Assessment of metal removal, biomass activity and RO concentrate treatment in an MBR-RO system.
This work investigated the removal of metals from wastewater using a combined Membrane Bioreactor-Reverse Osmosis (MBR-RO) system. The concentrate produced by the RO system was treated by a fixed bed column packed with zeolite. The average metal removal accomplished by the MBR treating municipal wastewater was Cu(90%), Fe(85%), Mn(82%), Cr(80%), Zn(75%), Pb(73%), Ni(67%), Mg(61%), Ca(57%), Na(30%) and K(21%), with trivalent and divalent metals being more effectively removed than monovalent ones. The metal removal achieved by the MBR system treating wastewater spiked with Cu, Pb, Ni and Zn (4-12 mg L(-1) of each metal) was Pb(96%)>Cu(85%)>Zn(78%)>Ni(48%). The combined MBR-RO system enhanced metal removal from municipal wastewater to the levels of >90.9->99.8%, while for wastewater spiked with heavy metals the removal efficiencies were >98.4%. Fixed bed column packed with zeolite was effective for the removal of Cu, Pb and Zn from the RO concentrate, while Ni removal was satisfactory only at the initial stages of column operation. The presence of heavy metals increased inorganic fouling.
Unit of Environmental Science and Technology, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou St., Zographou Campus, PC 157 73, Athens, Greece. malamis.simos@gmail.com
Simos
S
Malamis
Evina
E
Katsou
Konstantinos
K
Takopoulos
Prokopis
P
Demetriou
Maria
M
Loizidou
D018533:Biomass; D019149:Bioreactors; D004867:Equipment Design; D008567:Membranes, Artificial; D008670:Metals / Q000302:isolation & purification*; D009995:Osmosis; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
D008567:Membranes, Artificial; D008670:Metals; D014874:Water Pollutants, Chemical