Assessment of wastewater of Da River Left-bank Industrial Zone - Hoa Binh City on the 2013-2014 period

Header Page of 126 THAI NGUYEN UNIVERSITY UNIVERSITY OF AGRICULTURAL AND FORESTRY TRAN THI LAN HUONG TOPIC TITLE: ASSESSMENT ON SITUATION OF WASTEWATER OF DA RIVER LEFT-BANK INDUSTRIAL ZONE, HOA BINH CITY IN THE 2013 – 2014 PERIODS BACHELOR THESIS Study Mode: Full-time Major: Environmental Sciences and Management Faculty: International Training and Development Center Batch: 2010 - 2015 Thai Nguyen, 17/01/2015 i Footer Page of 126 Header Page of 126 Thai Nguyen University of Agriculture and Forestry Degree Program Bachelor of Environmental Science and Management Student name Tran Thi Lan Huong Student ID DTN 1053180056 Thesis title Assessment of wastewater of Da River Left-bank Industrial Zone - Hoa Binh City on the 2013-2014 period Supervisor(s) Assoc Prof Dr Do Thi Lan MA Truong Thi Anh Tuyet Abstract: The purpose of this study is to assess wastewater of Da River Left-bank Industrial Zone- Hoa Binh City in the 2013-2014 periods The main focus is in two aspects: to assess the status of wastewater treatment of Da River Left-bank Industrial Zone and to propose solutions for decreasing the water pollution Regarding to the state of wastewater treatment, Da River Left-bank Industrial Zone is a place that has largest amount of wastewater discharge in Hoa Binh City In the Industrial Zone, a number of companies discharged wastewater directly into Dung stream (flowing to Da River) an extremely large amount of domestic and industrial wastewater, that seriously exceed the permissible standards Besides, many companies had administrative violations in the discharge of wastewater or did not have enough legal documents following regulation in wastewater management Currently, Da River Left-bank Industrial Zone starts to build the wastewater treatment system in order to have effective wastewater treatment and simple discharge management After assessing the situation in the Industrial Zone, the essential solutions are proposed In term of management, local authorities need to take coercive measures against companies which discharged the untreated or unsatisfactory treated wastewater directly into environment With technological solution, the Industrial Zone has to select appropriate production technologies, innovative technology of wastewater treatment system Overall, the options considered and evaluated in the thesis indicated that Da River Left-bank Industrial Zone can implement those options to prevent and manage the quality of wastewater in order to protect environment in a legal, logical and financially practical way Keywords Number of pages: Date of submission: Industrial Zone, wastewater, treatment, pollution, discharge, industry, domestic, etc 58 January 15, 2015 ii Footer Page of 126 Header Page of 126 ACKNOWLEDGEMENT I would like to express my gratitude to my supervisors, Assoc Prof Dr Do Thi Lan and MA Truong Thi Anh Tuyet for their invaluable useful comments, remarks, encouragement and engagement through the learning process of this graduated thesis I sincerely thank the lecturers who enthusiastically imparted useful knowledge on water treatment during the University program to all class attendants I also thank the support of Thai Nguyen University of Agriculture and Forestry, the coordinators and program managers for their support and assistance I am using this opportunity to express my gratitude to my classmates, who supported me throughout this course, by their aspiring guidance, invaluably constructive criticism and friendly advice I am sincerely grateful to them for sharing their truthful and illuminating views on a number of issues related to my thesis Also, I like to thank the participants in my survey, who have willingly shared their precious time during the process of interviewing I would like to thank my loved ones, who have supported me throughout entire process, both by keeping me harmonious and helping me putting pieces together Thank you all very much! Sincerely yours, iii Footer Page of 126 Header Page of 126 TABLE OF CONTENT List of Tables List of Figures List of Abbreviations PART I INTRODUCTION 1.1 Rationale 1.2 Definitions 1.3 Aims of the study 1.4 Research questions 1.5 Research significance 1.5.1 Practical significance 1.5.2 Learning and scientific research significance 1.6 Limitations PART LITERATURE REVIEW 2.1 Theoretical background 2.2 Scientific background 2.2.1 Related definitions 2.2.2 Water quality assessment 10 2.3 Empirical background 14 2.3.1 Water resources and situation of water pollution in the world 14 2.3.2 Studies on water quality in Vietnam 15 2.4 Study area review 18 2.4.1 Natural and