title: Variation of algal viability during electrochemical disinfection using Ti/RuO2 electrodes.
abstract: This paper studied the influence of the operating conditions, e.g., current density, electrolyte and exposure time, on the variation of the algal viability during electrochemical disinfection processes. An electrochemical tube employing Ti/RuO2 as anodes was constructed for inactivation of cyanobacteria (often called blue-green algae) Microcystis aeruginosa. Viability of algal cells was determined by 2,3,5-triphenyl-tetrazoliumchloride (TTC) dehydrogenase activity assay and neutral red (NR) staining assay. Algal suspensions with cell density of 5-7 x 10(9) L(-1) were exposed to current densities from 1 to 8 mA cm(-2) at room temperature (25-30 degrees C) for 30 min. The results showed that the cell viability decreased obviously with the increase of current density. After exposure to 4 mA cm(-2) for more than 7 min, Microcystis aeruginosa didn't have the ability to resume growth. Comparative disinfection tests with different electrolytes were conducted, including chlorides, sulfates, nitrates and phosphates. Microcystis aeruginosa appeared to be sensitive to electro-generated chlorine oxidants. The inactivation effect was also demonstrated to occur in chlorine-free electrolytes. However, decrease of the inactivation effect by adding ascorbic acid as an oxidant scavenger indicated that the reactive oxygen species, especially *OH radicals, played an important role for chlorine-free electrolytes.
authors: College of Environmental Science and Engineering, Beijing Forestry University, No. 35, Qinghua East Road, Haidian District, Beijing 100083, PR China. lwybjfu@126.com
authors: Wenyan
authors: W
authors: Liang
authors: Ke
authors: K
authors: Wang
authors: Li
authors: L
authors: Chen
authors: Lingling
authors: L
authors: Ruan
authors: Lili
authors: L
authors: Sui
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry; D017606:Chlorine Compounds / Q000494:pharmacology; D004203:Disinfection / Q000379:methods*; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D046931:Microcystis / Q000187:drug effects* / Q000502:physiology; D009499:Neutral Red / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000737:chemistry; D017975:Ruthenium Compounds / Q000737:chemistry*; D013778:Tetrazolium Salts / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*
chemical_list: D017606:Chlorine Compounds; D017382:Reactive Oxygen Species; D017975:Ruthenium Compounds; D013778:Tetrazolium Salts; C029017:ruthenium dioxide; D009499:Neutral Red; C009591:triphenyltetrazolium; D014025:Titanium; D001205:Ascorbic Acid