Abstract: Aiming at the problem of effluent violating discharge standards due to the high fluorine content in coal gasification wastewater, this paper conducts a comparative analysis of the defluoridation technologies including activated alumina adsorption, cationic chelate resin adsorption, and defluoridation reagent coagulation and precipitation on the basis of clearly defined control indicators and comprehensive water quality analysis. According to the application results, the paper carries out the condition optimization experiments regarding different reagent dosages for fluoride removal and proposes appropriate technology. This provides technical support for reducing fluoride content in coal gasification wastewater pretreatment to achieve discharge in compliance with national standards?.

Key words: coal gasification, wastewater, defluoridation, reagent, coagulation sedimentation, discharge in compliance with national standards