Research on the removal of fluoride from low-concentration fluorine-containing industrial wastewater using adsorption methods

Abstract

To address the need for deep fluoride removal of low-concentration fluorine-containing industrial wastewater (2–10 mg/L) to below 1.5 mg/L in centralized industrial wastewater treatment plants, a study was conducted using adsorption methods. The adsorption performance and influencing factors of four adsorbent materials—active alumina (AA), hydroxyapatite (HAP), fly ash (FA), and bone char (BC)—were investigated. The results indicate that positioning the adsorption fluoride removal filter at the tail end of the industrial wastewater treatment process yields a fluoride removal efficiency that is over 10 % higher compared to placing it at the front end. The investigation into the adsorption effectiveness of the four adsorbents revealed that HAP dosage only needs 2 g to reduce 250 ml fluorinated industrial wastewater containing 2–10 mg/L to the target concentration of 1.5 mg/L or less. Moreover, the adsorption process requires only 30 minutes. From the perspective of adsorption performance, HAP is the most effective, followed by AA. However, considering the cost of these adsorbents, AA is more suitable as an adsorbent for treating low-concentration fluorine-containing wastewater. The findings of this study can serve as a valuable reference for the process design of deep adsorption fluoride removal in projects involving fluorine-containing industrial wastewater.