title: Effective removal of Microcystis aeruginosa and microcystin-LR using nanosilicate platelets.
abstract: Drinking water safety has been threatened by increasing harmful algal blooms (HABs) in water sources. HABs are closely associated with eutrophication in freshwater lakes, e.g. Lake Tai in China, and marine environments as well, e.g. Baltic Sea in Europe. Among all HABs, Microcystis aeruginosa attracted much attention due to its easy proliferation and potent toxins, microcystins. Most of the current control technologies can result in immediate release of microcystins which are hard to remove by drinking water treatment processes. Here we propose to simultaneously remove M. aeruginosa and its toxin, microcystin-LR (MC-LR), using nanosilicate platelet (NSP) derived from natural clay mineral. In this study, NSP showed strong selective growth inhibition and good settling enhancing effects on M. aeruginosa and highly efficient removal of MC-LR. NSP can inhibit the growth of M. aeruginosa (initial cell concentration at 3.00×10(6)cellmL(-1)) with a LC50 at 0.28ppm after 12h exposure. At the dosage of 100ppm, NSP can enhance settling of suspended M. aeruginosa. Bacterial growth inhibition tests showed NSP had very mild growth inhibition effects on Escherichia coli at high dosage but promoted the growth of Pseudomonas aeruginosa and Bacillus halodurans. For MC-LR removal, at an initial concentration of 100μgL(-1), NSP achieved higher than 99% removal. Thus, the results suggest that NSP could be an excellent candidate for controlling M. aeruginosa-related HABs in water bodies.
authors.affiliation: Department of Environmental Engineering, National Chung Hsing University, No. 250, Kuo-Kuang Road, Taichung 40227, Taiwan. Electronic address: shuchichang@nchu.edu.tw.
authors.forename: Shu-Chi
authors.initials: SC
authors.lastname: Chang
authors.affiliation: Department of Environmental Engineering, National Chung Hsing University, No. 250, Kuo-Kuang Road, Taichung 40227, Taiwan.
authors.forename: Cheng-Hao
authors.initials: CH
authors.lastname: Li
authors.affiliation: Institute of Polymer Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
authors.forename: Jiang-Jen
authors.initials: JJ
authors.lastname: Lin
authors.affiliation: Department of Chemistry, National Chung Hsing University, No. 250, Kuo-Kuang Road, Taichung 40227, Taiwan.
authors.forename: Yen-Hsien
authors.initials: YH
authors.lastname: Li
authors.affiliation: Department of Chemistry, National Chung Hsing University, No. 250, Kuo-Kuang Road, Taichung 40227, Taiwan.
authors.forename: Maw-Rong
authors.initials: MR
authors.lastname: Lee
mesh_terms: D002681:China; D004203:Disinfection / Q000379:methods; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005068:Eutrophication; D057097:Harmful Algal Bloom; D060106:Lakes / Q000737:chemistry; D008387:Marine Toxins; D052998:Microcystins / Q000737:chemistry*; D046931:Microcystis / Q000187:drug effects / Q000254:growth & development*; D049329:Nanostructures / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods
chemical_list: D008387:Marine Toxins; D052998:Microcystins; D017640:Silicates; C057862:cyanoginosin LR
keywords: Eutrophication; Harmful algal bloom; Microcystin-LR; Microcystis aeruginosa; Nanosilicate platelet