The invention discloses a composite dechlorination agent for removing high-concentration
chlorine-containing
wastewater and an application method thereof, which belong to the field of
sewage treatment in environment protection. The composite dechlorination agent is prepared by compounding organic acids and
inorganic salts, wherein the organic acids include two or more than two of nicotinic acid,
citric acid,
succinic acid, beta-
ketoglutaric acid, and ketosuccinic acid; the
inorganic salts include one or two of mercury
sulfate,
cadmium sulfate and
copper sulfate; and the weight percentages of the organic acids and
inorganic salts are 15-80% and 20-85% respectively. The application method comprises the steps of: adding the prepared composite dechlorination agent in percentage by weight of 0.05-0.5% into the high-concentration
chlorine-containing
wastewater and continuously stirring for 10-30min; adding a
methylene dichloride
solvent; standing for layering, separating, and subjecting obtained
wastewater to air flotation treatment; and finally scraping off a layer of residue floating on the surface of the wastewater by a residue scraping
machine to obtain the dechlorinated wastewater as the yielding water, wherein the dechlorinated wastewater can be lower than the national
emission standard I. The composite dechlorination agent and the application method disclosed by the invention have the characteristics of simple technological process, smaller dosage of
chemical agent, lower running expense, no
sludge, high removal rate of
chlorine ions in the wastewater, and the like; and the removal rate of chlorine ions in the wastewater can reach above 99.9%.