Study On The Technology And Application Of Vermicomposting Made From Sludge,Kitchen Waste And Stored Waste

The production of sewage sludge,kitchen waste and stored waste is increasing rapidly,and improper disposal will cause serious environmental pollution.Vermicomposting has been reported to be a viable,cost-effective and rapid technique for the efficient management of the organic solid wastes.For this reason,this study used sludge,kitchen waste and stored waste as vermicomposting raw materials,to analyze the changes in the growth of earthworms and the properties of composting materials during the process of multi-material vermicomposting,and explored the best process conditions for multi-material vermicomposting.Vermicomposting product was applied to soil,by different proportion to grow green plants(lolium multiflorum)and agricultural crops(cabbage).Studying the feasibility,optimal application proportion and safety of vermicomposting for greening and agriculture of sludge,kitchen waste and stored waste by measuring the soil properties and the growth status of ryegrass and cabbage.Research shows that:(1)A certain proportion(10%-30%)of kitchen waste in the sludge can promote the growth of earthworms,the average earthworm weight increases by 10.24-18.61%.Adding too much(50%)will affect its survival and reduce the average earthworm weight.Up to 5.07-24.09%.The addition ratio of the stock garbage(0%-20%)and the amount of earthworm inoculation(17-50 pieces/kg)have little effect on the growth of earthworms.(2)During the composting process,the organic matter content of each treatment decreased,and the decrease rate was 6.75-24.96%.The germination index of seeds all increased significantly,increasing by 24.84-118.62%.Through range analysis and variance analysis,the best process combination of multi-material vermicomposting is obtained: the mass ratio of sludge and kitchen waste is 7:3,the addition ratio of stock waste is 5%,and the number of earthworm inoculations is 33.The influence factors on vermicomposting ranked from high to low are ratio of sludge and kitchen waste,earthworm inoculation ratio and stored waste addition ratio.(3)After applying vermicompost to the soil,it can significantly increase the soil’s organic matter content,nutrient content and heavy metal content.Applying 5%-30% of vermicompost can promote the growth of ryegrass and pakchoi,but applying 40%-50%will inhibit the growth of ryegrass and pakchoi.The best vermicompost application ratio for planting ryegrass and pakchoi is 10% and 20%.(4)With the increase in the proportion of vermicompost(0%-50%),the potential ecological risk coefficient and comprehensive potential ecological risk coefficient of a single heavy metal in the soil increase,and the degree of ecological risk is slight ecological hazard.With the increase in the proportion of vermicompost,the heavy metal risk coefficient(HQ)of pakchoi in each treatment also increased,and all were less than1.0,indicating that pakchoi would not pose a threat to human health after human ingestion.