Research On Process Of Organic Pollutant Removal In Plating Waste Water

Organic pollutant in plating waste water is not only the contamination of environment but also the reason of blight for water reusing treatment. This paper is finding means to remove the organic pollutant in plating waste water by using three methods: physicochemical method, biochemical method and oxidation by ozone. This research can make reference for engineering design.Research has find the COD_Cr of plating waste water are different of each others. The COD_Cr of some plating waste water is below 100mg/L, however, the waste water of using citric acid to copper plating may contain COD_Cr=400mg/L and the waster water of using HEDP to copper plating may contain COD_Cr=300mg/L. So we should pay attention to these waster water.The waste water of using citric acid to copper plating may contain COD_Cr=400mg/L.Coagulation process can't get good treating effect, however, after biochemical treatment, COD_Cr come to 10mg/L. The results showed that the concentration of waste water affect the biochemical process; The heavy metal like Cu²⁺ had little effect on biochemical process when the concentration of Cu²⁺ was 5mg/L,furthermore, the concentration of Cu²⁺ drop to 0.57mg/L; The salinity of waste water had a little effect on biochemical process when the salinity was 5mg/L,as the salinity increased, it's effect on biochemical process also increased. Generally, The salinity of plating waste water is 5mg/L, and it raised to 15mg/L after membrane concentrate. So we should pay attention to the effect of salinity. The waster water of using HEDP to copper plating may contain COD_Cr=300mg/L. Coagulation process can't get good treating effect, biochemical method also can't get any treating effect. So we use ozone to oxidate organic pollutant. After 2 hours, COD_Cr was under 5mg/L. The results showed that COD_Cr would be removed obviously faster when there had more ozone. This phenomenon ended when the ozone was increased to 9.4mg/min. COD_Cr would be removed obviously faster when the pH of solution was higher. pH was the control of reaction, so we should keep the pH of solution at high level.The waste water of degreasing before copper plating may contain COD_Cr =700mg/L. Coagulation process can't get good treating effect, because this waste water contain a lot of surfactants and Emulsifier, however, after biochemical treatment, COD_Cr come to 146 mg/L. When we use ozone to oxidate organic pollutant, keeping ozone at 9.4mg/min, COD_Cr increased at first, and then decreased to 5mg/L. The colligating waste water of colligating plating waste may contain COD_Cr =700mg/L.When use different coagulants, we find when the Al₂(SO₄)₃ exceed 150mg/L, it would encumber coagulation. After coagulating, COD_Cr=160mg/L, biochemical treatment can let the COD_Cr=70mg/L. The waste water of membrane concentrate may contain COD_Cr =170mg/L, Coagulation process can't get good treating effect, however, after biochemical treatment, COD_Cr come to 77mg/L.Generally, process of organic pollutant removal in plating waste water is research the waste water of copper plating mostly. By using three methods: physicochemical method, biochemical method and oxidation by ozone, we can removal a lot of organic pollutants, to let the Wastewater Attained Standard.