CPC C02F 9/00 (2013.01) [C01D 5/16 (2013.01); C02F 1/004 (2013.01); C02F 1/283 (2013.01); C02F 1/32 (2013.01); C02F 1/42 (2013.01); C02F 1/441 (2013.01); C02F 1/442 (2013.01); C02F 3/1268 (2013.01); C02F 2001/425 (2013.01); C02F 2101/101 (2013.01); C02F 2103/32 (2013.01); C02F 2209/08 (2013.01); C02F 2301/066 (2013.01); C02F 2301/08 (2013.01); C02F 2303/18 (2013.01); C02F 2303/24 (2013.01)] | 17 Claims |
1. A system comprising:
(a) a membrane bioreactor unit configured to treat process water, the process water comprising sodium sulfate, being from a starch process and having a chemical oxygen content at least 1000 mg(O2/L), the membrane bioreactor by being configured to reduce the chemical oxygen content of the process to less than 250 mg(O2)/L;
(b) a cationic ion exchange unit configured to receive the permeate from the membrane bioreactor unit; and
(c) a high pressure filtration unit configured to: i) receive the permeate from the cationic ion exchange unit, ii) concentrate sodium sulfate in the permeate from the cationic ion exchange unit to obtain a concentrated sodium sulfate solution having at least 100,000 mg/L sodium sulfate; and iii) recycle the concentrated sodium sulfate solution to the starch process
wherein the high pressure filtration unit has a molecular weight cut off of less than 200 Da.
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