Study On Treatment Efficiency Of Heavy Metal Chelating Agents For Electroplate Wastewater And Its Application

This article adopt DTCR chelating agent to deal with heavy metal ions and their complexes in electroplating wastewater, the treatment capacity of DTCR to Cu²⁺, Ni²⁺, Cr³⁺ and their complexes(EDTA, citric acid, ammonia) was studied, the conditions of experiment include quantity of DTCR, pH value , quantity of flocculation and time of reaction, according the result of single condition experiment, the orthogonal test of DTCR dealing with heavy metal ions and their complexes, the treatment capacity of DTCR to mixed liquor of Cu²⁺, Ni²⁺, Cr³⁺ complex(EDTA, citric acid, ammonia), the stabilization experiment of DTCR chelating produces and the biology toxicity of DTCR were studied.DTCR heavy metal chelating agents condition experiment show that toward the heavy metal ions and their complexes wastewater it is difficult to be treated using some tradition methods in acid condition. The results show that these chelating agents all have high removing efficiency under the following conditions: pH is 3 11;in the Cu²⁺, Ni²⁺, Cr³⁺ and their complex(EDTA, citric acid, ammonia) wastewater the concentration of Cu²⁺ is 63.55mg/L, Ni²⁺ is 58.69mg/L, Cr⁶⁺ is 52.00mg/L;the used quantity of DTCR is 0.4⁰.6mL, this volume ratio of used quantity of flocculation(540.6mg/L) and DTCR(10% )is 1:1, the time of reaction is about 10min.The treatment capacity of DTCR to mixed liquor of Cu²⁺, Ni²⁺, Cr³⁺ complex show the mixed liquor of Cu²⁺, Ni²⁺, Cr³⁺ complexes have no influence, the treatment sequence is Cu²⁺ complex, Ni²⁺ complex, Cr³⁺ complex. The stabilization experiment show that the ions soak quantity of DTCR chelating produce is more lower than the hydroxides, it have more stabilization, and the sock toxicity of DTCR chelating produce is lower than the allowable criterion, so it can landfill safely, no second pollution.The biology toxicity of DTCR experiment show DTCR chelating agent has no inhabition to the bacteria from the Changjiang River under these conditions: temperature is 10℃, 20℃;pH is 5⁹, the used concentration of DTCR ≤0. 8mL/L, the disposed wastewater can let out directly, no second social effects of pollution.So utilizing DTCR heavy metal chelating agent to dispose electroplating wastewater have good society benefit and economy benefit, it has good applied foreground.