Affiliations: Department of Environment and Resource,Zhejiang
University,Hangzhou 310029,China, E-mail:shends @ mail.hz.zj.cn
Abstract: Activity development of key groups of enzymes involved in municipal
refuse decomposition was measured in laboratory landfill hioreactors with and
without leachate recycling and inoculation for about 210 days.The results
showed that the enzymes (amylase,protease,cellulase,lipase and pectinase ) were
present in fresh refuse but at low values and positively affected hy leachate
recycling and refuse inoculation.The total average of cellulase activity in
digesters D3 operated with leachate recycling but no inoculation,D4 and D5
operated with leachate recycling and inoculation was much higher than that in
digesters D1 and D2 without leachate recycling and inoculation by
88%-127%,117%-162% and 64%-98%.The total average of protease activity was
higher in digester D4 than that in digesters D1,D2,D3and D5 by 63%,39%,24% and
24%,respectively,and the positive effect of leachate recycli.ng and inoculation
on protease activity of landfilled refuse mainly was at the first two
months.The total average of amylase activity was higher in digesters D3,D4 and
D5 than that in digesters D1 and D2 by 83%-132%,96%-148% and 81%-129%.During
the early phase of incubation,the stimulatory effect of inoculation on lipase
activity was measured,but refuse moisture was the main factor affecting lipase
activity of landfilled refuse.The inoculation,initial and continuous
inoculation of microorganisms existing in leachate,was the mainly stimulatory
factor affecting pectinase activity of landfilled refuse.
