State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, China.
J Environ Manage. 2012 May 15;98:98-106. doi: 10.1016/j.jenvman.2011.12.018. Epub 2012 Jan 15.
Two adsorbents, magnesia-loaded fly ash cenospheres (MGLC) and manganese-loaded fly ash cenospheres (MNLC), were prepared by wet impregnation of fly ash cenospheres with MgCl(2) solution or a mixed solution of MnCl(2) and KMnO(4), respectively. Their physicochemical properties were characterized by scanning electron microscopy, X-ray diffractometry, X-ray fluorescence spectrometry, and Fourier transform infrared spectrometry. Sorption experiments were conducted to examine the effects of adsorbent dosage, pH, time, temperature, ionic strength and competing anions on As(V) removal by MGLC and MNLC. Both MGLC and MNLC had greater pH buffering capacity and were less affected by changes in ionic strength. Competing anions (carbonate and dihydric phosphate) had a larger impact on As(V) removal by MNLC than by MGLC. Adsorption on MNLC reached equilibrium at 60 min, while adsorption on MGLC reached equilibrium at 120 min. The Langmuir adsorption isotherm was a good fit for the experimental data of As(V) adsorption on MGLC and MNLC, and the adsorption kinetics for both followed the pseudo-second-order rate equation. MGLC and MNLC had a larger removal capacity for As(V) than the cenospheres. Compared with MNLC, MGLC is a better absorbent.
两种吸附剂，负载氧化镁的粉煤灰空心微珠（MGLC）和负载锰的粉煤灰空心微珠（MNLC），分别通过用 MgCl(2)溶液或 MnCl(2)和 KMnO(4)的混合溶液浸渍粉煤灰空心微珠来制备。通过扫描电子显微镜、X 射线衍射仪、X 射线荧光光谱仪和傅里叶变换红外光谱仪对它们的物理化学性质进行了表征。进行了吸附实验，以研究吸附剂用量、pH、时间、温度、离子强度和竞争阴离子对 MGLC 和 MNLC 去除 As(V)的影响。MGLC 和 MNLC 均具有较大的 pH 缓冲能力，受离子强度变化的影响较小。竞争阴离子（碳酸盐和二氢磷酸盐）对 MNLC 去除 As(V)的影响大于 MGLC。MNLC 上的吸附在 60 分钟时达到平衡，而 MGLC 上的吸附在 120 分钟时达到平衡。Langmuir 吸附等温线很好地拟合了 MGLC 和 MNLC 对 As(V)吸附的实验数据，两种吸附的动力学均遵循拟二级速率方程。MGLC 和 MNLC 对 As(V)的去除能力大于空心微珠。与 MNLC 相比，MGLC 是一种更好的吸附剂。
