title: Effects of Cd(II) on wastewater biological nitrogen and phosphorus removal.
abstract: Short-term and long-term effects of Cd(II) on wastewater biological nitrogen and phosphorus removal were investigated with respect to microorganism abundances, enzyme activities, and polyhydroxyalkanoates (PHAs) and glycogen transformations. Though no obvious effects on wastewater biological nutrient removal were observed after short-term exposure, the long-term exposure of 10 mg L(-)(1) Cd(II) inhibited nitrification and phosphorus uptake. Compared with the absence of Cd(II), the presence of 10 mg L(-1) of Cd(II) decreased total nitrogen and phosphorus removal efficiencies from 97% and 98% to 88% and 18%, respectively. Mechanism studies revealed that Cd(II) affected the transformations of intracellular PHAs and glycogen, and the activities of oxidoreductase and polyphosphate kinase, resulted in the decrease of nitrite oxidizing bacteria and polyphosphate accumulating organisms abundance, which might be the major reason for the negative effects of long-term exposure to 10 mg L(-1) Cd(II) on biological nitrogen and phosphorus removal.
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China.
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Chen
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China. Electronic address: w.dongbo@yahoo.com.
authors.forename: Dong-Bo
authors.initials: DB
authors.lastname: Wang
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China. Electronic address: xmli@hnu.edu.cn.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Li
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Yang
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Luo
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China.
authors.forename: Guang-Ming
authors.initials: GM
authors.lastname: Zeng
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China.
authors.forename: Mao-Lin
authors.initials: ML
authors.lastname: Tang
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001419:Bacteria / Q000187:drug effects* / Q000201:enzymology; D019187:Cadmium Compounds / Q000032:analysis / Q000633:toxicity*; D058465:Nitrification; D009584:Nitrogen / Q000302:isolation & purification*; D010758:Phosphorus / Q000302:isolation & purification*; D012722:Sewage / Q000382:microbiology; D062065:Wastewater / Q000737:chemistry / Q000382:microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D018508:Water Purification / Q000379:methods*
chemical_list: D019187:Cadmium Compounds; D009584:Nitrogen; D010758:Phosphorus; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Biological nutrient removal; Cd(II); Denitrification; Enzymes; Polyhydroxyalkanoates