Biochar obtained from pyrolysis of biomass finds multiple applications in combating environmental problems. However, the quality and quantity of biochar depends closely on the synthesis conditions and nature of the feedstock. The present study investigates the efficacy of employing rice husk–derived biochar for dual application: as a solid fuel and as an adsorbent. This study employs a response surface methodology (RSM) to optimize experimental parameters, temperature, time and heating rate. RSM provides linear and interaction effect amongst variables for selected responses, fuel ratio and percentage of fluoride removal. The optimum conditions for experimental factors (temperature, time and heating rate) were found to be 500 °C, 55 min and 7 °C/min. At the optimum conditions, the fuel ratio and percentage of fluoride removal were found to be 2.44 and 79.2% respectively. Moreover, the percentage of biochar yield at optimum conditions was found to be 40.7%. The Langmuir isotherm model was found to be applicable with a maximum monolayer adsorption capacity (Q_m) of fluoride of 1.856 mg/g at 303 K. Thermodynamic studies demonstrated enhanced adsorption at lower temperature, and parameters such as change in free energy (ΔG) − 23.32 kJ mol⁻¹, change in enthalpy (ΔH) 22.82 kJ mol⁻¹ and change in entropy (ΔS) 0.15 kJ mol⁻¹ K⁻¹ indicate spontaneous nature of reaction. This study successfully converted biomass-derived biochar into a value-added product which could be used either as a solid fuel or as a potential adsorbent for effective removal of fluoride.

从生物质的热解获得的生物炭在解决环境问题方面有多种应用。但是，生物炭的质量和数量密切取决于合成条件和原料的性质。本研究调查了将稻壳来源的生物炭用于双重用途的功效：作为固体燃料和吸附剂。这项研究采用响应面方法（RSM）来优化实验参数，温度，时间和加热速率。RSM在变量之间提供线性和交互作用，以用于选定的响应，燃油比和除氟百分比。发现实验因素（温度，时间和加热速率）的最佳条件是500  ° C，55 min和7  °C /分钟 在最佳条件下，燃油比和除氟百分比分别为2.44％和79.2％。此外，发现在最佳条件下生物炭产率的百分比为40.7％。发现Langmuir等温模型适用于303 K时最大的单层氟化物吸附容量（Q _m）为1.856 mg / g。热力学研究表明，在较低的温度下吸附增强，并且参数如自由能变化（ΔG） − 23.32 kJ mol ^-1，焓变（ΔH）22.82 kJ mol ^-1和熵变（ΔS）0.15 kJ mol ^-1  K ^-1表明反应是自发的。这项研究成功地将源自生物质的生物炭转化为增值产品，可用作固体燃料或用作有效去除氟化物的潜在吸附剂。