socio-economic conditions of Hoa Binh City 18 2.4.1.1 Natural conditions 18 iv Footer Page of 126 Header Page of 126 2.4.1.2 Socio-economic conditions 21 2.5 General assessment of review 25 PART III METHODS 26 3.1 Object and scope of study 26 3.2 Location and time of study 26 3.3 Research content 26 3.3.1 Basic characteristics of Da River Left-bank Industrial Zone – Hoa Binh City 26 3.3.2 Assessment of current status of water quality of the industry 26 3.3.3 Proposal of a number of solutions to reduce pollution and effects of wastewater to surrounding environment 26 3.4 Research methods 27 3.4.1 Secondary data collection method 27 3.4.2 Methods of getting, maintaining and analyzing samples 27 3.4.3 Question and Interview methods 29 3.4.4 Analyzing, synthesizing and assessing data methods 29 PART IV RESULTS 30 4.1 Overview of Da River Left-bank Industrial Zone 30 4.1.1 Status of operation and implementation of environmental protection of some companies in Da River Left-bank Industrial Zone 30 4.1.2 The situation of wastewater treatment of Da River Left-bank Industrial Zone 38 4.2 Assessment of current situation of water in Da River Left-bank Industrial Zone and surrounding areas 40 4.2.1 Current situation of Da River Left-bank Industrial Zone’s wastewater 41 4.2.1.1 Situation of wastewater of Da River Left-bank Industrial Zone in 2013 41 v Footer Page of 126 Header Page of 126 4.2.1.2 Situation of wastewater of Da River Left-bank Industrial Zone in 2014 43 4.2.2 Assessment of wastewater’s impacts of Da River Left-bank Industrial Zone to local people based on survey 48 4.2.2.1 Basic information of investigated subject 49 4.2.2.2 Assessment of wastewater’s impacts of the Industrial Zone to local people 49 4.3 Recommendation of solutions to overcome and minimize water pollution of Da River Let-bank Industrial Zone 54 4.3.1 Management solutions 54 4.3.2 Technological solutions 55 PART V DISCUSSION AND CONCLUSION 60 5.1 Discussion 60 5.2 Conclusion 61 REFERENCES 62 APPENDICES 65 vi Footer Page of 126 Header Page of 126 LIST OF FIGURES Figure 1: Diagram of wastewater treatment technology of Left Side Da River Industrial Zone .39 Figure 2: Concentration of BOD5, COD and TSS in 2013, 2014 in wastewater at discharged point into environment of wastewater treatment plant - Huu Nghi JSC for Agricultural and Forestry Products .44 Figure 3: The concentration of Absorbable Organic Halogens, 2013 and 2014 in wastewater sample at the discharged point into environment of wastewater treatment system , Huu Nghi JSC for Agricultural and Forestry Products 45 Figure 4: The concentration of BOD5 in 2013 and 2014 in the domestic wastewater sample at the discharged point into environment, R technical research Vietnam Co, Ltd 47 Figure 5: The concentration of Total Coliform in 2013 and 2014 in domestic wastewater at the discharged point into environment, R technical research Vietnam Co, Ltd 48 Figure 6: The proportion of men and women of investigated groups 49 Figure 7: The proportion of careers of investigated groups 49 Figure 8: Diagram of wastewater treatment technology 57 Footer Page of 126 Header Page of 126 LIST OF TABLES Table 1: Distribution of land use in Hoa Binh City in 2014 24 Table Fuel and water consumption of some operating companies in Left Side Da River Industrial Zone 31 Table 3: Result of analysis of wastewater samples at discharge point into the environment - Huu Nghi JSC for Agricultural and Forestry Products 41 Table 4: Result of analysis of domestic wastewater sample at discharge point - R technical research Vietnam Co, Ltd in 2013 42 Table 5: The result of analysis of industrial wastewater at discharge point into environment - Huu Nghi JSC for Agricultural and Forestry Products 43 Table 6: The result of analysis of domestic wastewater sample at the discharged point - R technical research Vietnam Co, Ltd in 2014 46 Table 7: The impact of wastewater of the Industrial Zone to agriculture production and the health of people living around there 51 Footer Page of 126 Header Page of 126 LIST OF ABBREVIATIONS AND ACRONYMS AOX : Absorbable Organic Halogens BOD : Biochemical Oxygen Demand COD : Chemical Oxygen Demand EPA : Environmental Protection Agency DNRE : Department of Natural Resources and Environment JSC : Joint Stock Company LEP : Law on Environmental Protection MNRE : Ministry of Natural Resource and Environment TSS : Total Suspended Solids VEA : Vietnam Environment Administration Footer Page of 126 Header Page 10 of 126 PART I INTRODUCTION 1.1 Rationale Environment is a system of natural and artificial material factors which impact on the survival and the development of humans and animals (Environmental Protection Act, 