Adsorption of Heavy Metals Ions from Mining Metallurgical Tailings Leachate Using a Shell-Based Adsorbent: Characterization, Kinetics and Isotherm Studies

Abstract

This study defines the optimal parameters that allow the use of waste mollusk shells (WS) to remove heavy metals from three mining and metallurgical leachates. First, the influence of parameters such as pH, contact time, initial metal concentration, adsorbent dose and the presence of co-ions in Cu2+, Cd2+, Zn2+ and Ni2+ adsorption was investigated in synthetic solutions. Metal uptake was found to be dependent on the initial pH of the solution, the removal rate increasing with the increase in pH, showing the highest affinity at pH 5–6. The removal efficiency at lower concentrations was greater than at higher values. The competitive adsorption results on bimetallic solutions showed that the adsorption capacity of the sorbent was restricted by the presence of other ions and suppressed the uptake of heavy metals compared to the single adsorption. Cu2+ was the metal that most inhibited the removal of Cd2+, Zn2+ and Ni2+. The Langmuir isotherm provided the best fit to the experimental data for Cu2+, Cd2+ and Zn2+ and the Freundlich isotherm, for Ni2+. The data showed that the maximum adsorption capacity amax for Zn2+, Cd2+ and Cu2+, was 526.32 mg g−1, 555.56 mg g−1 and 769.23 mg g−1, respectively. Sorption kinetics data best fit the pseudo-second-order kinetic model. The results obtained in the tests with three mining and metallurgical leachates showed that WS were effective in simultaneously removing several heavy metals ions such as Cu, Ni, Zn, Cd, Ni, As and Se.

Removal of Cr(VI) from Wastewater Using Acrylonitrile Grafted Cellulose Extracted from Sugarcane Bagasse

“…By enhancing the adsorbent mass from 1 to 3 g, no further increase was observed in removal efficiency because the number of active sites of adsorbent at this quantity (1 g) was high enough for picking Cr(VI) ions (50 ppm concentration). A similar trend was observed in other studies on heavy metal removal [50].…”

“…Natural cellulosic materials have a high content of hydrogen bonding within the cellulosic chains, which prevents their interaction with metal ions [48,49]. Grafted cellulose has additional side chains which can bind the adsorbate molecules and thus the removal efficiency of grafted cellulose is higher than that of nongrafted or raw cellulose [50,51]. Several researchers have used sugarcane bagasse as an adsorbent, either in raw form or chemically modified form, for the removal of heavy metals, dyes and other pollutants.…”

Yeast—As Bioremediator of Silver-Containing Synthetic Effluents

“…Zinc was the only element for which removal decreased from 88% at silver concentration in solution of 10 mg/L to 40% at silver concentration of 100 mg/L. In previously performed studies, it was shown that in complex systems where zinc, coper, and nickel ions are present their sorption did not differ considerably from singe metal systems [ 59 ]. Decrease of zinc removal can be explained for its competition with silver ions for binding sites with the increase of silver concentration in solution.…”

Study on the adsorption of Zn(II) and Cu(II) in acid mine drainage by fly ash loaded nano-FeS

“…Direct discharge can seriously threaten the soil and water environment and human health 3 . Currently, the commonly used treatment methods include the adsorption method 4 , 5 , biological method 6 , 7 , and ion exchange method 8 , 9 . Nevertheless, these methods still have some limitations in practical application due to the need for additional adsorbents, carbon sources, and long treatment cycles.…”