{
  "url": "https://openlegislation.uk/eu-decision-2013-732/annex/division-4/division-3",
  "json_url": "https://openlegislation.uk/eu-decision-2013-732/annex/division-4/division-3.json",
  "legislation": "eudn/2013/732",
  "legislation_title": "Commission Implementing Decision of 9 December 2013 establishing the best available techniques (BAT) conclusions, under Directive 2010/75/EU of the European Parliament and of the Council on industrial emissions, for the production of chlor-alkali (notified under document C(2013) 8589) (Text with EEA relevance) (2013/732/EU)",
  "legislation_url": "https://openlegislation.uk/eu-decision-2013-732",
  "path": "annex/division/4/division/3",
  "kind": "division",
  "number": "3",
  "heading": "Generation of waste water",
  "text": "BAT 4: In order to reduce the generation of waste water, BAT is to use a combination of the techniques given below.\nTechnique\nDescription\nApplicability\na\nBrine recirculation\nThe depleted brine from the electrolysis cells is resaturated with solid salt or by evaporation and fed back to the cells.\nNot applicable to diaphragm cell plants. Not applicable to membrane cell plants using solution-mined brine when abundant salt and water resources and a saline receiving water body, which tolerates high chloride emission levels, are available. Not applicable to membrane cell plants using the brine purge in other production units.\nb\nRecycling of other process streams\nProcess streams from the chlor-alkali plant such as condensates from chlorine, sodium/potassium hydroxide and hydrogen processing are fed back to various steps of the process. The degree of recycling is limited by the purity requirements of the liquid stream to which the process stream is recycled and the water balance of the plant.\nGenerally applicable.\nc\nRecycling of salt-containing waste water from other production processes\nSalt-containing waste water from other production processes is treated and fed back into the brine system. The degree of recycling is limited by the purity requirements of the brine system and the water balance of the plant.\nNot applicable to plants where an additional treatment of this waste water offsets the environmental benefits.\nd\nUse of waste water for solution mining\nWaste water from the chlor-alkali plant is treated and pumped back to the salt mine.\nNot applicable to membrane cell plants using the brine purge in other production units. Not applicable if the mine is located at a significantly higher altitude than the plant.\ne\nConcentration of brine filtration sludges\nBrine filtration sludges are concentrated in filter presses, rotary drum vacuum filters or centrifuges. The residual water is fed back into the brine system.\nNot applicable if the brine filtration sludges can be removed as dry cake. Not applicable to plants that reuse waste water for solution mining.\nf\nNanofiltration\nA specific type of membrane filtration with membrane pore sizes of approximately 1 nm, used to concentrate sulphate in the brine purge, thereby reducing the waste water volume.\nApplicable to membrane cell plants with brine recirculation, if the brine purge rate is determined by the sulphate concentration.\ng\nTechniques to reduce chlorate emissions\nTechniques to reduce chlorate emissions are described in BAT 14. These techniques reduce the brine purge volume.\nApplicable to membrane cell plants with brine recirculation, if the brine purge rate is determined by the chlorate concentration.",
  "extent": "E+W+S+N.I.",
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/eudn/2013/732/annex/division/4/division/3",
    "retrieved_at": "2026-11-01T15:14:56.261571+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}