2014) Those factors are considered as basic components of the environment; they formed and developed under the law of nature One of the most crucial and necessary factors for all life on earth in general and human in particular is water It does not only affect human’s health, dietary needs, daily activities, but it is also a factor to ensure the prosperity of mankind Nowadays, the development of science and technology has accelerated the pace of socio-economic development, creating a giant volume of material goods for meeting the growing demands of human However, the socio-economic development, especially the rapid development of the industry in recent years has discharged a huge amount of wastewater This is the direct cause of the environmental pollution in general and water quality decline in particular, that makes clean water on Earth become increasingly scarce and exhausted As a country with a growing economy, Vietnam has become the heavily polluted water on the world Among them, the Da River Left-bank Industrial Zone which located on Huu Nghi Ward, Hoa Binh City is one of the hot spots of wastewater pollutants, especially industrial wastewater The Industrial Zone is consisted of many companies operating in different fields such as productions of plastic sheet, insulator, plastic tube with hydrocarbon polymer, Footer Page 10 of 126 Header Page 60 of 126 To address water pollution of the Industrial Zone and bad effects of wastewater to human’s life, health and production activities, recommendation of solutions and minimization of water pollution are essential In order to achieve high efficiency, it is necessary to apply both management and technology solutions 4.3.1 Management solutions Management solutions in mechanisms, policies and technical require a synchronous coordination and assignment of responsibilities for related sectors If the causes of water pollution of the Industrial Zone are well-recovered , a huge of amount of pollutants would decrease and would be under the values regulated in column B of QCVN 40:2011, QCVN 12:2008 and QCVN 14:2008 To implement coercive measures against Da river Left-bank Industrial Zone if they continue to discharge untreated or unsatisfactory treated wastewater into the environment and pollute receiving water source * The functional units have to organize inspection and examination of the observance of regulations in environmental protection of the Industrial Zone * In addition, local government needs to apply mechanisms to charging fees for environmental protection and wastewater discharge according to regulations * For Da River Left-bank Industrial Zone - To timely build wastewater treatment system to treat wastewater for whole Industrial Zone At the same time, to operate wastewater treatment system regularly to affectively treat a huge of amount of wastewater in the Industrial Zone Footer Page 60 of 126 54 Header Page 61 of 126 - To maintain controlling of environmental pollution annually and report to functional authorities as a base for environmental management and monitoring; - To build plans for prevention and overcoming environmental incidents; - To implement solutions to protect environment in accordance with laws such as: + To urge wastewater treatment of factories and companies in the Industrial Zone, especially companies that are in the list of polluters of Hoa Binh DNRE; + To ensure wastewater treatment to meet the national technical standards; - To provide warning and discipline levels for irresponsible behavior leads to environmental incidents for the Industrial Zone At the same time, to provide reWard levels for individuals or groups having good initiative to reduce the level of pollution in the Industrial Zone; - To raise constantly awareness in environmental protection for workers and employees such as organizing short-term training through organizations to educate people the consciousness of environmental protection 4.3.2 Technological solutions In order to reduce to a minimum in both amount and concentration of pollutants, the Industrial Zone has to select appropriate production technologies Solutions should be made as follows: + To issue a number of policies to encourage companies which still use outdated technologies So, they would invest in improving production lines, apply clean technologies to minimize maximum the amount of wastewater Footer Page 61 of 126 55 Header Page 62 of 126 + To allow only investment projects which already have advanced technologies and create less amount of wastewater Besides of selection of advanced technologies and production lines, the disposal of wastewater in the Industrial Zone should also implement as following solutions: + For wastewater treatment system’s construction of Da River Left-bank Industrial Zone, according to technological diagram, the Industrial Zone only apply aerobic biological treatment, that is not highly effective in wastewater treatment Therefore, the Industrial Zone should combine physical, chemical and biological method together to thoroughly handle the problems At the same time, the Industrial Zone should install flow measurement system and continuous monitoring of all discharged points to measure automatic parameters of treated wastewater as pH, COD, TSS, TDS, NH 3, Color, etc On applying those methods, the Industrial Zone can ensure wastewater treatment meets QCVN 40:2011, QCVN 12:2008 and QCVN 14:2008, column B Through process of learning, researching and collecting references, the author suggests the Industrial Zone to use wastewater treatment process as following: Footer Page 62 of 126 56 Wastewater Header Page 63 of 126 Wastewater pit Pump Garbage blocking grid Compressor Conditioning aeration tank Oil separator tank Oil tank Neutral compounds Neutral reaction tank Adhesive compound Coagulated reaction tank Dissolved tank Sand filter tank Disinfecting tank Flow measurement and monitoring system Mud tank Mud vehicle Treated water storage tank Water reached permissible standard Discharge to receiving source Figure 8: Diagram of wastewater treatment technology Footer Page 63 of 126 57 Header Page 64 of 126 This system is a complex process, which includes several stages: preliminary treatment, aerobic microbial treatment and coagulated chemical treatment The technological process is described as following: Wastewater from various manufacturing companies in Industrial Zone flows with wastewater system to wastewater pit From wastewater pit, wastewater is pumped to conditioning aeration tank (the top of tank has garbage block in grid) to reduce COD and BOD5 concentrations Subsequently, wastewater is put into an oil separator tank to remove oil from wastewater; the separated oil will be put into oil tank Wastewater flows to neutral reaction tank to bring pH to appropriate value for coagulated treatment In coagulated reaction tank, suspended solids in water are coagulated Then, wastewater flow into settling tank to remove suspended solids, mud is put into the mud tank After that, wastewater is sent to sand filter tank to remove almost thoroughly suspended solids After crossing sand filter tank, wastewater is taken to disinfecting tank Finally, wastewater is passed into treated wastewater tank and flows drains and discharge to environment At the beginning of drains, there are measurement and monitoring systems for some pollutants in wastewater * Advantages and disadvantages of the system: - Advantages: + Wastewater treatment standards + Less the auxiliary works, less construction area + Simple operation line + Simple equipment, easy to monitor and manage Footer Page 64 of 126 58 Header Page 65 of 126 - Disadvantage + Mainly apply bioremediation technology So, it should be considered carefully to the conditions for the best of mud work Footer Page 65 of 126 59 Header Page 66 of 126 PART DISCUSSION AND CONCLUSION 5.1 Discussion Through research result, it can be discussed the specified contents as following: Firstly, the operation and implementation status of environmental protection in the Industrial Zone is relatively good Besides, some companies were still neglected and not strictly controlled to have been sanctioned for administrative violations of environmental protection Otherwise, the Industrial Zone did not have centralized wastewater treatment system Secondly, the wastewater situation of the Industrial Zone and surrounding areas are complex and alarming Some companies in the Industrial Zone have wastewater samples with very high levels of BOD5, COD, total Coliform, AOX, TSS, etc that cause serious pollution in the 2013 – 2014 periods Consequently, wastewater affected local people health and their agricultural production levels by making crop yield reduction, causing disease for human and animals, and reducing the growth of livestock Thirdly, solutions to minimize wastewater pollution are pointed out It is necessary to apply management and technology solutions together Authorities have to enhance regulations on water resources to the Industrial Zone Besides, it should be applied a clear mechanism for management of water resources and irrigation structures, to coordinate and manage the construction, approval of organizations and individuals that are directly Footer Page 66 of 126 60 Header Page 67 of 126 related to the exploitation and water resources In the coming years, the Industrial Zone has to operate and improve