Nickel sorption by acclimatized activated sludge culture

Area of Science:

• Environmental Science
• Microbiology
• Chemical Engineering

Background:

• Wastewater treatment often involves removing heavy metals like nickel (Ni2+).
• Activated sludge is a common biological treatment method.
• Acclimation of microbial communities can alter their metabolic and sorption capabilities.

Purpose of the Study:

• To investigate the sorption of Ni(2+) by acclimatized activated sludge.
• To determine the effect of influent Ni(2+) concentration and dilution rate on sorption.
• To understand factors influencing nickel removal efficiency.

Main Methods:

• Utilized a once-through completely mixed tank reactor.
• Acclimatized activated sludge to increasing Ni(2+) concentrations.
• Tested various influent Ni(2+) concentrations and dilution rates (0.11/h, 0.25/h, 0.45/h).

Main Results:

• Acclimation significantly enhanced the sorptive capacity of activated sludge for Ni(2+).
• Increased influent Ni(2+) concentration led to higher percentage adsorption and sorptive capacity.
• Dilution rate was identified as a significant operational parameter affecting Ni(2+) sorption.
• Biomass yield was stimulated by Ni(2+) exposure.
• Complexation of nickel with wastewater ligands reduced sorption capacity.

Conclusions:

• Activated sludge acclimation is an effective strategy for improving Ni(2+) removal from wastewater.
• Optimizing influent nickel concentration and dilution rate is crucial for efficient biological treatment.
• Wastewater complexation presents a challenge for maximizing nickel sorption by biomass.