Combination Of BAF And Ozonation For Enhancing Phosphorus And Organic Pollutants Removal Treating Petrochemical Secondary

Petrochemical Wastewater organic content is high, is difficult to handle.Petrochemical wastewater secondary effluent still contains large amounts of refractory organics, The petrochemical industry, new emission standards promulgated by the Ministry of Environmental Protection in 2015, improve the COD emission limits to 50mg/L or less. At the request of this environment, many of petrochemical complexes of the petrochemical wastewater treatment plants need advanced treatment of secondary effluent meet the new emission standards to reduce emissions of organic matter and nitrogen, reduce the load on the environment.This topic combination BAF and ozonation for enhancing phosphorus and organic pollutants remowal treating petrochemical secondary, study of adding different amount of FeSO4.7H2O on the BAF batch reactor for phosphorus removal, carbon removal, nitrogen removal and effect on microbial activity; Research reactor operating parameters to strengthen phosphorus removal pilot organic matter and nutrient removal; removal of organic and nutrients along the reactor was analyzed; Backwash strength parameters were optimized; To strengthen the combination of ozone and phosphorus BAF-depth treatment of petrochemical wastewater secondary effluent were studied, The optimum dosage of ozone, and the effect of ferrous iron on the oxidation of ozone was studied. Experimental results show that:1、When the dosage FeSO4.7H2O is 9mg/L, TP removal rate was 51.7%, not only pharmaceutical dosing removal 12.4%; COD removal rate of 4.1%, FeSO4.7H2O investment amount of not more than 9mg/L, the ammonia removal efficiency can be improved, Advantageously the removal of TN dosing FeSO47H2O cause hypoxic microenvironment; Tthe amount of microbial decreased after adding ferrous salt, but microbial activity increases, ferrous salt dosage when 12mg/L-1 showed inhibition of SOUR, then when 15mg/L showed inhibition of dehydrogenase activity.2、When HRT is 3h, gas-water ratio of 3:1, COD, ammonia nitrogen, TN, TP, SS removal efficiency is maximized, respectively,18.43%,70%,15.64%,49.71%,48.64%,BOD5 removal to 70.29%; When the filter layer height is 95cm, the highest COD, ammonia nitrogen, TP, SS removal efficiency; The effect of BAF on the removal of fluorescent organic compounds is not obvious.3、Washing intensity of 6 L/(m2.s), air wash strength of 12 L/(m2.s) is to strengthen phosphorus removal BAF pilot reactor optimal strength backwash backwash drainage SS peak in time 3min peak, the final backwash drainage SS concentration of 50 mg/L, backwash wastewater sludge respiration rate was 0.5 mg/(mg·h), the amount of micro-organisms from the water inlet 1.3 and 2.2 m at each loss 4.4% and 5.3%; increase the intensity of the air wash can cause losses of microorganisms increases, and have a greater impact on the late recovery, and reduced strength air wash is wash is not complete. After backwash the removal ability of COD and NH4+-N was decreased, but quickly removed the ability to recover, and as the run continues to slowly decline.4、On the basis of the optimum operating parameters of the BAF, when the ozone dosage is 10mg/L, the average removal rate of COD reached 38.03 percent, effluent COD reached 35.54mg L, TOC removal rate was 11.45%; TP concentration from 0.47mg/L decreased to 0.094mg/L, UV254 dropped from 0.65 to 0.167; effluent color are under 25, containing organic nitrogen by ozone oxidation into NH4+-N caused ammonia concentration increased, but does not affect the effluent discharge standards.5、Fe2+ subsequent ozone oxidation unit has a role in promoting, the average COD removal rate was 39.59%, the concentration of ozone water is 38.62mg/L, the COD removal rate was 20.75% without dosing FeSO4, UV254 dropped an average of 0.549, without FeSO4 dosing of UV254 an average drop of 0.406, and the removal of color dosing FeSO4 also have some effect. After ozonation, fluorescent substances significantly reduced, part of the organic matter mineralization to CO2 and H2O, the volume of each substance relative molecular mass of a decrease in a great extent.