Application Of Mabuchi Treatment Tailings For Municipal Solid Waste In Soil Amelioration

With the development of economy and society, the improvement of people's livelihood, and the rapidly increasing of urban population, municipal solid waste (MSW) increased dramatically, and had become a major environmental problem all over the world. Reduction, reuse and recycle are three main principles in MSW treatment. Traditional treatment methods, such as composting, landfill and incineration can reduce the amount of waste, but always cause secondary pollution. Therefore, recycle utilization of MSW under harmless condition is a profound and significant subject.Nowadays, with agricultural acreage decreased day and day, the problem of land use has become an urgent problem in China, and amelioration of low-productive farmland is an efficient path to ensure food security. Mabuchi tailings is the end product of Mabuchi treatment for MSW at 180-230℃, 1.8-2.4 Mpa for 1 hour. Mabuchi tailings as a new type soil amendment has many characteristics compared with others, i.e., extensive sources and low cost. Thus, safely utilize Mabuchi tailings in soil amelioration has profound theoretical meaning and practical value.In this paper, based on both the pot and field experiments and the analysis of physical and chemical properties of the Mabuchi tailings, the security and availability of the Mabuchi tailings application in soil amelioration was evaluated. And then, this paper puts forward some technical parameters for the Mabuchi tailings application in soil amelioration. The results showed as follows.(1) The contents of heavy metals and PAHs in Mabuchi tailings all meet relevant standards ("Control standards for urban wastes for agricultural use" (GB 8172-1987) and "Control standards for pollutants in sludges from agriculture use"(GB 4284-84)). The maturity of Mabuchi tailings can basically meet the requirement of seed germination. Its germination index is 67.4%.(2) Besides water content, the fertility indicators in Mabuchi tailings' all meet the requirements of "Control standards for urban wastes for agricultural use" (GB 8172-1987). The content of organic matter, phosphorus, nitrogen and potassium in Mabuchi tailings were 18.6%, 1.00%, 0.72% and 1.21% respectively.(3) Mabuchi tailings could significantly improve soil physical properties, increase soil aeration and soil water storage capacity, especially for low-yield red soil. Mabuchi tailings could effectively improve soil acidification problem in red soil, and could effectively increase soil organic mater content, and could improve soil structure and soil fertility.(4) Mabuchi tailings could significantly improve the chemical properties of Quaternary Red Soil under the condition of the use of 150 t/ha. And Mabuchi tailings could effectively improve the chemical indexs of Xiaofentu Soil under the condition of the use of 5% in the pot experiment.(5) Results in field experiment (red soil) showed that soybean (Taiwan75) biomass and greengrocery (Xizilu) biomass could reach to maximum at the Mabuchi tailings application rate of 75t/ha (dry weight) and 150t/ha, respectively. The recommended application rate of Mabuchi tailings was 75-150 tha for the amelioration in Quaternary Red Soil, and 30-37.5 t/ha in Xiaofentu Soil.(6) The compost maturity of Mabuchi tailings would affect seed germination and crop growth, therefore it should be paid high attention. Another important problem for the application of Mabuchi tailings in soil amelioration was its own high salt content, especially in salty soil, because Mabuchi tailings had high electric conductivity.