In this study, char was prepared from the Şırnak coal derivative as a new adsorbent by the pyrolysis process and successfully applied for Pb (II) removal. Prepared char adsorbent was characterized by analysis techniques such as thermogravimetric (TG)/differential thermogravimetric (DTG), iodine number, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and Brunauer-Emmett-Teller (BET) surface area. In the experimental design of the Pb (II) removal process, the relationship between operating factors (contact time, initial Pb (II) concentration and temperature) and process responses (adsorption capacity and removal efficiency) was modeled by applying response surface methodology (RSM). After that, the operating factors for the maximum adsorption capacity and removal efficiency of Pb (II) by char were optimized. In the removal of Pb (II), pseudo-first order and pseudo-second order kinetic models were used to determine the process mechanism. In addition, adsorption isotherm models such as Langmuir, Freundlich, and Dubinin-Radushkevich were applied to the equilibrium data to explain the adsorption mechanism between the adsorbent and adsorbate molecules. According to the results obtained, it was determined that kinetic and equilibrium isotherm data were better defined with pseudo-second order kinetic and Dubinin-Radushkevich isotherm models, respectively. The optimum values of the contact time, initial Pb (II) concentration, and temperature for maximum adsorption capacity (124.64 mg/g) and removal efficiency (92.35%) of Pb (II) were found as 150.00 min, 144.81 ppm, and 35.06°C, respectively. This study indicated the application potential of Şırnak coal-derived char as a promising cost-effective adsorbent for the removal of heavy metals.

Highlights

• Şırnak coal-derived char was successfully prepared, characterized, and applied for the removal of Pb (II) for the first time.

• The operating factors for the maximum adsorption capacity and removal efficiency of Pb (II) were optimized by applying RSM.

• Kinetics and isothermal studies were performed for the removal of Pb (II) by char.

• The maximum adsorption capacity and removal efficiency of char towards Pb (II) were found as 124.64 mg/g and 92.35%, respectively.

在这项研究中，焦炭是由Şırnak煤衍生物通过热解过程制备的，它是一种新型吸附剂，并成功地用于去除Pb（II）。通过热重（TG）/差示热重（DTG），碘值，扫描电子显微镜（SEM），傅里叶变换红外光谱（FT-IR）和布鲁诺-埃米特-泰勒（BET）等分析技术对制得的炭吸附剂进行表征。表面积。在Pb（II）去除过程的实验设计中，通过应用响应面方法（RSM）对操作因素（接触时间，初始Pb（II）浓度和温度）与过程响应（吸附容量和去除效率）之间的关系进行了建模。 ）。此后，优化了炭最大吸附容量和Pb（II）去除效率的操作因素。在去除Pb（II）时，使用伪一级和伪二级动力学模型来确定过程机理。此外，将吸附等温线模型（例如Langmuir，Freundlich和Dubinin-Radushkevich）用于平衡数据，以说明吸附剂和被吸附物分子之间的吸附机理。根据获得的结果，确定分别使用伪二级动力学模型和Dubinin-Radushkevich等温模型对动力学和平衡等温线数据进行了更好的定义。发现最大吸附容量（124.64 mg / g）和Pb（II）的去除效率（92.35％）的接触时间，初始Pb（II）浓度和温度的最佳值为150.00分钟，144.81 ppm和35.06分别为℃。

强调

• Şırnak煤制焦炭已成功制备，表征并首次用于去除Pb（II）。

• 通过应用RSM优化了Pb（II）的最大吸附容量和去除效率的操作因素。

• 进行了动力学和等温研究，以炭去除Pb（II）。

• 炭对Pb（II）的最大吸附能力和去除效率分别为124.64 mg / g和92.35％。