Influence of Operation Parameters on Concentration and Composition of Microbial Products in Wastewater Treatment

Abstract

Extracellular polymeric substances of microorganisms are responsible for fouling of membrane surface. The fou­ling affects the hydraulic efficiency and economics of membrane processes. The concentrations and composition of these products depend on sludge parameters, especially on sludge retention times. Concentrations of the microbial products, mostly decrease with increasing the sludge retention time and with decreasing the activated sludge loading. A significant decrease in the concentrations of extracellular polymeric substances was observed at the highest activated sludge concentration (12 g L^–1). No important chan­ges in the extracellular polymeric substances composition or in their retention on membrane surface were observed on changing the sludge retention time. Saccharides and proteins were the most retained compounds.