title: Improving the performance of membrane bioreactors by powdered activated carbon dosing with cost considerations.
abstract: Effects of powdered activated carbon (PAC) dosing on the overall performance of membrane bioreactors (MBR) were investigated in two bench-scale submerged MBRs. Positive impacts of PAC dosing on membrane fouling and the removal of 17beta-estradiol (E2) and 17alpha-ethyinylestradiol (EE2) were demonstrated over a six-month stable operational period. PAC dosing in the MBR increased the removal rates of E2 and EE2 by 3.4% and 15.8%, respectively. The average soluble extracellular polymeric substances (EPS) and colloidal total organic carbon (TOC) concentrations in the PAC-MBR sludge was 60.1% and 61.8% lower than the control MBR sludge, respectively. Lower soluble EPS and colloidal TOC concentrations in the PAC-MBR sludge resulted in a slower rate of trans-membrane pressure (TMP) increase during MBRs operation, which could prolong the lifespan of membranes. Cost assessment showed that PAC dosing could reduce the operating cost for membrane cleaning and/or membrane replacement by about 25%. The operating cost for PAC dosing could be offset by the benefit from its reducing the cost for membrane maintenance.
authors.affiliation: Department of Biosystems Engineering, University of Manitoba, Winnipeg, Canada. wyang@trojanuv.com
authors.forename: W
authors.initials: W
authors.lastname: Yang
authors.forename: M
authors.initials: M
authors.lastname: Paetkau
authors.forename: N
authors.initials: N
authors.lastname: Cicek
mesh_terms: D019149:Bioreactors / Q000191:economics; D002606:Charcoal / Q000737:chemistry* / Q000191:economics; D003365:Costs and Cost Analysis; D052244:Endocrine Disruptors / Q000302:isolation & purification*; D004967:Estrogens / Q000302:isolation & purification*; D008567:Membranes, Artificial; D018505:Waste Management / Q000191:economics / Q000295:instrumentation / Q000379:methods*
chemical_list: D052244:Endocrine Disruptors; D004967:Estrogens; D008567:Membranes, Artificial; D002606:Charcoal