| With the development of electroplating industry, electroplating species also increases, the quality of electroplating wastewater is complex, existing treatment process has been unable to meet the processing requirements. Therefore, the transformation of electroplating wastewater treatment plant is imperative.Since 2010, a circuit board manufacturer in Weihai has started to perform the table 2 emission standards of “electroplating pollutants discharge standards”(GB21900-2008), the standared requires the monitor position of total nickel in the plant or production facilities wastewater discharge outlet, so it is important to separate treat for nickel wastewater. In this paper, a study based on the nickel pretreatment wastewater from the original pool was carried out, the main components of wastewater are copper ions, copper complex and organic matter. In order to reduce the cost of original process and achieve the target of water quality stable, this subject design a new treatment process. This paper study the treatment technologies of wastewater, explore the optimum conditions and determine the treatment process, which is the basis of equipment modification and project commissioning of wastewater.(1) According wastewater characteristics to design two treatments process which are“sodium sulfide precipitation + coagulation sedimentation” process and“Fenton oxidation + coagulation sedimentation” process, research how the effect of water quality is influenced by various factors through single factor and orthogonal experiments, determine the optimum operating conditions. Then compare the water quality and pharmacy costs of the two treatments, the results show that “Fenton oxidation + coagulation sedimentation” process treatment costs and treatment effects are significantly better than the “sodium sulfide precipitation + coagulation sedimentation” process. Fenton pretreatment optimum condition is as follow:Fe2+/H2O2=0.5, H2O2 dosage is 2mmol/L, p H=3, reaction time is 10min; The optimum condition of coagulation sedimentation is as follow: PAC dosage is15mg/L, p H=8, reaction time is 10 min, PAM dosage is 12.5mg/L, settling time is50 min. Adopting “Fenton oxidation+coagulation sedimentation” to treat wastewater,Cu2+ and COD of effluent are 0.5613mg/L and 52.53mg/L.(2) This subject compare of activated carbon, zeolite, diatomite and kelp residue removal capacity for residual contaminant, the results show that activated carbon can effectively absorb Cu2+ and COD in wastewater. Researching the residual contaminants removal effect of activated carbon adsorption in wastewater.By static experiments to determine the optimum operating parameters of adsorptionexperiment, meanwhile, the activated carbon adsorption isotherm were studied; By adsorption column experiment to study the dynamic adsorption process of activated carbon, meanwhile, the activated carbon adsorption breakthrough curve were studied. The research results show that activated carbon can effectively remove residual Cu2+ and COD in wastewater. Finally, effluent of Cu2+、Ni2+ and COD can reach the emission standards of electroplating wastewater.(3) According to the optimum operating conditions to transform the wastewater treatment plants. After transformation, the process is: Fenton oxidation pretreatment raw water, convert heavy metal complexes to heavy metal ions,meanwhile, removes organic pollutants. The use of coagulation sedimentation process to remove heavy metal ions and organic matter, finally use of activated carbon for water depth treatment. The treatment process after transformation can be achieved the purposes of cost savings and the water quality stable meet the emission standards.Reconstruction of wastewater treatment plant can achieve the targets which are water quality stable and water quality indicators reach the limit of emission standards, its operating cost far less than the original cost of processing technology.The transformation process has tremendous environmental benefits, social and economic benefits. |
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