학위논문(박사)--서울대학교 대학원 :공과대학 건설환경공학부,2019. 8. 한무영. ; Currently, drinking water problems in Vietnam are more common due to high population growth, rapid urbanization, degradation of water quality and over exploitation of water resources. To date, the water supply system highly depends on centralized system by using the surface and groundwater; with a negligibility of rainwater. However, the conventional centralized water supply is facing many issues i.e. limited water resources (both quality and quantity) because of e.g. contaminated surface/ground water, drought, and salinization. For many decades in Vietnam, rainwater harvesting (with a relatively high yearly precipitation of around 1.680 mm) has been widely used as a nature-based solution in rural areas. But recently, rainwater for drinking has been gained much attention from the Vietnam Government. Therefore, this study implemented the demo RWH system in Vietnam to identify the technical, economical, and social barriers, and suggesting proper strategies to overcome and promoting RWH spread widely for Vietnam Government. Technical barriers are lack of the design guideline and manual, professional skill and established market for rainwater harvesting. While, economic barriers are that it is too expensive to install and maintain and that is not profit generating system. Social barriers are lack of (a) knowledge of rainwater and rainwater harvesting system, (b) communication amongst the users and stakeholders, and (c) high expectation about the tap water installation. In order to overcome the technical, economic and social barriers, four demo RWH systems for school at rural area in Vietnam have been installed and monitored for several years. Through these demo systems, the sustainability of the RWH was proved. Technically, the rainwater quality meets the Vietnam drinking water standard – QCVN 01-2009. Water can be supplied during the dry season. The maintenance fee can be collected by reducing the water-purchasing fee. The science group in school can be involved in the routine maintenance of the RWH system. All the village people should be involved in the activity of the rainwater education and promotion. New strategies to promote sustainable drinking water in Vietnam is suggested. Firstly, community RWH should be established and operated with self-monitoring and operation. Secondly, technical design guidelines and training to improve rainwater quality as well as operation and maintenance manual should be provided. Thirdly, encourage the private sector or enterprise to implement RWH for community by the incentive strategy. In addition, a market for rainwater harvesting equipment should be established. Fourthly, to promote RWH system widely, the communication can be implemented in the school through the student and teacher activities such as education, training, contest, event etc. These activities bring large positive impacts to the villagers and communities. Finally, Vietnam Government should support research activities and implement laws and regulations to promote RWH by providing financial incentives, and to encourage people to harvest rainwater for various purposes. ; CHAPTER 1 Introduction 1.1.Background…………………………………………… 1 1.2. Necessity………………………………………………… 5 1.3.The object of the dissertation……………………… 6 1.4.The structure of the dissertation…………………… 6 CHAPTER 2 Literature review 2.1. Water supply system in Vietnam………………… 8 2.2. History of the rainwater harvesting …………… 10 2.3.Rainwater harvesting roles ………………………… 13 2.4. Rainwater harvesting for drinking ……………… 15 2.4.1 Pretreatment methods…………………………… 15 2.4.1.1. Coarse screen…………………………………… 15 2.4.1.2. First flush tank…………………………………… 15 2.4.1.3 Role of sedimentation…………………………… 16 2.4.1.4 Role of bio-film …………………………………… 17 2.4.2. Post treatment methods ………………………… 19 2.5. Rainwater harvesting in Vietnam ………………… 22 2.6. Summary………………………………………………… 29 CHAPTER 3 Identify the barrier for rainwater harvesting system in Vietnam 3.1. Background …………………………………………… 31 3.2. Materials and methods……………………………… 32 3.2.1. Study area…………………………………………… 32 3.2.2. Survey………………………………………………. 33 3.2.3. Statistical analysis…………………………………… 39 3.3. Results and discussions………………………………. 39 3.3.1. Survey analysis ………………………………………. 39 3.3.1.1. Statistical characteristic………………………. 39 3.3.1.2. Satisfaction for individual RWH system ……. 45 3.3.1.3 Satisfaction for RWH system installation at school …………………………………………………………. 45 3.3.2 Barriers for rainwater use for drinking water………… 46 3.3.2.1 Technical barrier………………………………. 46 3.3.2.2 Economical barrier……………………………. 46 3.3.2.3 Social barrier…………………………………. 48 CHAPTER 4 Demo project to overcome barriers 4.1. Introduction…………………………………………………. 49 4.1.1. Water supply and drinking water for community-based at Vietnam rural area……………………………………… 51 4.1.2. Existing rainwater harvesting community- based……. 52 4.1.3. The barrier for rainwater harvesting at community-based 53 4.2. Cukhe Kindergarten and elementary school (period of Aug 2014- Sept)……………………………………………………… 54 4.2.1Site information……………………………………… 55 4.2.2. Information of demo system………………………. 57 4.2.2.1. Cukhe Kindergarten D1……………………… 57 4.2.2.2. Cukhe elementary school D2 ………………. 58 4.2.3. Rainwater Harvesting system information…………. 59 4.2.4. Maintenance and Operation………………………… 61 4.2.4.1. Water quality monitoring…………………. 61 4.2.4.1. Water quality monitoring…………………. 62 4.2.5. Lessons learnt……………………………………. 65 4.3.2. Daicuong elementary(D3) and middle (D4) school ……. 67 4.3.1. Site information……………………………………… 67 4.3.2. Information of demo system at Daicuong elementary school (D3) and middle school (D4)…………………………. 69 4.3.3. Rainwater Harvesting system information…………. 71 4.3.4. Maintenance and Operation………………………. 72 4.3.4.1 Water quantity monitoring…………………. 73 4.3.4.2 Water quality monitoring…………………. 74 4.3.5. Lessons learnt …………………………………… 77 4.4. Social communication of rainwater harvesting systems for drinking at school inVietnam…………………………………. 78 4.4.1. Introduction…………………………………………. 79 4.4.2. Material & Method…………………………………… 82 4.4.3. Result & discussion…………………………………. 83 4.4.4. Summary…………………………… 84 4.5. Social communication to promote rainwater harvesting system for drinking at school in Vietnam……………………… 85 4.5.1. Introduction ………………………………………… 85 4.5.2. Materials and methods……………………………… 88 4.5.3. Result and discussion…………………………………. 91 4.6. Conclusion…………………………………………………. 95 CHAPTER 5 Suggestions to promote sustainable drinking water by rainwater harvesting 5.1. Introduction………………………………………………. 98 5.2. Rainwater harvesting promotional strategies in other countries ………………………………………………………… 98 5.3. Technical suggestion to Vietnam Government ……………. 100 5.3.1. Rainwater harvesting component for school or community 100 5.3.2. Design guideline……………………………………… 103 5.3.2.1. Gutter and downspout………………………. 103 5.3.2.2. First-flush……………………………………. 105 5.3.2.3. Settling tank and storage tank………………. 106 5.3.2.4. Rainwater treatment system…………………. 108 5.3.2.5. Water meter, water level, and drinking water delivery…………………………………………………………. 109 5.3.3. Operation and Maintenance…………………………. 111 5.4. Strategy promotion to implement RWH system ………… 112 5.4.1. Authority agency……………………………………. 114 5.4.2. Enterprise or private sector…………………………. 119 5.4.3. Communities………………………………………… 120 CHAPTER 6 Conclusion and recommendation 6.1. Conclusion……………………………………………… 122 6.2. Recommendation…………………………………………. 124 Appendix 1: List of the domestic water quality parameter and allowable limit………………………………………………………………… 141 Appendix 2: Survey and investigation on rainwater harvesting…… 149 ; Doctor