Adsorption of Copper (II) from Aqueous Solutions with Alginate/Clay Hybrid Materials

Abstract

Massive amounts of industrial and agricultural water around the world are polluted by various types of contaminants that harm the environment and affect human health. Alginic acid is a very versatile green polymer used for heavy metal adsorption due to its availability, biocompatibility, low cost, and non-toxic characteristics. The aim of this paper was to prepare new low-cost hybrid composite beads using sodium alginate with treated montmorillonite and kaolin for the adsorption of copper (Cu) cations. Modified and unmodified clays were investigated by studying their morphology and elemental composition, functional groups, and mean particle size and particle size distribution. The characterization of alginate/clay hybrid composite beads was carried out by evaluating surface morphology (by scanning electron microscopy, SEM), crystallinity (by X-ray diffraction, XRD), and point of zero charge (pHpzc)(Zeta Potential Analyzer). Batch adsorption experiments of alginate/clay hybrid composite beads investigated the effect of metal concentration in the range of 1–4 mg L−1 on Cu(II) removal, adsorption kinetic for maximum 240 min, and Langmuir and Freundlich adsorption isotherms by using atomic absorption spectrometry. The pseudo-second-order kinetic model best fitted the adsorption for alginate/montmorillonite beads (R2 = 0.994), while the diffusion process was predominant for montmorillonite/kaolin beads (R2 = 0.985). The alginate/clay hybrid materials best fitted the Langmuir isotherm model.

Copper(II) ion removal by chemically and physically modified sawdust biochar

“…At low conc of Cu(II) ions, decreased removal with increasing initial conc was ascribed to the elevated driving force in terms of biosorbents binding sites accessible and available, whereas the increased struggle for limited sorptions sites at elevated conc led to reduced removal of Cu(II) ions and thus more Cu(II) ions are left unabsorbed in the solutions due to the rapid saturations of sorptions sites. These assertions reported in this study are also supported by the study of Gupta et al[22], Larous and Meniai[64], Eldeeb et al[67], Yu et al[71], and Râpă et al[72].…”

“…These results show that the biosorption of Cu(II) to the biochars was a rate-limiting step that has valence force between the biochars and the sorbate, with electron exchange or sharing [28]. Râpă et al [72] equally found in their biosorption of Cu(II) ions to alginate/clay hybrid composite beads study that the PSO model best described the biosorption process [72]. While in the studies of Bai et al [80], Hu et al [82], and Khan et al [81] where Humulus scandens-derived biochar, biochar derived from Chaenomeles sinensis seed, and muskmelon peel biochar were utilized for the biosorption of Cu(II) ions, it was noticed that the biosorption processes were best close-fitting to the experimental data using the PSO model [86][87][88][89][90][91][92][93].…”

Insights into Anthropogenic Micro- and Nanoplastic Accumulation in Drinking Water Sources and Their Potential Effects on Human Health

“…Adsorption is widely used for the removal of contaminants from aqueous solutions, being cost-effective and environmentally friendly [92][93][94]. The possible factors affecting the removal efficiency of MPs/NPs by adsorption include: pH, temperature, adsorbent types, dissolved organic matter (DOM), and ions [72].…”

Comparison of Acid- and Base-Modified Biochar Derived from Douglas Fir for Removal of Copper (II) from Wastewater

“…Continuous copper accumulation in the environment results from human activities, including industrialization, waste from copper mines, and poor waste management of copper-containing materials such as from electric wires, analytical reagents, and electroplating [6]. The United States Environment Protection Agency has recommended maximum drinking water copper concentration limits of 1.3 mg L −1 [7,8].…”

“…This, however, depends on the adsorbents used. Activated carbon, biochar, and clay are some of the common adsorbents used for water treatment [7,12]. Both activated carbon and biochar are characterized by large surface areas and surface functional groups that aid the removal of contaminants.…”