The Response Of Contaminant And Microbial Community Change During Aerobic Composting Of Sewage Sludge

The change of microbial community during the sludge composting was researched bythe phospho-lipid fatty acid (PLFA) technology. Theoretical basis for composting processoptimizing was provided on aspect of the microbial structure succession. The results pointthat bacterium is dominant and exuberant (33bacterial PLFAs in total) in microbialcommunity, The proportion of bacterial PLFA16:1ω7、18:1ω7c maintain at about60mol%,the structure changing of bacterium is related to composting temperature. The period ofbacterial proportion growing focused on high temperature term. The proportion of fungalPLFA16:00,18:1ω9c maintain at about30mol%, fungal can resist high-temperatureenvironment is speculated by the change of composting environmental parameters didn’thave much influence on fungus’s proportion, fungal also can metabolize lignin and cellulosethose hardly degradable organic materials and keep proportion level in the late. The ffectivestate Heavy metals of Cu, Cd, Pb, Zn is reduced in the late compost mainly, which changeswith the PLFA markers10Me16:0(actinomycetes),18:00(fungus), cy17:0(G+),10Me18:0(actinomycetes),18:1ω9c (fungus) of the content of the change of correlation is greater, thecorrelation coefficients between10Me16:0(actinomycetes) and18:1ω9c (fungus) changeandchangesoftheCu,Zn,Cd,Pbformswere0.861,0.977,0.789,0.583and0.665,0.703,0.71，0.42； degradation changes of ΣPAHscarc and ΣPAHs were focused in front of themid-composting, PLFA markers15:1isoG (aerobic bacteria), i17:0(G+aerobic bacteria),18:00(fungus), cy17:0(G-),10Me18:0relative content change and ΣPAHs (actinomycetes),etc., ΣPAHscarc degradation showed a large positive change in correlation, the larger correlation coefficient was PLFAmarkers cy17:0and i17:0, with ΣPAHs, degradation of thecorrelation coefficient changes ΣPAHscarc0.984and0.977, Benzene rings in each PAHdegradation low correlation between changes in the larger community PLFA markers ofGram-negative bacteria cy17:00, Burkholderia cy19:0ω8c, actinomycetes Me16:00, Bacillus16:1ω7c, Bacillus15:0iso3OH, Gram-positive aerobic bacteria i17:00; odd benzene ringPAHs degradation associated with multiple communities PLFA markers are aerobicGram-positive bacteria i15:00, Gram-negative methane oxidizing bacteria16:1ω5c,18:00thermophilicSolutionshydrogenbacteria,fungi,18:1ω9c,actinomycetes10Me18:00.