Experimental Study On Organics In The Double Membrance Water By Advanced Oxidation

Refining membrane concentrated water contains large amounts of bio-refractory organic matter, which are easy to enrich in the soil, water and other natural medium, and it also gradually enrich into the living body which will cause the living cells irreversible changing through the food chain, seriously affect the human health. The concentration of hazardous substances in double membrane separation water is generally 2 to 3 times than the biochemical effluent, the general activated sludge can not grow normally in it, so in the activated sludge culture process, in order to cultivate the general activated sludge growing in the double membrane concentration water,to increase the adaptability of microorganism of activated sludge to the double membrane concentrated water gradually, for that the microorganisms of the activated sudge can grow in the hazardous water normally. Therefore, this study use the ozone oxidation, O3/H2O2 combined oxidation and Fenton oxidation reducing the bio-refractory organics concentrated in the double membrane water; culturing the general activated sludge in the double membrane concentrated water that diluted by sewage; and stydying the result of biological activated carbon adsorbing and degrading the bio-refractory organics in the pretreatment water.This study firstly explore the optimal reaction conditions of the ozone oxidation, O3/H2O2 combined oxidation and Fenton oxidation as the pretreatment of the bio-refractory organic in the double membrane water, as the test results show that the optimal ozonation reaction conditions is that the flow of ozone is 2.5g/h, the pH is 9 and the reaction time is 30min; the optimal ozonation reaction conditions of O3/H2O2 combined oxidation is that the dosage of H2O2 is 150mg/L, ozone flow 2.5g/h, the pH is 7 and the reaction time is 30min; the optimal ozonation reaction conditions of Fenton oxidation is that the dosage of H2O2 is 300mg/L, the concentration of Fe2+ is 0.5mmol/L, the pH is 3 and the reaction time is 90 min. Comparing the treatment effect of the three advanced oxidation technology under optimal conditions for the double membrane concentrated organic water, the effect of Fenton oxidation as the pretreatment is the best, and the COD removal of the water samples which oxidated by Fenton is 36 %, B/C value increase from 0.08 to 0.20, indicating a substantial increase biodegradability. In addition, the general activated sludge and refinery activated sludge cultivated in the refining membrane concentrated water by a period of time, the microorganism gradually adapt to the double membrane dense water, which can grow normally in the concentrated water.After the pretreatment of the double membrane dense water by the Fenton oxidation, the concentration of organic matter in water is low, which can not meet the demand for energy of activated sludge microorganisms. Biofilm can handle low organic load of sewage, so pouring the acclimated activated sludge into the coal granular activated carbon columns to form biological activated carbon. Under the flow of 2 L/h, exploring the effect of the water that flow into and out of the device of biological activated carbon, the results showed that the treatment effect is better by refining biological activated carbon than the general biological activated carbon, but the general biological activated carbon can also get better treatment effect. Contrast of the degradation characteristics of the pretreated organic matter by the coal activated carbon and refining biological activated carbon under the same experimental conditions, the results show that the full adsorption time of activated carbon is 8h, but biological activated carbon don’t exist the full adsorption time during the four days continuous operation. In addition, scanning the water out of refining biological activated carbon by UV which the wavelength ranging from 200 to 450, by analying the UV chart we know that refining biological activated carbon do well in degradate the organic belong to the class of double bond and carbonyl compounds which response in the wavelength of 200-228 nm and 324-450 nm, especially organics responsing in the wavelength of 324-450 nm can be completely degraded, but activated carbon only adsorb the unsaturated hydrocarbons organic matter which response the wavelengths of 200-240 nm and 260-340 nm better.Summary the treatment effect of Fenton pre-oxidation + biological activated carbon advanced treatment to the refractory organic matter in the double membrane concentrated water, the COD removal of Fenton pre-oxidation + ordinary biological activated carbon advanced treatment of the refining double membrane concentrated organic matter water is 62.8%, but the Fenton pre-oxidation + refining biological activated carbon advanced treatment can get the result as high as 66%, the ultimate COD value is 37.4mg/L, reaching the refinery effluent standards.