Study On Co-composting Of Municipal Solid Waste With Matured Sludge About Quality Evaluation And Plant Toxicity

In order to improve the drawbacks of municipal refuse composting,based on actual waste composting engineering,we added varied proportion of mature sludge into refuse,setting refuse and mature sludge ratio(wet weight)as 1:1,2:1 and 4:1.The main content: Effect of mature sludge on physical-chemical properties and geenhouse gas emission during refuse composting process was investigated through monitoring the basic physical and chemical properties(e.g.,temperature,moisture content,organic matter)and the production of two kinds greenhouse gas(CH4 and CO2)during composting,then determining the mixing ratio;Evaluate the quality of the co-compost product through the rotten degree and heavy metals;Analyze the plant toxicity through the seed germination,root growth and pot experiment.The main results: Under the MSW/MS ratio(wet weight)as 1:1,2:1 and 4:1 can quickly heat up and meet the requirements of health standard of GB7959-2012?Sanitary standard for the non-hazardous treatment of night soil?,Aerobic composting can be performed.Adding mature sludge can improve the ventilation performance of pile body and achieve demands of harmless and hygiene.Moreover,the adding of mature sludge can relief the process of acidification,and effectively reduce the release of CH4 geenhouse gas.With adding matured sludge,co-compost product can achieve the degree of stabilization by observing the physical index,chemical index and biological index.The results of heavy metals detection and morphological analysis showed that,in the compost product,Zn is mainly in the unstable speciation and of high activity,so the stability is poor,prone to migration,influence to the environment.Heavy metals of Cu,Cr,Ni,Cd,Pb are mainly in the stable speciation and of low activity,so the stability is strong,not prone to migration,low environmental impact.Hg is not detected.Co-compost product has different effects on the plant at first,but low toxicity.If choose the appropriate ratio of fertilization,the co-compost product is beneficial to plant growing on the whole,so the compost of municipal solid waste and matured sludge can be used as fertilizer and soil conditioner.