Effects of pre-fermentation and influent temperature on the removal efficiency of COD, NH4+-N and PO43--P in slaughterhouse wastewater by using SBR

Abstract

A sequencing batch reactor (SBR) was used to remove COD, NH4+-N and PO43--P in slaughterhouse wastewater at different temperatures. A complete operation cycle was 7h, which consisted of fill, aeration(5h), settling(1h), stationary(1h) and drawing. Conventional treatment technologies were unsuccessful in treating slaughterhouse wastewater because it contained substantial amounts of fat, oil and grease (FOG). The SBR process showed great nutrient removal performances after 7 days prefermentation. The removals of COD, NH4+-N and PO43--P were 99%, 85% and 99%, respectively. The increase in effluent volatile fatty acid (VFA) and phosphate concentrations after prefermentation may explain the high levels of biological carbon, nitrogen and phosphorus removal observed. The results also showed that 30°C was found to be the most suitable temperature as the removal efficiency of COD, NH4+-N and PO43--P was 96%, 92% and 91%, respectively. © 2011 Published by Elsevier B.V.