Method for removing heavy metal in solid organic waste compost

Abstract

The invention relates to a method for removing heavy metal in solid organic waste compost, which comprises the following steps: (1) adding sulfur powder into solid organic waste compost according to a use amount of 10-150 g of sulfur powder for one 1kg of compost; (2) adding ferrous sulfate heptahydrate solution into the compost; (3) inoculating microorganism compound bacteria including thiobacillus ferrous oxide, thiobacillus thiooxidans, white rot fungi, yeast and penicillium according to a use amount of 1g of compound bacteria for 1 kg of compost; (4) spraying and leaching the inoculated compost which is arranged on a stacking bed and keeping water content in the stacking bed to be not lower than 65 percent; (5) during leaching time of 4-14 days, monitoring the concentration of heavy metal of leaching liquid in real time till the concentration of heavy metal meets the national standard; and (6) adding slaked lime into the compost to adjust pH value to 7 after the leaching is finished. The invention has the advantages that the removal rate of heavy metal in leaching reaches over 90 percent, the lose rate of nutrient elements such as N, P and the like is lower than 5 percent, and the method has simple operation and low running cost.

Description

technical field [0001] The invention relates to a method for removing heavy metals in solid composting products, in particular to a method for removing heavy metals in urban waste composting by adopting biological leaching technology. Background technique [0002] With the improvement of national material and cultural living standards, the output and composition of urban waste are rapidly increasing and changing. At present, my country produces 114 million tons of garbage every year. Urban garbage causes water, soil, and air pollution and the spread of diseases. It has become a social problem that pollutes the environment and plagues human beings. One of the solutions is to make garbage composting. It is a comprehensive resource utilization technology with small investment, low operating cost and high economic benefits. It is a treatment technology that has been widely valued at home and abroad. The potential economic value of the solid waste is in line with my country's sol...

AI Technical Summary

Problems solved by technology

[0003] At present, the main problem in the production of waste composting is that composting products contain excessive harmful substances (mainly heavy metals), which greatly affects the scope of use of the product (for example, it cannot be used in farmland), and also limits the price of the product. Users are prone to psychological problems. Contradictions have caused great difficulties for compost manufacturers and threatened the survival of enterprises, and caused the stagnation or even shrinkage of the entire industry

This issue is gradually attracting attention, and limited research has focused on changing the forms of heavy metals in compost products to reduce their bioavailability (Wang Yujun, Dou Sen, Li Yedong, et al. Effects of chicken manure composting on heavy metal forms[J ].Environmental Science.2009(03).), but long-term application of compost products, with the change of environmental conditions, heavy metal ions may change form and cause harm again

To sum up, a key problem affecting the survival and development of urban waste composting products is the problem of excessive heavy metals. People have carried out some useful explorations, but no technical means to effectively solve this problem have been found.

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