Powdered activated carbon augmented activated sludge process for treatment of semi-aerobic landfill leachate using response surface methodology.

This study was conducted to investigate aerobic biodegradation of semi-aerobic leachate with and without powdered activated carbon (PAC) addition. The experiment involved operating two 16L laboratory-scale activated sludge reactors in parallel at room temperature and adjusted to pH 6.5+/-0.5. One of the reactors was supplemented with PAC of 75-150microm size to observe its effect on semi-aerobic leachate biodegradation. Three hydraulic retention times (0.92, 1.57 and 2.22 d) and influent COD concentrations (750, 1800 and 2850mg/L) were applied in a factorial design for this study. The results showed enhanced reactor performance due to PAC addition with higher COD, colour and ammoniacal nitrogen removals. The PAC augmented reactor also had higher concentrations of NO(2)-N and NO(3)-N consequent of greater degree of nitrification.