Objective

In the present work, the potential use of raw date stone as an inexpensive carbonized adsorbent material for removal of Pb(II) has been demonstrated.

Methods

The adsorption of Pb(II) ions onto carbonized date stone has been studied by batch adsorption method. The variables (pH, adsorbent dose and initial concentration of Pb(II) ions) of the adsorption process were optimized by response surface methodology via Box-Behnken design (BBD).

Results

The optimum values of pH, adsorbent dose and initial concentration were 5.0, 0.3 g and 5.0 mg L⁻¹, respectively to achieve 88.50% removal efficiency. The adsorption data fitted well to both Langmuir and Freundlich isotherm models with coefficient of correlation (r) ˃0.9999. The maximum adsorption capacity of the described adsorbent material for Pb²⁺ ions with Langmuir model was found to be 9.03 mg g⁻¹. Kinetic data obtained at different concentrations have been analysed using pseudo-first-order and pseudo-second-order kinetic models. The experimental data obeyed pseudo-second-order kinetic model. Gibb’s free energy change (ΔG°) was evaluated and resulted with −17.91 kJ mol⁻¹ at 298 K, hence indicated favourable adsorption process.

Conclusion

Neghal carbonized date stone was found to be a promising natural adsorbent for removal of Pb(II).

中文翻译：

---

使用碳化的菲尼斯达菲亚种（Date stone）吸附去除阿曼地下水样品中的Pb（II）离子

目的

在目前的工作中，已证明了将生枣石作为廉价的碳化吸附材料去除Pb（II）的潜在用途。

方法

采用间歇吸附法研究了Pb（II）离子在碳化枣石上的吸附。通过Box-Behnken设计（BBD），通过响应表面方法对吸附过程的变量（pH，吸附剂剂量和Pb（II）离子的初始浓度）进行了优化。

结果

pH，吸附剂剂量和初始浓度的最佳值分别为5.0、0.3 g和5.0 mg L ^-1，以达到88.50％的去除效率。吸附数据非常适合Langmuir和Freundlich等温线模型，相关系数（r）≤0.9999。用朗缪尔模型发现所述吸附材料对Pb ²⁺离子的最大吸附容量为9.03 mg g ^-1。已经使用伪一级和伪二级动力学模型分析了在不同浓度下获得的动力学数据。实验数据服从伪二级动力学模型。评估吉布的自由能变化（ΔG°）并在298 K下得到-17.91 kJ mol ^-1，因此表明吸附过程良好。

结论

人们发现，碳化碳黑宝石是去除Pb（II）的有前途的天然吸附剂。