EFFECT OF AMMONIA AND COD TO SULFATE RATIO ONTREATMENT PERFORMANCE OF CONCENTRATED LATEXPROCESSING WASTEWATER

Abstract

The objective of this study is to investigate the effects of ammonia nitrogen (NH3-N) and COD to sulfate ratio on the treatment performance of concentrated latex processing wastewater (CLPW). In a batch experiment, the CLPW influent COD, % granular sludge and pH were controlled at about1,200 mg/l, 10% and 7, respectively. The influent NH3-N concentrations varied at 100, 500, 1000 and3000 mg/l, whereas COD/sulfate ratio varied at 0.3, 0.6, 1 and 1.3. Treatment performance was determined by methane generation rate and COD removal efficiency at different NH3-N and COD to sulfate ratio. The NH3-N concentration at 100 and 500 mg/l (which were presented in the real CLPW), did not result in inhibition on methane producing bacteria (MPB), since methane generation was detected. Inhibition on MPB was observed at 1,000 mg/l NH3-N. Strong inhibition occurred at 3,000 mg/l NH3-N, since % COD removal was relatively reduced to 7.98 % and nomethane generation. The COD/sulfate ratio at lower than 0.6 resulted in inhibition of MPB, but in the real CLPW the ratio is normally higher than 0.6. Ammonia concentration higher than 1000 mg/l and COD to Sulfate at lower than 0.6 resulted in inhibition of methane producing bacteria in the treatment of CLPW.