title: Rapid removal of bacterial endotoxin and natural organic matter in water by dielectric barrier discharge plasma: Efficiency and toxicity assessment.
abstract: Low-temperature plasma was used to control bacteria, endotoxins and natural organic matter (NOM) in water by a dielectric barrier discharge (DBD) device. Results indicate that DBD plasma has an obvious inactivation effect on various bacteria in water. The degree of inactivation from difficult to easy is as follows: Bacillus subtilis>Escherichia coli>Staphylococcus aureus. Activated ultrapure water treated using DBD plasma exhibited a sustained sterilization effect, but this sterilization effect decreased gradually after 1h. The total-endotoxin (free-endotoxin and bound-endotoxin) released by Escherichia coli during inactivation, as well as artificially simulated endotoxin in a control solution, was significantly controlled by DBD plasma. Both the metabolites that appeared after inactivation of microorganisms by plasma treatment, and the NOM in filtration effluent of a water treatment plant were well removed by DBD plasma if the treatment duration was sufficiently long. However, the acute toxicity increased significantly, and persisted for at least 2h, indicating that some long-life active substances were generated during the DBD process. Therefore, the removal of bacteria, endotoxins or NOM does not mean a safe water is produced. It is also important to eliminate the toxicity and byproducts produced during water treatment for the continuous promotion and industrial application of DBD plasma.
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China. Electronic address: zhangcancqu@163.com.
authors.forename: Can
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of National Defense Architecture Planning & Environmental Engineering, Logistic Engineering University, Chongqing 401311, China. Electronic address: fzdhg@tom.com.
authors.forename: Zhendong
authors.initials: Z
authors.lastname: Fang
authors.affiliation: School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Liu
authors.affiliation: School of Environmental Engineering, Nanjing Institute of Technology, Nanjing 211167, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Tian
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Miao
authors.initials: M
authors.lastname: Bai
mesh_terms: D001419:Bacteria / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D058491:Bacterial Load; D055664:Electrochemical Techniques; D004731:Endotoxins / Q000302:isolation & purification* / Q000633:toxicity; D005374:Filtration; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D013050:Spectrometry, Fluorescence; D014865:Waste Disposal, Fluid; D014867:Water / Q000737:chemistry*; D014877:Water Pollution, Chemical; D018508:Water Purification / Q000379:methods*
chemical_list: D004731:Endotoxins; D007202:Indicators and Reagents; D014867:Water
keywords: Acute toxin; Bacterial endotoxin; Dielectric barrier discharge (DBD) plasma; Natural organic matter (NOM); Water