Rapid field assessment of RO desalination of brackish agricultural drainage water

A perspective on reverse osmosis water desalination: Quest for sustainability

“…These feed pretreatment processes, while effective for minimizing membrane fouling due to particulate deposition, organic adsorption, and biological growth, do not remove mineral scale precursors. Mineral scaling is typically mitigated via: (a) the addition of polymeric antiscalants additives to the feed to suppress the nucleation and/or growth of mineral crystals and promote dispersion of crystals, (b) feed pH adjustment if calcium carbonate is an issue of concern, (c) regulation of water recovery to keep the level of retentate concentration within acceptable limits (as governed by mineral scaling kinetics), (d) periodic membrane cleaning (e.g., via fresh water flush, osmotic backwash, feed flow reversal, or chemical cleaning), and (e) removal of scale precursors via crystallization, nanofiltration, or ion exchange . In certain cases where boron and carbon dioxide removal are necessary and where silica scaling is to be avoided (at high recovery), RO operation at high pH may be necessary .…”

Pilot demonstration of concentrated solar-powered desalination of subsurface agricultural drainage water and other brackish groundwater sources

“…Such a monitoring device was constructed and tested using agricultural drainage water at the Panoche Water District in the San Joaquin Valley by Thompson et al [11] for rapid field evaluation and optimization. The study verified the effectiveness of such a monitoring device and validated the expectations of rapid scaling causing dramatic performance decline at 65% recovery from a 14,400 ppm TDS source [11]. Despite these advancements, due to the high scaling propensity of brackish groundwater and subsurface agricultural drainage water sources, pretreatment costs are high and recovery is limited for RO technologies and therefore cannot adequately address the environmental issue of brine waste disposal.…”

Silica scale mitigation for high recovery reverse osmosis of groundwater for a mining process

“…The use of lower pH and antiscalants is recommended for RO treatment of this water. The CaSO 4 saturation is slightly above the conservative upper limit of 230 -400% of saturation recommended by membrane manufacturers [19], indicating that calcium removal may also be needed if higher water recoveries than 90% are required. The software also predicts that a 90% water recovery will give rise to silica scale formation.…”