Activated alumina is a molecular adsorbent with a huge specific surface area. When the pH value of water is 7.1, the order of its affinity for adsorbing anions is OH>F>SO>CI>HCO,. (Deionized water equipment) When the pH and alkalinity of the raw water are low, the fluorine removal capacity is higher, the price is lower than that of synthetic resin, and it can also be used to remove arsenic from drinking water.
What is activated alumina filter?
The acid-base titration test and fluorine removal filtration test of activated alumina suspension confirmed that the microscopic mechanism of the adsorption mode and binding form of activated alumina to fluoride ions in water can be solved by the interface coordination reverse house mode to solve the content of various influence factors. .
The research methods and results are as follows.
(1) Materials and methods.
Preparation of activated alumina suspension. Firstly, activated alumina with an average drawing diameter of 20mm is soaked in 0.1mINaOH solution for 8h activation treatment, and then rinsed repeatedly with swallow storage water to neutrality, dried at 105~110C, and weighed for use Different concentrations of NaCI solution prepared 50g/L activated alumina suspension. Four titration test. First, use 0.1 mol/L superior grade pure hydrochloric acid or 0.1 mol/L superior grade pure caustic soda for 2.0-2.5 g/L activated alumina suspension containing 10-‘mol/L and 10-mol/L NaCI Carry out acid-base titration and pH value determination, then add different amounts of NaF to the 2.0-2.5g/L activated alumina suspension with the same Naa content, perform acid-base titration, and determine the pH value and F-concentration of the suspension.
@Back titration test. Use the same hydrochloric acid or caustic soda to perform a back titration test on the supernatant of the suspension that reaches the end of the titration. The end point is the pH value when the positive and negative loads are equal, referred to as pHro
@Measurement of fluoride absorption capacity. The concentration of F remaining in the activated alumina suspension when the adsorption equilibrium is reached is measured. 5 Fluorine absorption kinetics test. The fluorine content [F-] is 10mg/L. The raw water with a pH value of 5.5 flows through an activated activated alumina column (the length to diameter ratio of the column is 8:1), which contains y-Al, 0, activated alumina 300g, the water flow filtration rate is 1.5L/h, the fluorine content of the effluent is determined