Process kinetics of an activated-sludge reactor system treating poultry slaughterhouse wastewater

Abstract

The principal objective was to generate the essential kinetic parameters for model simulation and operation management of an activated-sludge reactor (ASR) system treating poultry slaughterhouse wastewater. By varying four different mean cell residence times (θc=4.6–24.3 d), the ASR system (26°C) removed effectively 93.5%–97.2% of chemical oxygen demand (COD) from wastewater. If a high COD removal efficiency and a low effluent volatile suspended solids (VSS) concentration are of great concern, a θc of 15–24 d or a food to microorganism (F/M) ratio of 0.3–0.7 kg COD/kg VSS-d is suggested; if resource sustainability and enhanced operation of the ASR system are of great concern, a θc of 9 d or an F/M ratio of 0.9 kg COD/kg VSS-d is suggested. The COD residual concentrations and COD removal efficiencies calculated by using the Monod model agreed well with the experimental results. When the parameters k and K s (Δ P/P) were respectively varied from−100% to+100%, the parametric sensitivity analysis showed that the COD residual concentration change (Δ S/S) was highly sensitive to k in the Δ P/P range between 0% and−40%, causing a marked increase in COD residual concentration.