel for disposing raw sewage. The sewage farm is primitive in nature and is environmentally non acceptable. Various studies Materials and methods show that the Parvathy Puthanar is highly polluted by the sewage farm discharge and the excess raw 3.1 Sources sewage flowing from the drains directly into the canal. Sewage sludge was mixed with the following Thus, to meet the need of the population of components in two bins at suitable proportions Thiruvananthapuram, KSUDP and LSG decided to shown in the table given below. establish Sewage Treatment Plant under JNNURM • Sludge scheme with the help of ADB loan. The estimated • Cow dung average flow is 107 MLD. The implementation • Paper bits agency is Kerala Water Authority. • Vegetable waste But the sludge that is obtained after the treatment becomes a problem to the surrounding people due to its dangerous health hazards. Also the sludge began Table.1:Shows the various composition of mixing for composting. to heap without proper disposal. If this condition is continuing, it will result the closure of the plant. Vegetable Therefore finding a suitable solution is necessary for Sludge Cow dung waste the working of this treatment plant. So effective (kg) (kg) disposal of sewage sludge is necessary. (kg)

CONTROL 12 0 0 Objectives SAMPLE 1 12 6 2 The main objective of this work is to find a suitable solution for sludge disposal problem facing SAMPLE 2 12 8 0 by 107 MLD sewage treatment plant, Muttathara, Thiruvananthapuram. Finding a solution to this problem is not an easy 3.2 Composting process task, because sludge consists of slightly varying parameters. The heavy metal contents, pathogenic  The sludge used in this study was obtained contents, Nitrogen and phosphorous content etc. from Muttathara 107 MLD Sewage present in sludge are to be properly managed in order treatment plant, Trivandrum. to maintain effective disposal of sludge. Moreover the sludge can be used as a fertilizer in agriculture  This is mixed with cow dung and vegetable industry. waste collected from various sources near to Through various chemical, biological and college. experimental methods, the analyzing of the sludge sample is done and find out effective methods to  We followed the bin type composting and convert it in to a fertilizer thereby it become the dimension of the bins were 40cm x ecofriendly without causing any health hazards. 30cm x 10cm (length ×width ×depth). Composting is an effective method to convert the sewage sludge to an effective fertilizer. Composting  The mixture is composted for 30 days in a mainly due to the presence of microorganisms shaded area and the bins are provided with present in sample. There exists a large variety of holes and mixing for proper aeration. methods of neutralization of sewage sludge; however, their cost is a serious limitation in practice.  The compost was maintained at moisture In this work effective sludge disposal by composting condition. method is used.[3,4,5]  The temperature was recorded using Various analytical and chemical methods are thermometer. adopted for finding the heavy metal content, pathogenic content, nitrogen-phosphorous and  The pH was measured using a pH paper. carbon content and compare the results before composting and after composting. More over germination test,[7] field study, solubility tests are carried out for analyzing the sample in before and

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Imperial Journal of Interdisciplinary Research (IJIR) Vol-2, Issue-6, 2016 ISSN: 2454-1362, http://www.onlinejournal.in

second and the third sets had 10 ml single strength broth. All the tubes contained Durham tubes before sterilization. The three sets of tubes received 10 ml, 1 ml and 0.1 ml quantities of water samples using sterile pipettes. The tubes were incubated at 370C for 24-48hrs for estimation of total coliforms and at 44.50C for faecal coliforms for 24-48 hrs. and examined for acid and gas production. Gas production was checked for by entrapment of gas in the Durham tube. The MPN was then estimated from table for three tube test.

(ii) Confirmed test Figure 2: Compost bins for carry out composting. Confirm test was carried out in line with [2] by transferring a loopful of culture from a positive tube from the presumptive test into a tube of Brilliant Green Lactose Bile (BGLB) broth (Oxoid) with Durham tubes. The tubes were incubated at 370C for 24-48hrs for total coliforms and 44.50C for 24-48hrs for faecal coliforms and observed for gas production.

