Abstract Laser–induced breakdown spectroscopy (LIBS) and atomic absorption spectroscopy (AAS) techniques were applied for quantitative analysis of the remaining Pb content in water samples after treatment with a raw montmorillonite (MMT) and an organic derivative (MMO) clays for heavy metal removal, an issue of crucial importance for decontamination of water bodies. The Pb sorption capabilities of MMT and MMO clays were assessed by using solutions with known Pb concentrations, in the range 100–500 ppm. To carry out the LIBS analysis, the samples were prepared in the form of solid pellets with powdered calcium hydroxide addition. The measurement conditions were optimized to achieve reliable analytical results and the plasma parameters, i.e., temperature and electron density, were obtained. For quantification purpose, a calibration curve was constructed with the Pb I emission line at 4057.8 A measured at the time window 30–45 μs by using reference samples with Pb concentrations in the range 56–715 ppm. The Pb residual content in the liquid samples determined with LIBS showed a good agreement with those measured with AAS. The sorption efficiency of Pb from contaminated water was calculated through a sorption percentage SPb%. The calculated SPb% was higher for MMT (56%–100%) than for MMO (27%–47%). The results also demonstrated the usefulness of LIBS method for the determination of Pb concentrations in liquid samples.

中文翻译：

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使用激光诱导击穿光谱和原子吸收光谱评估蒙脱石粘土从水中去除铅的吸附能力

摘要 激光诱导击穿光谱 (LIBS) 和原子吸收光谱 (AAS) 技术被用于定量分析用水样品中的残留铅含量在用原料蒙脱石 (MMT) 和有机衍生物 (MMO) 粘土处理后的重金属去除，一个对水体净化至关重要的问题。MMT 和 MMO 粘土的 Pb 吸附能力通过使用已知 Pb 浓度（100-500 ppm）的溶液进行评估。为了进行 LIBS 分析，样品以固体颗粒的形式制备，并添加了粉末状氢氧化钙。优化测量条件以获得可靠的分析结果并获得等离子体参数，即温度和电子密度。出于量化目的，使用铅浓度在 56-715 ppm 范围内的参考样品，在 30-45 μs 的时间窗口测量的 Pb I 发射线在 4057.8 A 处构建了校准曲线。用 LIBS 测定的液体样品中的 Pb 残留含量与用 AAS 测定的结果非常吻合。污染水中铅的吸附效率通过吸附百分比 SPb% 计算。MMT (56%–100%) 的计算 SPb% 高于 MMO (27%–47%)。结果还证明了 LIBS 方法可用于测定液体样品中的 Pb 浓度。用 LIBS 测定的液体样品中的 Pb 残留含量与用 AAS 测定的结果非常吻合。污染水中铅的吸附效率通过吸附百分比 SPb% 计算。MMT (56%–100%) 的计算 SPb% 高于 MMO (27%–47%)。结果还证明了 LIBS 方法可用于测定液体样品中的 Pb 浓度。用 LIBS 测定的液体样品中的 Pb 残留含量与用 AAS 测定的结果非常吻合。污染水中铅的吸附效率通过吸附百分比 SPb% 计算。MMT (56%–100%) 的计算 SPb% 高于 MMO (27%–47%)。结果还证明了 LIBS 方法可用于测定液体样品中的 Pb 浓度。