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US 12,479,748 B2Granted
Methods and systems for treating phosphogypsum-containing water
AssigneeEvoqua Water Technologies LLC
InventorsHao Dang, Wenxin Du, George Y. Gu, Michael J. Shaw
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Abstract
Methods for processing pretreated phosphogypsum wastewater are disclosed. The pretreated wastewater may be subjected to electrodialysis involving at least one monovalent cation selective membrane. Further downstream membrane treatment may be applied. Upstream precipitation and air-stripping techniques may optionally also be employed. Related systems are also disclosed.
Claims11
A method of treating a phosphogypsum-containing water, comprising:
- removing ammonia from the phosphogypsum-containing water to form a pretreated supernatant;
- subjecting the pretreated supernatant to asymmetric electrodialysis (ED) in a first unit operation comprising an alternating series of monovalent cation selective membranes and anion selective membranes to produce a treated water meeting at least one predetermined discharge requirement;
- subjecting the treated water to further electrodialysis (ED) in a second unit operation comprising an alternating series of non-monovalent cation selective membranes and anion selective membranes to produce a product water;
- recycling a first reject stream from the first unit operation and a second reject stream from the second unit operation to the phosphogypsum-containing water;
- and
- discharging the product water.
3 more elements
Dependencies are inferred from the claim text.