| Coking wastewater is essential in the production of coking industry in our country and is a high concentration of organic wastewater discharged in the process of coal coking, raw gas cooling and product processing. The article takes biochemical water treatment system of Heimao coking plant as the research object makes use of different test methods to analyze the effluent from each biochemical tank and studies some problems of biochemical system and provides solutions. At last, make use of pulverized coke to treat the biochemical effluent of deep water in system. Results are as follows:(1) According to the water pollutant emission standard (GB13456-1992) of the iron and steel industry in our country, the water quality of the Heimao coking plant is as follows:The content of NH3-N and volatile phenols was in full compliance with the national emission standard, and the removal rate was as high as 100%; COD emissions basically meet the emission standards, the removal rate is 94.8%; The discharge of sulfide and cyanide is overwhelm the discharge standard, the removal rate of cyanide is only 69%; pH value is maintained at a stable value to ensure the growth and reproduction of microorganisms.(2) Study the effect of temperature change and system load on biochemical water treatment system and know that the different handling capacity in four seasons. In spring, temperature is moderate. Not only the most suitable for water treatment system operation, but also the higher removal rate of pollutants; But in winter temperature is low, the treatment efficiency of biochemical system is decreased, and the removal rate of pollutants is generally decreased; When the temperature is high in summer, the treatment efficiency of biochemical system is the lowest, and the removal of pollutants is not obvious System loading of biochemical water treatment system is significant. A2/O water treatment system of NH3-N removal basically paralyzed While wastewater emissions and pollutant concentration is too high. NH3-N concentration decreasing instead, two main index of sulphide and COD have also been affected, the removal efficiency decreased remarkable.(3) The author explores problems of sludge floating, bubble problem and sludge return ratio during coking plant normal operation. Sludge floating occurred mainly in aeration tank and secondary sedimentation tank. Due to aging caused by the sludge, aeration tank can be taken timely discharge of sludge method to solve; Secondary sedimentation tank is mainly caused by the sludge removal nitrogen and sludge decay, sludge nitrogen removal can reduce the aeration tank in water, sludge rot can increase the amount of aeration.(4) In the advanced treatment of fine coke, the method of using fine coke to adsorb Coke-chemical wastewater is studied to reduce the pollutant in water. In the experiment of the single factor of COD and chroma removal rate of the fine coke, five factors are examined mainly:fine coke dosage, fine coke particle size, temperature, solution pH and adsorption time. Through experiments, in the conditions of 200g/L,5?6mm,25? room temperature, pH=8,3hrs, the temperature is 25?, the adsorption efficiency is the highest. Make use of orthogonal experiment to study the effect of fine coke on COD removal rate and chroma removal rate and obtain an optimum experimental method:fine coke- 200g/L, the size of coke powder-5-6mm, pH-8, the adsorption time 2.5hrs. All five validation experiments were carried out under this condition. The average removal rate of COD was 66.79%, and the chroma removal rate was 72%.It can be known that the coke powder has a certain significance to the advanced treatment of Coke-chemical wastewater. |
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