Surface functionalized diatomaceous earth for effective adsorption of strontium from aqueous solution

Effective cesium removal from Cs-containing water using chemically activated opaline mudstone mainly composed of opal-cristobalite/tridymite (opal-CT)

“…2 b), the bands at 1034 and 3396 cm −1 of base-activated OM showed insignificant changes in width and intensity, indicating that Cs adsorption was related to the siloxane and hydroxyl functional groups. These results were similar to the adsorption sites of silicate minerals such as diatom frustules and opal reported in the previous studies 21 , 25 , 32 . We also conducted the SEM and TEM analyses to confirm the Cs adsorbed on the opal-CT. We conducted the SEM–EDS analyses to confirm the adsorption of Cs cation on the surface of opal-CT in acid- and base-activated OMs (Fig.…”

“…However, the Si‒O‒Si functional groups (1034 cm −1 ) of acid-activated OM had a slightly narrower width compared with other activated OMs. According to the previous studies 21 , 25 , 32 , the siloxane and hydroxyl functional groups such as bands ranging from (1034 to 1071) cm −1 and (3396 to 3623) cm −1 were active adsorption sites. The change in these absorption bands was observed after Cs adsorption (Fig.…”

“…However, a band at 1034 cm −1 represented as Si‒O‒Si stretching vibration of acid-activated OM was slightly narrow compared to that of non-activated OM. It might be that acid-activation caused the deformation of Si‒O‒Si functional groups of the mineral surface 25 . In terms of physico-chemical properties (Table 1 ), the SSA and CEC increased from (67.58 to 101.62) m 2 /g and (12.21 to 24.44) cmol/kg, respectively.…”

“…Hence, diatomite has widely been used as a filtration medium. Previous studies 20 – 23 , 25 reported that diatomite was used as an adsorbent for various cations such as copper, cadmium, lead, and strontium. Other studies 24 , 26 also reported that the diatomite was used to remove the radioactive Cs.…”

A SERS platform based on diatomite modified by gold nanoparticles using a combination of layer-by-layer assembly and a freezing-induced loading method

“…13 The main commercial use of processed diatomite is in the food and construction industries, but it also has applications in the chemical, agricultural and related industries. [14][15][16][17][18][19][20][21] Besides, many studies have demonstrated the potential of diatomite as a drug delivery system owing to its biocompatibility, non-toxicity, highly porous structure, high surface area, easy functionalization, and low cost. [22][23][24][25][26][27][28] The advances made using diatomite as a source of silica, silicon-based materials, and templates for energy-related applications are provided in the latest review article.…”