EVALUATION OF ANIONIC SURFACTANT ADSORPTION EMPLOYING BATCH REACTORS

Few studies have evaluated the influence of LAS (linear alkylbenzene sulfonate) adsorption in the process of anaerobic biodegradation. This study evaluated the adsorption of LAS (from commercial laundry) on the sludge using batch reactors. In all, 18 reactors were operated with 30 mL of culture medium (Del Nery, 1987) containing 8 mg LAS/L and 2.5 g of dry sludge. The reactors were sterilized by autoclave and incubated at 30 °C and 150 rpm. The reactors were monitored every 24 h for COD (chemical oxygen demand) and LAS in triplicate. At the end of the operation (6 days), the LAS adsorbed on the sludge was analyzed. During the operation, COD and LAS decay were observed, reaching at the assay end, removal efficiencies of 36% and 73%, respectively. For each reactor, LAS analyzes were performed in triplicate and the average LAS concentration adsorbed on the biomass was 5.34 mg/L (at the end of the reactors operation) and around 2.12 mg LAS/g sludge was detected in this study. With this preliminary study, the adsorption of LAS on the sludge was verified. These data will serve as a subsidy for future researches involving the anaerobic degradation of LAS employing real wastewater.