In this study, magnesium oxide biochar-chitosan composite (MgO-BCR-W) prepared through modification with MgCl₂ and chitosan was investigated as an adsorbent for the removal of Cd from the aquatic and soil environment. Kinetic and thermodynamics revealed that the Cd(II) adsorption onto MgO-BCR-W was well fitted by pseudo-second-order and the Langmuir adsorption isotherm. The adsorption capacities of rice husk biochar (BCR) and MgO–BCR-W for Cd(II) reached 11.09 mg/g and 59.66 mg/g, respectively. Attractively, the computed values of R_L ranged between 0 and 1, suggesting that the adsorption of Cd(II) onto MgO-BCR-W is favourable. Characterisations of the adsorbents revealed that the synergistic effect of surface complexation and precipitation mechanisms played a major role in the removal of Cd. In soil incubation experiment, the addition of MgO-BCR-W at the level of 2% was most effective in Cd stabilization compared to the control, which reduced the content of bioavailable Cd by 22.32%. Furthermore, it reduced the acid extractable Cd by 24.77%, while increased the residual Cd content by 22.24%. The results demonstrated that MgO-BCR-W could be used as an effective and eco-friendly adsorbent for Cd remediation in both water and soil environment.

在这项研究中，研究了通过用MgCl ₂和壳聚糖改性制备的氧化镁生物炭-壳聚糖复合材料（MgO-BCR-W）作为从水和土壤环境中去除Cd的吸附剂。动力学和热力学表明，Cd（II）吸附到MgO-BCR-W上的拟二阶拟合和Langmuir吸附等温线拟合得很好。稻壳生物炭（BCR）和MgO-BCR-W对Cd（II）的吸附能力分别达到11.09 mg / g和59.66 mg / g。有吸引力的是，R _L的计算值范围介于0和1之间，表明Cd（II）在MgO-BCR-W上的吸附是有利的。吸附剂的特征表明，表面络合和沉淀机理的协同作用在去除Cd中起主要作用。在土壤培养实验中，与对照相比，以2％的水平添加MgO-BCR-W对Cd稳定最有效，这使可生物利用Cd的含量降低了22.32％。此外，它使可酸萃取的Cd减少了24.7％，同时使残留Cd含量增加了22.24％。结果表明，MgO-BCR-W在水和土壤环境中均可作为有效和环保的Cd修复吸附剂。