Granular activated carbon/pyrite composites for environmental application: synthesis and characterization.
Granular activated carbon/pyrite composites for environmental application: synthesis and characterization.
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DOI：
10.1016/j.jhazmat.2012.06.048
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发表时间：
2012-09
影响因子：
13.6
通讯作者：
C. Liang;Po-Han Lee
中科院分区：
文献类型：
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作者：
C. Liang;Po-Han Lee
本研究的目标是生产一种用于环境修复的涂有黄铁矿 (FeS2) 的活性颗粒活性炭 (GAC)，它将结合 GAC 吸附和 FeS2 还原反应的功能。通过初湿铁浸渍、300℃煅烧转化为赤铁矿（Fe2O3）和400℃煅烧硫化的连续工艺成功制备了GAC-FeS2复合材料。用硝酸 (HNO3) 清洗的活性炭的零电荷点 (pHPZC) 降低，以改善铁离子物质进入活性炭孔隙的能力，并且 FTIR 的结果证实了导致活性炭表面带负电的羧酸基团的优势。 XRD结果表明，煅烧后的复合材料为过渡态GAC-Fe2O3和最终GAC-FeS2。使用Scherrer公式计算得到的FeS2晶粒尺寸约为31-34nm，SEM/SEI显示FeS2具有角形形状。 GAC 中 FeS2 的存在导致 BET 表面积和孔体积显着减少。然而，尽管与原始 GAC 相比，这些减少可能导致吸附能力下降，但涂覆的反应性 FeS2 可能会导致吸附物（如三氯乙烯 (TCE)）的非生物转化，这将补偿吸附的损失。此外，GAC-FeS2吸附/脱氯的TCE实验的初步结果表明，该复合材料最初在GAC上积累并限制了TCE，并通过嵌入的FeS2逐渐对TCE进行脱氯。
The goal of this study was to produce a reactive granular activated carbon (GAC) coated with pyrite (FeS2) for environmental remediation, which would combine both functions of GAC adsorption and FeS2reduction reactions. GAC–FeS2composite materials have been successfully prepared via sequential processes, i.e., incipient wetness iron impregnation, transformation into hematite (Fe2O3) by calcination at 300°C and sulfurization by calcination at 400°C. The point of zero charge (pHPZC) of GAC washed with nitric acid (HNO3) decreased to improve the drawing of iron ionic species into the pores of GAC and the results of FTIR confirmed the predominance of carboxylic acid groups which cause a negative charged GAC surface. XRD results indicated that the calcined composites are transitional GAC–Fe2O3and final GAC–FeS2. The obtained FeS2crystallite size calculated using Scherrer formulae was around 31–34nm and SEM/SEI showed FeS2had an angular shape. The existence of FeS2in GAC gave rise to a significant reduction of BET surface and pore volume. However, even though these reductions may result in the decrease of adsorption capacity when compared to the virgin GAC, the coated reactive FeS2may result in the abiotic transformation of adsorbates such as trichloroethylene (TCE) and this would compensate for the loss of adsorption. Furthermore, the preliminary results of TCE experiments on GAC–FeS2adsorption/dechlorination revealed that the composite initially accumulated and confined TCE on GAC and gradually dechlorinated TCE by embedded FeS2.