Removal of chromium by riverbed sand from water and wastewater: effect of important parameters.
Removal of chromium by riverbed sand from water and wastewater: effect of important parameters.
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DOI：
10.1016/j.jhazmat.2007.06.054
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发表时间：
2008-03
影响因子：
13.6
通讯作者：
Y. Sharma;Bhaskar Singh;A. Agrawal;C. Weng
中科院分区：
文献类型：
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作者：
Y. Sharma;Bhaskar Singh;A. Agrawal;C. Weng
研究了河床沙（一种无毒物质）在水溶液中去除 Cr(VI) 的应用。 Cr(VI) 的去除取决于初始浓度，在 25°C、1.0×10−2M NaClO4 离子强度和 100rpm 下，通过将初始浓度从 7.5×10−5M 降低到 1.0×10−5M，去除率从 43.2% 增加到 74.3%。吸附剂颗粒尺寸越小，去除率越高。通过将温度从 25°C 升高至 35°C，去除率从 74.3% 下降至 40.7%，表现出去除过程的放热性质。计算了热力学参数，即自由能（ΔG°）、焓（ΔH°）和熵（ΔS°）的变化，发现在25°C下分别为-0.81kcalmol−1、-17.21kcalmol−1和56.94calmol−1。溶液的 pH 值对去除率有显着影响，在酸性 pH 范围内获得了更高的去除率，在 pH 值 2.5 时达到最大值 (74.3%)。
Application of riverbed sand, a non-toxic substance for the removal of Cr(VI) for aqueous solutions has been investigated. Removal of Cr(VI) was dependent on initial concentration and removal increased from 43.2% to 74.3% by decreasing initial concentration from 7.5×10−5M to 1.0×10−5M at 25°C, 1.0×10−2M NaClO4ionic strength and 100rpm. Higher removal was obtained at particles of smaller sizes of the adsorbent. Removal decreased from 74.3% to 40.7% by increasing temperature from 25°C to 35°C exhibiting exothermic nature of the process of removal. Thermodynamic parameters, namely change in free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°), were calculated and were found to be −0.81kcalmol−1, −17.21kcalmol−1and 56.94calmol−1, respectively at 25°C. pH of the solution has pronounced effect on the removal and higher removal was obtained in acidic pH ranges, maximum (74.3%) being at 2.5 pH.