Cost-effective phosphorus removal from aqueous solution by a chitosan/lanthanum hydrogel bead: Material development, characterization of uptake process and investigation of mechanisms

Removal of Low-Concentration Phosphate Adsorption by La–Ca–CO3 Material: Performance, Mechanism, and Applicability

“…However, Wu et al reported that the presence of SO 4 2– may inhibit the phosphate removal by La-based materials because of the similar ionic radius of SO 4 2– and PO 4 3– , in which such two anions may compete for the same active adsorption sites . This also indicates that La–Ca–CO 3 adsorbent has superior selective adsorption performance for phosphate, probably due to the strong inner-sphere complexation between lanthanum and phosphate . In contrast, the presence of HCO 3 – could inhibit the phosphate removal with around 27% decrease in the adsorption capacity, which is consistent with other studies which reported La-based adsorbents for the phosphate removal .…”

Efficient removal of tetracycline from aqueous solution by K2CO3 activated penicillin fermentation residue biochar

“…Once the site was taken up by an adsorbed molecule, the site cannot be further adsorbed ( Zheng et al, 2021b ). Whereas the Freundlich isotherm model has an assumption about the non-homogeneity of the adsorbent surface, which is applicable to multilayer adsorption layers ( Koh et al, 2022 ). The correlation coefficient of IKBCH to the Langmuir model ( R 2 > 0.997) exceeds that of the Freundlich model (R > 0.626), indicating that the adsorption of TC on IKBCH occurred on the monolayer.…”

Green synthesis of a potential magnetic and mesoporous EG-nZVI/CA-MCM41 nanocomposite for reductive sorption of europium

“…49 Kinetic analysis can reveal the mechanisms of the sorption process, i.e., mass transfer and chemical reaction. 50 The pseudo-first-order (PFO) and pseudo-secondorder (PSO) kinetic models are applicable to elucidate the physical adsorption and chemosorption process based on the availability of vacant sites on the surface of the adsorbent and the rate of sorption, 51 as described in eqn ( 10) and (11). (11) The intraparticle diffusion (IPD) model, also referred to as the "Weber-Morris model", describes the intraparticle diffusion properties of adsorbate ions on a porous sample.…”

“…The pore diffusion of Eu(III) sorbed by the inner surface of the nanocomposite is likely to explain the second stage of progressive adsorption on vacated adsorption sites, i.e., intraparticle diffusion rate. 50 The significant intercept of the second segment (in the q t vs. t 0.5 plot) suggests an impact of external mass transfer as a rate-determining step, although external diffusion and pore diffusion jointly control the entire Eu(III) adsorption mechanism. The fit of kinetic data to the Elovich model, which assumes no interaction between the adsorbed species, remains appreciably good (R 2 0.923-0.985) as shown in Fig.…”