(iii) Completed test

Completed test Completed test was carried out in Figure 3: Sludge mixture inside the Bin. accordance with [5] by streaking a loopful of broth from a positive tube onto Eosine Methylene Blue Compost microorganisms operate best under neutral (EMB) agar plate for pure colonies . The plates were to acidic conditions, with pH's in the range of 5.5 to incubated at 370C for 24-48hrs. Colonies developed 8. During the initial stages of decomposition, organic on EMB agar, were further identified as coliforms or acids are formed. The acidic conditions are favorable faecal coliforms (Escherichia coli) using cultural for growth of fungi and breakdown of lignin and characteristics, morphology and biochemical tests. cellulose. As composting proceeds, the organic acids For faecal coliforms, colonies with green metallic become neutralized, and mature compost generally sheen were Gram stained and the IMVIC test was has a pH between 6 and 8. carried out to identify the colony as E.coli. The MPN per 100 ml water was determined using the 3.3 Test for coliforms completed test.

A basic laboratory test is the best way to tell if 3.4 Heavy metal test Coliform organisms are present, as they can be there with no appearance or taste difference. When water  Samples were subjected to acid digestion, is tested for Fecal or Total Coliform, the results are and then heated at 900C. usually given as the number of colony forming units per 100 milliliters (CFU/100ml) of water sampled.  During digestion, care was taken to ensure No sample should contain Fecal Coliform or E. coli, that the samples did not dry out. and ideally there should be no Total Coliform, however a single sample may contain up to 10 Total  heavy metals were quantified in accordance Coliform CFU/100 ml. with the laboratory analysis of Aakkulam Centre for Earth Science Studies. The test basically consist of 3 steps 1. Presumptive test 3.5 NPK Test 2. Confirmed test 3. Completed test Samples were dried and given to soil testing (i) Presumptive test laboratory museum, paruthippara for further analysis of NPK content. Coliform count was obtained using the three tube assay of the Most Probable Number (MPN) 3.6 Conductivity test technique [3]. Presumptive coliform test was performed using lactose broth. The first set of three Conductivity is measured with a probe and a meter. tubes had sterile 10 ml double strength broth and the A voltage is applied between the two electrodes in

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Imperial Journal of Interdisciplinary Research (IJIR) Vol-2, Issue-6, 2016 ISSN: 2454-1362, http://www.onlinejournal.in the probe immersed in the sample water. The drop in 3.8 Field study voltage caused by the resistance of the water is used to calculate the conductivity per centimeter.

Conductivity (G), the inverse of resistivity (R) is Figure 4: Shows the plants in agro bag for field determined from the voltage and current values study according to Ohm’s law. The meter converts the probe measurement to micro mhos per centimeter and displays the result for the user.[12,13]

Procedure:

1) Switch on the conductivity meter (at least 30 min before the test).

2) Prepare 0.1 M potassium chloride solution.

3) Calibrate the conductivity meter to 14.12 mhos using the standard solution of 0.1 KCL by adjusting the calibration knob.

4) Read the conductivity meter by inserting the sample.  Field study is a collection of data that occurs outside of an experimental or lab Sample preparation setting. Mostly done in natural and 1) The sludge was dried in hot sun. environmental settings. 2) The dried sludge was powdered thoroughly and  In our work we are doing the field study in mix with deionized distilled water. order to find out the impact of compost on 3) The sample was stirred well with vortex mixer. 4) Filter the solution using a cotton cloth. plants and findings for suitable or not. 5) The sample was ready for analysis.  Soil is collected from college compound 3.7 Germination test and mixed in the ratio (1:2) into various agro bags.  Aqueous extracts (10 %) of the samples were prepared for germination studies using  The seeds are added and the agro bags are Lycopersicon esculentum. kept in the shade for first germination.

