|Title||Enhancement of removal of trace organic contaminants by powdered activated carbon dosing into membrane bioreactors|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||Nguyen LN, Hai FI, Nghiem LD, Kang J, Price WE, Park C, Yamamoto K|
|Journal||Journal of the Taiwan Institute of Chemical Engineers|
|Keywords||Adsorption, Membrane bioreactor (MBR), Powdered activated carbon (PAC), Trace organic contaminants, Water recycling|
This study compared the removal efficiency of 22 widespread trace organic contaminants by a laboratory-scale membrane bioreactor (MBR) with and without direct addition of powdered activated carbon (PAC) into the activated sludge reactor over a period of 312 days. The removal of hydrophilic and biologically persistent trace organic contaminants was immediately improved to above 95% after the addition of PAC into MBR. However, a compound-specific gradual decrease in removal underscored the requirement for the addition of fresh PAC. Adsorption onto PAC-added sludge appeared to play a significant role in the relatively more effective aqueous phase removal of a few resistant compounds such as carbamazepine in this study. A slower reduction in removal efficiency of compounds showing extraordinary persistence such as fenoprop and diclofenac was observed after raising the PAC concentration in the MBR from 0.1 to 0.5 g/L. Nevertheless, comparison of extent of removal in terms of PAC usage indicated the suitability of more frequent dosing of smaller amounts of PAC.