centralized wastewater treatment system 5.2 Conclusion With the title “Assessment of wastewater of Da River Left-bank Industrial Zone in the 2013-2014 periods”, the study has shown both environmental protection work and situation of wastewater treatment in the Industrial Zone currently With whole scene of pollution and its impacts, it is an alarm for not only the Industrial Zone but also local people and authorities in environmental protection It is urgency to prevent water pollution by thorough solutions Although the study has yielded some initial findings, some of its limitations still exist The findings from this study can be examined in a pilot process to check its compatibility A further research for this study can focus more on solutions to improve wastewater in the Industrial Zone, then to propose amendment and adjustment for the next step of implementation Footer Page 67 of 126 61 Header Page 68 of 126 REFERENCES Advanced Chemical Systems (n.d) The Importance of pH in wastewater treatment Retrieved from http://advancedchemsys.com/importance-ph-wastewater-treatment/ Ashbolt, N., Grabow, W., & Snozzi, M (n.d) Indicators of microbial water quality Retrieved from http://www.who.int/water_sanitation_health/dwq/iwachap13.pdf Center for Educational Technologies (n.d) Water quality assessment: Physical: Temperature Retrieved from http://www.cotf.edu/ete/modules/waterq3/WQassess4h.html Chairman of Hoa Binh Provincial People’s Committee (2013) Decision on approving list of enterprises that seriously pollute environment in the area in 2013 Da River – Thang Long Joint Stock Company, Hoa Binh Branch (2013) Assessment of impact on environment of infrastructure building and trading project in Da River Left-bank Industrial Zone Environment analyzing and technique, JSC (2013A) Results of analyzing wastewater of R Vietnam Technical Research Co, Ltd Environment analyzing and technique JSC (2013B) Results of analyzing wastewater of Huu Nghi Joint Stock Company for Agricultural and Forestry Products Environment analyzing and technique, JSC (2014A) Results of analyzing wastewater of R Vietnam Technical Research Co, Ltd Environment analyzing and technique JSC (2014B) Results of analyzing wastewater of Huu Nghi Joint Stock Company for Agricultural and Forestry Products Filter and Separation (n.d) Definition of Solid Concentration http://www.filtration-and-separation.com/concentration.htm Retrieved from Hellawell, J.M (1989) Chemical indicators of Freshwater pollution and Environmental management Netherlands: Elsevier Science Publisher, p 206-215 Hoa Binh Department of Natural Resources and Environment (2012) Assessment of progress of ground water quality of Hoa Binh province in 2011-2012 Hoa Binh Department of Natural Resources and Environment (2013A) Assessment on natural resources – environment indicators and sustainability of Hoa Binh Province Hoa Binh Department of Natural Resources and Environment (2013B) List of enterprises in Da River Left-bank Industrial Zone Hoa Binh Department of Natural Resources and Environment (2013C) Special report on assessment of surface water’s quality in Hoa Binh Province in 2012-2013 Hoa Binh Department of Natural Resources and Environment (2014A) Review report on bioFooter Page 68 of 126 62 Header Page 69 of 126 diversity’s current situation and action plan for bio-diversity of Hoa Binh Province in 2011-2015 periods and orientation to 2020 Hoa Binh Department of Natural Resources and Environment (2014B) Summary of investment projects of industrial zones in Hoa Binh Province Hoa Binh Statistic Office (2012).Statistics of Hoa Binh Province Le Van Khoa, Nguyen Xuan Quynh & Nguyen Quoc Viet (2013) Environmental chemical indicators Hanoi: Educational Publishing House Le Van Thien (2007) Lecture on environment pollution Hanoi: VNU University of Science Ministry of Science and Technology (2002) Handbook on Environmental Observation and Analysis Ministry of Natural Resources and Environment (2008A) National technical regulations on the effluent of pulp and paper mills (QCVN 12:2008/BTNMT) Ministry of Natural Resources and Environment (2008B) National technical regulations on domestic wastewater (QCVN 14:2008/BTNMT) Ministry of Science and Technology (2009) Vietnam’s State standards on environment Ministry of Natural Resources and Environment (2011) National technical regulations on industrial Wastewater (QCVN 40:2011/BTNMT) NORWECO (n.d) Tests on water and http://www.norweco.com/html/lab/WhatTests.htm wastewater Retrieved from Pham Song.