 Twenty pea seeds soaked for 30 min in the  Growth is observed periodically. above extract samples placed on to Petri dishes covered with filter paper and kept 3.9 Toxicity content test moist during the entire period of study. Toxicity of tomatoes and Amaranthus produced in  The germination and growth were observed field study is tested in pesticide residue laboratory, for 10 days. College of Agriculture vellayani, Thiruvananthapuram. The pesticide residue  The number of seeds germinated in each laboratory at College of Agriculture is NABL Petri-plate used during the test was counted Accredited. Various food products testing facilities are available in this lab.[14] The presence of toxicity Rate of germination was calculated using the in the plants and fruits grown on control, compost formula given below. mixture 1 and compost mixture 2 are given to this Germination (%) = laboratory for the analysis. 4. Results and discussions.

4.1 Result of coliform group of bacteria.

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Imperial Journal of Interdisciplinary Research (IJIR) Vol-2, Issue-6, 2016 ISSN: 2454-1362, http://www.onlinejournal.in

Table 2 : Result analysis of test for coliform Table 3: Result of the sample before Composting. group of Bacteria. Parameters Value

Organic carbon content, % 7.57

Nitrogen (kg/hectare) 550

Phosphorous, % 0.688

Potassium, % 0.014

The Coliform bacteria are often referred to as “indicator organisms” because they indicate the potential presence of disease-causing bacteria. Not all microorganisms are harmful. Main harmful species of Coliform bacteria that present in the sewage sludge are E.Coli. Even though not all species of E.coli are harmful, only certain strains of E.coli are harmful. But the absence of E.coli indicates the sample is safe. The Control has Table 4: Result of the sample after Composting. indicated the presence of E.coli. After composting (C1 & C2) there is no indication of the presence of 4.4. Result of conductivity test E.Coli. Therefore this shows the sample is pathogenic free. But in drinking water standard the Figure 5: Shows the result of conductivity test. indication of the presence of E.Coli should be less than 1 CFU/1000 ml. So this sample is safe for used as a manure for agriculture Purposes. Among the composts C2 is the better combination.

4.2. Result of heavy metal test

In Aakulum Centre for Earth Science Studies. laboratory, the results obtained is there is no Chromium content in the sample of sludge. Therefore there is no Chromium content in compost also. Table 5: Result analysis of conductivity test. Chromium is an important heavy metal that is presently contains in most industrial related sewage and it is very dangerous to health. But the sludge has slightly varying property and moreover the sewage sludge obtained from Muttathara plant is related to hospital waste mainly, Industrial wastes are lower because huge industries are only limited in the city.

4.3. Result of NPK Test

From the results obtained from Soil testing Laboratory, Paruthippara are Provided below: Electrical conductivity is used to measure the amount of nutrients in the compost that are in the form of salts. EC is a common measure you will also find on your soil and water tests. Compost is mixed with a set amount of water and an electrical conductivity meter measures how much electricity moves through

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Imperial Journal of Interdisciplinary Research (IJIR) Vol-2, Issue-6, 2016 ISSN: 2454-1362, http://www.onlinejournal.in the water. Electricity moves better through solutions high in salts, so the higher the EC reading the saltier the product. Since nutrients occur in compost as 4.7. Result analysis of field study salts, high EC may also indicate high levels of nutrients. Control Tomato

4.5. Result of germination test

Control C2 C1

Amaranthus Figure 6: Shows the germination of tomato seeds in petri dishes.

The purpose of laboratory testing of seed germination is to assess seed quality or viability and to predict performance of the seed and seedling in the field. Sludge is rich in nutrients such as nitrogen and phosphorous and contains valuable organic matter. The organic matter and nutrients in sludge are considered as the two factors that make sewage sludge potentially suitable as a fertilizer in agriculture production.

In germination test the growth rate of tomato seeds is Figure 7: Shows the First Stage comparison after very low. In Compost 1 (C1) high growth rate than 4 days. control. Compost 2 (C2) has high growth rate among others. This shows compost two is a better composition mixture.

4.6 Result of toxicity content test

From the result obtained from the pesticide residue laboratory of College of Agriculture, vellayani, Thiruvanathapuram shows that the fruit and leaves obtained from plant that is grown in Compost 2 is edible for consumption. The crop and leaves obtained from compost 1 have some minor effects of C1- Tomato C2-Tomato toxicity, but it can be used for other non-consumable plants.

