The effect of heavy metals on the membrane biofouling in membrane bioreactors

Presence of heavy metals is considered to be a major challenge in wastewater treatment. In this research the effect of heavy metals such as Nickel (Ni), Chromium (Cr), and Manganese (Mn) on biofouling in membrane bioreactors (MBRs) was investigated. Biofouling tendency of a cellulose acetate membrane was evaluated in MBRs with different concentrations of the mentioned compounds. The concentrations of extractable EPS in the mixed liquor at the steady-state condition and different concentrations of heavy metals were compared. Also the effects of concentration of heavy metals on mean floc diameter and hydrophobicity, and hence the biofouling propensity of membrane was investigated. Results showed that different concentrations of heavy metals in wastewater had different effects on sludge properties and hence induced the different fouling tendency of sludge.

Keywords:

Biofouling , Extracellular polymeric substances , Floc size , Heavy metals , MBR , Wastewater