English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The removal capacity of Pb(II) present in aqueous solution was evaluated, using as a sorbent the nanche stone (Byrsonima crassifolia) naturally (NS), modified with citric acid (MNS) and as activated carbon (AC). The point of zero charge (pHPZC) and the active sites (using the Boehm method and FTIR spectroscopy) were determined. The pHPZC of NS, MNS and AC were in an acid range. The concentration of active sites of NS, MNS and AC were 0.1037, 0.1123 y 0.1404 mol/g, respectively. The infrared spectra (FTIR) detected the formation of acid functional sites associated with the phenol group, carboxylic acids and lactones. The adsorption capacity of lead ions using NS, MNS and AC increases with the increment of the pH of the solution from 3 to 5; nevertheless, at pH 5, precipitation of lead ions is observed. Due to the above, the evaluation of the three materials was carried out at pH 4. Comparing the maximum capacity of adsorption of Pb(II) on NS with respect to MNS and AC at pH 4, it was increased in 2.2 and 10 times, respectively. The chemical modification applied to precursor, as well as its formation to AC, improved their adsorption capacity due to a greater generation of acid sites. The experimental data were represented with the models of Langmuir, Freundlich and Prausnitz-Radke and the parameter values of these isotherms were estimated using a least-squares method which utlilizes an optimization algorithm.

Adsorption of Lead (Ii) from Aqueous Solution Using Adsorbents Obtained from Nanche Stone (Byrsonima Crassifolia)