Development of a biological system employing Aspergillus lentulus for Cr removal from a small-scale electroplating industry effluent

In spite of the abundant work on biological Cr removal from simple synthetic solutions, very few studies demonstrate the potential of the tested strain for treatment of potentially toxic and complex industrial effluents. In the present study, the efficiency of an environmental isolate, Aspergillus lentulus AML05, to remove Cr from a small-scale electroplating industry effluent (pH 2.5, Cr (VI) 259 mg l(-1) and total Cr 295 mg l(-1)), was investigated. To bring about Cr removal using growing biomass, dilution and nutrient supplementation of the effluent was tested. The removal of Cr (VI) after 9 days of treatment was 100% in the diluted effluent (1 : 1; effluent : growth media) and 99% in the undiluted nutrient supplemented effluent. About 73% of the total Cr was also removed. While using the non-growing (pre-cultivated) biomass, Cr (VI) removal within 2 h of contact was 75% (resting biomass) and 91% (autoclaved biomass). The maximum Cr (VI) removal was 90-92% after 24 h of treatment at various doses in the non-growing mode. Comparison with earlier studies revealed that A. lentulus is a promising strain that can be efficiently utilized for Cr removal from industrial effluents. Overall, the study reveals that integrated system incorporating A. lentulus in both growing as well as non-growing modes assumes significance in terms of an inbuilt assurance of the proper functioning of the biological system under any unforeseen fungal growth situation in the field. (C) 2010 Curtin University of Technology and John Wiley & Sons, Ltd.