磁性LDH/PU材料提取SCFAs作为碳源的性能

以蛋壳为原料采用超声辅助法将超顺磁性铁氧体材料与制备的水滑石（LDH）进行复合改性合成磁性LDH，采用一步发泡法将磁性LDH与聚氨酯（PU）进行复合制备得磁性LDH/PU复合材料，研究以其作为支架从污泥发酵液中吸附提取短链脂肪酸（SCFAs），并将其作为外部碳源用于生物脱氮过程.XRD、SEM和TEM分析显示，所制备的磁性LDH具备典型水滑石层片状结构，所制备的磁性LDH/PU复合材料不仅具备PU泡沫疏松多孔比表面积大的特点，同时将LDH吸附材料均匀分散在整个体系中.结果表明：磁性LDH/PU复合材料对污泥发酵液中SCFAs的提取效率最大达到79.3%，经提取后的磁性LDH/PU-SCFAs作为碳源较葡萄糖作为碳源在反硝化作用中碳源利用率提升了6.7%，并且该碳源具备明显缓释效果，表明磁性LDH/PU-SCFAs可以作为生物脱氮过程中的一种新型高效外加缓释碳源.

Performance of SCFAs extracted by magnetic LDH/PU materials as denitrification carbon source

Ultrasonic assisted method was used to synthesize magnetic layered double hydroxide (LDH) with super-paramagnetic ferrite and eggshell-based LDH, then magnetic LDH/PU composite material was synthesized with magnetic LDH and polyurethane (PU) by one-step foaming method. The external carbon source of biological denitrification process was obtained by the magnetic LDH/PU composite material which adsorped by short-chain fatty acids (SCFAs). Results of X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) indicated that magnetic LDH had a typical layer structure of hydrotalcite, and magnetic LDH/PU composite materials not only had the characteristic of large porous surface area of PU, but also evenly dispersed the LDH throughout the entire system. The result showed that the maximum extraction efficiency of short-chain fatty acids from sludge reached 79.3%, and magnetic LDH/PU-SCFAs with sustained release performance could increase carbon source utilization by 6.7% in denitrification over using glucose. This research indicated that the magnetic LDH/PU-SCFAs can be used as a new type of high-efficiency biodenitrification carbon source.