The preparation of novel iron oxide-flax seeds-based hybrid nanocomposite, referred to as magnetic flax-seeds, and its application for water treatment has been reported herein. A simple co-precipitation method was followed and the detailed mechanism of the preparation has been discussed. The prepared magnetic flax-seeds powder was characterized by employing several spectroscopic and microscopic techniques. The characterization results showed that the magnetic nanocomposite possessed massive functional groups of flax seeds and hydroxyl groups of iron oxide. The nanocomposite has a porous structure with particles size distributions in the range 1–14.32 nm. The magnetic composite was investigated for adsorption utility, in water treatment technology, by picking malachite green dye, under the effect of various process parameters, such as pH, contact time, temperature, concentration, and amount of adsorbent. The equilibrium adsorption capacity of the magnetic nanocomposite (dosage = 1.0 g L⁻¹) for malachite green (concentration = 10 mg L⁻¹) was found to be approximately 10 mg g⁻¹ at 30 °C, 7 pH, and 60 min contact time with maximum adsorption capacity Q_max = 52.910 mg g⁻¹. The sorption process was proved feasible and endothermic at all the tested temperatures (30–50 °C) and concentrations (10–60 mg L⁻¹). The adsorption data followed Freundlich isotherm (K_f value 20.893 mg g⁻¹) which suggested the multilayer physisorption process. The kinetic investigation suggested a pseudo-second-order sorption process (K₂ = 0.050 g mg⁻¹ min⁻¹) and governed through particle diffusion. The ease in preparation, low cost, magnetic characteristic, and high adsorption capacity will make the water treatment technique more efficient with the magnetic flax-seeds.

本文报道了新型氧化铁-亚麻籽基杂化纳米复合材料（称为磁性亚麻籽）的制备及其在水处理中的应用。遵循了一种简单的共沉淀方法，并讨论了制备的详细机理。采用多种光谱和显微技术对制备的磁性亚麻籽粉进行表征。表征结果表明，磁性纳米复合材料具有大量的亚麻籽官能团和氧化铁的羟基。纳米复合材料具有多孔结构，粒度分布范围为 1-14.32 nm。研究了磁性复合材料在水处理技术中的吸附效用，通过挑选孔雀石绿染料，在各种工艺参数的影响下，如 pH、接触时间、温度、浓度和吸附剂的数量。磁性纳米复合材料的平衡吸附容量（剂量 = 1.0 g L^-1 ) 孔雀石绿（浓度 = 10 mg L ^-1）在 30 °C、7 pH 和 60 分钟接触时间下约为 10 mg g ^-1，最大吸附容量 Q _max  = 52.910 mg g ^-1 . 在所有测试温度（30-50°C）和浓度（10-60 mg L ^-1）下，吸附过程被证明是可行的和吸热的。吸附数据遵循 Freundlich 等温线（K _f值 20.893 mg g ^-1），表明多层物理吸附过程。动力学研究表明存在伪二级吸附过程（K ₂  = 0.050 g mg ^-1  min ^-1) 并通过粒子扩散进行控制。易于制备、成本低、磁性特性和高吸附能力将使磁性亚麻籽水处理技术更有效。