Experimental Study On Advanced Treatment Of Coking Wastewater By BAF

After secondary treatment, Coking wastewater contains higher COD and ammonia nitrogen, and so on, which can not reach the effluent standard. So, it shoud be treated deeper. Ordinary activated sludge process is adopted, which comes to fruition and which thallus drains easily, leads to higher pollutant concentration in the effluent. Therefore, it is imperative to develop a kind of coke plant wastewater treatment, which should be economic and technique feasible.A technology of Immobilization Organism and activated sludge process gets over these deficiencies, BAF contents these, BAF is adopted for deeper treating coking wastewater. It shows that several factors, such as temperature, HRT, organic load and the media height, can influence the efficiency of UBAF. The total height of reactor is two meter and the media height is 1.4 meter. The most of COD is removed in the bottom of 460mm and in the bottom of 1120mm. In the same course, chroma and COD is removed. In the whole course, COD and NO₂^--N perform inflexion, ammonia nitrogen drops all along. NO₂^--N drops first, then rises. While COD<101.68mg/L and chroma<176.3, the two keep linear relation. In the Organic load range(load of COD between 0.5 and 0.8 kg/(m³Â·d), load of ammonia nitrogen between 0.2 and 0.4kg/(m³Â·d)), the removal of COD and ammonia nitrogen with the rising organic load. However, it can not keep linearity all along, after organic load exceeds some point, the removal drops. When the average concentration of COD in influent is 207.3～326.5 mg/L, ammonia nitrogen is 82.5～154.3mg/L, and chroma is 500, air input is 100mL/min, inflow is 8mL/min, the average concentration of COD in effluent is 101.68mg/L, and the average removal of COD is 60.74% . The datas for ammonia nitrogen is 8.5mg/L and 94.2% . The datas for chroma is 176.3 and 65.3%. after debugging the back washing several times, deciding period of back washing is 7days. Times of back washing persists 10 minute, fist, air input and inflow of back washing are 120L/h, 20L/h, respectly. Then bck washing with inflow for five minute.