Views: 0 Author: Site Editor Publish Time: 2023-09-15 Origin: Site
Today share you the testing process of CHEMXIN activated alumina KA402 for fluoride removal :
1.Bring fluorinated drinking water sample to measure the fluoride ion concentration as C0 by ion selective electrode method.
2. At pH value of 4-6 and 20°C, add a certain amount of activated alumina to the water sample, mix evenly, and react for a period of time (usually 30-60 minutes).
3.Stirring then let it stand. After the activated alumina precipitates, filter out the precipitate.
4.Measure the residual fluoride ion concentration in the filtrate as C by ion selective electrode method.
5.Calculate the fluoride removal rate R according to the formula R=(C0-C)/C0×100%.
R is the fluoride removal rate, %;
C0 is the fluoride ion concentration of the raw water, mg/L;
C is the fluoride ion concentration after treatment, mg/L.
How to Restore Activated Alumina Adsorption Efficiency？
Regenerating with aluminum sulfate: the concentration is 2% to 3%, and the amount of aluminum sulfate can be calculated based on “60-80g of solid aluminum sulfate (AL2 (sO4) 3-18h2O) is required for removing 1g of fluoride”, The regeneration time around 2-3 hours, and the flow rate roughly 1-2.5m/h. The regenerated solution in the filter must be removed after finish the regeneration process.
Regenerating with sodium hydroxide (NAOH): the concentration is o.75% to 1%, and the amount of aluminum sulfate can be calculated based on “8-10g of solid NAOH is required for removing 1g of fluoride”, the quantity of regeneration liquid is 3-6 times of alumina beads, the regeneration time around 1-2 hours, and the flow rate roughly 3-10m/h. The filter layer is alkaline after regeneration, it must be converted to acidic to remove F-ions from the water.
Chemical formula Of Regeneration :
(Al2O3)n·2HF + SO4 →(Al2O3)n·H2SO4 + 2F
CHEMXIN is one of leading ISO cetificated China manufacturer of activated alumina adsorbents since 2002. Our factory covers an area of 50,000M2 and have own R&D team. Our annual production capacity is 5000 tons, any needs, welcome contact us any time.