Closed-Loop Water Filtration

Closed-Loop Water Filtration

Much of the water used by households goes down the drain directly to wastewater management systems without being reused. A closed-loop filtration system aims to fight water waste and reduce consumption of freshwater by purifying and recirculating water for domestic or industrial purposes.

Closed-loop water filtration is designed to treat the water used by the appliance or system to minimize the volume of water entering and leaving the system. A combination of micro filters such as string filters and sand filters and Nanofiltration methods such as Ceramic Membranes and high-performance filters remove bacteria and nanoparticles while also maintaining water pressure and water flow. The system then recycles water without producing a considerable amount of waste by using methods such as purification treatments, such as Plasma-Based Water Purification or High-Efficiency Reverse Osmosis. Reverse Osmosis removes up to 99% of impurities by using a pump to create pressure, forcing water through a semi-permeable membrane. Impurities are removed from the system for disposal or recycling. The purified used water circulates until it is usable again, then it is sent back through the pipes.

While significantly reducing water consumption and energy use –because it retains heat through the recycling process– this solution maintains hygiene and sanitation standards. Although household appliances such as showers may seem like the obvious end goal, disruptive closed-loop recycling systems can also be deployed within industries.

Key Players

• The OrbSys circular shower system, created by Swedish-based Orbital Systems, is a patented closed-loop design that cuts water consumption by up to 95% and energy costs by 80%. The system uses water quality monitoring sensors to ensure that water that cannot be filtered efficiently is removed from the system and replaced with fresh water. Internal heaters ensure that precision temperature is maintained, and the purification loop utilizes UV-light and purification capsules to ensure water is suitable for reuse. Orbital Systems has been granted Certified Space Technology designation by the United States Space Foundation. The OrbSys circular shower is particularly useful in areas where drought is a concern, or where water is in short supply —in fact, the Swedish armed forces have installed OrbSys showers in their most remote outposts.

• UK-based WorkingWater is specialized in vehicle wash water recycling and reclaim systems, as well as rainwater harvesting techniques to feed closed-loop systems. WorkingWater systems incorporate reclaim settlement tanks and interceptors to recycle water and prevent effluent from entering the foul sewer network while treating water for re-use.

• Detroit-based Ebbco is a full-service design and manufacturer of metalworking filtrations systems for industrial facilities which include closed-loop filtration systems. Filtration systems include settling weirs to ensure no dissolved solids are discharged, meanwhile, water consumption can be reduced by 90%.

Future Perspectives

From showers to car washes to space missions, and a host of use cases in between, there is a wide range of applications for closed-loop water filtration systems. Reducing freshwater consumption is becoming more pressing, as is reducing effluent discharge.

Industries handling Zero Liquid Discharge (ZLD) systems could be more closely integrated with communities, bridging the social gap between those who can afford access to technological developments and those who do not. Connecting the industrial wastewater to houses, citizens could once again use the water, making entire eco and social systems sustainable and waste-free.