Patent ID: 8236178
Filing Date: 2012-08-07
Classification: B01D

Abstract:
1. A method for operating reverse osmosis membrane filter systems with membrane filters to recover water by using both the filtrate and brine retentate, comprising: a. injecting sulfur dioxide (SO b. filtering the sulfur dioxide treated water through the reverse osmosis membrane filters to produce a filtrate and separated brine retentate containing less than 0.15% by weight of the salts of Na, Ca, Mg, Cl, SO c. adjusting the pH of the filtrate and discharging the same for reuse, d. monitoring the brine concentrations of the retentates for at least one of the following: e. adding at least one of the following to adjust the pH and calcium ion concentration of the discharged brine retentates: f. applying the pH and calcium ion adjusted discharged brine retentates to soils until soil and soil water concentrations of sodium absorption ratio (SAR) are less than 15, electrical conductivity (EC) less than 2 dS m