Comprehensive Evaluation of Social-Economic and Environmental Policies with Emphasize on Reclaimed Water Utilization to Effectively Achieve Sustainable Development: A Case Study in , China

Graduate School of Life and Environmental Sciences, University of Tsukuba Nan XIANG※ Graduate School of Life and Environmental Sciences, University of Tsukuba Feng XU Graduate School of Life and Environmental Sciences, University of Tsukuba Takeshi MIZUNOYA Graduate School of Life and Environmental Sciences, University of Tsukuba Yoshiro HIGANO

1. Introduction Water resources are one of the most important things for human existence and social development. Also, with the increase of economic and population in developing countries, water scarcity and pollution problems are becoming more and more prominent recently. Wastewater reuse has drawn increasing attention worldwide as an integral part of water resources management. Such a move is driven by two major forces: scarcity of clean water resources and heightened environmental concerns1. Reclaimed water reuse has been used in large municipalities in many parts of the world, especially in areas where the water resources are scare and population and economic growth is rapid 2. Tianjin is one of the typical areas in point. In 2009, only 2.01% of total water supply in Tianjin comes from reclaimed water reuse, the reclaimed water projects have just started. Reclaimed water reuse practice can be traced back to several centuries ago. And there are a large number of studies on waste water treatment from technological and engineering aspects. However, there is rather rare research on reclaimed water utilization modeling and prediction. In most of these studies, conclusions are derived from simple data analysis and foreign experiences 3. Research on construction and analysis of a comprehensive simulation policy that includes the introduction of current treatment technologies to control water pollutant emissions without deteriorating the socio-economic activities level are badly needed. In the study, we selected Tianjin city as an objective region, and utilized linear modeling as research method, constructed comprehensive evaluation model to prove the feasibility and possibility on using reclaimed water promotion and water quality control policy to improve economic and social development. 2. Current situation of the catchment area Tianjin, one of four biggest municipalities in China, is located in northern China, near Beijing, capital of China, and the downstream of Haihe River basin. 2-1 Local situation There are 15 districts and 3 counties in Tianjin, the land area is 1,191,970 hectares. About the land usage, agriculture land accounts for the biggest part, 60.87%; construction land accounts for 32.13%; and unused land is 829.85ha, accounts for 7%. The total population in Tianjin in 2009 is 122.816 million, and with the urbanization process, the urban population increasing rate is much higher than rural population4. From the following figures, we can see that Tianjin’s GDP keeps a steady increasing trend; the increase rate is above 10% per year. Also, the three industries composition demonstrates that Secondary Industry is the monopoly industry while its composition steady rises; primary industry only contributes a little to Tianjin’s economic, and its composition is low; tertiary industry’s GDP contribution declines year by year5. 2-2 Water supply situation Water shortage is a serious problem in Tianjin. Total water resource amount in 2009 is 2337 million m3. The per capita water resources in Tianjin is 190 m3 in 2009, it is only 1/13 of China average, and only 1/52 of world average. And the water supply structure is not stable for future development. Water supply is largely depending on surface water which is highly pullulated. And over 25% of water supply comes from water transferred from the other

area, such as Luan River in Hebei province. Reclaimed water only contributes to 0.51% of total water supply. Large transferred water supply dependence is not only leading to resource waste, but also causing water supply unstable. Reclaimed water can be a potential supply resource in saving water shortage problems.

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6000 15 GDP(Billion 4000 10 Yuan)

2000 5 GDP increase rate(%) 0 0

Fig.1 Location of Tianjin City, China Fig.2 GDP trend in Tianjin 2-3 Water quality situation Surface water quality in Tianjin is not enlightened; over 70% of surface water in Tianjin is in inferior V level. Also, from figure 4, rivers with red line are over qualified, and large amount of waste water is directly discharged to the ocean, Bohai Bay, without treatment. This will cause hidden danger for local area.

200 186 150 146 133 130 137 143 103 137 133 100 106

(1000ton) 50

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Fig.3 Surface water classification in 2009 Fig.4 COD emission amount in Tianjin Source: Tianjin Statistical Year Book 2010 Figure 4 shows the COD emission amount from 2002 to 2009. Limited to data availability, Tianjin only use COD in water pollution monitoring, this paper uses COD as the water pollutant control index in simulation. From 2001, Tianjin government has put proposals to improve water quality, therefore, with the economic rapid development, COD amount has been controlled stably, and the trend is declining. However, the total COD amount and water quality still need to be improved badly. Tianjin government has proposed to reduce and control COD amount in development plant until 2020. 2-4 Reclaimed water utilization situation Furthermore, waste water reuse situation has just started in this area; the reclaimed water reuse rate is really low, only 2.01% of reclaimed water is used in Tianjin. While the waste water disposal rate is 72.40%, a large amount of treated waste water has not been used. Compared with Beijing, the reclaimed water reuse rate is 57.55%, there is a large gap of reclaimed water utilization between these 2 Adjacent areas. It also demonstrates that there is large potential to use reclaimed water in Tianjin. Tianjin government also realized the importance to use recycle water in improving water quality and saving water. Local government established a 10 years target to increase reclaimed water recycle rate to 50-60% in 2020. Table1. Reclaimed water utilization (2009) units:( 10,000ton) Total amount of waste water sewage disposal sewage reclaimed water reclaimed water water resource discharged amount disposal utilization utilization rate rate amount Tianjin 15.24 8.23 5.96 72.40% 0.12 2.01% Beijing 34.2 13.21 10.43 78.92% 6 57.55%

