Experimental Study Of FentonOxidatio-coagulation On Pre-Treatment Of The Wastewater From Natural Gas Purification

The wastewater from natural gas purification is comprised of normal purifying wastewater,and examining and repairing wastewater.The concentration of organics in normal purifying wastewater is low and this wastewater is easy to dispose;while the concentration of organics in examining and repairing wastewater is high,while the hard to deal with.Fenton reagent has a super oxidation and appeared to be applicable for the treatment of bio-refracrory wastewater,so Fenton reagent reaction has become one of effective means in the treatment and control of waster water. In this thesis ,Fenton oxidation- coagulation process was used in Pre-Treatment of the wastewater from natural gas purification which from Yinjin Department ,and the varing effects were investigated.The whole experiment includee two steps.In this research, the Fenton oxidation is firstly used to treat the wastewater from natural gas purification. Then the wastewater is treated by coagulation again. Firstly, orthogonal experiments areused to determine the main factors of different processing units. Then single-factor rotates are used to research how every factor effect the results of theexperiments and to get relationship curves of the factor and the results of theexperiments (the removal efficiency of COD and colority) to determine the best values of the factors.In the research, the effects of FeSO₄·7H₂O dosage, pH, H₂O₂/Fe²⁺, reaction time and other factors on the Fenton reagents oxidation treatment result are inspected; Finally inspected the effects of pH, coagulant type and coagulant dosage on the later coagulation treatment are inspected.the optimal Fenton oxidation condition was: pH value was 3, dosage ofFeSO₄·7H₂O was 0.028mol/L,H₂O₂/Fe²⁺ rate was 8:1; reaction time was 45 min, the optimal coagulation condition was: pH value was 8,dosage of PAM was 5mg/L. The results of the test showed that, using the said combined process to treat wastewater of Diluting five times which COD mass concentration was 4138.2 mg/L。After the oxidation wastewater which coloritywas 80 times, the removal rate of COD and colorityreached 79.62%, 94.0% respectively. BOD/COD rate increases from0.147 to 0.53,it means the wastewater was biodegradable.