Treatment Of Coking Wastewater Using A Process Including Fenton-oxidation, Coagulation And Cedimentation

Coking Wastewater is produced in the coal carbonization process at high temperature, coal gas purifying and the process of refining chemical products, etc. Components in the wastewater are very complex, which includes many pollutants, such as hydroxybenzene, ammonia (usually recovered ammonium sulfate), cyanogen, phenol, indole, quinnoline, and so on. Due the high concentration, toxicity and stabilization of thus pollutants, coking wastewater in high color becomes as a kind of typical organic wastewater that difficult to degrade.The effluent of coking wastewater treated by common procedures is very difficult to meet the increasingly stringent environmental standards in China. How to improve the effluent water quality becomes a hot point in present studies. In recent years, some new methods and technologies were employed to remove coking wastewater, which bring some disadvantages as advantages. For instance, the content of COD and NH3-N in the effluent after treatment by bio-oxidation is relatively high, which couldn't reach the discharge standard. Although the adsorption is efficient to remove COD, the density of NH3-N in the effluent is a bit high, which also leads to the problems of regeneration of the adsorbent and even the secondary pollution. Photocatalytic oxidation could remove the difficult organic matter effectively, but it exits large distance for industrial application, since the replacement of ultraviolet ray with sunlight is a difficult and enormous break-through. The method allied Anocix and Oxic to remove coking wastewater has broad prospect for practical application. It could be predicted that, the process allied many treatment technology for the removal of coking wastewater will be the developing direction.The technology is being widely studied by using Fenton reagent (Fe²⁺+H₂O₂) as oxidant to oxidize non-biodegradable pollutants in wastewater. This paper was studied on the removal of coking wastewater in a factory using pre-oxidation-coagulating method. The whole experiment included two steps. Firstly, the best experimental condition of coagulation using ferric chloride, PAM as coagulant was studied. Secondly, the best experimental condition of pre-oxidation-coagulation was studied. The results showed that, the method of pre-oxidation-coagulating is much better than the method which only used coagulating sedimentation. In the treatment of coking wastewater using...