Source: Tianjin Water Bureau Statistical Year Book 2010, Beijing Water Bureau statistical Year Book 2009 From the current situation analysis, we can see that Tianjin water supply structure need to be perfected; over 70% of surface water in Tianjin is in inferior V level, water quality is not well; and waste water treatment coverage proportion still needs to be improved, reclaimed water utilization rate is low, 2.01%. With the rapidly regional development, water scarcity is intensifying and water pollution is deteriorating. Thus, it is important to research on waste water utilization in order to solve water shortage and water pollution problems. 3. Research model construction 3-1 Case setting In this comprehensive simulation model, we will compare the results of the following cases to propose the optimal policies for Tianjin city of China. We set the water pollutants (TP, TN, COD) reduction rate by 2020 compared with that in 2019 as case setting basis. For example, case2-20 means water pollutants will be reduced by 20% by 2020 compared with that in 2009, and this case will introduce new reclaimed water technologies and comprehensive environmental policies. Table 2. Case setting of the comprehensive simulation model Cases Scenarios Water pollutants Reclaimed water technology Comprehensive policies reduction rate introduction introduction Case 0 Case 0-20 20% No No Case 1 Case 1-20 20% Yes No Case 2-10 10% Yes Yes

Case 2 Case 2-15 15% Yes Yes Case 2-20 20% Yes Yes Case 2-25 25% Yes Yes

3-2 Region Classification Regards to the simulation framework, the catchment area is divided into 11 areas based on these administration division and regional plan. Table3. Tianjin’s regional division Index Name Distinct Inde Name x Heping 3 1 Central Urban Hedong District 4 Area Hexi District 5 6 7 8 2 New 9 Ninghe County Area Han'gu District 10 Jinghai County 11 Jixian County

3-3 Water supply and demand classification And the water supply is divided into three types, direct water usage, pipeline water, and reclaimed water, from five kinds of water resources: local surface water, ground water, transfer water, reclaimed water, and others. Water demand resource is separated into three groups: household living water, industry water, and ecological water, and industry are divided into Primary industry, secondary Industry and Tertiary Industry.

3-4 New technologies choice We will introduce five kinds of technologies in simulation. New sewage plants and reclaimed water treatment plants will be installed with selection of these five technologies. These technologies can contribute their efforts on water pollutants reduction, and sewage treatment coverage improvement. Table 4 Technology introductions in simulation A B C D E Active CBR MBR DMBR CMBR sludge ( Contacted (Membrane (Double (Ceramic Baffled Bio-Reactor ) Membrane Membrane Reactor) Bio-Reactor ) Bio-Reactor ) construction cost(million Yuan) 180 161 130 165 70 water treat amount (million ton) 30 18.25 13 36.5 10.95 reclaimed water production 22 13 10 29.2 9.3 Influent COD 360 360 360 360 360 (mg/L) TN 32 32 32 32 32 TP 4 4 4 4 4 Effluent (mg/L) COD 30 30 30 15 6 TN 10 1 1 1 0.5 TP 1 0.6 0.5 0.5 0.1

4. Simulation Results Analysis In this study, 6 scenarios are established to evaluate the contribution of reclaimed water to economic development under COD constraint. The following results can be achieved: 4-1 Objective function From figure 5 and figure 6, the total GRP is the largest when we just reduce water pollutants to 10% when new technology and comprehensive policies are introduced. And water pollutants reduction is the highest in case2-25. However, considering economic development and environmental conservation together, case2-20 can be chosen as the optimal case for its high economic development and large pollutants control. Also, here is large gap between no technology introduction and comprehensive policy establishment between case0-20, case1-20, and case2-20.

