Water pollution by heavy metals like Co(II) is particularly of concern because of their persistence in the environment, toxicity, and ability to bioaccumulate in organisms. In this study, the influence of contact time at three initial concentration, pH, adsorbent dose, temperature, and kinetics, thermodynamics, and one-, two-, and three-parameter isotherm modeling of the adsorption of Co(II) on neem leaves (DNL) was investigated. The adsorbent was characterized using FTIR, TGA-DSC, EDX, and nitrogen adsorption-desorption. DNL is composed of many Co(II) surface-binding groups and a BET surface area of 0.2783 m²/g dominated by meso- and macropores. Equilibrium was attained in 10 minutes for the three concentrations with a removal efficiency of 85–97%. ∆G° of −5.424 to −6.068 KJ/mol at 25 to 60°C, respectively, indicated spontaneous adsorption with increasing temperature. D-R adsorption energies of 0.649 to 2.433 KJ/mol revealed physical adsorption. Maximum adsorption capacity of 9.201–523.900 mg/g was obtained by Freundlich and Jovanovic isotherms. Adsorption was very favourable as evident by the high Kiselev equilibrium constant (11.652–172.78 L/mg) and very low R_L values of 0.001–0.026. Adsorption occurred by repulsive mechanism as indicated by Fowler–Guggenheim and Hill–de Boer negative interaction energies (−16.182 to −90.163 and −111.102 to −3328.86 KJmol⁻¹_, respectively), confirming maximum Co(II) adsorption at pH 3. Results can be used in the design of an efficient adsorption system using neem leaves which is very efficient in removing low and high levels of heavy metals like cobalt ions from wastewater.

中文翻译：

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使用死Ne叶从水溶液中去除Co（II）的一参数，两参数和三参数等温线，动力学和热力学评估

由于重金属在环境中的持久性，毒性以及在生物体内的生物蓄积能力，因此特别需要关注重金属如Co（II）的水污染。在这项研究中，接触时间在三个初始浓度，pH，吸附剂剂量，温度，动力学，热力学以及一，二和三参数等温线模型对印em叶上Co（II）吸附的影响（DNL）进行了调查。使用FTIR，TGA-DSC，EDX和氮气吸附-脱附对吸附剂进行表征。DNL由许多Co（II）表面结合基团组成，BET表面积为0.2783 m ² / g，以中孔和大孔为主。三种浓度在10分钟内达到平衡，去除效率为85-97％。△ G在25至60°C下分别为-5.424至-6.068 KJ / mol的°表示温度升高时自发吸附。DR吸附能为0.649至2.433 KJ / mol，表明存在物理吸附。Freundlich和Jovanovic等温线获得的最大吸附容量为9.201-523.900 mg / g。高Kiselev平衡常数（11.652-172.78 L / mg）和非常低的R _L值0.001-0.026证明了吸附是非常有利的。如Fowler-Guggenheim和Hill-de Boer负相互作用能（−16.182至-90.163和-111.102至-3328.86 KJmol ^-1）所示_，通过排斥机理发生了吸附_。 ），确认在pH 3时最大的Co（II）吸附。结果可用于设计使用印em叶的​​高效吸附系统，该系统对从废水中去除高含量和低含量的重金属（如钴离子）非常有效。