title: The behaviors of Microcystis aeruginosa cells and extracellular microcystins during chitosan flocculation and flocs storage processes.
abstract: This work aimed to study the effects of chitosan on cell integrity and extracellular microcystins (MCs) of Microcystis aeruginosa cells during flocculation and flocs storage processes. The impacts of chitosan addition, flocculation stirring and flocs storage time were comprehensively detected to prevent or reduce cell lysis and MCs release. Response surface method (RSM) was applied to optimize the chitosan flocculation. Under chitosan concentration 7.31 mg/L and optimized mechanical conditions, 99% of M. aeruginosa cells were integrated removed. Furthermore, amounts of extracellular MCs were adsorbed by chitosan polymers in this process. With chitosan flocs protect, though cells showed some damage, extracellular MCs concentration in flocculated samples lower than background level within first 2 d. However, lots of MCs release was observed after 4d which may result from chitosan degradation and cells lysis. Therefore, chitosan flocs should be treated within 2d to prevent the adsorbed MCs releasing again.
authors.affiliation: School of Environmental Science and Engineering, Shandong University, Jinan 250100, China; Shandong Provincial Engineering Center on Environmental Science and Technology, Jinan, China. Electronic address: haiyanhup@126.com.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Pei
authors.forename: Chun-Xia
authors.initials: CX
authors.lastname: Ma
authors.forename: Wen-Rong
authors.initials: WR
authors.lastname: Hu
authors.forename: Feng
authors.initials: F
authors.lastname: Sun
mesh_terms: D000327:Adsorption; D000704:Analysis of Variance; D048271:Chitosan / Q000494:pharmacology*; D005110:Extracellular Space / Q000737:chemistry*; D005427:Flocculation / Q000187:drug effects; D052998:Microcystins / Q000378:metabolism*; D046931:Microcystis / Q000166:cytology* / Q000187:drug effects; D015203:Reproducibility of Results; D013499:Surface Properties; D013997:Time Factors
chemical_list: D052998:Microcystins; C078588:microcystin; D048271:Chitosan
keywords: Cell damage; Chitosan flocculation; Flocs storage; Mechanical action; Microcystins release