ANAEROBIC DEGRADATION OF LINEAR ALKYLBENZENE SULFONATE IN FLUIDIZED BED REACTOR

An anaerobic fluidized bed reactor was used to assess the degradation of the surfactant linear alkylbenzene sulfonate (LAS). The reactor was inoculated with sludge from an UASB reactor treating swine wastewater and was fed with a synthetic substrate supplemented with LAS. Sand was used as support material for biomass immobilization. The reactor was kept in a controlled temperature chamber (30+/-1 degrees C) and operated with a hydraulic retention time (HRT) of 18 h. The LAS concentration was gradually increased from 8.2+/-1.3 to 45.8+/-5.4 mg.L-1. The COD removal was 91%, on average, when the influent COD was 645+/-49 mg.L-1. The results obtained by chromatographic analysis showed that the reactor removed 93% of the LAS after 270 days of operation.