Nickel sorption by acclimatized activated sludge culture.
The sorption of Ni(2+) by acclimatized activated sludge treating Ni(2+) bearing wastewater was investigated using a once-through completely mixed tank reactor. The culture developed from sewage was acclimatized to 85.2 microM/l Ni(2+) influent concentration by stepwise increases, at a low dilution rate 0.11/h. Acclimation was found to enhance the sorptive capacity of the activated sludge. In fact, at all of the intermediate concentrations, percentage Ni(2+) adsorbed by the biomass and also the sorptive capacity of the activated sludge drastically increased with an increase in the influent Ni(2+) concentration. All influent Ni(2+) concentrations were found to significantly stimulate the observed biomass yield of the culture over that observed in the base line. Experimental findings obtained at two other dilution rates; namely, 0.25/h and 0.45/h revealed that dilution rate is a significant operational parameter affecting the Ni(2+) sorption characteristics of acclimatized activated sludge microorganisms. Considerable complexation of nickel and organic and inorganic ligands in the wastewater appeared to be responsible for a relatively lower Ni(2+) sorption capacity.
Arican
Betul
B
Department of Environmental Engineering, Middle East Technical University, 06531 Ankara, Turkey.
Yetis
Ulku
U
D000327:Adsorption; D018533:Biomass; D019149:Bioreactors; D008024:Ligands; D009532:Nickel / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid
D008024:Ligands; D012722:Sewage; D009532:Nickel