Study On Comprehensive Treatment And On-line Monitoring Technologies In Composting Management Of Municipal Domestic Waste

Environmental planning and management is an integrative processincluding scientific evaluation and prediction,decision making,andadministration for environmental system.The content of managementinvolves water management,atmosphere management,soil resourcemanagement,solid waste management and urban environmental management.It is necessary for solid waste management that executing the entireadministration of production,collection and transportation,and treatment(disposal) of solid waste.Solid waste management is an important part ofenvironmental planning and management.Municipal domestic waste is one ofthe major objects of solid waste management,and there are some kinds ofmanagement (treatment) methods for municipal domestic waste.Compostingtechnology is known as an environment-friendly method with a low cost,high resource utilization and ecological benefit,which has attractedattention of researchers.And the efficient management of the compostingprocess of municipal domestic waste is very important.The developmentand improvement of some key technology in composting process are relatedwith the compost quality and the final disposal.Therefore,exploringcomprehensive treatment and on-line monitoring technologies has becomethe research emphasis of composting process management.The aim of this study is to improve composting management bydeveloping the key technologies related to the compost production.Theefficient methods of limit-step factor adjustment and toxic hydroxybenzenecontrol in composting are studied,and the on-line monitoring technologiesof microbial indexes and toxic matter are also investigated.In addition,theoptimization method of humus quality in compost product is discussed.It isexpected to provide some references for the development of comprehensivetreatment and on-line monitoring technologies in composting management,which might benefit the improvement of composting management system.Complex microbial inoculant (JX1) with strong lignin degrading ability is obtained through the screening experiments,and the efficientcomposting method controlling the limit-step factor by JX1 is developed.Itis showed that inoculum of JX1 promote the lignin degradation andaccelerate the composting process.During the composting process by JX1,the lignin degradation is mainly attributed to the catalytic action ofpolyphenol oxidase.The study of efficient composting method benefits therealization of efficient management.Composting of pentachlorophenol (PCP) contaminated waste byinocula of white-rot fungi is proved to be feasible.The PCP concentrationand the content of lignin and coarse fiber decrease obviously duringcomposting by white-rot fungi,which might be because white-rot fungidegrade PCP effectively and alleviate the inhibition of PCP.The highermicrobial biomass content and germination index (121% on day 80) arefound in composting with white-rot fungi than that without inoculants,which confirm that high microbial activities maintain in composting withinoculants by the reduction of PCP toxicity.This method could providetechnical assistance for the related management section.The dynamic succession of microorganism populations duringcomposting of municipal domestic waste is successfully analyzed byPCR-DGGE method,and an electrochemical enzyme sensor is developed torapidly monitor the activities of lignin peroxidase (LiP) and mangansesperoxidase (MnP) in composting.The results show that there is an obvioussuccessive change of microorganism populations.The community diversityof fungi and actinomycetes are observed during the thermosphere phase,whereas there is a decrease in microorganism population during the coolingperiod.The optimal parameters for catalytic reaction of LiP or MnP on theelectrode in electrochemical enzyme sensor are obtained,which are pH of4.2,H₂O₂ concentration reaching 0.1875 mM,0.25 mM hydroquinone and 6mM veratryl alcohol.In the optimal reaction system,LiP and MnP aredetermined exactly by the sensor.The study of rapid monitoring methodwould provide strong technical support for the efficient monitor and controland reasonable management.An immunosensor monitoring the picloram during composting isdeveloped.According to the current response and picloram measurementexperiments,the liner equation related to the concentration of picloram is obtained.The liner range of picloram measurement by the sensor is 0.01-10μg/mL,and the detection limit of the immunosensor for picloram is 1×10^-8μg/mL.A novel inhibition based biosensor of glucose oxidase (GOx) formercury detection in composting is developed.The detection limit of theinhibition-based sensor for mercury is 0.49μg/L.And the linear responseranges are 0.49μg/L-783.21μg/L and 783.21μg/L-25.55 mg/L.The sensoris used for mercury determination in compost extract with good results.Thedevelopment of these sensors could provide useful information for theon-line detection of the toxic organic matter and metal ions,which wouldpromote the secure management of compost.The effects of microbial inoculant on humification and humus qualityare studied.The results show that inoculating Phanerochaete chrysosporiumin second fermentation phase of composting could promote the formation ofhumus,increase the humus content,and reduce the humification time by 7days.The promotion of humus formation by inoculant might be becauseinoculant increases the humic acid content and decreases the fulvic acidcontent.This could provide some references for optimizing the humusquality in compost.