Effects of metabolic uncouplers on excess sludge reduction and microbial products of activated sludge.
The present study investigated the influences of three metabolic uncouplers (pCP, oCP and oNP) on excess activated sludge reduction and microbial products of extracellular polymeric substances (EPS) and intracellular storage product (polyhydroxybutyrate, PHB) in short-term tests. Results showed sludge was reduced 58.2%, 59.8% and 80.8%, respectively, at pCP, oCP and oNP concentrations of 20mg/L. The dosage of three uncouplers had no obviously influences on COD removal and sludge settleability, but had significant inhibition effect on ammonia removal, especially for oNP. Low concentration of pCP and oNP (5mg/L) dosing resulted in protein and polysaccharide content increased in EPS, however, they were decreased at high pCP and oNP concentrations (>5mg/L). To oCP, the protein content in EPS was increased linearly with oCP concentration. Furthermore, metabolic uncouplers addition stimulated the production of PHB. Among three uncouplers, oCP could be an alternative uncoupler for sludge reduction in activated sludge process.
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China. Electronic address: ffang65@hhu.edu.cn.
Fang
F
Fang
College of Environment, Hohai University, Nanjing 210098, China.
Hai-Lan
HL
Hu
College of Environment, Hohai University, Nanjing 210098, China.
Min-Min
MM
Qin
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
Zhao-Xia
ZX
Xue
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China. Electronic address: caojiashun@163.com.
Jia-Shun
JS
Cao
EnviroSim Associates Ltd, McMaster Innovation Park, 175 Longwood Road South, Suite 114A, Hamilton, Ontario L8P 0A1, Canada.
Zhi-Rong
ZR
Hu
D001421:Bacteria, Anaerobic / Q000187:drug effects / Q000378:metabolism*; D001704:Biopolymers / Q000096:biosynthesis*; D006885:Hydroxybutyrates / Q000378:metabolism*; D011091:Polyesters / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*; D014475:Uncoupling Agents / Q000494:pharmacology*; D000094122:Polyhydroxybutyrates
D001704:Biopolymers; D006885:Hydroxybutyrates; D011091:Polyesters; D012722:Sewage; D014475:Uncoupling Agents; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates
Activated sludge; Extracellular polymeric substances (EPS); Metabolic uncouplers; Polyhydroxybutyrate (PHB); Sludge reduction