ADSORPTIVE

The persistence of atrazine in agricultural runoff and groundwater has raised serious environmental and public health concerns due to its chemical stability and resistance to conventional water treatment methods. This study investigates the synthesis, modification, characterization, and adsorption performance of zinc–aluminum layered double hydroxide (Zn–Al LDH) and its disodium EDTA-modified derivative for the removal of atrazine from aqueous solutions. The Zn–Al LDH was synthesized by the coprecipitation method at a Zn²⁺:Al³⁺ molar ratio of 3:1 under alkaline conditions and aged at 110 °C. Modification with disodium EDTA was achieved via anion exchange, producing a hybrid adsorbent with enhanced surface functionality and interlayer chemistry. Characterization with Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), and thermogravimetric/differential thermal analysis (TGA/DTA) confirmed the formation of a highly crystalline and thermally stable Zn–Al LDH structure. FTIR spectra revealed new carboxylate bands at 1600 cm⁻¹ and 1390 cm⁻¹, indicating successful EDTA incorporation, while XRD patterns showed an expansion of basal spacing from 7.6 Å to 9.8 Å, signifying effective interlayer modification XRF analysis indicated a significant increase in aluminum content and compositional uniformity after modification, confirming Zn–Al integration. Batch adsorption studies were conducted to evaluate the influence of contact time and adsorbent dosage on atrazine uptake. The adsorption process exhibited a pattern, characterized by a rapid initial phase attributed to surface adsorption followed by a slower diffusion-controlled phase. Increased adsorbent dosage enhanced the removal efficiency due to the greater availability of active sites. The EDTA-modified Zn–Al LDH demonstrated superior adsorption capacity compared to the unmodified form, owing to improved surface reactivity and functional group availability. overall, the study establishes that EDTA modification enhances the structural integrity, surface chemistry, and adsorption performance of Zn–Al LDH, positioning it as a promising low-cost and eco-friendly material for the remediation of atrazine-contaminated water.