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Polysaccharides like starch, chitosan, and pectin are attractive for removing heavy metal ions from water. Chitosan (n+) is mixed with pectin (n−) to enhance ion adsorption from aqueous media. This study involves two parts. First, 1 g/L stock solutions of pectin and chitosan at pH 5 are prepared and used to create polyelectrolyte complexes (PECs) with varying molar charge ratios (n−/n+). Pectin is added to stirred chitosan solutions to form PECs, relying on ionic interactions between chitosan's amino groups and pectin's carboxyl groups. However, the resultant PEC concentration is insufficient for effective heavy metal ion removal. In response, the second part of the study focuses on a specific PEC with n−/n+ of 0.84. The stock solution concentration is increased to 5 and 10 g/L at pH 5, enhancing efficiency and forming a gel. The gel dispersion is freeze‐dried, and the resultant PECs are used for adsorption experiments with Cd2+, Ni2+, Fe2+/3+, Mn2+, and Cu2+ sulfate solutions. Adsorption rates are in the order Cu2+ > Fe2+/3+ > Cd2+ > Ni2+ > Mn2+ for a 20 mg/L salt concentration, indicating high PEC affinity for heavy metal ions. [ABSTRACT FROM AUTHOR]

Polyelectrolyte complexes (PECs) have gained increasing attention in recent decades due to their importance in various applications, such as water treatment and paper processing. These complexes are formed by mixtures of polycations (n+) and polyanions (n−), known as polyelectrolytes (PEs). In this study, a series of PECs were prepared with different molar charge ratios (n−/n+) using biopolymers such as chitosan (lch) and pectin (p) at pH 5, in addition to the synthetic polymer poly(ethylene alt maleic acid) (PEMA) at the same pH. Two types of chitosan—low molecular weight chitosan (lch) and high molecular weight chitosan (hch)—were used as polycations, and these were mixed with two types of pectin with either a high esterification degree (hp) or a low esterification degree (lp), as well as PEMA as polyanions. These components interacted via electrostatic forces to form the following PEC combinations: (lch&lp), (lch&hp), (hch&hp), and (lch&PEMA). The charge density, turbidity, and particle size of the formed PECs were examined to evaluate the influence of molecular weight and mixing speed on the formation process. [ABSTRACT FROM AUTHOR]