Effect of temperature on composition of extracellular polymeric substances from activated sludge

Effects of temperature on the composition of Extracellular Polymeric Substances (EPS) from 3 types of activated sludge (from treatment of municipal wastewater and anaerobic, aerobic treatment of Cola wastewater) were investigated. The results showed, for all of the three types of EPS, the compositions were most stable at -20°C, most changeable at room temperature. The situation at 4°C was the medium of that at -20°C and room temperature. EPS from municipal wastewater sludge and aerobic treatment of Cola wastewater were seemed proper to be stored at -20°C. In this way, the changeable rates of these two types of EPS were 9%, 20% for protein concentration respectively and both of 20% for sugar concentration. Changeable rates of EPS from anaerobic treatment of Cola wastewater were high at all of the three temperatures (at room temperature; protein, 85%; sugar, 80%. at 4°C; protein, 80%; sugar, 70%. at -20°C; protein, 30%; sugar, 60%), suggesting this type of EPS is not proper to be stored.