Membrane bioreactor treatment of oily wastes from a metal transformation mill

Abstract

The performance of a membrane bioreactor treating wastewater from a metal transformation industry was compared with the ultrafiltration system at the mill. Toxicity analysis using the microtox and algal tests on the untreated and treated effluents from both systems showed a 130 fold reduction in toxicity due to the ultrafiltration step and a further 10 fold reduction due to the biological step. This resulted in a biomass which must be disposed of as a hazardous waste. In comparison with the present situation, the overall quantity of hazardous waste was reduced by a factor of 3 due to the combination of the bioreactor and the ultrafilters.

The fate of metals in wastewater treated by the activated sludge process and membrane bioreactors: A brief review

“…The study of metals in wastewater, as they relate to MBRs, largely falls into three groups: a) use of metal-based coagulants for anti-fouling, 79 b) treatment of metals-laden industrial effluents, [80][81][82] and c) fate of metal micropollutants in municipal and industrial wastewater treatment. 83,84 An advantage of an MBR is its ability to operate with uncoupled hydraulic and solids retention times (HRT and SRT respectively).…”

Performance evaluation and modeling of a submerged membrane bioreactor treating combined municipal and industrial wastewater using radial basis function artificial neural networks

“…The interest of using MBR instead of classical activated sludge system for the treatment of industrial wastewater was demonstrated [ 6 , 7 ]. Zhao et al [ 8 ] used a laboratory-scale anaerobic/anoxic/oxic membrane bioreactor system to treat heavily loaded and toxic coke plant wastewater and operated for more than 500 days.…”

Tubular ceramic membrane bioreactor: operating characteristics and treatment performance

“…HRT for MBR applications in industrial wastewater treatment ranged from 10 hours (62 days SRT} for pharmaceutical effluents with 63-86% COD removal (Benitez et al, 1995) to 24 hours (both 10 and 550 days SRT) for tannery wastewaters with 94% COD removal (Yamamoto and Win, 1991). For oily wastewater, Zaloum et al (1994) reported 99.6% BOD and 73% NH3-N removal using an HRT of 240 hours (75 days SRT) while, for landfill leachate, Ahn and Song. (1999) reported 99.6% BOD and 90% COD removal using an HRT of 240 hours (30 days SRT).…”

“…In addition, because of the density of oil and its ability to emulsify, conventional settling tanks are generally not very effective. Among the available physicochemical treatment methods, ultrafiltration is perhaps most advantageous for treatment of oil-water emulsions (Lipp et al, 1988), Membranes, especially ultrafilters, were initially used as a standard process to reduce the volume of oily wastewater by separating the oily matter from water (Zaloum et al, 1994). Lee et al (1994) reduced the volume of oily waste 10 times while Leikness and Semmens (2000) concentrated the oil emulsion by 5 times with ultrafiltration.…”

“…The results show that ultrafiltration is an effective means of reducing the volume of the oily waste; however, the ultrafiltration alone was inadequate in removing the aromatics, leaving an effluent incapable of meeting the requirements of the effluent discharge standards. MBR with the membrane separation phase can improve the treatment efficiency of oily wastewaters and is more stable under highly varying influent organic matter concentration than conventional treatment systems (Zaloum et al, 1994;Seo et al, 1997).…”