Submerged membrane bioreactor using fly ash filters: trials with distillery wastewater

This work presents preliminary results for distillery wastewater treatment in a MBR equipped with filters prepared from waste fly ash. The system was fabricated locally and employed submerged membranes in the 2–8 μm pore-size range. Distillery wastewater, after anaerobic digestion, was used as the feed and the bioreactor was inoculated with sludge obtained from a local distillery unit. The MBR was operated for around 250 days. The wastewater quality was monitored in terms of COD (chemical oxygen demand), colour, phenol, and MLSS (mixed liquor suspended solids) concentration. An average COD and phenol removal of 36% and 60% respectively was obtained. The maximum suspended solids retention by the ash filter was as high as 98%. The results were encouraging and further trials are currently underway to improve the performance.