title: Performance of UASB based sewage treatment plant in India: polishing by diffusers an alternative.
abstract: In India, recently, upflow anaerobic sludge blanket (UASB) based sewage treatment plants (STPs) have come up in a big way. Sequence adopted: screens- grit chambers- UASB reactors followed by one-day detention ponds (DP). Performance of DPs located at five STPs (27-70 ML/d) was evaluated over a period of one year from July 2004 to July 2005. The installation of these non-algal ponds reduced land requirement, but from treatment point of view it at best offered only removal of solids washed out of the UASB reactor. Total coliform count in the effluent from ponds ranging from 10(6) to 10(9) MPN/100 mL is more than the maximum permissible limit of 10,000 MPN/100 mL. A need has, therefore, been felt to evaluate the possibility of aerating the effluent from UASBR. During aeration, ORP and DO increase, whereas COD and BOD decrease. In a continuous aeration ~50% reduction in COD and nearly 50% increase in DO saturation (DO/DOs) can be achieved by increasing ORP from -100 to 122 mV. Regression equation established between ORP and COD/CODi & DO/DOs may find wide application.
authors.affiliation: Department of Civil Engineering, Rajarshi Shahu College of Engineering, Tathawade, Pune 411 033, India. waliarinks@rediffmail.com
authors.forename: R
authors.initials: R
authors.lastname: Walia
authors.forename: P
authors.initials: P
authors.lastname: Kumar
authors.forename: I
authors.initials: I
authors.lastname: Mehrotra
mesh_terms: D000388:Air; D004785:Environmental Pollutants / Q000032:analysis / Q000302:isolation & purification; D007194:India; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D018505:Waste Management / Q000295:instrumentation / Q000379:methods*
chemical_list: D004785:Environmental Pollutants; D012722:Sewage