C1 & C2 Amaranthus

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Imperial Journal of Interdisciplinary Research (IJIR) Vol-2, Issue-6, 2016 ISSN: 2454-1362, http://www.onlinejournal.in

Figure.8 Second Stage comparison after 15 days 6. Future studies

The disposal of sewage sludge can be done by various methods. But the cost effective method is more affordable.

Composting is one of the affordable methods.

 This compost can be effectively used as a manure in nonedible crops

 (Especially for industrial purposes: - paper industry, rubber plantations and energy plantations). Because, there is no problem of toxicity.

 Teak plantations. Figure 9: Shows the graphical analysis of field  Flowering nurseries. study.  Silk worm plantations. Compost 2 has better growth rate in field study. Therefore Compost 2 is the better composition. The  Cotton and jute plantations. height of plants are also compared. The plants grown in Compost 2 are taller than compost 1 and control. 7. Acknowledgements 5. Work summary and conclusions We would like to thank Sree Chitra Thirunal College of Engineeringfor opportunity and we would also In this research work the sludge is collected from express our gratitude towards Mr. Narayanan sewage treatment plant Muttathara, Namboothiri sir for their support. Thiruvananthapuram and it is dried and mixed by various proportions consisting of cow dung, 8. References vegetable waste and bids of paper according to the [1]"Manual on sewage and sewage treatment", Central suggestions of faculty members and co- Public Health and Environment Organisation, Ministry of workers.Proper monitoring of moisture, pH and care Urban Development, New Delhi, 2nd edition, December should be taken daily during the composting period. 1993 Experiments were done for the analysis of Coliform [2]"Operation and maintenance manual for sewage group of bacteria, Heavy metal content, Nitrogen- treatment plant based on activated sludge process with extended aeration" at Valiathura, Thiruvananthapuram, Phosphorous-Potassium content, Concentration of UEM India Pvt. Ltd. ions by conductivity test, ability of growth by Germination test etc. based on standard procedures. [3]"Introduction to Activated Sludge Study Guide"- December 2010 Edition, Wisconsin Department of Natural Field studies were carried out for proper implantation Resources of the compost mixture in the agriculture field. More [4] Lindsay b. j., logan t. j.: Field Response of Soil over the toxicity content of the fruits, leaves etc. Physical Properties to Sewage Sludge, J. Environ. Qual., were also checked for any sign of health effects 27,534, 1998. while consumption. [5]https://www.famic.go.jp/ffis/fert/TestingMethodsFor Fertilizers2013 From the result analysis the composition mixture of compost 2 is better for agriculture purposes. The [6] http://www.sciencedirect.com/science/article/pii/S187 composition of compost 2 is 12kg of sludge and 8 kg 8535210001334 of cow dung. So it can be used as good manure for agriculture field. [7]http://seednet.ap.nic.in/Stl/htmlpages/Germination Testing.html. Thus effective disposal of sludge that is obtained [8]"Preliminary risk assesment for pathogens in landfilled from sewage treatment plant, Muttathara, municipal sewage sludge Environmental criteria and Thiruvananthapuram is possible. assessment office" U.S. Environmental Protection Agency EPA/600/R-94/110 ,september 1993

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Imperial Journal of Interdisciplinary Research (IJIR) Vol-2, Issue-6, 2016 ISSN: 2454-1362, http://www.onlinejournal.in

[9] Rydin e., Otabborg e.: Potential Release of Phosphorus from Soil Mixed with Sewage Sludge, J. Environmental Quality, 26, 529, 1997. [10] www.grainger.com/category/conductivitymeters/testing [11]www.fssai.gov.in/Portals/0/Final_test_manual_part_I (16-08-2012). [12] "Technical Support Document for Land Application of Sewage Sludge", Environmental Protection Agency, Ireland, Volume-I, 1992 [13]The influence of temperature and moisture contents regimes on the aerobic microbial activity of a bio solids composting blend. Bio resource Technology .,86: 131-137. [14] "Waste water treatment Manuals- Primary, secondary and Tertiary treatment", Environmental Protection Agency, Ireland, 1997

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