Study On Oxidation Of Phenol By Catalyzed Persulfate In Aqueous Solution

This paper taked simulated phenolic wastewater as the research object and taked phenol ofactual semi-coking wastewater as target pollutants.Five catalytic conditions ofheating,Fe²⁺,Fe⁰,sime-coke and iron carbon micro electrolysis were studied and the effects ofvarious factors on the degradation rate of phenol were also discussed. The results showed thatunder the same conditions of sodium persulfate dosage and reaction time,the degradation ofphenol under heating condition was higher than room temp erature.When Fe²⁺was used tocatalyze sodium persulfate,the experiment determined the optimum molar ratio of sodiumpersulfate to Fe²⁺was1:1. Under the condition of the molar ratio of sodium persulfate to Fe²⁺was1:1,reaction time was90min,the degradation rate of phenol was75.1%.The effect ofpolymeric ferric sulfate produced in the process of reaction on phenol degradation was verysmall.When Fe⁰was used to catalyze sodium persulfate,the experiment determined theoptimum molar ratio of sodium persulfate to Fe⁰was1:1. Under the condition of the molarratio of sodium persulfate to Fe⁰was1:1,reaction time was75min,the degradation rate ofphenol was94.5%. The catalytic effect of Fe⁰on sodium persulfate was better thanFe²⁺.Through the comparison of experiments confirmed: the effect of Fe⁰on phenoladsorption was not obvious.Fe⁰mainly played a role in catalysis.Under the best adsorptioncondition,semi-coke on phenol removal rate was only5.9%,indicating poor adsorption rate ofsemi-coke on phenol.In the process of reaction,semi-coke mainly played a role incatalysis.The degradation rate of phenol was increased with increasing dosage ofsemi-coke.However,the dosage of semi-coke was excessive,the degradation rate of phenolwas reduced.When iron carbon micro electrolysis catalyzed sodium persulfate and the dosageof sodium persulfate was3.33g/L,the degradation rate of phenol was96.7%at90min.Based on the orthogonal experiment L16（45）,the optimum reaction parameters weredetermined.Under the condition,the removal rate of COD of semi-coking wastewater reached70%.