11,500,000 11,314,750 1,800,000 11,000,000 10,721,700

1,600,000 case0-20

10,500,000 10,253,940 10,144,710 1,400,000 case1-20 10,000,000 9,732,362 1,200,000 case2-10 9,536,509 9,500,000 TGRP

MillionCNY 1,000,000 case2-15

9,000,000 800,000 case2-20 8,500,000 600,000 case2-25

2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

Fig.5 Total GRP of case 50 to case 75 Fig.6 GRP changing trend from 2010 to 2020

Table 5 shows the water pollutants emission intensity of each case, the TP emission coefficient is the lowest in case2-20, and TN and COD emission intensity is the lowest in case 2-10. With consideration of the local government water pollutants reduction targets, we can select case2-20 as the optimal choice for the local government. Table.5. Water pollutants emission intensity of 6 cases in Tianjin from 2010 to 2020 Cases TP emission TN emission COD emission intensity (Ton/ million CNY) intensity intensity case0-20 0.0021 0.0255 0.1093 case1-20 0.0020 0.0242 0.1037

case2-10 0.0023 0.0197 0.0921 case2-15 0.0021 0.0216 0.0971 case2-20 0.0020 0.0239 0.1025 case2-25 0.0022 0.0239 0.1059

5-2 Reclaimed water utilization trend Through simulation, we get the reclaimed water utilization potential in Tianjin from 2010 to 2020. With the economic development and financial support in research area, reclaimed water facilities are established and the total reclaimed water usage amount is growing significantly. Also, reclaimed water will be developed speedily for its high contribution on water saving and pollutnats reduction. Reclaimed water can substitue 20% of clean water in 2020 which is a large amount for Tianjin city who suffers from heavy water shortage.

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1500 600 Direct supply Untreated sewage 500 1000 Pipeline water Million m³ 400 Reclaimed water Sewage treated by new Miillion m³ Miillion 300 500 installed plants 200 100 Sewage treated by 0 existing plants 0 2010201120122013 20142015201620172018 20192020

Fig.7 Water supply from 2010 to 2020 Fig.8 Reclaimed water substitution trend from 2010 to 2020 Furthermore, new sewage plants can substitute existing sewage plants step by step for their high water pollutants treatment ability and reclaimed water production ability. In 2020, over 70% sewage will be treated by new installed sewage plants in case2-20. Overall, the wastewater treatment rate will reach 95% in 2020, while that in 2009 is only 72%. 5-3 New sewage plant construction and distribution As we introduced before, there are 5 kinds of new technologies will be used to construct new sewage treatment and reclaimed water production plants. Figure shows the sewage treatment amount by each new plants. Sewage plants A, D, and E will be constructed majorly, for their advantages in construction cost, sewage treatment efficiency, and treatment capacity. This can be basis for government to choose technology introduction in the research area.

800 700

600 SPNET 500 SPNDT 400 SPNCT

Million Million m³ 300 SPNBT 200 SPNAT 100 0 20102011201220132014201520162017201820192020

Fig.9 Sewage amount treated by 5 kinds of new plants of Tianjin Fig.10 Financial budget of case 2-20 Furthermore, subysidy distribution can be achieved. From 2010 to 2020, there will be 3,875 million subsidy being put on water environment improvement. Among these, the biggest part will be put in sewage plant construciton, and then supporting system for reclaimed water utilization. The simulation results can be policy-making basis for local government to set their financial budgets. 5. Conclusion and discussion Comprehensive evaluation of integrated water resource management policies, especially focused on reclaimed water utilization, can be easily applied in regional plans or policy-making. The modeling approach can be used to identify preferred design-variable values and operating policies for integrated water resources management. This study utilized an optimization simulation model to evaluate the reclaimed water potential and feasibility in achieving the dual targets of water environment restoration and socio-economic development. The significance of this study is the proof of a new method to evaluate the comprehensive impacts caused by reclaimed water utilization. The simulation model was originally constructed, and can be effective in simulating the socio-economic and environmental realities. From comprehensive simulation towards environmental policies evaluation with emphasize on reclaimed water usage, we can compare the economic and environmental development under different circumstances. Simulation results suggest that it is probable to reduce 25% of water pollutants in 2020 compared with that level in 2010. In the optimal case, when water pollutants are reduced by 20% in 2020, simulation can achieve suitable economic development, with a total GRP is 10,253 billion Yuan, which is 521 billion Yuan more than Case 0-20 without new technology and comprehensive policies introduction. Reclaimed water that is produced by new installed sewage plants can substitute 20% of the total water supply in 2020, and sewage treatment rate is increased from 72% in 2009 to 95% in 2020. Water shortage and water pollution problems can be effectively solved by reclaimed water. Also, reclaimed water can effectively contribute to economic development which is shown by the simulation. Moreover, specific technology instruction and sewage plant construction plans can be provided in each region at different times for Tianjin, China. Reference: Angelakis, A.N., L. Bonoux and V. Lazarova, 2003. Challenges and prospective for water recycling and reuse in EU countries, Water Sci. Technol. , 3, 59–68. Bai, X. M. and H. Imura, 2001. Towards Sustainable Urban Water Resource management: a Case Study in Tianjin, China, Sustainable Development, 9, 24-35.

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