Ultrasonic Pretreated Sludge Derived Stable Magnetic Active Carbon for Cr(VI) Removal from Wastewater
Ultrasonic Pretreated Sludge Derived Stable Magnetic Active Carbon for Cr(VI) Removal from Wastewater
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DOI：
10.1021/acssuschemeng.7b04421
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发表时间：
2018-06-01
影响因子：
8.4
通讯作者：
Guo, Zhanhu
中科院分区：
文献类型：
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作者：
Gong, Kedong;Hu, Qian;Guo, Zhanhu
以活性污泥为碳前驱体制备了稳定的磁性炭。超声波预处理可以破坏活性污泥中的细胞，释放出可溶性碳源，提高磁性炭的稳定性。确定了800 W为活性污泥预处理的最佳超声功率。然后，碳化参数，如热解温度，升温速率，和停留时间分别为800 ℃，10 ℃/min，和60 min的优化。更具体地说，该活性污泥衍生磁性碳可以在10分钟内还原几乎所有的六价铬（Cr（VI））（2.0 mg/L），并且具有高达203 mg/g的最大容量。合成的活性污泥衍生磁性炭降低了铁的释放速率，提高了零价铁的电子利用率。该复合材料被证明具有良好的稳定性和可回收性。最后，阐明了在酸性和自然条件下Cr（VI）的去除机理。
A stable magnetic carbon was synthesized using activated sludge as the carbon precursor. The ultrasonic pretreatment was used to destroy the cells in the activated sludge and to release the soluble carbon source, which was responsible for the improved stability of the synthesized magnetic carbon. 800 W was demonstrated as the optimized ultrasonication power for the pretreatment of activated sludge. Then, the carbonization parameters, such as pyrolysis temperature, heating rate, and dwell time were optimized as 800 degrees C, 10 degrees C/min, and 60 min, respectively. To be more specific, this activated sludge derived magnetic carbon can reduce almost all the hexavalent chromium (Cr(VI)) (2.0 mg/L) in 10 min and has a maximum capacity as high as 203 mg/g. The iron release rate of the synthesized activated sludge derived magnetic carbon was decreased, which improved the electron utilization of zerovalent iron (ZVI). This composite was demonstrated to have a good stability and recyclability as well. Finally, the Cr(VI) removal mechanisms were clarified under the acidic and the natural conditions.