Predatory bacteria in combination with solar disinfection and solar photocatalysis for the treatment of rainwater

WATER RESEARCH

卷:169

Article

Waso, M.¹  Khan, S.²  Singh, A.³  McMichael, S.³  Ahmed, W.⁴  Fernandez-Ibanez, P.³  Byrne, J. A.³  Khan, W.¹ 

[1] Stellenbosch Univ, Fac Sci, Dept Microbiol, Private Bag Xl, ZA-7602 Stellenbosch, South Africa

[2] Univ Johannesburg, Fac Hlth Sci, POB 17011, ZA-2028 Doornfontein, South Africa

[3] Ulster Univ, Nanotechnol & Integrated BioEngn Ctr, Jordanstown Campus,Shore Rd, Belfast BT37 0QB, Antrim, North Ireland

[4] CSIRO Land & Water, Ecosci Precinct, 41 Boggo Rd, Brisbane, Qld 4102, Australia

关键词: Harvested rainwater;    Bdellovibrio bacteriovorus;    Biological pre-treatment;    Solar disinfection;    Photocatalysis;   

DOI  :  10.1016/j.watres.2019.115281

来源: Elsevier

【 摘 要 】

The predatory bacterium, Bdellovibrio bacteriovorus, was applied as a biological pre-treatment to solar disinfection and solar photocatalytic disinfection for rainwater treatment. The photocatalyst used was immobilised titanium-dioxide reduced graphene oxide. The pre-treatment followed by solar photocatalysis for 120 min under natural sunlight reduced the viable counts of Klebsiella pneumoniae from 2.00 x 10(9) colony forming units (CFU)/mL to below the detection limit (BDL) (<1 CFU/100 mu L). Correspondingly, ethidium monoazide bromide quantitative PCR analysis indicated a high total log reduction in K. pneumoniae gene copies (GC)/mL (5.85 logs after solar photocatalysis for 240 min). In contrast, solar disinfection and solar photocatalysis without the biological pre-treatment were more effective for Enterococcus faecium disinfection as the viable counts of E. faecium were reduced by 8.00 logs (from 1.00 x 10(8) CFU/mL to BDL) and the gene copies were reduced by similar to 3.39 logs (from 2.09 x 10(6) GC/mL to similar to 9.00 x 10(2) GC/mL) after 240 min of treatment. Predatory bacteria can be applied as a pre-treatment to solar disinfection and solar photocatalytic treatment to enhance the removal efficiency of Gram-negative bacteria, which is crucial for the development of a targeted water treatment approach. (C) 2019 Elsevier Ltd. All rights reserved.

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