Removal of Copper and Magnesium Cations from Aqueous Solutions by Clinoptilolite Zeolite Adsorption

Abstract

The aim of this study is to determine the potentials of clinoptilolite zeolite in removing selected heavy metals, that are copper and magnesium in aqueous solutions. The removal of both metal cations has been studied by using the batch techniques. Three experimental variables were carried out under predetermined conditions of contact time (20 – 100 minutes), effect of dosage (0.20 – 1.00 gram), and effect of pH solution (pH 2 to 10). Adsorption capacity of zeolite towards heavy metal removal was then determined at various initial concentrations of metal ions between 20 to 100 ppm. Results obtained shows that adsorption of Cu 2+ and Mg 2+ on zeolite has been shown to depend significantly on the pH, adsorbent amount and contact time. The significant value of pH was reached at pH 6, followed by 1 hour of contact time for 1 gram of adsorbent; for both metal ions studied. Studies on the rate of uptake of heavy metal ions by the zeolite indicated that the process was quite rapid and maximum adsorption occurred within the first hour of contact. The results show that high silica zeolite such as clinoptilolite is a promising adsorbent as they combine high adsorption capacities and molecular sieve properties.

Batch adsorption studies on copper removal from an aqueous solution using natural zeolite: Process optimization

“…This may be due to it reduces H⁺ on the adsorbent surface, which increases the surface's negative charge and boosts the adsorbent's ability to bind metal ions [13]. The aforementioned result is consistent with the outcomes reported by Aziz et al [11], Pavan Kumar et al [14], and El-Azim and Mourad [15], which state that when the pH value (1) increases, then the percentage of copper removal using zeolite also increases. The result of optimum pH 6 was chosen for the removal of copper using zeolite.…”

“…There was a modest and gradual improvement in the removal of copper as the dosage of adsorbent increased due to the greater availability of exchangeable sites or surface area [10]. The number of zeolite adsorption sites or surface area increases with the increased weight of the adsorbent, causing a more effective metal removal after the experiment and permitting easier adsorbate penetration into the adsorption sites [11]. The results obtained in this study also align with the outcomes reported by Zendelska et al [7] and Meena et al [10].…”

“…At high pH such as pH 7 and pH 8, the high copper removal was not due to adsorption mechanisms but more to precipitation and complexation reactions. pH value influences the ability of metal ions to attach on the adsorbent surface and chemically changes the nature of the adsorbent [11]. As pH increases, more negatively charged surface area becomes accessible, allowing for an increased percentage of copper removal [12].…”

H-Clinoptilolite as an Efficient and Low-Cost Adsorbent for Batch and Continuous Gallium Removal from Aqueous Solutions

“…These characteristics make the clinoptilolite particularly suitable for adsorption of metals from wastewater. Many researchers have previously used this material to treat aqueous systems polluted with different metals in batch mode, such as Zn 2+ , Cu 2+ , Pb 2+ , or Cd 2+ , among others [12][13][14][15][16]. However, the utilization of clinoptilolite in fixed bed has not been widely used, only to remove metals like Mn 2+ , Cr 3+ , Cd 2+ , and Zn 2+ [17,18] and, more specifically, the use of clinoptilolite to remove gallium has not been extensively studied.…”