Study On Coking Waste Water By Coagulation

In this paper , processing coking wastewater from BaoSteel biologically treated for further treatment aimed to remove F^-, CODcr, chroma, is researched..Exploit an new agent aimed at coking effluent on the basis of Series coagulation experiments.Coking wastewater is treated by calcium hydroxide, aluminum sulfate polyaluminium chforide ,polyferric sulfate and M180 respectively ,to research optimum coagulation reaction conditions such as pH ,dosage of coagulant .Then use these coagulants together with Ca(OH)₂ and the additive B .confirm optimum coagulation reaction conditions also includes pH and proportion of eachingredient.experiments indicate calcium hydroxide is not so good neighter in F^- removal nor in CODcr removal, aluminum sulfate is superior to others in F^- removal,polyferric sulfate is better than others in CODcr removal, while as to the given coking effluent , PAC is not so better than Al₂(SO₄)₃. Optimum coagulation conditions as follows, optimum dosage of Al₂(SO₄)₃ is 1200ppm,pH range from 6.5 to 7; optimum dosage of PAC is 0.5ml pH range from 6.6 to 7; optimum dosage of PFS is 1000-1200 ppm, pH condition is 5 around.As to M180 , pH condition is 7 around,maximal dosage is 1500ppm.The results show that the optimum decolouration pH is lower then the optimum CODcr removal pH,while as achieving the best defluorination performance the optimum pH is 7 around.The coagulation reaction progressing very quickly ,complete the reaction in 30mins. Higher F^- removal efficiency will get by using coagulant together with Ca(0H)₂ and the additive B. But along with the dosage of B increasing ,CODcr value enhancing.A kind of efficient fluoride removal agent is attained during this study.All the experiments indicate that more than 95% F" are removed by the efficient fluorideremoval agent. The agent is applying to coking wastewater from BaoSteel.