Effects of Anaerobic Granular Sludge Characteristics on Initial Adsorption of Organic Pollutants

Abstract

The adsorption capacity of anaerobic granular sludge is affected in varying degrees by its characteristics, thus the efficiency of anaerobic treatment of organic pollutants in wastewater is restricted by these characteristics too. This paper studied with a static batch method at the laboratory scale the effect of characteristics of anaerobic granular sludge on initial adsorption of organic pollutants in wastewater. The results showed that the initial organic pollutant adsorption efficiency of anaerobic granular sludge was significantly related with its specific surface area and extracellular polymers. When specific surface area increased to 178.9 m2g-1from 108.2 m2g-1, the adsorption efficiency was increased by 6.1% from 70.2% to 76.3%;the increase of extracellular polymer content raised the adsorption rate by about 6.0%; the increase of hydrophobic and Zeta potential of anaerobic granular sludge could also greatly improve the adsorption efficiency of organic pollutants by 15.6%and 10.2% respectively. The initial organic pollutant adsorption performance presented a parabolic curve with increase of the sludge particle size, settling velocity and sludge volume index of anaerobic granular sludge. The above results indicated significant effect of the characteristics of anaerobic granular sludge itself on its adsorption removal efficiency of organic pollutants in waste water. Therefore, cultivating anaerobic granular sludge with excellent adsorption performance is a key to improving anaerobic biological treatment efficiency of organic wastewater.