Treatment Of Organic Phosphorus Wastewater By Photochemical Oxidation Combined With Ferrate Pre-treatment

Phosphorus is the main factor of eutrophication, so the treatment of phosphorus wastewater is very important. At present, the methods of removing phosphorus mainly are biological treatment and physico-chemical treatment. The removal of phosphorus by the biological treatment is lower than the physico-chemical treatment. Fe(Ⅵ) is concerned as a"green"agent used in water treatment. In this paper, the preparations of Fe(Ⅵ), the application of Fe(Vl) + UV process in the field of treatment of phosphorus wastewater and the mechanism of the Fe(Vl) + UV process is researched.Fe(Ⅵ) was produced through DC-electrolysis in the laboratory. The concentration of Fe(Ⅵ) is 17.84mmol?L-1. The study indicated that the best condition of producing Fe(Ⅵ) is that: electrolyte concentration: 14~16mol/L, voltage: 6V,temperature: 30℃~ 45℃,electrolysis time 2.5~3h.The removal of glyphosate can reach 90% after the pre-oxidation of Fe(Ⅵ) and the photodegradation by UV lamp(15w,λ= 254 nm, I = 48.4 W/cm2).The removal of phosphorus in landfill leachate can be reached 80% by the process of Fe(Ⅵ) pre-oxidation+UV after 1h light., when the when ferrate dosage is 10mL(C=17.84mmol?L-1).The main mechanism of phosphorus removal by Fe(Ⅵ) pre-oxidation + UV process is as followings. Fist the organic phosphorus was oxidized by Fe(Ⅵ), than the organic phosphorus left was oxidize in photocatalytic oxidation reaction. Last,the inorganic phosphorus was removed by the coagulation of Fe(Ⅲ).This study demonstrates the remval of phosphorus is very good by the process of Fe(Ⅵ) pre-oxidation + UV.