| Coal chemical industry wastewater is a kind of refractory industrial wastewater, mainly composed of gas washing wastewater. The water composition is complicated, pollutant concentration is high, the traditional water treatment technology is difficult to ensure effluent COD, total phenol, ammonia nitrogen and colority reached the national standard. The wastewater treatment of coal chemical enterprises at home and abroad always restricts the development of the industry. To seek an economic and efficient coal chemical industry wastewater treatment process is imminent. So this topic is based on A domestic coal chemical industry wastewater treatment engineering, based on the project of "biologically enhanced- multistage A/O system" process and the engineering data, to study the process of coal chemical industry wastewater denitrification effect, and through the field test in simulation experiment, to explore the optimal operation parameters of the process, etc., will provide practical experience for other coal chemical industry wastewater treatment project.This topic is divided into three parts. The first part through the field test, the coalification biochemical factory wastewater treatment engineering section of the "biological enrichment and improvement of AO" process condition during start-up and stable operation. During the stable operation of the biological enrichment inside temperature of 25 ℃ ~ 30 ℃, p H 6.5 ~ 6.5, the sludge concentration remain at around 5000 mg/L, the DO concentration between 0.3 ~ 0.5 mg/L, in a state of low dissolved oxygen. Improved pool pool during stable operation of A/O p H 6.5 ~ 7.5; Temperature stability in 30 + /- 5 ℃, sludge concentration is about 2500 ~ 3000 mg/L, and oxygen area to keep the DO value of 0.1 ~ 0.5 mg/L, the aerobic zone to keep the DO value is about 5 mg/L. This technology has a strong ability of dealing with waste water in coal chemical industry, the removal rate of COD, total phenol and ammonia nitrogen are around 90%, the water concentration in 100 mg/L respectively; About 20 mg/L and 10 mg/L.The second part through the field test and simulated field improved A/O process. Experiment shows that the improved A/O process the best section water ratio of 1:1; C/N on the system the water denitrification efficiency, with the increase of C/N ratio, nitrogen system more efficient, but the C/N increases to a certain value, continue to increase, the system denitrification performance is not obvious, consider running cost, a reasonable test to determine the C/N = 15. Circulate fluid backflow test found in the absence of the improved system of A/O denitrification effect under the condition of good in the inner loop flow condition, the total nitrogen removal rate was 88%, which is about 60%. It may be considered according to the practical engineering in the actual water quality, adjust the size of the reflux ratio.The third part through to the improved A/O process for ammonia nitrogen and COD degradation dynamics research, it is concluded that the reaction of ammonia nitrogen degradation series n=0.357, the reaction rate constant k=0.462; COD degradation kinetics equation =2.72S35.81+S, which Ks = 35.81 mg COD/d.From what has been discussed above,we can think " biologically enhanced-multistage A/O " combination of biological nitrogen removal process is suitable for coal chemical wastewater treatment units, can effectively deal with recalcitrant coal chemical wastewater, can be applied to promote. |
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