Fluoride removal in a water treatment plant using alum 2

Don't know where to getthe information, other then EPA Toxicology website, but you would be better off looking at Lanthanum chloride to grab the arsenic and floride, as alum does not work well at pH's over 7.5. Lanthanum has been used by the Japense to remove high levels of arsenic (3parts lanthanum to 1part arsenic)and I know Lanthanum grabs selenium, chromuim, carbonates, other metals. Works at pH's up to 12, and won't release till exposed to acid at levels below pH 3. Lanthanum now being used to remove phosphate's in humans (liver transplant receipients) - product called Fesnerol. Alum will create a toxic sludge at a lake, river, stream substrate, where lanthanum does not.

Bone char is effective in both these ions, although it is more effective on Arsenic III rather than V. In floride removal Bone char will remove 80% of the ions present

The AWWA has information available.


You might purchase the textbook "Water Quality and Treatment" published by the AWWA.

Hi

If you can use bone char to remove fluoride effectively, let's say 90 % removal, remaining concentration is still higher than its standard for drinking water. It can cause flourosis, anyway.

I found this information from "Water Treatment Principles and Design" by James M Montgomery that fluride was reduced from 3.6 to 1.4 mg/L using 250 mg/L of alum.

hope it can give you some idea.

Al2(SO4)3 is good for As removal. FeCl3 is better.
(I´m working on F-, I´m also looking for F- removal wastewater treatment.) CaF2 is very insoluble but I think it is not enought for drinking-water. No bad will do to use Ca(OH)2 to adjust pH.
You may need a poliacrilamide as floculant.
I recommend laboratory assays (Jar Tests) and analysis.

There is a pretty good bit of information on arsenic removal at: 2the4.net/arsencart

Included is a discussion of ferric ion coprecipitation of arsenic. This should tie into removal of Flouride with ferric chloride.

Also included is a rather extensive list of references relating to arsenic treatment

Hope this info is useful