THAI NGUYEN UNIVERITY UNIVERSITY OF AGRICULTURE AND FORESTRY PHAM MY ANH TOPIC TITLE: MATERIAL FLOW ANALYSIS OF PHOSPHOROUS AND CHEMICAL OXYGEN DEMAND IN DOMESTIC WASTEWATER AND FOOD WASTE IN SONG CONG TOWN, VIETNAM BACHELOR THESIS Study Mode : Full-time Major : Environmental Science and Management Faculty : International Training and Development Center Batch : 2011-2016 Thai Nguyen, 30/06/2015 Thai Nguyen University of Agriculture and Forestry Degree Program: Bachelor of Environmental Science and Management Student name: Pham My Anh Student ID: DTN 1153170001 “MATERIAL FLOW ANALYSIS OF PHOSPHOROUS AND CHEMICAL OXYGEN DEMAND IN DOMESTIC Thesis Title: WASTEWATER AND FOOD WASTE IN SONG CONG TOWN, VIETNAM” Supervisor: Nguyen Huu Tho, PhD. Abstract: Vietnam’s fast economic growth has to a large extent been achieved on the expense of a rapid deterioration of the natural environment, including eutrophication of local water sources. Proper planning is needed to move towards a sustainable wastewater management and one recognized tool for such planning is material flow analysis (MFA). This thesis uses MFA to define the current flows of phosphorus (P) and organic matter, measured as COD, in domestic wastewater and food waste in Song Cong town, Thai Nguyen province, Vietnam.
The aim is further to compare two different improved wastewater management scenarios with a business-as-usual scenario. The methods used to find data for the MFA are literature review, interviews and a survey questionnaire. The literature review presents challenges facing the wastewater sector of Vietnam and treatment techniques for wastewater and septage. The wastewater sector is affected by technical difficulties such as lack of capacity and organizational challenges as a result of adjacent and overlapping authorities.
Contradictions and gaps in legislation, poor governance, and problems with financing are all issues that need to be addressed. Although the number of wastewater treatment plants in Vietnam is increasing, ii not more than 10% of the wastewater is being treated. Various techniques are tried out in Vietnam, among others constructed treatment wetlands and activated sludge techniques, such as Sequencing Batch Reactors and Anaerobic/Anoxic/Oxic processes. These and other techniques are explained and compared in the literature review.
From the gathered data three future scenarios for Song Cong’s wastewater and food waste treatment were created along with one of the current situation. The future business-as-usual scenario (BAU-2030) shows the development in Song Cong if no changes are implemented before year 2030, while the centralized scenario (CTP- 2030) redirects flows of wastewater to a conventional chemical/biological treatment plant. The third scenario, semi-centralized (STP-2030), implements one treatment plant with enhanced biological phosphate removal (EBPR) followed by a constructed treatment wetland, and a bigger EBPR plant followed by disinfection. Both of the improved scenarios also use food waste and sludge to produce biogas and digit ate that can be used as compost in agriculture.
The results of the MFA indicate that if nothing is done to change the current management, a 24% increase of pollutants to the Song Cong is imminent in just 15 years. In addition, if one of the improved scenarios is implemented, 92% (CTP- 2030) or 90% (STP-2030) of the P will be available for reuse in agriculture, reducing the need for artificial fertilizer. Further biogas is produced, which can substitute petroleum based gas for domestic purposes or be used to generate electricity. Wastewater, Material flow analysis (MFA), Keywords Phosphorus (P), Chemical oxygen demand (COD).
Number of pages 52 pages Date of submission 30/09/2015 Supervisor signature iii ACKNOWLEDGEMENT My bachelor thesis in environmental engineering at Thai Nguyen University of Agriculture and Forestry, Viet Nam. The thesis is part of a partnership project between the municipality of Linköping, Sweden, and the Thai Nguyen province, Vietnam. The overall aim of the partnership is to achieve a democratic and transparent planning process, involving stakeholders at different levels in the field of wastewater and organic waste management in Song Cong town. This includes giving stakeholders new methods and tools for a participatory planning process.
