title: Electrochemical treatment of reverse osmosis concentrate on boron-doped electrodes in undivided and divided cell configurations.
abstract: An undivided electrolytic cell may offer lower electrochlorination through reduction of chlorine/hypochlorite at the cathode. This study investigated the performance of electrooxidation of reverse osmosis concentrate using boron-doped diamond electrodes in membrane-divided and undivided cells. In both cell configurations, similar extents of chemical oxygen demand and dissolved organic carbon removal were obtained. Continuous formation of chlorinated organic compounds was observed regardless of the membrane presence. However, halogenation of the organic matter did not result in a corresponding increase in toxicity (Vibrio fischeri bioassay performed on extracted samples), with toxicity decreasing slightly until 10AhL(-1), and generally remaining near the initial baseline-toxicity equivalent concentration (TEQ) of the raw concentrate (i.e., ∼2mgL(-1)). The exception was a high range toxicity measure in the undivided cell (i.e., TEQ=11mgL(-1) at 2.4AhL(-1)), which rapidly decreased to 4mgL(-1). The discrepancy between the halogenated organic matter and toxicity patterns may be a consequence of volatile and/or polar halogenated by-products formed in oxidation by OH electrogenerated at the anode. The undivided cell exhibited lower energy compared to the divided cell, 0.25kWhgCOD(-1) and 0.34kWhgCOD(-1), respectively, yet it did not demonstrate any improvement regarding by-products formation.
authors.affiliation: Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia; Department of Environmental Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia.
authors.forename: Arseto Y
authors.initials: AY
authors.lastname: Bagastyo
authors.affiliation: Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia.
authors.forename: Damien J
authors.initials: DJ
authors.lastname: Batstone
authors.affiliation: Curtin Water Quality Research Centre, Resources and Chemistry Precinct, Department of Chemistry, Curtin University, Bentley, Perth, WA 6102, Australia.
authors.forename: Ina
authors.initials: I
authors.lastname: Kristiana
authors.affiliation: National Research Centre for Environmental Toxicology (Entox), The University of Queensland, Brisbane, QLD 4108, Australia.
authors.forename: Beate I
authors.initials: BI
authors.lastname: Escher
authors.affiliation: Curtin Water Quality Research Centre, Resources and Chemistry Precinct, Department of Chemistry, Curtin University, Bentley, Perth, WA 6102, Australia.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Joll
authors.affiliation: Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia. Electronic address: j.radjenovic@uq.edu.au.
authors.forename: Jelena
authors.initials: J
authors.lastname: Radjenovic
mesh_terms: D048908:Aliivibrio fischeri / Q000187:drug effects; D001681:Biological Assay; D057919:Biological Oxygen Demand Analysis; D001895:Boron / Q000737:chemistry* / Q000633:toxicity; D002244:Carbon / Q000302:isolation & purification; D002713:Chlorine / Q000737:chemistry; D055664:Electrochemical Techniques; D004566:Electrodes; D006997:Hypochlorous Acid / Q000737:chemistry; D009995:Osmosis
chemical_list: D002713:Chlorine; D006997:Hypochlorous Acid; D002244:Carbon; D001895:Boron
keywords: Boron-doped diamond; Electrochemical oxidation; Electrolytic cell configuration; Reverse osmosis brine; Vibrio fischeri bioassay