The Treatment Of Nickel Electroplating Wastewater

Most of the nickel electroplating wastewater come from wash water during nickelplating.It can be divided into two types.One of them is electronickeling wastewater,the other one is electroless nickelplating wastewater.Electroless nickelplating wastewater contains a large number of complexing agent,accelerating agent,buffering agent and other additives to ensure the quality of the coating requirements.Common complexing agent mainly including:citric acid,tartaric acid,EDTA and so on.Increasing the difficulty of the Electroless nickel plating wastewater treament.Using conventional neutralization has limitations on removel of nickel.It is hard to make sure the nickel below the emmision stardards.This paper presents a variety of chemical treatment combination processing method.Add a theoretical basis for the effective treatment of electroplating wastewater process.In this paper,in the process of research adopted the method of Fenton joint chemical precipitation?Fenton-chlorine oxidation,active carbon adsorption,etc.The results showed that using Fenton joint chemical precipitation process the best parameters are as follows: a H2O2 dosage of 2 ml / 100 ml,Fe2 + /H2O2 around 0.1~0.5,initial reaction p H was 3 ~ 6,05h~2h of the reaction time,the removal rate was 95%,the nickel in the plating water is higher than the emmision limits.Fenton chlorine oxidation process of nickelplating wastewater optimum operat parameters are as follows: the first oxidation oxychloride orp between 200 mv ~ 400 mv,secondary oxidation orp between 750 mv ~ 950 mv,reaction of 60 min;the first chlorine oxidation p H between 10~ 12,secondary chlorine oxidation p H of 7 ~ 9.The quantity of water containing nickel data can be stable in the range of 0.1 mg/L to 0.3 mg/L.Removal rate as high as 99%.Comparing the adsorption effect of four common adsorbent,comprehensive consider to choose activated carbon on the depth of wastewater treatment after oxidation processing.Combined Fenton-chlorine oxidation process with activated carbon adsorption process,When activated carbon dosage was 0.8 g / 100 ml,the reaction time of 30 min,the optimum reaction p H between 6 ~ 8,it can reach the best effect.Using 0.2 mol/L hydrochloric acid regeneration of activated carbon,after repeating 4 times,the regeneration of activated carbon adsorption performance is close to the new activated carbon adsorption capacity.After the depth treatment,effluent nickel content in 0.1 mg/L,lower than the emmision limits.