Brackish Water RO Plant

A brackish water RO (BWRO) plant is a water treatment facility that uses reverse osmosis membranes to remove dissolved salts, minerals and contaminants from brackish water sources, typically groundwater, boreholes or surface water with TDS levels between 1,000 and 10,000 mg/L. The treated permeate meets drinking water or industrial-grade quality standards and is widely used for community supply, agriculture and industrial process water.

BWRO systems treat lower-salinity feed water (up to 10,000 mg/L TDS) at significantly lower operating pressures (10–25 bar) compared to seawater RO (55–70 bar). This results in substantially lower energy consumption (0.5–1.5 kWh/m³ vs 2–3 kWh/m³) and higher product water recovery rates (65–85% vs 35–45%). Brackish water-grade membranes are optimised for these lower-pressure, higher-recovery operating conditions.

BWRO pre-treatment typically includes coarse intake screening, multimedia or sand filtration to reduce suspended solids and SDI, 5-micron cartridge filtration ahead of the membrane array, and antiscalant dosing to prevent calcium carbonate, calcium sulphate and silica scaling on the membrane surface. pH adjustment and dechlorination may also be required depending on source water chemistry. Correct pre-treatment is essential to achieving rated membrane performance and service life.

BWRO permeate typically has a TDS of 50–300 mg/L depending on feed water salinity and membrane configuration. For drinking water applications, post-treatment including remineralisation, pH correction, UV disinfection and chlorination brings the product water into compliance with WHO guidelines or applicable local standards. For industrial applications, permeate quality is adjusted to the specific process requirements.

Yes. BWRO plants are well-suited to solar-powered operation due to their relatively low energy intensity compared to seawater desalination. IWTE designs solar-compatible BWRO systems with variable-frequency drives, battery storage or grid-hybrid configurations for remote and off-grid applications. Solar-powered BWRO is increasingly the preferred solution for rural community water supply in sun-rich, water-stressed regions.

Brackish water RO systems typically achieve recovery rates of 65–85%, meaning 65–85% of the feed water volume is converted to product water. Recovery rate is a critical design parameter, higher recovery reduces water wastage and concentrate disposal volumes, but increases the risk of scaling on the membrane surface. IWTE engineers optimise recovery based on feed water chemistry, antiscalant selection and system configuration.

Concentrate disposal options depend on the site location, volume and regulatory requirements. Common approaches include discharge to a municipal sewer or drainage system, evaporation ponds for arid sites, land application for low-salinity concentrates, or re-injection into a suitable aquifer. IWTE assesses concentrate management requirements during the design phase and designs the reject stream volumes and chemistry to be compatible with the available disposal pathway.

Yes. IWTE provides a complete project scope from process design and engineering through civil and structural works, equipment supply, pipework, electrical installation, commissioning, operator training and ongoing service support. For remote or packaged applications, containerised BWRO systems can be supplied as factory-assembled units requiring minimal civil works at the installation site.