Foremost, I would like to express my sincere gratitude to my supervisor: Nguyen Huu Tho, PhD of Department of Science Management and International Relation, Thai Nguyen University of Agriculture and Forestry (TUAF), Viet Nam for giving permission to accomplish my Bachelor thesis there, and also his constant motivating supervision during my studies in the research group of Sweden. I wish to express my thanks to Mr. Duong Manh Cuong of Faculty of Biotechnology and Food Technology, (TUAF), Viet Nam for support, help, and encouragement, advise me during visit to Song Cong town. Besides my supervisors, most of all thank Mr.
Olli Sammalisto and Ms. Zanna Sefane at the University of Gävle, Sweden for helping, giving necessary advices and guidance, support me during doing the experiment and completing my thesis. Last but not least, I would like to say thankful my family and good friends who encourage and backing me unceasingly. Thank you so much! Thai Nguyen, October 2015 Sincerely, Pham My Anh iv TABLE OF CONTENTS ACKNOWLEDGEMENT.
iv TABLE OF CONTENTS. v LIST OF FIGURES. 1 LIST OF TABLES. 3 LIST OF ABBREVIATIONS.
Limitation of the research. Challenges in the Vietnamese Wastewater Sector. Wastewater Treatment Solutions in Vietnam. Conventional Wastewater Treatment Plants.
Activated Sludge Techniques. Enhanced Biological Phosphorus Removal. Sequencing Batch Reactor. Compilation of P and COD Removal Efficiency in WWTP.
Constructed Treatment Wetlands. Free Water Surface (FWS) Wetlands. Floating Treatment Wetlands (FTW). Compilation of P and COD Removal Efficiency in Constructed Treatment Wetlands.
Further Comparison of the Wastewater Treatment Techniques. Sludge and Food Waste Treatment. Compilation of the Survey Results. Mass Flow and Stock Change Quantification.
MFA in STAN. Survey Results and Scenario Development. The Survey Results. Background Data on Song Cong Town.
Current Wastewater Management in Song Cong. Future Wastewater Management in Song Cong. Business as Usual (BAU-2030). Centralized Treatment Plant (CTP-2030).
Semi-centralized Treatment Plant (STP-2030). Semi-centralized Treatment Plant (STP-2030). Material Flow Analysis of Song Cong. Business as Usual (BAU-2030).
Centralized Treatment Plant (CTP-2030). Semi-centralized Treatment Plant (STP-2030). Compilation of the MFA results. DISCUSSION AND CONCLUSION.
Analysis of the MFA Results. Sources of Error. Parameters for import of P to inhabitants. Requested data from Song Cong town authorities.
Song Cong survey. Quantification of the confidence interval. Modified parameters in the BAU-2030, CTP- 2030 and STP-2030 scenarios. Parameters used in the MFA.
71 vii LIST OF FIGURES Figure 1. The steps of the different EBPR treatment processes, showing Anaerobic/Oxic (A/O) at the top, Anaerobic/Anoxic/Oxic (A2O) in the middle and University of Cape Town (UCT) at the bottom. STAN flowchart showing the processes involved in the treatment of Song Cong’s wastewater and food waste. The six urban wards of Song Cong town, with the Cong River running in the east.
Wastewater canal in Bach Quang ward, Song Cong. Detail planned map of future Song Cong. Three locations have been identified by local authorities as suitable for construction of wastewater treatment plants, location 1, 2 and 3. Solid waste collection in Song Cong town.
Flowchart of P in the Baseline Scenario (BLS-2015). Flowchart of COD in the Baseline Scenario (BLS-2015). Flowchart of P in the Business as Usual (BAU-2030) scenario. Flowchart of COD in the Business as Usual (BAU-2030) scenario.
Flowchart of P in the Centralized Treatment Plant (CTP-2030) scenario. Flowchart of COD in the Centralized Treatment Plant (CTP-2030) scenario. Flowchart of P in the Semi-centralized Treatment Plant (STP-2030) scenario. Flowchart of COD in the Semi-centralized Treatment Plant (STP- 2030) scenario.
