https://www.jinaipu.com/UpFile/20130417145549.pdf

Preparation of agricultural by-product based anion exchanger and its utilization for nitrate and phosphate removal

Adsorption removal of ammonium and phosphate from water by fertilizer controlled release agent prepared from wheat straw

Adsorption of phosphate from aqueous solutions onto modified wheat residue: Characteristics, kinetic and column studies

https://www.app-one.com.cn/UpFile/20130417144948.pdf

Optimized conditions in preparation of giant reed quaternary amino anion exchanger for phosphate removal

Preparation, characterization of wheat residue based anion exchangers and its utilization for the phosphate removal from aqueous solution

Purification of dilute hydrofluoric acid by commercial ion exchange resins

The removal of As(III), Fe(III), and Cr(III) at trace levels from HF solutions by means of specialty ion exchange resins has been investigated. These impurities are usually found in technical‐grade HF, and they need to be removed to prepare metal‐free HF for the semiconductor industry. It was assumed that Fe(III) and As(III) species in dilute HF were present in anionic form, while Cr(III) was probably in neutral form, CrF3. First, a selection of specialty ion exchangers was performed. Then, fixed‐bed experiments were carried out to check the ability of selected resins to reach the impurity levels required in SEMI C29 for 5 wt.% HF (5 ppb of As, and 10 ppb of Cr and Fe). The effect of the flow rate and the HF concentration on the metal removal was studied with Purolite D‐3777 and Fuji PEI‐CS‐07 resins respectively. Fuji PEI‐CS‐07 showed the best performance for Fe(III) removal, even at high HF concentration (25 wt.%). A strong decrease in the Cr(III) and As(III) removal capacity with increasing concentrati...

J. L. Fernández

Papers

Purification of dilute hydrofluoric acid by commercial ion exchange resins

Removal of Arsenic(III), Chromium(III) and Iron(III) Traces from Hydrofluoric Acid Solutions by Specialty Anion Exchangers