The invention relates to a
treatment system and a treatment method for reducing the amount of volatile heavy
metal sludge in desulfurization
wastewater. A two-stage chemical
precipitation technique is adopted to treat desulfurization
wastewater,
hydrochloric acid is added to regulate the
wastewater in the first stage of chemical
precipitation, so that the wastewater becomes acidic,
polyaluminium chloride as polycoagulant and
polyacrylamide as coagulant aid are added for
flocculation reaction, consequently, the content of the volatile heavy
metal in the
sludge in the first stage of chemical
precipitation is greatly reduced, while the amount of the
sludge is increased, and thereby the sludge can be added into a boiler and burnt;
calcium hydroxide is added to regulate the wastewater in the second stage of chemical precipitation, so that the wastewater becomes alkaline, heavy
metal precipitator-organic
sulfur (TMT15) is added to combined with the heavy metal in the wastewater to form highly stable chelate, molysite as polycoagulant and
polyacrylamide as coagulant aid are added, so that the sludge in the second stage of precipitation is rich in the heavy metal, while the amount of the sludge is little, and thereby the sludge can be buried alone.
Hydrochloric acid and
sodium hypochlorite are added into
clean water, so that the treated discharged water can meet the requirements of GB8978-1996 and DL / T 997-2006 standards.