REMOVAL AND RECOVERY OF CU(II) FROM INDUSTRIAL EFFLUENT BY IMMOBILIZED CELLS OF PSEUDOMONAS-PUTIDA II-11

A copper [Cu(II)]-accumulating strain, Pseudomonas putida II-11, isola ted from electroplating effluent removed a significantly high amount o f Cu(II) from growth medium and buffer. A laboratory-scale fixed bed r eactor with cells of P. putida II-11 immobilized in polyacrylamide gel was constructed. The adsorption of Cu(II) by the immobilized cells wa s pH-dependent. Maximum removal of Cu(II) by the immobilized cells was at pH 8.0. The presence of Cr(IV), Ni(II) and Zn(II) did not signific antly inhibit Cu(II) uptake whereas the presence of Pb(II) reduced Cu( II) uptake by five-fold. The presence of borate, carbonate, chloride a nd sulphate did not significantly inhibit Cu(II) uptake. The Cu(II) re moval capacity of the bioreactor with immobilized cells did not change significantly when operated at retention times greater than 3 min. Mo re than 90% of Cu(II) adsorbed on immobilized cells could be recovered by eluting with 0.1 M HCl. The bioreactor could be used for at least five loading-elution cycles without loss of Cu(II) removal capacity. T he feasibility of using this bioreactor to remove and recover Cu(II) f rom electroplating effluent is discussed.