Comprehensive Evaluation of Social-Economic and Environmental Policies with
Emphasize on Reclaimed Water Utilization to Effectively Achieve Sustainable
Development: A Case Study in Tianjin, China
Graduate School of Life and Environmental Sciences, University of Tsukuba
Nan XIANG※
Graduate School of Life and Environmental Sciences, University of TsukubaFeng 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 theincrease 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 ofwater resources management. Such a move is driven by two major forces: scarcity of clean water resources andheightened 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 fromreclaimed 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 ofstudies on waste water treatment from technological and engineering aspects. However, there is rather rare researchon 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 policythat 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 waterpromotion 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 is829.85ha, 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 population 4.
From the following figures, we can see that Tianjin’s GDP keeps a steady increasing trend; the increase rate isabove 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.

2-2Water supply situation

Water shortage is a serious problem in Tianjin. Total water resource amount in 2009 is 2337 million m3. The percapita 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. Largetransferred 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.
8000

20

6000

15

4000

10

2000

5

0

0

Fig.1 Location of Tianjin City, China

GDP(Billion
Yuan)
GDP increaserate(%)

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 tothe ocean, Bohai Bay, without treatment. This will cause hidden danger for local area.

(1000ton)

200

186

150
100

106 103130 137

146 143

137

133
133

50
0

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 amountand 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 oftreated waste water has not been used. Compared with Beijing, the reclaimed water reuse rate is 57.55%, there is alarge 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 ofwater resource

waste water
discharged

sewage disposal
amountTianjin

15.24

8.23

5.96

sewagedisposalrate
72.40%

Beijing

34.2

13.21

10.43

78.92%

reclaimed water
utilization
amount0.12
6

reclaimed water
utilization rate
2.01%
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 theoptimal 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 andcomprehensive 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 0Case 1Case 0-20
Case 1-20
Case 2-10

20%
20%
10%

No
Yes
Yes

No
No
Yes

Case 2

Case 2-15

15%

Yes

Yes

Case 2-20
Case 2-25

20%
25%

Yes
Yes

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

1
Central Urban
Area

2Binhai New
Area

Distinct

Name

Heping District

Inde
x
3

Hedong District

4

Xiqing District

Hexi District

5

Jinnan District

Nankai District

6

Beichen District

Hebei District

7

Wuqing District

Hongqiao District

8

Baodi District

Tanggu District

9

Ninghe County

Han'gu District

10

Jinghai County

Dagang District

11

Jixian County

Dongli District

3-3 Water supply and demand classification
And the water supply is divided into three types, direct water usage, pipeline water, and reclaimed water, fromfive 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, andindustry 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 onwater 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

Bio-Reactor )Bio-Reactor )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

COD

30

30

30

15

6

TN

10

1

1

1

0.5

TP

1

0.6

0.5

0.5

0.1

Effluent (mg/L)

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 newtechnology 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 notechnology introduction and comprehensive policy establishment between case0-20, case1-20, and case2-20.
11,314,750

11,500,000

1,600,000

case0-20

1,400,000

case1-20

1,200,000

case2-10

1,000,000

case2-15

9,000,000

800,000

case2-20

8,500,000

600,000

case2-25

10,500,000

10,144,710

10,000,000 9,732,362

10,253,940
9,536,509

9,500,000

TGRP

2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020

Million CNY

1,800,000

10,721,700

11,000,000

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

intensity

intensity

case0-20

0.00210.02550.1093

case1-20

0.00200.02420.1037case2-10

0.00230.0197

0.0921

case2-15

0.0021

0.0216

0.0971

case2-20

0.00200.02390.1025case2-25

0.00220.02390.1059(Ton/ million CNY)

COD emission intensity

5-2 Reclaimed water utilization trend
Through simulation, we get the reclaimed water utilization potential in Tianjin from 2010 to 2020. With theeconomic 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 highcontribution 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.
2500

900
800

2000

1000

Direct supply
Pipeline water
Reclaimed water

500

Miillion m³

Million m³

700
1500

600

Untreated sewage

500
400

Sewage treated by new
installed plants

300
200

Sewage treated byexisting plants

100

0

0
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

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 only72%.

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

Million m³

600

SPNET

500

SPNDT

400

SPNCT

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, andthen 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 isthe 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 andenvironmental 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 newtechnology 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, specifictechnology 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.
Chatila, J.G, 2004. Reclaimed waste water in some Middle Eastern countries: Pricing and perspective, Canadian J.
Development Studies, 25, 481–497.
Cheng, H.F. and Y.N. Hu, 2010. J. Environ. Monit., 12, 119-126.
Shen, D.J. and B.Liu, 2010. Integrated urban and rural water affairs management reform in China: Affecting factors ,Pysics and Chemistry of the Earth, 25(3), 857-873.