Sulfide heavy metal chelating trapping agent and preparation method thereof

Abstract

The invention discloses a sulfide heavy metal chelating trapping agent. The trapping agent is prepared by a method of: dissolving 550g of mercaptoethylamine hydrochloric acid into 3L of chloroform; adding 900g of triethylamine as an acid binding agent; adding 400g of 3,3',5,5'-biphenyl 4-formyl chloride into 2L of chloroform; stirring and mixing the two kinds of solution, wherein the stirring velocity is between 30 and 100 r.min<-1>; performing a condensation reaction in an ice bath for 3 to 8 hours under protection of nitrogen; filtering the mixture, and extracting with water and the chloroform respectively; and distilling out redundant solvent with a rotary evaporator to obtain a white precipitate, namely a target product. The trapping agent fast reacts with various heavy metal ions in waste water at the normal temperature and generates a water-insoluble sulfide precipitate. The sulfide heavy metal chelating trapping agent has the advantages of simple preparation process and convenient use. The particle size of the produced sulfide precipitate is large, the floc is compact, the precipitation time is reduced, the concentration of heavy metal ions in the waste water below the national discharging standard, generated residue can be used for recycling heavy metal, and no secondary pollution is generated, The trapping agent can also be used for recycling precious metal in aqueous solution.

Description

technical field [0001] The invention relates to the removal, purification or trapping technology of heavy metal ions in water bodies, in particular to the preparation of a sulfide heavy metal chelating trapping agent and its application method in water treatment. Background technique [0002] Heavy metals refer to metals with a specific gravity greater than 4 or 5, such as copper (Cu), zinc (Zn), lead (Pb), cobalt (Co), nickel (Ni), chromium (Cr), cadmium (Cd), mercury (Hg ), etc., there are about 45 kinds. Although arsenic (As) is not a heavy metal, it is usually included in the heavy metal category because of its source and hazards similar to heavy metals. The above-mentioned heavy metal ions have the characteristics of stable properties in the natural environment, accumulation in organisms, low concentration, and long-term toxic and side effects. If they are not properly treated, they will cause serious pollution to the environment. [0003] The traditional pH adjustment...

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Problems solved by technology

[0005] In addition, the control of heavy metal pollutants by hydroxide precipitation or sulfide precipitation, especially for the treatment of electroplating wastewater containing chelated heavy metal ions, has certain limitations in practice: first, the hydroxide precipitation or sulfide of heavy metals The precipitates will be re-dissolved when encountering acid, or oxidized and decomposed by the air, resulting in secondary pollution; secondly, the sludge produced by the above two heavy metal precipitations has a large water content, and the precipitation is not complete, so it is difficult to ensure the discharge of heavy metal wastewater completely up to the standard

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