Treatment Of Refractory Organic Wastewater Using UV-Fenton Process

Oxidation experiments of phenol and dyeing wastewater in an annular reactor was conducted. The effects of reaotion c.or.riitior.s such as the dos~g~ of T-bfl-~ proportion of Fe2~ and H202, initial pH, initial phenol concentration, reaction temperature, carrier gas were studied in terms of chemical oxygen demand (CODer) removal. Under the condition of adding H2O2(Q~), Fe2~:H2O2~l :20, 300C, pH3.0 and adding of 02, 93% COD removal can be achieved after 40mm.In order to overcome the drawbacks of UV-Fenton process such as a limited p1-I range 3-5 and leakage of iron regeneration, immobilization of iron using the supportssuch as zeolite 1 3X, silica gel. Ab03 was made. The results of heterogeneous iron2+catalysts employed in the treatment of phenol wastewater showed that zeolite-Fewas the best catalyst compared with others and can achieve 80% CODcr removal rate within 30mm. Photo-Fenton process using heterogeneous Fenton-type catalysts such as zeolite 1 3X may be a promising technology for the treatment of organic wastewaters due to the cheapness and ~ffe~LAeness.The difference of UV-VIS spectra between UV-Fenton and UV-H202 showed that the phenol decomposition mechanism in these two systems is distinct. Such parameters as the reduction of 1-1202, the change of Fe2~, quantum yields were also investigated to explore the mechanism. All the results showed that decomposition ofiv j-~.~ompicx IS u.te main reaction way in UV-Fentoit pruc~ss aud iiydxuxyi radicals just work a minor role. Kinetic model was also proposed for this process, prediction of this model was found to agree well with experimental results, thus confirming the proposed reaction mechanism.