| Aiming at the current design of small oil refinery wastewater treatment relatively simple, the sewage of which can not achieve stable discharge according to new standards, the wastewater treatment plant of a refinery in one group of Shandong was used as the research object, the grease + flotation + SSF + water + Hydrolysis of biological contact oxidation + BAF's technological transformation process was adopted in the premise of making full use of the original structures and reducing energy consumption through analyzing the problems to the sewage treatment plant. The units of stripping of the acid water, suspended sludge filtration system and the aerobic system and other key elements were tested, and the expected results and the investment budget unit were also studied.In acidic water stripping unit, the influence of temperature to stripping effect was studied through four kinds of programs. The experimental results showed that with the increase of temperature of the acidic water into the tower, the removal rate of ammonia nitrogen increased, the concentration of H2S in exhausted gas also increased, the impact of which to COD unpaired linear, but the removal effect of high temperature to COD was still good. When acidic water temperature reached 70℃, the removal rate of ammonia nitrogen could reach 47%, the concentration of H2S in exhausted gas could reach 15000mg/m3, and the COD decreased 62.6%. Without increasing pH value and power consumption, various kinds of pollutants all achieved a better removal effect through the air stripping. Because of the lower water amounts, the concentration of pollutants could decrease after mixing with other water, which could reach the influent conditions of ammonia nitrogen less than 100mg/L in sewage treatment plant. So this experimental program was feasible.The pilot test results of suspended sludge filtration system (SSF) showed that after treatment by SSF process, most of the oil slick and emulsifying oil of sewage could be removed, and the removal rate of oil could increased 20 percent compared with the original flotation device, which could also make the oil content (dissolved oil) of sewage entering the biological treatment system stable. Thus the biological wastewater treatment system could be ensured long-term stable operation. In addition, the flotation device could be ceased, the sewage treatment process could be shorten and the operation,maintenance and running costs could be reduced after applying SSF technology.The test results of aeration system shock resistance showed that the method of adding dosage strengths and microbial activity inducing agents adopted by biological growth-promoting could raise the removal rate of COD and biochemical stability, but which could not significantly increase the removal rate of ammonia nitrogen. During the experimental period, the irritating odor of aeration tank disappeared, the sludge concentration increased and gradually became healthy color. Even if the pollutant concentration of runoff increased, the sludge still had no substantial mortality, the impact resistance of which had a substantial increase, which indicated that the program of using biological growth-promoting to improve the impact of sludge aeration tank capacity was feasible.The research results on the expected effect and investment budget to the device of total processing capacity of 120m3/h showed that after treatment by the device, the CODcr, ammonia nitrogen, oil and pH value of sewage all could reach, and the total project investment was 3.63 million yuan. If the waste water treatment capacity was measured by 480,000 tons/year, a ton of water treatment costs would increase 0.9 yuan if achieving discharge standards after the process was modified.
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