Flax Retting Wastewater Part 1: Anaerobic Treatment by Using UASB Reactor

Abstract

The performance of UASB (Up-flow Anaerobic Sludge Blanket) reactor was investigated in the present study for treatment of flax retting wastewater. Batch and continuous experiments on a pilot scale were designed. The initial seed for granules (bacteria acclimation) formed earlier was from municipal sewage treatment plant with VSS of 18 - 20 g/L. Batch experiments proved that the sludge retention time (SRT) was 77 days. Under steady state conditions, continuous experiments were conducted at organic loading rates (OLRs) in the range of 1.2 to8.6 kgCODs m–3·d–1, where the hy- draulic retention time (HRT) decreased from 72 to 12 hrs. The results proved that the UASB technology provides good COD removal efficiency from 64.5% to 90.5% as COD loading rate decreased and good biogas production at proper food: micro-organism (F:M) ratios.