Bio-drying Of Perishable Domestic Waste

With the implementation of waste classification policy,the amount of perishable domestic waste has increased significantly,and its treatment and disposal has become the key to waste treatment.Due to the characteristics of high moisture content and high organic matter content,perishable domestic waste is not suitable for direct landfill or incineration,so it needs to be dehydrated and dried.As one of the popular drying technologies,biodrying technology can not only remove free water and adsorbed water,but also activate bound water,so as to achieve better drying effect.However,there are few studies on biodrying technology in the dehydration of perishable domestic waste,and its technology is not mature.In view of the above problems,this paper took the perishable domestic waste as the research object,studies the influence of Bacillus subtilis,Phanerochaete Chrysosporium and compound bacteria inoculation amount,ventilation amount and thermal assistance on the biodrying of perishable domestic waste,and studies a set of biodrying process of perishable domestic waste.The main results of this study are as follows:1)The study on the best inoculation ratio of different inoculants for biodrying of perishable domestic waste showed that:Under the conditions of room temperature（about23℃）,full ventilation and residence time of 14 days,the microbial activity of the compost was improved.The optimal inoculation ratio of Bacillus subtilis,Phanerochaete Chrysosporium and compound bacteria were 5%,5%and 1%,respectively.The water removal rates 82.47%,80.62%and 84.40%,respectively,which were increased by 3.84%,1.51%and 6.27%,compared with the control,respectively.2)The best inoculation ratio of inoculant was selected to study the optimum ventilation rate of biodrying of perishable domestic waste,the results show that:Under the conditions of room temperature（about 22℃）,10:20 min（on:off）intermittent ventilation,and the residence time of 14 days（20 days of inoculation of compound bacteria）,considering the operation cost and biodrying performance,the optimal ventilation rate of the three inoculants were all 40 L·h^-1kg TS^-1,and the corresponding water removal rates were 86.41%,79.30%and 84.45%,respectively.Compared with the control,the corresponding water removal rates were 86.41%,79.30%and 84.45%,respectively.Compared with the control,the corresponding water removal rates were increased by19.68%,9.83%and 9.41%,respectively.3)The results of study on the effect of thermal assistance on the bioldrying of perishable domestic refuse with different inoculation agents showed that:Under the condition of optimal inoculation ratio,40 L·h^-1kg TS^-1 and 10:20 min（on:off）intermittent ventilation,and the residence time of 14 days,thermal assistance can improve the biodrying effect by improving microbial activity and promoting water evaporation.The three inoculants at 55℃ had the best thermal assisted effect,and the corresponding water removal rates were 88.81%,95.13%and 84.87%,respectively,which were increased by16.18%,33.67%and 19.30%compared with the control,respectively;the biodrying index were 1.71,1.25 and 1.12,respectively,which were increased by 0.07,0.23 and 0.12compared with the control,respectively.4)Considering the effect of biodrying and operation cost,the optimal process parameters of biodrying of perishable domestic waste were as follows:inoculation of Phanerochaete Chrysosporium 5%,40 L·h^-1kg TS^-1 and 10:20 min（on:off）intermittent ventilation,55℃ thermal assisted,and the residence time of 14 days.