Random-packed anaerobic filter in piggery wastewater treatment

Abstract

The anaerobic filter has been used on a laboratory scale to treat piggery wastewater. Screened wastewater was digested in a 21-litres effective volume reactor random-packed with plastic media. Feed wastewater was introduced into the filter in an upflow mode at regular intervals using a timer-controlled pump at loading rates representing hydraulic retention times (HRT) of 6·3 to 2·1 days. COD reductions ranged from 97% to 83% of influent COD while VSS reductions ranged from 99% to 90%. Transient-state gas quality in terms of methane content was very stable. Methane content in the biogas increased as retention times decreased and ranged from 75% to 84% methane. Results indicate that a high potential reduction of required digester volume is possible through application of the fixed-film concept. © 1987.