MBR-11: Optimised treatment of landfill leachate in MBRs
RWTH |
01/2007 - 03/2008 |
Because of the high concentration and slow degradability of pollution in landfill leachate waters, their biological treatment is difficult. This leads to high effluent concentrations of COD and nitrates, since denitrification is not feasible in the lack of readily biodegradable substrate. Besides that, slowly degradable and salty influent leads to the production of biomass with adverse separation properties. This can be solved by use of membrane bioreactors (MBRs), but the permeability of membranes is lower compared to application for treatment of municipal wastewater.
On the other hand, the treatment of landfill leachates in membrane bioreactors has several advantages compared to physico-chemical treatment processes (e.g. reverse osmosis): lower trans-membrane pressure, high nitrogen elimination rate in case of external substrate dosing and relatively high retention of potentially endocrine disruptive chemicals (as nonylphenol and bisphenol A) which are frequently found in elevated concentrations in landfill leachates.
The main aim of this project is to optimize the performance of a laboratory-scale MBR plant for landfill leachate treatment with respect to nitrogen and COD removal. The relation between basic technological parameters (sludge concentration, solids retention time, recirculation ratio, COD:N ratio) and treatment efficiency is being monitored. The membrane performance will be characterized by measurement of its permeability and particle size exclusion chromatography in both retentate and permeate. Additional measurements will be carried out to characterize the elimination of bisphenol A.