Summary of the results for P flows to each export destination for all scenarios. The BLS-2015 scenario is included to show the difference from the future improved and unimproved scenarios. Summary of the results for COD flows to each export destination for all scenarios. The BLS-2015 scenario is included to show the difference from the future improved and unimproved scenarios.
46 2 LIST OF TABLES Table 1. Removal rates of P in WWTP based on different literature sources, ranging from 25 % to 95 %. Removal rates of COD in WWTP based on different literature sources, ranging from 76 % to 97%. Removal rates of P in wetlands based on different literature sources, ranging from 41% to 84%.
Removal rates of COD in wetlands based on different literature sources, ranging from 45% to 93%. Comparison between the biological wastewater treatment techniques (Tilley et al. Terminology used in MFA (Brunner & Rechberger, 2003). List and description of the MFA processes involved in the treatment of Song Cong’s wastewater and food waste .29 3 LIST OF ABBREVIATIONS A/O Anaerobic/Oxic A2 O Anaerobic/Anoxic/Oxic AS Activated sludge BAU Business as usual COD Chemical oxygen demand CTP Centralized treatment plant CW Constructed wetland STP Semi-centralized treatment plant EBPR Enhanced biological phosphorus removal ECPS Environmental Cooperation and Public Work of SongCong FDI Foreign direct investment FTW Floating treatment wetland FWS Free water subsurface HLR Hydraulic loading rate HRT Hydraulic retention time HSSF Horizontal subsurface flow MFA Material flow analysis N Nitrogen NGO Non-governmental organization P Phosphorus PAO Phosphorus accumulating organisms SBR Sequencing batch reactor SSF Subsurface flow TEUC Thai Nguyen Environment and Urban Works Joint Stock Company (author’s abbreviation) UCT University of Cape Town VFA Volatile fatty acids VSSF Vertical subsurface flow WWTP Wastewater treatment plant 4 PART I.
Research rationale Worldwide problems including climate change, eutrophicated water sources and increasing amounts of waste are all direct long-term effects of man’s pursuit of increased prosperity. Today many developing countries, The Socialist Republic of Vietnam being one of them, face a decision. A choice between a path leading to long term growth in a sustainable fashion, or a path focusing on rapid economic growth at the expense of a deteriorating natural environment. Vietnam is in many ways an example of how fast a country can develop economically.
After a history of war and poverty, Vietnam can boast of having left the designation of a low-income country in only a few decades. As of 2009 the World Bank recognized Vietnam as a lower middle economy (World Bank, 2014). Much of this development can be attributed to the economic reform of 1986 called Đổi Mới. The term literally translates into renovation and the process brought the country from a centrally planned agricultural economy towards a more industrialized market economy (World Bank, 2014).
One negative effect of the past decades’ focus on economic growth is visible in the polluted water sources. Vietnam faces severe problems with eutrophication because of poor or nonexistent wastewater treatment from both households and industries. As late as in 2004, “none of Vietnam’s cities collected or treated municipal wastewater” (World Bank, 2011, p. In 2009 six cities had wastewater treatment plants and by 2013 the number had increased to eight (WEPA, 2013).
Despite these figures only 10 % of the wastewater is actually being treated (World Bank, 2013). The pollution degrades water reserves available for human consumption, agriculture and aquaculture, amplifying the shortage of freshwater in and around the region (Dan et al. Thus, in order to continue the journey towards becoming a high-income country, Vietnam must ensure functioning and sustainable wastewater treatment systems, which can only be completed through proper planning. A recognized method for decision-making in wastewater treatment planning is material flow analysis (MFA) (Montangero & Belevi, 2007; Montangero et al., 2007; Montangero & Belevi, 2008; Nga et al.
This thesis uses 5 the method to define the current flows of two important pollutants, phosphorous and organic matter, in domestic wastewater in the Vietnamese, Song Cong town. It in the flatlands of northern Vietnam, and was inhabited by 52 056 persons at the beginning of 2015. The purpose of the thesis is to compare different systems for wastewater treatment and their effect on substance flows, as a basis for implementation of a sustainable wastewater management in Song Cong.