Zn2+, Ni2+ and propylene glycol methyl ether were simultaneously removed from simulated wastewater in a column consisting of an aerated packed bed and an electrochemical cell with a porous aluminium. foam cathode and a porous stainless steel anode. After 48 h of sole electrochemical treatment at a liquid rate of 0.00183 m(3) m(-2) S-1, Zn2+ and Ni2+ were reduced by 95 and 80% respectively. In the turbulent flow regime with liquid rates varied from 0.0137 to 0.0366m(3) m(-2) s(-1), both Zn2+ and Ni2+ removal decreased by about 15% rather than increased as expected for a mass transfer-controlled process. This can be attributed to bubble formation at the cathode surface under turbulent flow, which led to a lower active surface area for the electrodeposition of metal ions. Porous electrodes enhanced the metal removal by 17 and 60% for Zn2+ and Ni2+ respectively as compared with flat plate electrodes. Using combined biological and electrochemical treatment at a water rate of 0.00183 m(3) m(-2) s(-1) and an air rate of 0.0518m(3) m(-2) s(-1), 99% of Zn2+ and 95% of Ni2+ were removed. In addition, the 5 day biological oxygen demand (BOD5) was reduced by 58% concurrently over 72 h of treatment. (c) 2006 Society of Chemical Industry.