Research In Total Nitrogen Removal Of Coking Wastewater Of Baosteel Chemical Company

Coking wastewater is a kind of wastewater with high concentration of organic matter which is difficult to deal with,which contains a lot of substances which are degraded by microorganisms.Coking wastewater is a kind of high concentration organic wastewater which is toxic and difficult to be degraded.The high nitrogen content in the coking wastewater,a large amount of nitrogen into the natural water will lead to a sharp decline in dissolved oxygen in the water,the fish will die,excessive algae breeding,resulting in eutrophication and other hazards.Therefore,it is very important to improve the nitrogen removal rate of coking wastewater.In 2009 the requirement of the Shanghai Integrated Wastewater Discharge Standard(DB31/199-2009),which put forward clear requirements for the total nitrogen,total nitrogen in the wastewater is required 35mg/L.Series of tests and the industrial transformation have been completed to remove the total nitrogen in coking wastewater of Baosteel.With all these steps,the coking wastewater treatment of Baosteel reached the established goal:total nitrogen≤35mg/L,reached the requirements of the new standard of ShanghaiThrough research shows the nitrogen removal efficiency of A/A/O/O and A/A/O process in Baosteel chemical industry is poor,its nitrogen removal efficiency is poor,only 62.29%and 48.26%,can not meet the requirements of the Shanghai Integrated Wastewater Discharge Standard(DB31/199-2009).The total nitrogen in the effluent was 84.2mg/L and 121.4mg/L,the data of total nitrogen in effluent can not meet the requirements of the new standard of Shanghai.Through the study of SBR nitrogen removal in Baosteel,the denitrification efficiency of coking wastewater can be increased from less than 65%to more than 95%,using sodium acetate and sodium acetate as the carbon source.The experimental results are applied to engineering reconstruction,using A/O/A/O technology,composite carbon source using methanol and sodium acetate,through two step process for nitrogen removal of coking wastewater can achieve the drainage of total nitrogen is less than or equal to 35mg/L,reached the new emission standards for the requirements of Shanghai city.The nitrogen removal efficiency was increased to 96.38%and 95.01%,and the cost is reduced RMB 21.6 million yuan per year.