Department of Environmental Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Department of Environmental Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Chemosphere. 2019 Mar;219:130-139. doi: 10.1016/j.chemosphere.2018.12.014. Epub 2018 Dec 3.
Biomass washout from high-speed anaerobic suspended bed bio-reactors is still a challenge to their stable operation. Preserving active biomass to efficiently retain biomass in the reactor is one of the solutions to this problem. Herein, two carriers (polyvinyl alcohol/chitosan (PVA/CS) and PVA/CS/Fe gel beads) were prepared using the cross-linking method. The fourier transform infrared (FTIR) and C nuclear magnetic resonance (C NMR) analyses showed that PVA/CS gel beads formed mainly through hydrogen-bonds (NHOH). Furthermore, FTIR, C NMR, energy dispersive spectrum (EDS), X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS) analyses showed that PVA/CS/Fe gel beads formed mainly through chelate bond (NH-FeOH). The scanning electron microscope (SEM) results affirmed that the gel beads had rough and well-developed porous structure for the attachment of microbes. Furthermore, the abilities of gel beads on the cultivation of granular sludge in an up-flow anaerobic sludge bed (UASB) reactor were effectively demonstrated while treating wastewater polluted with glucose and alkali lignin. The results showed that the gel beads-assisted reactors had a higher performance than those without the gel beads. The cultivation of granules in these reactors was accelerated, while the granules became bigger and exhibited better settling velocities. The reactor with gel beads was easier to withstand a higher organic loading rate due to dense microbial aggregates, which were caused by more humic-like substance. Particularly, the reactor with PVA/CS/Fe gel beads was able to improve the overall robustness of the system due to stronger mechanical properties of gel beads, and also prevented cells detachment.
高速厌氧悬浮床生物反应器中的生物量冲洗仍然是其稳定运行的挑战。保留活性生物量是解决这个问题的方法之一。在此，使用交联法制备了两种载体（聚乙烯醇/壳聚糖（PVA/CS）和 PVA/CS/Fe 凝胶珠）。傅里叶变换红外（FTIR）和 C 核磁共振（C NMR）分析表明，PVA/CS 凝胶珠主要通过氢键（NHOH）形成。此外，FTIR、C NMR、能谱（EDS）、X 射线衍射仪（XRD）和 X 射线光电子能谱（XPS）分析表明，PVA/CS/Fe 凝胶珠主要通过螯合键（NH-FeOH）形成。扫描电子显微镜（SEM）结果证实，凝胶珠具有粗糙且发达的多孔结构，有利于微生物的附着。此外，当处理含有葡萄糖和碱木质素的废水时，凝胶珠在升流式厌氧污泥床（UASB）反应器中培养颗粒污泥的能力得到了有效证明。结果表明，凝胶珠辅助的反应器性能优于没有凝胶珠的反应器。这些反应器中的颗粒培养加速，颗粒变得更大，沉降速度更好。由于更多类腐殖质物质引起的密集微生物聚集体，带有凝胶珠的反应器能够承受更高的有机负荷率，这使得反应器更容易操作。特别是，由于凝胶珠具有更强的机械性能，PVA/CS/Fe 凝胶珠反应器能够提高系统的整体鲁棒性，并且还可以防止细胞脱落。
