Treatment of slaughterhouse wastewater using an activated sludge/contact aeration process

Abstract

This study combines a two-phase biological treatment system of activated sludge/contact aeration process by adding biological contact filters into the rear sector of the activated sludge aeration tank of the slaughterhouse wastewater treatment plant. This system keeps the advantages of complete mixing of substrates and microorganisms and flexible operation of the activated sludge process, and increased biological phase, less sludge, process stability and good settleability of sludge of the contact aeration process. This system could avoid the defects of sludge bulking, increased sludge production and difficult operation of the activated sludge process, and system clogging and rigid operation of the contact aeration process. Because suspended microorganisms are flowing into the contact aeration system, which then degrade or suspend within the biological contact filters after being adsorbed by the fixed biological film, on which partial bio-solids will act as seeding microorganisms. Suspended microorganisms and the dropped biological film will settled in the secondary settling tank, then reflux into the activated sludge aeration tank. The partial dropped biological film will decompose in the activated sludge aeration tank to achieve the function of decreasing sludge. Large specific gravity and good settling ability of biofilm sludge will provide better effluent quality. It has been proven through a practical experiment at a slaughterhouse wastewater treatment plant in Taiwan, that the activated sludge process effluent COD value of 150-200 mg/L and SS value of 80-100 mg/L were decreased to around 40 mg/L and 22 mg/L, respectively, after changing its system to the two-phase biological treatment system of activated sludge/contact aeration process.

Indirect Electrochemical Oxidation with Multi Carbon Electrodes for Restaurant Wastewater Treatment

“…2000]; physical methods through ultrafiltration and nanofiltration membranes [Zulaikha et al 2014]; as well as the biological method with a combined activated sludge-contact aeration system [Chen and Lo. 2006].…”

Net biomass production under complete solids retention in high organic load activated sludge process

“…Activated sludge (AS) processes have been applied worldwide in municipal and industrial wastewater treatment practices including applications for slaughterhouse wastewater (Chen and Lo, 2003;Devikarani and Thiruvenkatachari, 2005). Slaughterhouses produce high strength wastewater (European Commission, 2005), which contains high concentration of biodegradable organic matter, as fecal, undigested food, blood, suspended material.…”

“…Slaughterhouse wastewaters are characterized by high biochemical oxygen demand (BOD) to chemical oxygen demand (COD) ratio, which suggests an easily biodegradable wastewater (Chen and Lo, 2003). The concentration of contaminants in slaughterhouses wastewater vary, with COD, total Kjeldahl nitrogen (TKN) and total suspended solids (TSS) concentration ranging from 1 to 20 g L À1 , 0.15 to 10 g L À1 and 0.25 to 5 g L À1 respectively (Li et al, 2008).…”

Enhanced Biodegradability of Aerobic Sludge by Bioaugmentation for Pulping Effluent Treatment

“…The activated sludge process was developed in the early 1900s for the treatment of domestic wastewater, and it has since been adapted for removing biodegradable organic matter from industrial wastewater (Dufresne et al 1998;Sarlin et al 1999;Frolund et al 1995;Chen and Lo 2006). Currently, it is widely employed in the treatment of both municipal and industrial wastewaters.…”