Study On Fenton-ammonia Stripping-SBR Treatment Of Anaerobic Digestion Water Of Livestock Feces

This paper uses Fenton-ammonia stripping-SBR to process anaerobic digestion water, whose COD was1000mg/L. The purpose of Fenton-preoxidation is to improve its biodegradability, and after that, using ammonia stripping and SBR technology in-depth treatment of the water. The research studied the influence of pH, oxidant dosage, reaction time and catalyst to the oxidation reaction of wastewater organics, and the optimum reaction conditions of SBR technology. The main results are as follows:1. Influence of the raw water pH. When the initial water pH was between3and5, the effect of Fenton oxidation is the best, the removal rates of COD is up to67%. When the initial pH is greater than6, due to the influence of OH-, the catalytic reaction by Fe2+will be inhibited, as a result, the efficiency of oxidation is reduced.2. Influence of the oxidant dosage. The removal rates of COD is proportional to the dosage of hydrogen peroxide, the more the greater the removal efficiency. But out of regard for the economic of wastewater treatment, the subsequent biochemical treatment can be achieved by controlling the dosage of hydrogen peroxide in2.5ml/L3. Influence of the catalyst. The catalyst FeSO4plays a crucial role in the wastewater treatment by Fenton oxidation. In this experiment, the dosage of FeSO4is controlled at1g/L, which can achieve the oxidation reaction, and reduce the color degrees produced by Fe2+4. Influence of reaction time. Reaction time does not exist a significant effect on the Fenton reaction. In the single-factor test, when reacted120minutes, the removal efficiency of COD is maximal, while the optimum reaction is60minutes in the orthogonal experiment. Out of economic consideration, reactions time can be controlled in60minutes.5. Through the orthogonal experiment, the best reaction conditions was eventually identified as H2O22.5mL/L,FeSO4·7H2O1g/L, and reacted60minutes, After Fenton preoxidation, the BOD5/CODcr of wastewater increased from0.183to0.484, the biodegradability significantly improved, and so the follow-up biological treatment can be achieved.6. Fenton oxidant has no obvious effect on oxidation of ammonia, so stripping the high concentration of ammonia nitrogen in water after biochemical treatment, final effluent ammonia concentration dropped to20mg/L, the effect is obvious.7. Using SBR technology in-depth treatment of the water after Fenton pre-oxidation, in the effective volume for18L of the reaction containers, with sludge concentration for3000mg/L, oxygen for15L/h, after2h of aeration, when treated2h, the final effluent COD was maintained at about50mg/L, the results are satisfactory.