Activity, structure, and stratification of membrane-attached methanotrophic biofilms cometabolically degrading trichloroethylene

摘要: A membrane-attached methanotrophic biofilm reactor was developed for the cometabolic degradation of trichloroethylene (TCE). In this reactor, CH4 and O2 are supplied to interior through membrane, while TCE-contaminated water is exterior, creating a “counter-diffusional” effect that minimizes competitive inhibition between TCE CH4. addition, novel design provides 100% transfer efficiencies, promotes development thick biofilm, negative effects byproduct toxicity. The sustained 80-90% removals at loading rates ranging from 100-320 μmol/m2/d. Chloride mass balances demonstrated 60-80% removed mineralized. maximum transformation yield 1.8 mmol per mole utilized, although higher yields expected rates. utilization rate 0.20 mol/m2/d. Scanning electron microscopy (SEM) revealed dense with thickness least 400 μm. SEM transmission (TEM) analyses indicated “holdfast” material associated rosette formation in planktonic Methylosinus trichosporium OB3b ( M.t. OB3b) cells might also contribute pure-culture development. fimbriae-like structures not commonly bacteria were observed biofilms. Finally, fluorescent situ hybridization (FISH) showed presence discrete microcolonies serine-pathway methanotrophs within mixed-culture