Abstract The equilibrium, sorption kinetics and thermodynamic parameters of nitrate ions sorption using a cationic modified Lagenaria vulgaris shell as a sorbent were studied. The sorption of nitrate ions was carried out from synthetic aqueous solutions in a batch mode. For this purpose, a sorbent based on waste lignocellulosic biomass was utilized. The cationic quaternary ammonium sorbent was obtained by chemical modification of raw Lagenaria vulgaris shell using (3-chloro-2-hydroxypropyl) trimethylammonium chloride reagent. The obtained results of nitrate sorption from synthetic solutions of different concentrations (2–100 mg/L) were examined by non-linear regression analysis of different reaction kinetic and multi-linear diffusion models. To describe the sorption equilibrium in the liquid–solid system, the experimentally obtained data were fitted with typical non-linear models of sorption isotherms (Langmuir, Freundlich, Temkin, Dubinin-Radushkevich and Sips isotherms). To determine the thermodynamic parameters (Δ G , Δ H and Δ S ), nitrate sorption experiments on CMLVS sorbent were performed at different temperatures (20, 40, 60 °C), under previously determined optimal conditions. Nitrates desorption and CMLVS sorbent regeneration was also studied. Graphic Abstract The exploitation of waste lignocellulosic biomass of Lagenaria vulgaris shell as a valuable sorbent for anionic pollutants, primarily for nitrates, is proposed. Equilibrium, sorption kinetics and thermodynamic parameters of nitrate sorption using the cationic modified sorbent are characterized. The sorption capacity of the sorbent (15.869 mg/g) is comparable to the results of other cationically modified lignocellulosic agricultural wastes. The nitrate-loaded sorbent can be effectively regenerated in HCl and used repeatedly in the sorption–desorption cycles.

中文翻译：

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通过从 Lagenaria vulgaris 的废弃木质纤维素生物质中提取的吸附剂去除硝酸盐：动力学、平衡和热力学

摘要 以阳离子改性的紫薇壳为吸附剂，研究了硝酸根离子吸附的平衡、吸附动力学和热力学参数。硝酸根离子的吸附是以分批模式从合成水溶液中进行的。为此，使用了基于废弃木质纤维素生物质的吸附剂。用（3-氯-2-羟丙基）三甲基氯化铵试剂对生Lagenaria vulgaris壳进行化学改性得到阳离子季铵吸附剂。通过不同反应动力学和多线性扩散模型的非线性回归分析，对从不同浓度 (2-100 mg/L) 的合成溶液中获得的硝酸盐吸附结果进行了检查。为了描述液固系统中的吸附平衡，实验获得的数据与吸附等温线的典型非线性模型（Langmuir、Freundlich、Temkin、Dubinin-Radushkevich 和 Sips 等温线）拟合。为了确定热力学参数（Δ G 、Δ H 和 Δ S ），在先前确定的最佳条件下，在不同温度（20、40、60 °C）下对 CMLVS 吸附剂进行了硝酸盐吸附实验。还研究了硝酸盐解吸和 CMLVS 吸附剂再生。图形摘要 建议利用 Lagenaria vulgaris 壳的废弃木质纤维素生物质作为阴离子污染物（主要是硝酸盐）的宝贵吸附剂。表征了使用阳离子改性吸附剂的硝酸盐吸附的平衡、吸附动力学和热力学参数。吸附剂的吸附能力 (15. 869 mg/g) 与其他阳离子改性木质纤维素农业废物的结果相当。载有硝酸盐的吸附剂可以在 HCl 中有效再生，并在吸附-解吸循环中重复使用。