Porous sodium alginate/ Polyvinyl alcohol composites cross-linked with Glutaraldehyde for crystal violet dye and Pb۲+ ions removal from aqueous solution

Progress in industrialization in particular textile industries have led to the discharge of unprecedented amount of wastewater containing synthetic dyes, which pollutes the rivers and consequently causes harm to human and other living organisms[۱]. Organic dyes, which are commonly used for color clothing, are pollutants that need to be treated for environmental protection. In particular, azo dyes, identified by the presence of azo (-N = N-) groups, are toxic, carcinogenic, and mutagenic to organisms. According to the US Environmental Protection Agency (USEPA), the maximum allowable concentration of Lead ions (Pb(II)) is ۶ μg/L inground or surface water[۲]. The purpose of the present work is to develop a novel, environmentally friendly and reusable adsorption material with low-cost and excellent adsorption capacity for removing the heavy metal ions from sewage. sodium alginate (SA) contains a significant presence of functional groups, such as hydroxyl (OH) and COOH groups, in addition to negatively charged sites. Such functionalized groups play a crucial role in the capture of molecular pollutants in water. In the presented study, a novel clay/ sodium alginate / PVA/ Glutaraldehyde nanocomposite was synthesized for efficient removal of crystal violet dye and Pb۲+ions from contaminated water. The nanocomposite structure, thermal stability, surface morphology, and surface area were studied using FT-IR, SEM, EDX, TGA, and BET techniques. The adsorption capacity of crystal violet was ۴.۷۷ mg/g, and the removal percentage was ۹۵.۴۳ %. Langmuir and pseudo-second-order models were used on this study to obtain information on the isotherms and kinetics of the adsorption process. These findings suggest that the adsorption process is a monolayer and involves chemical adsorption. Thermodynamic analyses (ΔG°, ΔH°, and ΔS°) demonstrated that the adsorption process of Pb۲+ ions was endothermic and spontaneous.

کلیدواژه ها:

Adsorption ، Lead ions ، Sodium alginate ، Crystal violet