MD technology application in ZLD
High salinity of waste water mainly includes RO brine, FGD waste water, oilfield produced water, gasification ash water, boiler blow-down water and so on, containing complicated species and high concentration of salts. Currently, there are many technologies and processes for this kind of waste water, but the process with low CapEx and OpEx, reliable technique, stable operation is developing trend.
For example, FGD waste water treatment for coal-fired power plant is always difficult due to high concentration of Ca2+, Mg2+, SO42- and high scaling potential. At the same time, high concentration of Cl- leads to high quality of construction materials. The traditional treatment process is mainly to reduce turbidity, hardness and heavy metals, but cannaot separate salt for water recycling, leading to waste of water source. CSRE MD technology is integrated with crystallizer to fulfill ZLD of FGD waste water with energy saving and emission reduction through concentrating FGD waste water to reduce total volume of crystallizaiton utilizing residue heat of power plant; also CSRE MD can be integrated with salt separation technology to fulfil salt recycling.
CSRE MD can substantially increase salt concentration to reduce the waste water volume in subsequent crystallization stage, leading to low capacity and CapEx of crystallizer. This is a new direction of MD applicaiton in ZLD. CSRE MD can reduce electricity consumption to 2kW·h/m3 utilizing waste heat of power plant.