Heavy metals in the environment are a problem due to their toxicity and bioaccumulation. Adsorptive removal of heavy metals by clay minerals has garnered increasing attention due to the abundance, low cost, and exceptional physicochemical properties of the clays. The purpose of the present study was to investigate the utilization of two Turkish sepiolite samples, nodular sepiolite (NS) and industrial sepiolite (IS), as adsorbents in removing Ni2+ ions from aqueous solutions. The specific surface areas of NS and IS are 182.19 m2 g–1 and 63.78 m2 g–1, respectively. The effects of adsorbent dosage, initial pH, contact time, initial concentration, and temperature on the adsorption of Ni2+ ions onto the sepiolite samples were investigated using a batch method. The optimum adsorbent dosage was determined as 0.6 g/50 mL of adsorbent and the optimum pH value was 6.0, for both sepiolite samples. The adsorption process obeyed the Freundlich isotherm model (KF: 4.89–9.73 mg1–1/n L1/n g–1 for NS and 4.27–6.42 mg1–1/n L1/n g–1 for IS) and the pseudo-second order kinetics model (k2: 0.0049–0.0397 g mg–1 min–1 for NS and 0.0688–0.1195 g mg–1 min–1 for IS). The adsorption process was spontaneous and endothermic, and the randomness increased. The samples exhibited large adsorption capacities through three cycles of adsorption-desorption tests. The results revealed that the sepiolite samples are promising as cost-effective adsorbents for the removal of Ni2+ ions from aqueous solutions.

中文翻译：

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通过球状海泡石（海泡石）和来自土耳其 ESKIŞEHIR 的工业海泡石样品吸附去除水溶液中的 Ni2+ 离子

环境中的重金属因其毒性和生物累积性而成为一个问题。粘土矿物对重金属的吸附去除由于粘土丰富、成本低和优异的物理化学性质而受到越来越多的关注。本研究的目的是调查两种土耳其海泡石样品，球状海泡石 (NS) 和工业海泡石 (IS) 作为吸附剂从水溶液中去除 Ni2+ 离子的利用情况。NS 和 IS 的比表面积分别为 182.19 m2 g-1 和 63.78 m2 g-1。使用批量方法研究了吸附剂用量、初始 pH 值、接触时间、初始浓度和温度对 Ni2+ 离子吸附到海泡石样品上的影响。最佳吸附剂用量确定为 0。两种海泡石样品的吸附剂用量为 6 g/50 mL，最佳 pH 值为 6.0。吸附过程遵循 Freundlich 等温线模型（NS 为 4.89–9.73 mg1–1/n L1/ng–1，IS 为 4.27–6.42 mg1–1/n L1/ng–1）和准二级动力学模型（k2：NS 为 0.0049–0.0397 g mg–1 min–1，IS 为 0.0688–0.1195 g mg–1 min–1）。吸附过程是自发吸热的，随机性增加。通过三个循环的吸附-解吸测试，样品表现出较大的吸附容量。结果表明，海泡石样品有望作为从水溶液中去除 Ni2+ 离子的经济高效的吸附剂。42 mg1–1/n L1/ng–1 对于 IS）和伪二级动力学模型（k2：0.0049–0.0397 g mg–1 min–1 对于 NS 和 0.0688–0.1195 g mg–1 min–1 对于 IS ）。吸附过程是自发吸热的，随机性增加。通过三个循环的吸附-解吸测试，样品表现出较大的吸附容量。结果表明，海泡石样品有望作为从水溶液中去除 Ni2+ 离子的经济高效的吸附剂。42 mg1–1/n L1/ng–1 对于 IS）和伪二级动力学模型（k2：0.0049–0.0397 g mg–1 min–1 对于 NS 和 0.0688–0.1195 g mg–1 min–1 对于 IS ）。吸附过程是自发吸热的，随机性增加。通过三个循环的吸附-解吸测试，样品表现出较大的吸附容量。结果表明，海泡石样品有望作为从水溶液中去除 Ni2+ 离子的经济高效的吸附剂。