In the past two or three decades, a great deal of research has been conducted on the treatment of fluorine-containing water in China and abroad. Some progress has also been made in the research on defluorination technology and related basic theories. At present, fluoride removal methods for fluorine-containing water include adsorption, electrocoagulation, reverse osmosis, ion exchange, chemical precipitation, and coagulation sedimentation. Among these methods. In the process of fluoride removal by adsorption, the adsorbent needs to be regenerated to recover its adsorption capacity after reaching saturation. At present, the most commonly used adsorbent is activated alumina adsorption.
When activated alumina adsorption reaches saturation, regeneration treatment is required. It can be regenerated using aluminum sulfate or sodium hydroxide. Activated alumina regeneration process will have a high concentration of fluoride-containing wastewater. Including an average F-1000mg/L or so, according to "Integrated Wastewater Discharge Standard" (GB8978-1996), F- is 10mg/L, so it must be discharged after special treatment.
Activated alumina regeneration wastewater treatment process test basic conditions: test device dimensions Φl60mmx3000mm, built-in activated alumina 30L, loading height 2000mm; regeneration method using 1 times 3% NaOH solution shower 2h, followed by 5 times water leaching 1.5 h, then neutralize the solution with 1 times of 1% H2S04 for 1.5 hours, and finally wash with 0.5 times of 2 times of clean water to the pH value of the effluent of 6-7; the regeneration flow rate is 60L/h.
It has been verified through practice that the best treatment method for activated alumina fluoride-removing wastewater is: The three-stage chemical coagulation and precipitation method using CaCl2+PAC+PAM is an effective and applicable process for treating high-content fluorine-containing wastewater, and can be stably achieved. The first-class discharge standard for comprehensive wastewater discharge standards.
For high effeciency activated alumina for water treatment, please choose XR105 activated alumina. It is good performance in the defuorinating.