Environmental Impact And Pollution Control Strategies Of Typical Biomass Waste In China

Annual quantity of solid waste in China is about 7160 million tons, in which 62.1% is biomass waste. Biomass waste is not only a considerable source of environmental contaminants, but also is the renewable resources with huge recovery potential. This thesis, therefore, attempts the consideration of biomass waste as an independent concept in order to solve the following issues: (1) to rethink the problem of waste management; and (2) to assess the relationship among waste management, treatment of eutrophication contaminants, reduction of greenhouse gas (GHG) emission, and the development of renewable resources. Accordingly, the research not only has the ability to comprehensively improve the level of waste management, but also has advantage in enhancing system efficiency of environmental pollutants treatment and optimizing structure of resources utilization, thereby indicating significance to implement'energy saving strategy'.It is found out that amount of biomass waste derived from food consumption takes up 95.2% of its total generation, which is unique in China and considered as an independent research system. The system boundary of this research is thus designed as food chain and treatment of pollution generated from food chain; thereafter, a methodology concerning environmental impact assessment of biomass waste in China is developed herein, based on the substance flow analysis (SFA) and life cycle assessment (LCA). According to the methodology, a Biomass Waste Research Model is developed through trace analysis on substance flow of food chain and clear understanding of the source of the biomass waste generated and the treatment process.With the model developed in this thesis, environmental impact of biomass waste in China is assessed. The research findings clearly indicate that 4264 million tons of main biomass waste was generated in 2005 (1306 million tons of dry matter). Amount of eutrophication contaminants derived from biomass waste including livestock wastewater is about 2.98 times of that from municipal sewage and food processing industry. Further, amount of CH₄ and N₂O emitted from biomass waste accounts for about 6.07% into national overall GHG emissions. GHG emission intensity in harmless treatment is high. Animal waste is the major source of eutrophication contaminants and GHG. Harmless treatment ratio of biomass waste was merely 2.82% in 2005, with 1687 million tons (478 million tons of dry matter) being disposed without any treatment, which is the major way in causing the serious environmental pollution.Biomass waste has a high recourse utilization rate seemingly; however, the utilization structure is not reasonable. From the perspective of reduction of eutrophication contaminants and GHG emission, recycling hierarchy of biomass waste should be the exploitation of feed resources, development of clean and efficient resources, and utilization of organic fertilizer.? ? The potential resources from feed biomass waste are about 558 million tons of dry matter while the value from fuel source is about 278 million tons of dry matter. Recycling of biomass waste is strongly regarded as the fundamental way of solving the problem of treatment of biomass waste.