RESEARCH PROGRESS ON VERMICOMPOSTING OF SLUDGE

Compared with other sludge disposal methods， vermicomposting has the advantages of simple process，no secondary pollution， low running cost and high agricultural fertilizer efficiency from earthworm cast． The research outlined the option of earthworm species in sludge composting． Four influencing factors including C to N ratio，pH and EC， temperature，and moisture were introduced． It listed the types， function， effect of the normal amendments and analyzed five kinds of chemical and biological indexes for determining maturity as follows: dissolved organic carbon ( DOC) ， ammonia nitrogen and nitrate nitrogen ( NH + 4 －N and NO3－N) ，C to N ratio in solid phase，dissolved organic carbon to dissolved organic nitrogen ratio ( DOC/DON) ， germination index ( GI) ． Suggestions on further research were proposed based on the current existing problems．