Coking Wastewater Treatment by Manganese Ore Oxidation and Magnesium Ammonium Phosphate Precipitation

摘要

Manganese ore has strong oxidation capabilities under acidic conditions,so phosphoric acid and sulphuric acid were used to adjust pH,volatile phenol,COD and sulfide of the coking wastewater were oxidized and removed by manganese ore： then ammonium-nitrogen and phosphate were removed and recovered by magnesium ammonium phosphate(MAP) precipitation in the wastewater.When pH of the influent was 1.2.the removal rates of CODcr and volatile phenol resulted 70%and 99%.Adding 18g/L magnesia to the effluent and stirring 48h.the removal rate of ammonium was 94%.Most of ammonium has been recovered in the forill of MAP. Others were removed from the wastewater in the fom of ammonia gas.CO2 would consume alkalinity in solution to hinder the increase of pH.but had no effect on crystal morphology and composition.X-ray difiraction and transmission electron microscope unveiled crystalline products and revealed the reaction mechanism.The biodegradability of coking wastewater can be greatly improved via Manganese ore oxidation and MAP precipitation.