ĐẠI HỌC QUỐC GIA HÀ NỘI TRƯỜNG ĐẠI HỌC KHOA HỌC TỰ NHIÊN ------------o0o------------ NGUYỄN VĂN THÁI STUDY ON COMPACT DEVICE FOR WASTE PROCESSING BASED ON MECHANICAL BIOLOBICAL TREATMENT IN DONG VAN TOWN, DUY TIEN DISTRICT, HA NAM PROVINCE, VIETNAM CHUYÊN NGÀNH: QUẢN LÝ CHẤT THẢI VÀ XỬ LÝ VÙNG Ô NHIỄM (CHƯƠNG TRÌNH ĐÀO TẠO QUỐC TẾ) LUẬN VĂN THẠC SĨ CÔNG NGHỆ HÓA HỌC NGƯỜI HƯỚNG DẪN KHOA HỌC: PGS. TS NGUYỄN THỊ DIỄM TRANG HÀ NỘI- NĂM 2007 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com HANOI UNIVERSITY OF SCIENCE DRESDEN UNVERSITY OF TECHNOLOGY NGUYEN VAN THAI STUDY ON COMPACT DEVICE FOR WASTE PROCESSING BASED ON MECHANICAL BIOLOBICAL TREATMENT IN DONG VAN TOWN, DUY TIEN DISTRICT, HA NAM PROVINCE, VIETNAM MASTER THESIS Field: waste management and contaminated site treatment Supervisor: Assc. Nguyen Thi Diem Trang HANOI, DECEMBER 2007 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com INTRODUCTION The rapid economic development has resulted in the difficult task of identifying way to manage the increasing waste generation, especially solid waste problem. Solid waste is generated from production and life activities in all sectors such as households, industry, hospitals, commerce, and agriculture.
Vietnam, a developing country, is certainly facing with a big problem of rapid waste generation. Therefore, finding out effective solutions of waste management and treatment has become an important issue in Vietnam. Actually, the Vietnamese government has tried to carry out preliminary steps in order to control waste generation in recent years. However, most of these steps just focus on available technologies in large-scale applications in industrial cities.
Whereas waste treatment technologies in small-scale applications has not been paid much attention. The main reasons are due to high cost and skillful requirements of operation and management. Moreover, there has not any effective waste management model for small capacity in townships where the population is not so big and amount of waste is 20 – 40 tons/day [Dong Van URENCO, 2006]. If waste management does not implement well in these areas, risks from pollution will, as a result, be highly serious.
Therefore, finding out the best solutions to protect environment is a very necessary and urgent matter in townships. Taking that serious problem into account, one of model companies named Hydraulic and Machine Company Ltd. has completely manufactured an effective system, which was named Compact Device, for municipal solid waste treatment (so-called CD-Waste System). This system was designed based on mechanical biological treatment system which has been applied since long time before.
It has considered to be suitable in small-scale applications in townships. Besides, another company named Dong Van Urban Environment Company Ltd. has also been established in Dong Van town, Hanam province in order to respond to national 1 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com policies of socialization in environmental protection. The two companies have closely cooperated to implement a project named “Waste Collection and Treatment System Using CD-Waste Technology with Capacity 20-30 tons per day” in Dong Van town, Duy Tien district, Hanam Province.
Based on this project, I had carried out this study named “Study on Compact Device for Waste Processing based on Mechanical Biological Treatment in Dong Van town, Duy Tien district, Hanam province, Vietnam”. This study aims at: Completion of clearness about theoretical and practical issues from CD- Waste Technology applications. Assessment of CD-Waste Technology applicability in Dong Van town, Duy Tien District, Hanam Province Cost planning and pre-calculation of waste treatment Plant in Dong Van Town, Duytien District, Hanam Province. 2 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com Chapter 1: OVERVIEW 1.1 Definitions and concepts The term waste is defined in the Vietnamese law on environmental protection of November 29 th, 2005.
According to this definition “Waste means materials that take solid, liquid, gaseous, or other forms, are discharged from production, service, daily life or other activities [Environment law, 2005]. Municipal solid waste (MSW) includes the solids discarded by the end of consumers, i. private households, small business and public areas and typically collected by public authorities for disposal. Normally, separated collected waste for recycling such as paper, metals, aluminum, glass etc.
is included in the MSW quantities given. MSW refers specifically to that part of MSW which is sent to landfill, incineration, or other final treatment [Christian Ludwig et al. Waste management refers to all activities engaged with waste segregation, collection, transport, reduction, reuse, recycling, treatment and disposal [Environment law, 2005].2 Waste generation in Vietnam Solid waste generation in Vietnam is approximately 15 million tons per year. Among them, municipal waste generation is about 12.8 million tons (making up 80%), and industrial and agricultural waste generation normally contribute the rest 2.2 million tons per year (making up 20%) as shown in figure 1 [VEM, 2004 ].40% hazardous healthcare waste industrial waste others 80% Figure 1: Different waste generated (by percent) in Vietnam, 2003 3 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com In Vietnam, big and industrial cities are major waste generation sources.
According to national statistical report in 2004, big cities and urban areas keep only 24 percent of the total nationwide population; however, they produce over 6 million tons of municipal waste (making up 50% of nationwide municipal waste amount). This is due to an affluent lifestyle, larger quantities of trade and commercial activities, and more intense industrialization and urbanization. Along with, these activities also increase high proportion of hazardous waste (such as batteries and chemical solvents) and non-degradable waste (such as plastic, metal, and glass) normally found in municipal solid waste. In contrast, people living in rural areas make up 76% of the total nationwide population but produce just less than half of waste generation rate of those in urban areas.
