Effect of Temperature on UASB Reactor Performance Treating Textile Sludge

The sludge generated in wastewater treatment systems in the textile industry has the potential to be treated by reducing the amount destined for landfills and the generation of energy by biogas produced in the anaerobic treatment. This treatment can be influenced by a number of factors including the temperature. Thus, this study evaluates the influence of the parameter variation in the temperature efficiency during the treatment of textile sludge and biogas production in a UASB reactor, operating at laboratory scale. The UASB reactor of 16 L operated with a hydraulic retention time (HRT) of 24 h for the temperatures of 33±2°C (phase 1) and 45±2°C (phase 2). The reactor was fed with 100% sludge from the textile industry, making the raw influent to be treated. The parameters monitored during 250 days of reactor operation were: pH, total alkalinity, volatile acids, biochemical oxygen demand (BOD), chemical oxygen demand (COD), organic and total carbon, total solids, fixed total solids, total volatile solids, total suspended solids, total phosphorus, total nitrogen and biogas production. It was found that the average removal efficiencies were 86% in phase 1 and phase 2 at 91% for total volatile solids, COD was 96% in both phases, BOD removal was 92% and 81%, respectively, total phosphorus removal was 98% in two phases monitoring and total nitrogen, 95% and 90%, respectively. Regarding the production of biogas, it was found that production increased considerably from phase 1 to phase 2, with the average yield of 0.67 L and 1.3 d-1, respectively. The results showed that the UASB reactor in the mesophilic temperature of 35°C was more effective in the treat ability of textile sludge, but in the production of biogas, it had a considerable increase when the temperature change, with increasing the production biogas.