[Effect of polymeric aluminum-iron on EPS and bio-flocculation in A2/O system].
Polymeric aluminum-iron (PAFC) was added at the end of aeration tank to enhance phosphorus removal, so that the phosphorus concentration in the effluent could meet the calss A standard in municipal sewage treatment plant pollutant discharge standard (GB 18918-2002). The characteristics of extracellular polymer substances (EPS) and bio-flocculation for the activated sludge in the A2/O system were analyzed in the experiment. The results showed that, the gross of EPS varied little with the increase in PAFC dosage, while, the ratio of albumen to polysaccharide declined from 3.30 to 2.30. When the PAFC dosage increased, the concentration of Al3+ in EPS increased during the whole anaerobic-anoxic-aerobic cycle. The flocs of activated sludge became larger after PAFC addition, Zeta potential of the effluent dropped significantly from - 15.83 mV to -21.20 mV and sludge yield increased. Therefore, bio-flocculation of the activated sludge in the A2/O system improved when a proper amount of PAFC was added, subsequently improve the water quality of the effluent.
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China. wqxshelly@263.net
Qin-Xue
QX
Wen
Ai-Cui
AC
Liu
Zhi-Qiang
ZQ
Chen
Han-Chang
HC
Shi
Bing-Nan
BN
Lü
D000332:Aerobiosis; D000535:Aluminum / Q000737:chemistry*; D019149:Bioreactors; D005110:Extracellular Space / Q000378:metabolism; D005427:Flocculation; D007501:Iron / Q000737:chemistry; D010758:Phosphorus / Q000302:isolation & purification*; D011108:Polymers / Q000737:chemistry; D012722:Sewage / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*
D000535:Aluminum; D007501:Iron; D010758:Phosphorus; D011108:Polymers; D012722:Sewage; D062065:Wastewater