Abstract:The reduction of Cr(VI) by Fe0 is self-inhibiting and Fe0 easily agglomerates in groundwater. As such, iron cannot be fully utilized in Fe0-permeable reactive barrier (PRB) as the PRB is prone to compaction and blockage. To overcome these limitations, this study adopted sodium alginate (SA) to immobilize copper-iron bimetallic particles (SAB). Experimental results demonstrate that application of SA and copper-iron bimetallic particles dramatically increase the removal capacity of Cr (VI) by Fe0. Application of SA could decrease copper loading and obtain higher Cr (VI) removal rate than copper-iron bimetallic particles. SAB loaded with 0.9% copper (SAB0.9) were found to be the most optimal filler. From scanning electron microscopy images pore structures are observed, created by cross-linking SA with Ca2+, which increases the surface area of the copper-iron bimetallic particles. Field emission scanning electron microscope (FESEM) and X-ray photoelectron spectroscopy (XPS) demonstrate that the copper loaded onto the Fe0 surface presents a loose layer structure that acts as a catalyst to improve the utilization rate of Fe0 through variation of valence to transfer electrons. Based on permeability coefficient experiments, SAB0.9 can control the release of precipitation from the reduction of Cr(VI) by Fe0 and resolve the deficiency that Fe0-PRB is prone to compaction and blockage.
朱文会, 王兴润, 董良飞, 王琪, 何洁. 海藻酸钠固定化Fe-Cu双金属去除Cr(Ⅵ)的作用机制[J]. 中国环境科学, 2013, 33(11): 1965-1971.
ZHU Wen-Hui, WANG Xing-Run, DONG Liang-Fei, WANG Qi, HE Jie. Mechanism of copper-iron bimetallic particles immobilized by sodium alginate in removal of Cr(Ⅵ). CHINA ENVIRONMENTAL SCIENCECE, 2013, 33(11): 1965-1971.