title: Inhibitory effect of cyanide on nitrification process and its eliminating method in a suspended activated sludge process.
abstract: Inhibition of nitrification by four typical pollutants (acrylonitrile, acrylic acid, acetonitrile and cyanide) in acrylonitrile wastewater was investigated. The inhibitory effect of cyanide on nitrification was strongest, with a 50% inhibitory concentration of 0.218 mg·gVSS-1 being observed in a municipal activated sludge system. However, the performance of nitrification was recovered when cyanide was completely degraded. The nitrification, which had been inhibited by 4.17 mg·gVSS-1 of free cyanide for 24 h, was recovered to greater than 95% of that without cyanide after 10 days of recovery. To overcome cyanide inhibition, cyanide-degrading bacteria were cultivated in a batch reactor by increasing the influent cyanide concentration in a stepwise manner, which resulted in an increase in the average cyanide degradation rate from 0.14 to 1.01 mg CN-·gVSS-1·h-1 over 20 days. The cultured cyanide-degrading bacteria were shaped like short rods, and the dominant cyanide-degrading bacteria strain was identified as Pseudomonas fluorescens NCIMB by PCR.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Han
authors.forename: Xibiao
authors.initials: X
authors.lastname: Jin
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang
authors.forename: Yongdi
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiurong
authors.initials: X
authors.lastname: Chen
mesh_terms: D000097:Acetonitriles / Q000633:toxicity; D000179:Acrylates / Q000633:toxicity; D000181:Acrylonitrile / Q000633:toxicity; D001419:Bacteria / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D003486:Cyanides / Q000633:toxicity*; D004269:DNA, Bacterial / Q000235:genetics; D008969:Molecular Sequence Data; D058465:Nitrification / Q000187:drug effects*; D012335:RNA, Ribosomal / Q000235:genetics; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000097:Acetonitriles; D000179:Acrylates; D003486:Cyanides; D004269:DNA, Bacterial; D012335:RNA, Ribosomal; D012722:Sewage; D014874:Water Pollutants, Chemical; C036658:acrylic acid; D000181:Acrylonitrile; C032159:acetonitrile