Treatment of WESP Effluent Using Magnesium Hydroxide Slurry

As emission limits tighten, fossil fuel electrical power generation plants are employing wet electrostatic precipitators (WESP) to control pollutants.  WESPs generally use this post-combustion emissions control sequence:

                      SCR → DESP → WFGD → WESP

WFGD scrubbers remove sulfur dioxide (SO2), but do not significantly remove sulfur trioxide (SO3).  WESPs remove SO3that combines with water to form H2SO4, remove ultra-fine (PM2.5) particulates, and decrease stack plume opacity.

Water-intensive WESP operation dramatically reduces water demand with closed-loop, recirculation and reuse.  UtiliMag®H magnesium hydroxide slurry effectively neutralizes WESP effluent.  Advantages of UtiliMag®H over alternative technologies:

  • provides more alkalinity per pound, on a dry basis, than other alkalis such as caustic soda and hydrated lime.  One gallon of UtiliMag®H replaces 1.77 gallons of 50% caustic soda.
  • generates less TDS than other alkalis
  • provides superior pH controllability – naturally buffers at about 9 pH, the pH upper control limit of most state EPAs
  • as a high purity, industrial grade Milk of Magnesia, UtiliMag®H is non-toxic (when used properly), non-corrosive, non-hazardous, and safe for employees