Removal of nitrates from ground water
AssigneeTechnion Research & Development Foundation Limited
InventorsMichal Green, Ori Lahav, Razi Epsztein, Oded Nir
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Abstract
The present invention relates to a process for the selective removal of nitrates from ground water using a hybrid nanofiltration (NF)—reverse osmosis (RO) filtration system. The process generates product water that is low in nitrate and can be used for drinking, irrigation and other purposes, as well as waste water that is relatively low in salinity and can be safely discarded to sewage systems and recycled, e.g., for irrigation purposes.
Claims12
A process for removal of nitrates from water, to produce (i) product water and (ii) a waste brine comprising sodium (Na+) concentration below about 250 mg/L and a chloride (Cl−) concentration below about 450 mg/, the process comprising the steps of:
- a. passing a sample of water through a nanofiltration (NF) membrane to obtain a NF permeate and a NF retentate;
- b. passing the NF permeate obtained in step (a) through a reverse osmosis (RO) membrane to obtain an RO permeate and an RO retentate;
- wherein steps (a) and (b) further comprise controlling NF and RO recovery ratios to result in RO retentate comprising waste brine having sodium (Na+) concentration below about 250 mg/L and a chloride (CI−) concentration below about 450 mg/L;
- c. combining the NF retentate obtained in step (a) with the RO permeate obtained in step (b) so as to produce product water;
- and
- d. discarding the RO retentate obtained in step (b).
Dependencies are inferred from the claim text.