The use of low-cost adsorbents produced from rice husks that can selectively remove zinc (II) ion from wastewater effluent has been investigated. The disorder and fatal diseases can be triggered in living organisms by accumulating the heavy metals in the wastewater. Adsorption is an operative cleansing and separation method used in the industry to remove contaminants from effluents. In order to convert the rice husk to the adsorbent, digestion and carbonization processes were performed. Rice husks digested nitric acid at 1.0 M to reduce the organic constituents and further carbonized at 400, 600 and 800 °C to eliminate the non-carbon element in rice husks. The physiochemical characteristics of the digested and carbonized rice husks were analyzed using scanning electron microscope (SEM), X-ray diffraction (XRD) and atomic adsorption spectrophotometer (AAS). The SEM morphological characteristics showed the high pyrolysis effect on the organic matter left the samples with more pores and cavities, which enhanced the surface area and uptake, especially for 800 °C carbonized samples. The samples’ physical characteristics using XRD showed that the treatment with HNO₃ illustrated a pattern close to the activated carbon with slightly lower intensities. The applied feed-forward back-propagation neural network algorithm showed high validity (R² ≈ 0.9686) for the tested experimental data sets and hence can be applied for forthcoming studies with nearby conditions. The outcomes showed that the increment of the carbonization temperature is correlated with the contact time and can increase the metal uptake percentage and adsorption capacity. The adsorption followed the Langmuir isotherm, which indicates monolayer coverage. The data showed that adsorption kinetics follow the pseudo-second-order rate expression.

中文翻译：

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硝酸消化稻壳上锌离子吸附的平衡，动力学和人工智能特性分析

已经研究了使用由稻壳制成的低成本吸附剂，该吸附剂可以选择性地从废水中去除锌（II）离子。通过在废水中积累重金属，可以在生物体内引发疾病和致命疾病。吸附是工业上使用的一种有效的清洁和分离方法，用于去除废水中的污染物。为了将稻壳转化为吸附剂，进行了消化和碳化过程。稻壳用1.0 M的硝酸消化以减少有机成分，并在400、600和800°C下进一步碳化以消除稻壳中的非碳元素。使用扫描电子显微镜（SEM）分析消化和碳化的稻壳的理化特性，X射线衍射（XRD）和原子吸收分光光度计（AAS）。SEM的形态学特征表明，对有机物的热解效果高，使样品具有更多的孔和腔，从而增加了表面积和吸收率，尤其是对于800°C碳化的样品。使用XRD的样品物理特性表明，HNO处理_图3示出了强度略低的接近活性炭的图案。所施加的前馈反向传播神经网络算法表现出较高的效度（- [R ² 所测试的实验数据集≈0.9686），并且因此可以被应用用于与附近的条件即将研究。结果表明，碳化温度的升高与接触时间有关，可以增加金属的吸收率和吸附能力。吸附遵循Langmuir等温线，这表明单层覆盖。数据表明吸附动力学遵循假二级速率表达。