This study aims to investigate leaching characteristics of zinc slag according to leaching tests, including; TCLP (Toxicity Characteristic Leaching Procedure), SPLP (Synthetic Precipitation Leaching Procedure), ASTM-D3987 (American Society for Testing and Materials), and TS EN-12457-4 (Turkish Standards Institute) tests methods. The present study describes the adsorption potential of natural and biochar walnut shells for removing ions from the zinc leachate. TCLP leachate, with a value of 38.575 mg/L, has a high zinc (Zn+2) concentration compared to other methods. Therefore, TCLP leachate was used in the adsorption experiments. Adsorption experiments were carried out at different adsorbent dosages, pH values, and contact time conditions. In the dosage study, the highest removal efficiency was obtained as 84% and 92% in natural and biochar walnut shell adsorbents, respectively. As a result of pH study, it was observed that adsorption under alkaline conditions had a much higher removal efficiency. Moreover, adsorption studies performed against contact time were applied to four different kinetic models and both adsorbents were found to be fit with the pseudo-second-order model. This kinetic model showed that the Zn+2 adsorption mechanism of natural and biochar walnut shells is chemical adsorption. With this study, it was shown that a very high 96% zinc removal can be achieved under optimum adsorption conditions. This may be the first study of zinc removal after leaching from industrial slag in the literature. This study has shown that high removal efficiencies can be obtained by an economical adsorbent.

中文翻译：

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使用天然和生物炭核桃壳从工业渣浸出液中的浸出性能和锌离子去除

本研究旨在根据浸出试验研究锌渣的浸出特性，包括：TCLP（毒性特性浸出程序）、SPLP（合成沉淀浸出程序）、ASTM-D3987（美国测试与材料协会）和 TS EN-12457-4（土耳其标准协会）测试方法。本研究描述了天然和生物炭核桃壳从锌浸出液中去除离子的吸附潜力。与其他方法相比，TCLP 渗滤液的值为 38.575 mg/L，具有较高的锌 (Zn+2) 浓度。因此，在吸附实验中使用TCLP浸出液。在不同的吸附剂剂量、pH 值和接触时间条件下进行吸附实验。在剂量研究中，在天然和生物炭核桃壳吸附剂中，去除效率最高，分别为 84% 和 92%。作为 pH 研究的结果，观察到碱性条件下的吸附具有更高的去除效率。此外，针对接触时间进行的吸附研究应用于四种不同的动力学模型，发现两种吸附剂都符合伪二级模型。该动力学模型表明，天然和生物炭核桃壳对Zn+2的吸附机理是化学吸附。通过这项研究，表明在最佳吸附条件下可以实现非常高的 96% 锌去除率。这可能是文献中对工业渣浸出后除锌的首次研究。该研究表明，经济的吸附剂可以获得高去除效率。