TREATMENT OF BYPRODUCT SALT

摘要

PROBLEM TO BE SOLVED: To surely and efficiently lower the concentration of heavy metals in wastewater in which byproduct salts are dissolved and satisfy the discharge standards of heavy metals by bringing a specified solution from which insoluble components of byproduct salts are separated and removed into contact with a chelating resin having specified various functional groups in a specified pH condition and removing Hg from the solution. SOLUTION: Insoluble components of byproduct salts are separated and removed from a solution in which byproduct salts generated by reaction of acidic components of a waste gas with sodium carbonate, sodium hydrogen carbonate, or the like are dissolved. The resultant solution after the separation and removal of the insoluble components is brought into contact in a condition of pH 1-8 with a chelating resin having one or more types of functional groups selected from various functional groups having respective formulas to remove Hg from the solution. The concentrations of Cr, Cd, Se, As, Pb, Ni, Mn and Cu in the solution after the separation and removal of the insoluble components are all less than 0.1 mg/L. The Hg concentration in the solution after contact with the chelating resin is controlled to be less than 0.005 mg/L.