Removal of heavy metals in wastewater by membrane bioreactor: Effects of flux and suction period

The effects of flux and suction period on the removal of selected heavy metals including nickel,arsenic,cadmium,antimony and lead by membrane bioreactor was investigated. the sludge-age was arranged as 25 days and mlss concentration was about 13 g/l. the flux was increased from 13 to 26 l/m2-h to understand the effects of flux on the removals. moreover,to understand the effect of bio-film formation on the membrane plate surfaces,different samples were taken at different periods of the suction cycle. cod removal during the study was over 95%. influent concentration of each of the heavy metals spiked directly to the wastewater was about 100 μg/l. effluent concentrations of cadmium and lead were under the limit of detection in all samples meaning that all the cadmium and lead were removed. removals of over 50,96,and 95% for arsenic,nickel and antimony were achieved,respectively. the highest removal was achieved in the first minute of the suction where the metals were accumulated in the surface biomass.