Qin Juan, Yuan Sujuan, Córdova-Udaeta Mauricio, Oyama Keishi, Tokoro Chiharu
School of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, China.
Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
Materials (Basel). 2023 Feb 3;16(3):1314. doi: 10.3390/ma16031314.
Cadmium (Cd), as a type of heavy metal, can increase the incidence of many diseases, even in low concentrations. In this study, tobermorite was hydrothermally synthesized and then applied to adsorb Cd from an aqueous solution. The physicochemical characteristics of the synthesized tobermorite were detected, and the results indicated that the well-crystallized tobermorite had a lot of mesopores and a large specific surface area of 140.92 m/g. It acquired a pH self-adjustment ability via spontaneously releasing Ca and OH into the aqueous solution. The effects of different factors on Cd removal were investigated. For Cd, the removal efficiency could reach 99.71% and the maximum adsorption capacity was 39.18 mg/g using tobermorite. The adsorption data was best fitted with the pseudo-second-order kinetic and Langmuir isotherm models. In addition, there was no strict limit on the solution pH in Cd adsorption because the tobermorite could adjust the solution pH to an alkaline atmosphere spontaneously. The efficient removal of Cd using tobermorite was a result of surface complexation and ion exchange.
镉（Cd）作为一种重金属，即使在低浓度下也会增加多种疾病的发病率。在本研究中，水热合成了雪硅钙石，然后将其用于从水溶液中吸附镉。对合成的雪硅钙石的物理化学特性进行了检测，结果表明，结晶良好的雪硅钙石有许多中孔，比表面积大，为140.92 m/g。它通过向水溶液中自发释放钙和氢氧根而获得了pH自我调节能力。研究了不同因素对镉去除的影响。对于镉，使用雪硅钙石时去除效率可达99.71%，最大吸附容量为39.18 mg/g。吸附数据最符合准二级动力学和朗缪尔等温线模型。此外，镉吸附过程中对溶液pH没有严格限制，因为雪硅钙石可以自发地将溶液pH调节到碱性环境。雪硅钙石对镉的高效去除是表面络合和离子交换的结果。
