Performance review of large scale up-flow anaerobic sludge blanket sewage treatment plants

摘要

This article evaluates the performance of 10 large scale upflow anaerobic sludge blanket (UASB)nsewage treatment plants (STP) located in semi-tropical areas, 7 plants were located in Brazil, 2 innIndia and 1 in the Middle East. In addition to the UASB, essential functional units of the STP whichnpotentially impact on the UASB are also evaluated. Most grit removal systems were performingnadequately, however in one plant very little grit was being removed. This could have seriousnimplications for the performance of the plant as in a relatively short period of time the reactorsncould become full of grit. The performance results obtained in this study (COD, BOD and TSSnremoval efficiencies) are compared to the results of recent literature publications and also to thenresults of some early pilot and full scale studies. The results found here are broadly similar tonthose result reported in the recent literature but show a lower performance in comparison withnthe early pilot scale plants. Factors such as improper design, poor operating procedures,ninsufficient maintenance and the presence of high sulphate concentrations have been identified asnthe main reasons for the lower performance.