Adsorption of Atrazine Herbicide from Aqueous Solution

Atrazine is a widely used triazine herbicide employed for the control of broadleaf weeds in maize cultivation. However, its persistence, toxicity, and mobility in aquatic environments have made it a serious environmental and public health concern. Conventional water treatment methods such as coagulation and chlorination are often ineffective for atrazine removal due to its high stability and low reactivity. In this study, a zinc–aluminum layered double hydroxide (Zn–Al LDH) with a metal composition ratio of 3:1 was synthesized by the co-precipitation method and subsequently modified with disodium ethylenediaminetetraacetate (EDTA) to enhance its surface and structural properties for the adsorption of atrazine from aqueous solution. Adsorption experiments were carried out using a constant atrazine concentration of 100 mg/L and a fixed contact time of 120 minutes, while varying the adsorbent dosage between 0.1 g and 1.0 g. Results showed that the modification of Zn–Al–Cl LDH with disodium EDTA led to an increase in surface area and thermal stability, as evidenced by broadened XRD peaks, new carboxylate and amine bands in FTIR spectra, and improved decomposition temperature in TGA analysis. The modified LDH exhibited higher atrazine uptake compared to the unmodified sample, demonstrating the beneficial effect of EDTA in enhancing surface reactivity and active site availability. This study demonstrates that EDTA-modified Zn–Al LDH is an efficient, low-cost, and thermally stable material for the removal of atrazine from contaminated water. The findings
highlight the potential of modified LDHs as promising adsorbents for environmental remediation and sustainable water treatment applications.