Sorption of heavy metals by natural biopolymers

Abstract

The sorption properties of modified hydrolysis lignin towards Cu[Formula: see text], Zn[Formula: see text], Ni[Formula: see text], Co[Formula: see text] ions in the pH range from 2 to 8 at temperature of 298.15 K solution are studied. The analysis of kinetic curves of ions sorption on modified lignin at pH 7 shows that sorption equilibrium in heterogenic system ion–metal–sorbent is attained in 30–60 min. Obtained results indicate good equilibrium kinetic properties of sorbent. Supposed that reaction between sorbate and functional group of sorbent are the second-order reaction and they interact between each other in ratio 1:1. The character of the obtained electrokinetic curve suggests that the zeta potential of modified lignin strongly depends on the pH. The dependencies of cations metals sorption coefficients on the pH value of water phase are S-shaped. Maximal extraction of studied cations is observed at pH values of equilibrium solutions close to neutral ones.

Application of raw volcanic rock found in Etna valley as an adsorbent of chromates, arsenates and selenates

“…Plenty of mineral raw material fulfill all requirements of the potential cheap adsorbent. Today the most prevalent research of materials which may be noted as cheap adsorbents are natural alternative materials such as chitosan [3], lignin [4], clays [5,6], zeolites [7] and waste biomaterials (rice husk [8,9], tea waste [10], wheat straw [11], peach stone [12], various agriculture waste [13]) which are readily available. Currently, there is a high interest in researching the possibility of using other mineral sources as adsorbents such as clays, zeolites, and other porous minerals but shallow interest in researching the natural raw rocks.…”

Heavy metal removal by biopolymers-based formulations with native potato starch/nopal mucilage

“…Similarly, during the adsorption of metals over time, a constant decrease in concentration is observed, with a similar behavior for all the biopolymer formulations (Figure 3), although at longer contact times, the increase in removal is minimal [9,13,38,39,40].…”

Karakteristik C–4–etoksi–3–metoksifenilkaliks[4]resorsinarena trifenilfosfonium klorida dalam mengadsorpsi anion Cr2O72–

“…Berbagai usaha telah dilakukan untuk mengurangi konsentrasi pencemar di perairan, salah satunya adalah adsorpsi. Adsorpsi merupakan cara paling sederhana dalam menyerap zat pencemar kation maupun anion (Efimova et al, 2017;Jumin et al, 2019). Senyawa kaliksarena seperti C-4-etoksi-3-metoksifenilkaliks[4]resorsinarena (CKR) telah digunakan sebagai adsorben Cr 2 O 7 2-(Gambar 1).…”