Chemistry Department, School of Science, Tianjin University, Tianjin 300072, China.
School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600, China.
Chemosphere. 2016 Feb;144:621-7. doi: 10.1016/j.chemosphere.2015.09.032. Epub 2015 Sep 21.
The rectorite (REC)/carbon composites (RECCs) were prepared with hydrothermal carbonization using starch as carbon source and REC as the template. RECCs were modified with carbon disulfide (CS2) to obtain RECC xanthate (RECCX) composites. The hydrothermal process introduced a large number of oxygen-containing groups by depositing carbon layers onto the surface of REC, and the CS2 modification brought xanthate groups into REC. The adsorption process of Pb(2+) was investigated. Compared with REC, both RECC and RECCX could absorb more Pb(2+). The oxygen-containing groups increased the Pb(2+) adsorption in RECC. With the increasing of CS2 dosages, the adsorption capacities of RECCXs obviously improved due to the formation of the chelation between Pb(2+) and xanthate groups. The kinetic adsorption and the isotherm data matched the pseudo-second-order model and the Langmuir model well. The maximum adsorption capacities could reach 225.7 and 431.0 mg/g for RECC and RECCX, respectively. RECCXs were competitive with other absorbents, because REC, carbon layers and xanthate groups in RECCX composites all contributed to the Pb(2+) adsorption. RECCX could be easily regenerated with ethylenediaminetetraacetic acid disodium salt (EDTA) solution.
水热碳化淀粉原位合成了具有 REC 模板的碳复合材料（RECCs）。CS2 对 RECC 进行了改性，得到了 RECC 黄原酸盐（RECCX）复合材料。水热过程通过在 REC 表面沉积碳层引入了大量含氧基团，CS2 改性将黄原酸盐基团引入 REC。研究了 Pb(2+)的吸附过程。与 REC 相比，RECC 和 RECCX 都可以吸附更多的 Pb(2+)。含氧基团增加了 RECC 中 Pb(2+)的吸附。随着 CS2 剂量的增加，RECCX 的吸附容量明显提高，这是由于 Pb(2+)和黄原酸盐基团之间形成了螯合作用。动力学吸附和等温线数据很好地符合准二级模型和 Langmuir 模型。RECC 和 RECCX 的最大吸附容量分别达到 225.7 和 431.0 mg/g。RECCX 与其他吸附剂具有竞争力，因为 REC、RECCX 复合材料中的碳层和黄原酸盐基团都有助于 Pb(2+)的吸附。RECCX 可以用乙二胺四乙酸二钠盐（EDTA）溶液很容易地再生。
