Study On Electroplating Comprehensive Wastewater Treatment Technology

With the rapid development of electroplating industry,economically people who have received considerable interests, but theproduction process of wastewater, Because it contains a large amount ofpoisonous heavy metal ions such as chromium, nickel, copper, zinc, etc.,If discharged wastewater directly, heavy metal ion not only can causeair pollution, but also influence people’s life and health, So it must dealwith it no time to delay. This thesis mainly used the compositeflocculation and heavy metal chelating agent processing platingcomprehensive wastewater chromium, nickel ion, the first to compoundwith aluminium potassium sulfate, PAC, PFS and CPAM finded the bestratio, and optimized through orthogonal test, the application for thetreatment of electroplating chromium nickel mixed wastewater; Then akind of heavy metal chelating agent（HMCA） was synthesized usingdiethylenetriamine （DETA）, carbon disulfide, epichlorohydrin andNaOH as raw materials, studied the influence factors of synthesisprocess, investigated the molar ratio of different material, reactiontemperature, stirring speed, reaction time on the influence of thesynthetic product, the product structure, shape and flocculation of rawmaterials DETA, HMCA and capture heavy metal chromium nickel ioncorresponding chelates are characterized by Infrared VisibleSpectrometer（FT-IR）, Scanning Electron microscopy （FE-SEM）, Theresults show that:（1）Using a single flocculant to treat plating chromium, nickel mixedwastewater, flocculation effect is not ideal. So choosed aluminiumpotassium sulfate, PAC, PFS and CPAM as investigation factors, toρ[Cr（Ⅲ）],ρ(Ni²⁺) as the index, determined orthogonal test optimizedconditions, further compounded with four kinds of flocculant the ratio of m （aluminium potassium sulfate）: m （PAC）: m （PFS）: m （CPAM）=50:35:2, used in the treatment containing chromium, nickel mixed wastewater, waste water treatment of ρ [Cr （Ⅲ）]0.12mg/L, ρ (Ni²⁺)0.26mg/L, lower than the state allows emissions standards, ρ （insolubles）for265mg/L, and industrial water and drinking water close, can beused as the plating production circulation water.（2）Through the experimental research show that, the optimumprocess conditions for heavy metal chelating agent HMCA synthesiswere: Na0H and diethylenetriamine molar ratio was2.7:1, CS2anddiethylenetriamine molar ratio was0.8:1, the reaction temperature forroom temperature conditions, stirring speed of200r/min or so, thereaction time is3.5h. the product through the infrared spectralcharacterization analysis, in the HMCA molecules C═S stretchingvibration peak appeared in1221cm1and1109cm1place,1502cm1place appeared N─C of N─C═S characteristic absorption peak,1056cm1,999cm1,971cm1place appeared C─S stretching vibrationpeak, for the performance of the strong peak, the molecular connectedto the─CSS radical successfully, this chelating agent and the desiredobjectives product consistent.（3）Heavy metal chelating agent HMCA were applied to chromeplating, nickel plating wastewater treatment and were characterizedusing the infrared spectral spectrum, SEM and electronic energyspectrum diagram analysis. In the chrome plating wastewater treatment,chelating product S and Cr atomic number ratio was4.097:1, and wasclose to the theoretical value, the optimum pH value and HMCAquantity added to were determined, making Cr3+removal rate reached99.94%, ρ [Cr （Ⅲ）]0.16mg/L, Dealing with nickel plating wastewater,chelating product S and Ni atomic number ratio was4.016:1, the qualitypercentage was2.1897:1, the proportion of measured was close to thetheoretical value respectively, basically by n（─CSS）:n(Ni²⁺)=2:1form chelate, the pH value and HMCA quantity added to weredetermined the best value range, Ni²⁺removal rate was more than98.5%,ρ (Ni²⁺) minimum was0.45mg·L^-1. （4）Study on the compound flocculating-chelate combining themethod of processing chrome plating wastewater, when PAC, PFS,CPAM quality than to10∶12∶1,pH was7.5, the quality of thewastewater chromium ion concentration dropped substantially, thesupernatant fluid of ρ [Cr （Ⅲ）] reduced to143.26mg/L, used thechelating agent dealing with composite flocculation of wastewater,HMCA and Cr3+generated stable chelate product, when pH was8.5,HMCA quantity added to was3.87g/L.