4.The effect of adding earthworms on the maturation ofgangue sludge into soil

Abstract:

In order to solve the problem of the disposal of coal gangue as a large solid waste in the coal development process,and toimprove the maturation speed of artificial soil prepared from gangue,aerobic solid waste maturation into soil experiments were conducted using coal gangue and urban sludge as substrates by adding earthworms. The results showed that the addition of earthworms significantly reduced the biological toxicity of the material. The germination index of the seeds reached maturity level after 15 days of addingearthworms,and the dynamic heavy metal content was significantly reduced;The addition of earthworms significantly increased the effective nutrient content of the material,showing an increase in total nitrogen content and a significant decrease in total organic carboncontent. After 35 days,the comprehensive fertility was optimal;Adding earthworms promotes the carbon and nitrogen conversion of materials,and the humification indicators RI ,RD ,and RP all significantly increase over time. This provides a theoretical basis for thepreparation of artificial soil from bulk disposal of gangue solid waste.

Keywords: coal gangue;sludge;earthworm;artificial soil maturation;aerobic composting