In this work, a potential biosorbent is prepared from agricultural waste material (ash seed) without any treatment. This biomaterial could be successfully used as a low-cost adsorbent for the removal of an anionic dye named Cibacron Blue (CB), under optimal conditions. The prepared adsorbent was characterized by scanning electron microscope (SEM) coupled with EDX, Fourier transforms infrared spectrometer (FTIR), thermogravimetric analysis (TGA), and point of zero charge (pHpzc). The adsorption experiments were carried out in batch mode at room temperature. Results show that the rate of CB dye removal exceeds 95 % using a dose of 2 g/L ash seed at C₀ = 25 mg/L and pH = 2.2. The kinetic data were analyzed using the pseudo-first-order, pseudo-second-order, Elovich’s, Bangham, intraparticle diffusion, and Boyd kinetic. Results show that the pseudo-second-order model fits better the experimental data. The isotherm data of the CB dye adsorption were analyzed with several theoretical models (Langmuir, Freundlich, and monolayer model coupled to real gaz (MMRG)). It was found that the adsorption process of the CB dye is well described by monolayer model coupled to real gaz (MMRG) compared to other models. The negative enthalpy (ΔH°) and free enthalpy (ΔG°) indicate the physical and spontaneous nature of CB adsorption. Therefore, the prepared material can serve as a potential adsorbent for removal of CB dye from industrial effluents.

Graphical abstract

中文翻译：

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源自农业废弃物前体的高效天然生物吸附剂，可在合成废水中吸附阴离子染料

在这项工作中，无需任何处理即可从农业废料（灰种）中制备潜在的生物吸附剂。这种生物材料可以成功地用作低成本吸附剂，以在最佳条件下去除名为Cibacron Blue（CB）的阴离子染料。制备的吸附剂通过扫描电子显微镜（SEM）结合EDX，傅立叶变换红外光谱仪（FTIR），热重分析（TGA）和零电荷点（pHpzc）进行表征。吸附实验在室温下以间歇模式进行。结果表明，在C _0下使用2 g / L灰烬剂量的CB染料去除率超过95％ = 25 mg / L，pH = 2.2。使用伪一级，伪二级，Elovich，Bangham，粒子内扩散和博伊德动力学分析动力学数据。结果表明，伪二阶模型更适合实验数据。用几种理论模型（Langmuir，Freundlich和与真实天然气（MMRG）耦合的单层模型）分析了CB染料吸附的等温线数据。已发现，与其他模型相比，单层模型与真实气体（MMRG）耦合可以很好地描述CB染料的吸附过程。负焓（ΔH°）和自由焓（ΔG°）表示CB吸附的物理和自然性质。因此，所制备的材料可以用作从工业废水中去除CB染料的潜在吸附剂。

图形概要