Upflow anaerobic sludge bed (UASB) technology assay for AOX removal from mixed municipal-industrial wastewater

Environmental agencies in many countries have added to the list of the principal organic pollutants many organic-halogen compounds (OX) due to their toxicity, persistence and their suspected carcinogenity. Effluents from urban wastewater treatment plants, have been demonstrated to be polluted by such substances. This kind of effluents are often reused for irrigation representing a potential source of contamination for soils, nevertheless, for the receiving bodies such as rivers or protected lagoons. This study shows the results of an experimental test run with a UASB-Biopaq® pilot-scale plant fed with wastewater from a municipal treatment plant and loaded with rising simulated industrial AOX containing water. Results confirm that UASB technology is successful in removing AOX with a rate of abatement ranging from 50 to 70% for inlet concentration up to 3000 μg/l with no evident inhibition effects. Also, COD (Chemical Oxygen Demand) and TSS (Total Suspended Solids) removal is evident (60-80%) and gas production after the acclimatisation period stabilised at 0.6 l/dm 3 .d.