Study On Treatment Of Coking Wastewater By Hydrolytic Acidification+SBR Process

Coking wastewater is a kind of the organic wastewater containing large amount of deleterious harmful pollution, when discharging large amount of this water, which can take direct or indirect carcinogen that are harmful to a lot of living things to environment , do harmful to the environment, and threat to human being's health directly. The experiment applyed hydrolyzation acidification + SBR on coking wastewater which from sewage treatment station of Liu Zhou iron and steel Corp.During these experiments, the proper operation parameters of ammonia distillation treating coking wastewater was discussed mainly, and discussed the feasibility of the technology of hydrolyzation acidification +SBR, and the proper operation parameters of flocculation, which can give scientific basis for actual project. The main conclusions are as follows:â‘´The experiment of ammonia distillation indicates that coking wastewater'pH value is obviously affected to the effect of ammonia distillation , when pH value is high , the effect is better. When adjusting pH value at 10, the removal rate of COD is 50% , ammonia nitrogen is 56.3%.⑵The coking wastewater which from the process of ammonia distillation firstly comes to the hydrolyzation acidification process. When COD in influent is 1000 mg/L, HRT is 6hs, and the temperature is 25℃- 30℃, the removal rate of COD is 20%, BOD5/COD has improved 0.09, this can improve the biodegradability of wastewater, and crate benefit conditions for further treatment.⑶In the process of aerated nitrification of SBR, when COD and the ammonia nitrogen in influent are 1000 mg/L and 300 mg/L, respectively, pH value is 7.5-8.5, sludge loading is controlled in 0.26kgCOD/kgMLSS·d, and the temperature is 35℃, the removal rate of COD and ammonia nitrogen are 64% and 42%, respectively; in the process of denitrification of SBR, controlling the time of stiring for 4hs, and the temperature is 25℃, the removal rate of nitrite nitrogen amounts to 80% , the effect of denitrification is well.â‘·The result of the hydrolyzation acidification + SBR experiment indicates that: When COD and the ammonia nitrogen in influent are 1000mg/L and 300mg/L, respectively, the temperature in hydrolyzation acidification is 25℃-30℃, HRT is 6hs, HRT of aerated nitrification of SBR is 12hs, stiring in anoxic denitrification process for 4hs, the COD in the effluent is 260mg/L, ammonia nitrogen is 168 mg/L. But the water still can not reach the standard.⑸Flocculation is used for the further treatment of coking wastewater which came from SBR reactor.The result of the experiment shows that: To Fe₂(SO₄)₃ ,which has the better flocculation effect, when the reagent feeding quantity is 300mg/L, pH value is 7, the removal rate of CODcr and chroma is 50% and 75%, respectively. When adding PAM1mg/L , the removel rate of COD has increased by almost 10%, when compared with adding no PAM. The effect has been improved.