Water treatment device and method

A water treatment device, comprising:

• an electro-coagulation (EC) unit for treating a stream of feed water to produce a stream of EC treated water of lower salinity than the stream of feed water;
• an electrical separation unit for treating the stream of EC treated water to obtain a stream of product water of lower salinity than the EC treated water, the electrical separation unit comprising at least one of an electrodialysis reversal desalination (EDR) device and a supercapacitor desalination (SCD) device;
• and
• a precipitation unit for providing a stream of wash water to wash the electrical separation unit and become a stream of reject water flowing back to the precipitation unit, wherein precipitation in the precipitation unit produces the stream of wash water of lower salinity than the stream of reject water,
• wherein the stream of EC treated water flows to the electrical separation unit without flowing through the precipitation unit.