Abstract The adsorbent was prepared from pyrolyzed rice husk -an agricultural industry waste- efficiently utilized for the removal of dye molecule (malachite green) from a water-based mixture in a bioreactor. The maximum removal of dye by the biochar was about 99.98% with an adsorbent dosage of 0.2 mg L−1 at pH 6.2, 20 mg L−1 dye concentration after 2 h. In the present research study, adsorption isotherm and equilibrium kinetics on Malachite green dye molecule by pyrolyzed biochar was analyzed. Intraparticle Diffusion Model, Elovich models, pseudo second order, and Pseudo-first order model was utilized for the analysis of adsorption kinetics whereas the Freundlich, Langmuir, Temkin, and D-R model was used to describe the equilibrium isotherm. Pseudo second order kinetics best describes the adsorption uptake rate of dye on biochar surface with R2=0.996. Equilibrium isotherm was only worthy fitted by Langmuir Isotherm with R2=0.999. A comparative study between non-linearized and linearized methods of determining the isotherm and kinetic parameters were done. Four different pseudo second order and Langmuir isotherm expressions have been discussed in detail in this paper. The R2 (coefficient of determination) was employed to determine the best-fit expression. It can be concluded from the results, that the non-linearized model is the best fit for both the parameters.

中文翻译：

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热解生物炭的合成及其在染料去除中的应用：线性和非线性数学分析的批次、动力学和等温线

摘要 该吸附剂由热解稻壳（一种农业废弃物）制备而成，可有效去除生物反应器中水基混合物中的染料分子（孔雀石绿）。生物炭对染料的最大去除率约为 99.98%，吸附剂剂量为 0.2 mg L-1，pH 6.2，2 小时后染料浓度为 20 mg L-1。在本研究中，分析了热解生物炭对孔雀石绿染料分子的吸附等温线和平衡动力学。粒子内扩散模型、Elovich 模型、伪二阶和伪一阶模型用于分析吸附动力学，而 Freundlich、Langmuir、Temkin 和 DR 模型用于描述平衡等温线。伪二级动力学最能描述染料在 R2=0 时生物炭表面的吸附吸收率。996. 平衡等温线仅值得朗缪尔等温线拟合，R2=0.999。进行了确定等温线和动力学参数的非线性和线性化方法之间的比较研究。本文详细讨论了四种不同的伪二阶和朗缪尔等温线表达式。R2（决定系数）用于确定最佳拟合表达。从结果可以得出结论，非线性模型最适合这两个参数。R2（决定系数）用于确定最佳拟合表达。从结果可以得出结论，非线性模型最适合这两个参数。R2（决定系数）用于确定最佳拟合表达。从结果可以得出结论，非线性模型最适合这两个参数。