As shown in waste generation rate is approximately 0.3 kg/cap/day in rural areas compared to 0.4 kg/cap/day in urban areas. Table 1: Municipal solid waste generation at the glance [VEM, 2004] Municipal solid waste generation (tons/y) • National 12,800,000 • Urban areas 6,400,000 • Rural areas 6,400,000 Municipal waste generation (kg/per/day) • National 0.3 Collection of waste (% of waste generated) • Urban areas 71% • Rural areas <20 % • Among urban poor 10-20% Number of solid waste disposal facilities • Dumps and poorly operated landfills 74 • Sanitary landfills 17 Generally, comparing to the standard on domestic solid waste (DSW) in other countries, the amount of domestic in Vietnam is much lo wer [Luu Duc Hai, 2001]. Forecasting in 15-20 years, domestic solid waste amount in big cities in 4 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com Vietnam will reach the same level of 1.2 kg/cap/day as big cities in other Asian countries [Pham Ngoc Dang, 2000]. Waste composition varies spatially and temporally based on life and industrial activities.
Each city has its own lifestyle, civilization level, and development rate. As a result, they have different waste composition. Besides, waste composition normally varies in different times of the year. For e xample, in holidays and festive occasions such as Lunar New Year, organic and yard waste ratios are commonly higher than those in the rest of the year [Nguyen Khac Kinh et al.
Generally, there are two main components in DSW in Vietnam: (i) bio -waste (making up 30-50%); and (ii) soil, sand, construction materials and other inorganic stuffs (making up 20-40%) [Nguyen Thanh Yen, 2004]. Compared to those of many other countries, increasing rates of glass, plastic, metal, paper are lower due to waste activities of potential scavengers (garbage pickers) in Vietnam [Nguyen Thuy Thu Thi, 2005]. Table 2 shows domestic solid waste compositions in some big cities in Vietnam. Table 2: Composition of MSW in some cities in Vietnam in 2002 [NEA, 2003] Unit:% Composition Provinces, cities Hanoi Viet Tri Ha Long Tay Ninh Organic 53 55.3 Municipal solid waste management in Vietnam 1.1 Waste collection Municipal solid waste collection in urban areas in Vietnam has been systematically organized.
And, state-owned companies so-called Urban Environment Companies (URENCOs) in the whole country are responsible for waste collection. Each city and/or town has either one or more than one URENCOs. It depends on their size and population. Nowadays, some private companies begin 5 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com to take part in implementation of waste collection in some cities and towns.
This trend is expanding in many urban areas in accordance to the Government‟s policy as an attraction of all economic sectors to take part in municipal waste collection and treatment. Waste collection rate has been improving, however it remains low in many cities. The national average collection rate of municipal waste in urban areas rose from 65% to 71% between 2000 and 2003. Collection rates are typically higher in larger cities, and range from 45% in Long An to 95% in Hue City in 2003 [NEA, 2003].
But in small and medium town the waste collection rate is only 20-30% of the total volume of solid waste discharged [Nguyen Loan Thi, 2003]. In addition, funding sources for the operation of waste collecting and transporting organization in urban and rural areas is somewhat dependent on the budget of local administration and contribution of households as user‟s fee (the contribution rate is decided by the local administration and often is VND 2,000- 3,000/person/month in major cities. Figure 2 shows the model of solid waste collection and treatment in urban areas in Vietnam in which mainly urban environment organizations collect and transport waste to landfills. Collection Transport Transport Waste Collecting Transfer Treat ment sources organization station Handcart Handcart truck Household URENCOs and Transfer Landfills office Environment stations of school sanitation wastes hospital cooperatives collected daily market environment roads sanitation team Figure 2: Model of collection and treatment of municipal solid waste in Vietnam [Nguyen Danh Son et al., 2005] 6 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com Besides, complete separation of solid waste at source has not yet been done widely in Vietnam at present.
Waste separation at source is being experimented in some major cities (Hanoi, Da Nang, Ho Chi Minh…) and will be expand in the future to reduce the pressure for treatment of solid waste (disposal, reusing, recycling, composting etc.2 Municipal solid waste disposal Waste recovery, recycle and reuse are somewhat limited in state level. Most of the solid waste is treated by disposal at landfills. Landfills in all localities including major cities which have already been built do not reach sanitary standards and are not planned to match the rapid development of industrialization and urbanization. Of the 91 disposal sites in the whole country, only 17 are consi der as sanitary landfills [VEM, 2004].
By the middle of 2004 only half of the provinces and cities in the country (32/64) had the investment projects on the construction of sanitary landfills, of which 13 cities have already started construction [VEM, 2004]. The existence of landfills in different localities has caused urgent environmental problems to not only surrounding communities but also people in the areas where waste is collected. Incinerating waste is not a common practice in Vietnam. A few hospitals in the country have incinerators which they use but overall the healthcare industry‟s waste is primarily disposed in landfills.
For the hospital waste that is incinerated, little data is available on the amount or type of waste being incinerated because they do not keep records [Nguyen, 2005]. Whatever the case, even though the incinerators are assessed by the government for technical standards and gas emissions, Vietnam lacks the technology to be able to analyze dioxin concentrations emitted by the incinerators [Nguyen, 2005].3 Reusing and recycling Reusing and recycling of solid waste are a trend of development in environmental management in general and waste management in particular. A network of recycling waste has been formed for many decades with collectors of 7 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com domestic waste from households (waste paper, plastic, metal and glass), dealing points of collected waste materials and recycling establishments.