Ballast water treatment and bacteria: Analysis of bacterial activity and diversity after treatment of simulated ballast water by electrochlorination and UV exposure
| Autor: | Niels O. G. Jørgensen, Nanna Bender Petersen, Torben Madsen, Mikkel A. Glaring, Fred C. Dobbs |
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| Rok vydání: | 2018 |
| Předmět: |
Environmental Engineering
010504 meteorology & atmospheric sciences Halogenation Ultraviolet Rays Microorganism 010501 environmental sciences Bacterial growth Wastewater medicine.disease_cause 01 natural sciences Waste Disposal Fluid medicine Environmental Chemistry Organic matter Food science Waste Management and Disposal 0105 earth and related environmental sciences chemistry.chemical_classification Photolysis biology Bacteria Chemistry Pathogenic bacteria Bacterioplankton Electrochemical Techniques biology.organism_classification Pollution Vibrio Electrochlorination |
| Zdroj: | The Science of the total environment. 648 |
| ISSN: | 1879-1026 |
| Popis: | Effects of ballast water (BW) treatment by ultra-violet (UV) light and electrochlorination (EC) on survival, activity and diversity of marine bacterioplankton and release of organic matter from cell damage were examined at discharge in a large-scale BW test facility (250 m3 tanks) at Hundested harbour, Denmark. The tests were performed in accordance with the requirements for type approval testing by International Maritime Organization (IMO) and US Coast Guard. After treatment, the water was held in the tanks for one day (EC) before discharge, or 6 days (UV, including also a final UV re-treatment) before discharge. In the discharged and treated water, numbers of viable bacteria and bacterial growth rate had decreased significantly relative to the untreated water, but the total number of bacteria only was reduced in the EC-treated water. After additional storage for up to 10 days in small-scale laboratory incubations, significant regrowth of bacteria was observed after either treatment. Sequencing of 16S rRNA gene amplicons demonstrated that α-Proteobacteria initially were dominant, but γ-Proteobacteria dominated after regrowth. Bacteria used to document BW treatment efficiency (E. coli, Vibrio spp., enterococci) survived both treatments; neither treatment reduced the risk of pathogen dispersal. Concentrations of amino acids in the water were used as indicators of treatment-induced cell damage and demonstrated higher concentrations at discharge, but only after the EC treatments. Our results indicate that activity of bacteria, rather than their abundances, should be used when examining effects by ballast water treatment on microorganisms and that none of the examined treatment technologies could eliminate pathogenic bacteria. |
| Databáze: | OpenAIRE |
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