Desalitech's Closed-Circuit DesalinationTM (CCDTM) technology can be incorporated into an existing water treatment plant to improve process performance, increase permeate production and save operating costs.
Existing brackish water reverse osmosis (BWRO) and industrial water treatment plants are often not as efficient as they could and should be. Changes in feed water conditions, water quality requirements, aging equipment or non-optimal original designs can compromise performance and result in significant excess treatment cost.
Desalitech offers two main retrofit alternatives:
1. Complete Retrofit of Existing RO Plants
Existing RO plants may be reconfigured to the CCD process design, providing increased permeate production capacity and recovery with reduced energy consumption. Because the CCD process utilizes standard RO equipment, most of the components necessary for the redesigned plant are typically already installed in the existing plant. Desalitech engineers will work with plant owners to specify any additional equipment necessary to convert the core RO process and significantly upgrade its performance and reliability.
2. Add-On Units for Increased Recovery and Improved Permeate Quality
Add-on CCD systems leverage residual brine pressure and require very little additional energy input. A Desalitech RO unit can be installed on the high-pressure reject outlet stream of an existing RO plant. The residual pressure drives the CCD process, increasing permeate production and recovery. Alternately, the permeate from the Desalitech unit can be sent upstream of the existing plant, becoming part of the feed of the existing plant and improving its performance.
Case Study: 165 m3/d (30 gpm) BWRO unit retrofit
A conventional BWRO unit was purifying 50 ppm TDS tap water to high purity for industrial process water supply. The unit operated at 75% recovery, producing a 2.3 m3/h (10 gpm) brine stream and consuming 0.65 kWh/m3 power in the core RO process.
The unit was retrofit by adding a low-cost circulation pump, piping the brine discharge to the membrane feed, and making other minor modifications to the existing equipment. The resulting BWRO-CCD unit operates at over 90% recovery, producing 1/3 as much brine reject while consuming just 0.52 kWh/m3 or 20% less energy.
· Increased Recovery
· Reduced Energy Consumption
· Reduced Fouling and Scaling
· Same Footprint as Original System
Note that increasing recovery is practical when the scaling characteristics of the feed water allow it. Although this is often the case, chemical analysis of the feed and the brine must be performed prior to system implementation.
Click here to learn more about CCDTM technology.
