Simultaneous recovery of Cu2+ and Pb2+ from metallurgical wastewater by two tandem columns fixed respectively with tetraethylenepentamine and phosphoric acid modified bagasse

Abstract

Abstract Two tandem column fixed, respectively, with tetraethylenepentamine modified bagasse (AM-BS) and phosphoric acid modified bagasse (PA-BS) were prepared and used to simultaneously recycle Cu2+ and Pb2+ from metallurgical wastewater containing Cu2+, Pb2+, Cd2+, Zn2+, Ca2+ and Mg2+. For comparison, removal of Cu2+ and Pb2+ by single column fixed either with AM-BS or PA-BS was also carried out in unitary and wastewater system. Results in single column experiments showed that AM-BS column showed high adsorption affinity toward Cu2+ while PA-BS showed high affinity toward Pb2+. AM-BS could selectively remove Cu2+ while PA-BS could selectively remove Pb2+ from aqueous solution. Adsorption mechanism verified by EDX illustrated that Cu2+ and Pb2+ was selectively adsorbed through competitive substitution reaction, where metal ions with higher affinity substituted the others with lower affinity during sorption process. Two tandem column experiments showed that amount of Cu2+, Pb2+, Cd2+, Zn2+, Ca2+ and Mg2+ adsorbed on AM-BS was 0.17, 0.003, 0.001, 0.006, 0.013 and 0.009\u202fmmol\u202fg−1 and that on PA-BS was 0.04, 0.24, 0.002, 0.018, 0.028 and 0.005\u202fmmol\u202fg−1, respectively, demonstrating that Cu2+ and Pb2+ were simultaneously removed from wastewater. Tandem columns fixed with different modified biosorbent had great potential in multi-metal recovery.