title: Tetrachloroethylene (TCE) removal during anaerobic granulation in an upflow anaerobic sludge blanket (UASB) reactor.
abstract: The anaerobic biotransformation of TCE was investigated during the granulation process by reducing the HRT and increasing the chemical oxygen demand (COD) and TCE loadings in a 21 laboratory-scale upflow anaerobic sludge blanket (UASB) reactor. Anaerobic unacclimated sludge and glucose were used as seed and primary substrate, respectively. Initial granules were developed after 1.5 months of start-up, which grew at an accelerated pace for 7 months and then became fully grown. The effect of operational parameters such as influent TCE concentrations, COD and TCE loading, food to microorganism (F/M) ratio and specific methanogenic activity (SMA) were also considered during granulation. The granular sludge cultivated had a maximum diameter of 2.5 mm and SMA of 1.32 gCOD (gTSS day)(-1) while 94% COD and 90% TCE removal efficiencies were achieved when the reactor was operating at loading rates as high as 160 mg TCE (1 day)(-1) and 14 gCOD (1 day)(-1), respectively after 230 days of continuos operation. This corresponds to HRT of 0.28 day and F/M ratio of 0.60 gCOD (gTSS day)(-1). Kinetic coefficients of k (maximum specific substrate utilization rate), Ks (half velocity coefficient), Y (growth yield coefficient) and b (decay coefficient) were determined to be 2.38 mgCOD (mgTSS day)(-1), 108 mgCOD 1(-1), 0.17 mgTSS (mgCOD)(-1) and 0.015 day(-1), respectively during TCE biotransformation based on glucose-COD during granulation.
authors.affiliation: Dokuz Eylül University, Engineering Faculty, Environmental Engineering Department, Izmir, Turkey. delya.sponza@deu.edu.tr
authors.forename: Delia Teresa
authors.initials: DT
authors.lastname: Sponza
mesh_terms: D001421:Bacteria, Anaerobic / Q000502:physiology*; D019149:Bioreactors; D001711:Biotransformation; D004785:Environmental Pollutants / Q000378:metabolism*; D007700:Kinetics; D010100:Oxygen / Q000737:chemistry; D012722:Sewage; D013750:Tetrachloroethylene / Q000378:metabolism*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D004785:Environmental Pollutants; D012722:Sewage; D010100:Oxygen; D013750:Tetrachloroethylene