Interstage Hardness Removal from RO Brine, China

Interstage Hardness Removal from RO Brine, China

Continuous Ionic Filtration

Clean TeQ Water provided a 2m3/h CIF® pilot plant in China to remove hardness between reverse osmosis stages.


The client was a coal to chemical plant that required a large volume of industrial quality water for chemical processes. The existing solution consisted of a 1 stage RO that achieved roughly 50% water recovery. High hardness was making 2nd and 3rd stage RO impossible, leading to much larger brine streams and less water recycling than foreseen. Direct softening is capable of reducing the hardness but only a limited amount, and has high chemical cost. Water is scarce in the region the plant is located in, and brine handling is a key factor for the water treatment.

Clean TeQ Water provided the engineering, procurement and construction of a 2m3/h CIF® (Continuous Ionic Filtration) mobile treatment plant, which removes hardness from Reverse Osmosis (RO) brine. The pilot plant was finished in 2019 and put into operation.

Using CIF® technology, the mobile water treatment plant was able to achieve a 98% reduction in Ca (mg/L) and a 97% reduction in Mg (mg/L) whilst achieving a high water recovery of over 90%.

Typical Water Quality for a CIF® Plant

ParameterUnitFeed WaterTreated Water
Hardness as CaCO3mg/L900˜0


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