A Summary of the Academic Symposium on the Treatment and Management of City Wastes

With the continuous worsening of theproblems of urban wastes about 60 urbanscientific workers gathered in Guiyang to dis-cuss the present state of the treatment andmanagement of urban wastes and find rela-tive solutions to the problems.The“Guiyang Symposium on the Treat-ment and Management of City Wastes”jointly sponsored by the Chinese Urban Sci-entific Research Institute,the Urban Con-struction Department of the Ministry of Ur-

Solid Waste Management and Incineration Practice: A Study of Bangladesh

Considering the geographical location and one of the very densely populated countries in the world, Bangladesh is very vulnerable to climate change and its adaptability. This paper has been designed with an attempt to inform the policy maker of Bangladesh regarding the potentiality of MSW as a renewable source of energy in Bangladesh. It deals with modern waste collection, management and incineration practices based on densely populated cities or towns like Bogura Municipality and Chattogram City Corporation. Waste to Energy (WtE) conversions not only reduce the land pressure problem in urban areas, but also generate electricity and heat to supply to the surrounding urban areas. The increase in generation of methane (CH4) from municipal solid wastes (MSW) alarms the world to take suitable initiative for the sustainable management of MSW, as it is stronger than carbon dioxide (CO2). By burning one mole of CH4, 890 kJ·mol-1 heat is produced which is a major source of energy. This treatment technology is used in destruction of solid waste by controlled burning at high temperatures. With the release of heat, it can be accompanied and this heat from combustion can be converted into energy. This type of incineration is a high-quality treatment for Municipal or City Corporation solid waste like Bangladesh where were over crowded cities, towns and it can reduce the quantity and volume of a large amount of waste to landfill, which can recover energy and dispose in the compact zone. The results also examined that the total amount of solid waste produced in Bogura municipality is lower than that of Chattogram City Corporation. The percentage compositions of waste patterns are shown in both the Cities. The paper discusses these problems, analyses and finally, a recommendation has been proposed in order to understand the industrial situation enhanced.

Quality Assessment of Different Industrial Effluents for Irrigation in Agriculture

A laboratory experiment was undertaken in Soil Science Division of BRRI （Bangladesh Rice Research Institute） during 2010 to assess the quality of industrial effluents and city waste as a source of irrigation water for agriculture. The treatments of the studies were the effluents of five different industrial sources like polyvinyl, dyeing, pharmaceuticals, beverage, tannery, mixed waste water （contaminated with effluents from many industries）, CWW （city waste water） and underground water as control. The industrial effluents, MWW （mixed waste water）, CWW and control water were tested for electrical conductivity, pH, and soluble ions such as Na^＋, Ca^2＋, Mg^2＋, K^＋, HCO3-, CO3^2-, NH4^＋-N and H2PO4^-. Micronutrients （Fe, Mn, Cu and Zn） and heavy metals （As, Pb, Cd, Cr and Ni） were analyzed from the samples. Beverage industry effluent showed acidic reaction, while the other industrial effluents showed alkaline reaction （pH 7.25-9.07）. Pharmaceutical, dyeing and tannery effluents showed EC of 3.40, 4.30 and 9.49 dS m^-1, respectively, compared to 0.54 dSm^-1 of the control. All the effluents except polyvinyl and beverage effluents and CWW recorded higher carbonate and bicarbonate content than that of control. Industrial effluents and CWW were higher in micronutrient content as compared to control. Dyeing, pharmaceutical and tannery effluents contained 2.51, 3.94 and 4.29 mg L^-1 lead, 0.15, 0.14 and 0.38 mg L^-1 chromium and 0.25, 0.24 and 0.16 mg L^-1 nickel, respectively which might be concemed for health hazard through food chain.

Sustainable waste management for zero waste cities in China:potential,challenges and opportunities

Waste is a valuable secondary carbon resource.In the linear economy,it is predominantly landfilled or incinerated.These disposal routes not only lead to diverse climate,environmental and societal problems;they also represent a loss of carbon resources.In a circular carbon economy,waste is used as a secondary carbon feedstock to replace fossil resources for production.This contributes to environmental protection and resource conservation.It furthermore increases a nation’s independence from imported fossil energy sources.China is at the start of its transition from a linear to circular carbon economy.It can thus draw on waste management experiences of other economies and assess the opportunities for transference to support its development of‘zero waste cities’.This paper has three main focuses.First is an assessment of drivers for China’s zero waste cities initiative and the approaches that have been implemented to combat its growing waste crisis.Second is a sharing of Germany’s experience-a forerunner in the implementation of the waste hierarchy(reduce-reuse-recycle-recover-landfill)with extensive experience in circular carbon technologies-in sustainable waste management.Last is an identification of transference opportunities for China’s zero waste cities.Specific transference opportunities identified range from measures to promote waste prevention,waste separation and waste reduction,generating additional value via mechanical recycling,implementing chemical recycling as a recycling option before energy recovery to extending energy recovery opportunities.