(2013) Hanoi region for providing clean water and environmental sanitation Pham Tuyen (2012) State of water environment http://www.nuoc.com.vn/content/view/27/35/ in Vietnam Retrieved from Phan Thi Anh Đao, Do Thi Thanh Binh, Phan Văn Mach, Tran Thi Thanh Binh, Le Xuan Tuan (2013) Current state of aquatic plants in some river branches in Cau River basin The Encyclopedia of earth (2013) Water http://www.eoearth.org/view/article/157013/ resources Retrieved from The National Center for Science and Technology Information (2013) Environment Bulletin in October 2013 The National Assembly of Vietnam (2014) Law on Environment Protection The Vietnamese Government (2003) National strategies for environmental protection towards 2010 and orientation to 2020 UNDA.(2013) Environment Concepts and issues: A focus on Cambodia Footer Page 69 of 126 63 Header Page 70 of 126 United Nations - Economic and Social Commisssion for Asia And The Pacific (n.d) Urban Water Resources Management USGS (n.d) Definition of Turbility Retrieved from http://water.usgs.gov/edu/turbidity.html Vietnam Environment Administration (2013) Inspection’s results on environmental protection in Da River Left-bank Industrial Zone Vietnam Environment Administration (2014) Inspection’s results on environmental protection in Da River Left-bank Industrial Zone VOV (2013) State of water pollution in Vietnam Retrieved from http://www.kccottellvietnam.com.vn/story/tinh-trang-o-nhiem-moi-truong-nuoc-tai-viet-nam WHO.(2013) Basic epidemiology Retrieved from http://apps.who.int/iris/bitstream/10665/435 41/9/9241547073_vie.pdf Footer Page 70 of 126 64 Header Page 71 of 126 APPENDICES APPENDIX I: SAMPLE SURVEY QUESTIONNAIRE ASSESSMENT OF WASTEWATER’S IMPACT ON DA RIVER LEFT-BANK INDUSTRIAL ZONE TO LOCAL PEOPLE This survey questionnaire is part of real study of students in K42 -Environmental Science Management (Advanced Education Program) - Thai Nguyen University of Agriculture and Forestry Information that you provide will help students collect data and information for research: "Assessment on situation of wastewater of Da River Left-bank Industrial Zone – Hoa Binh City in the 2013 – 2014 periods” With permission and supervision of Hoa Binh Environmental Protection Agency and Thai Nguyen University of Agriculture and Forestry, I guarantee that the information done by students will not cause any effects to you We appreciate your enthusiasm in providing information in high accuracy during this survey Sincerely yours! Interviewer: Tran Thi Lan Huong Class: K42 - Environmental Science and Management (Advanced Education Programs) Thai Nguyen University of Agriculture and Forestry Footer Page 71 of 126 65 Header Page 72 of 126 PART I GENERAL INFORMATION Name: Address: Age: Gender: EthniCity: Telephone number: Interview Time (DD/MM/YY): Please answer or mark "X" in appropriate answers for your opinions! PART II ASSESSMENT OF WASTEWATER’S IMPACT ON DA RIVER LEFT-BANK INDUSTRIAL ZONE TO LOCAL PEOPLE Question 1: Does wastewater of the Industrial Zone impact to your crop?  Absolutely yes Sometimes It depends Absolutely no Question 2: Does wastewater of the Industrial Zone impact to your breeding?  Absolutely yes Sometimes It depends Absolutely no Question 3: Does wastewater the Industrial Zone impact to your health?  Yes No Question 4: How are your crop activities when the Industrial Zone discharges into the environment? Footer Page 72 of 126 66 Header Page 73 of 126  Normally Reduces crop yields Cannot continue to produce Others Question 5: How are your breeding activities when the Industrial Zone discharge into the environment?  Normally Cause disease for animals Reduced the growth of animals Others If you answer “Absolutely yes”, “It depends”, “Sometimes” or “Othes”, please write the reasons belows? Informer (Signature and full name) Footer Page 73 of 126 67 Header Page 74 of 126 APPENDIX PHOTOS OF THE DA RIVER LEFT-BANK INDUSTRIAL ZONE’S WASTEWATER The end point of wastewater of the Industrial Zone discharged into Dung stream Wastewater canal in the Industrial Zone Wastewater receiving point of Dung stream from Huu Nghi AFP JSC , Sugar Hoa Binh JSC and Sankok Vietnam Company, Ltd) Wastewater stagnant point in the Industrial Zone Footer Page 74 of 126 68 ... wastewater of Da River Left-bank Industrial Zone- Hoa Binh City in the 201 3-2 014 periods The main focus is in two aspects: to assess the status of wastewater treatment of Da River Left-bank Industrial. .. wastewater of Da River Left-bank Industrial Zone on the 2013 – 2014 periods” 1.2 Definitions This study assesses the status of wastewater of Da River Left-bank Industrial Zone on the 2013 – 2014 periods... Da River Left-bank Industrial Zone and surrounding areas 40 4.2.1 Current situation of Da River Left-bank Industrial Zone s wastewater 41 4.2.1.1 Situation of wastewater of Da River Left-bank