College of Environmental Science and Engineering, Hunan University, Changsha, PR China.
Chemosphere. 2013 Apr;91(5):579-85. doi: 10.1016/j.chemosphere.2012.12.002. Epub 2012 Dec 23.
In our previous study, it has been proposed that the hydrolysis of waste activated sludge (WAS) can be enhanced by hydrolytic enzymes. In this study, fluorescence spectral characteristics of extracellular polymeric substances (EPSs) and dissolved organic matter (DOM) during anaerobic digestion were investigated using three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy to explore the destruction mechanisms of WAS enhanced by additional enzymes (protease, α-amylase and the mixture). Two individual fluorescence peaks associated with protein-like fluorophores (aromatic and tryptophan protein-like substances) were identified in the EEM fluorescence spectra of the EPS after 1 and 6d, and only aromatic protein-like substances were observed after 12d of anaerobic digestion for all treatments. As for the DOM, three individual fluorescence peaks were identified, but the peaks associated with visible humic acid-like fluorophores disappeared after 12d. The EEM fluorescence intensity of EPS decreased during the entire anaerobic process, whereas that of the DOM increased at 1d and then decreased till the end. In the EPS, the residual protein-like substances were found to be the lowest during the entire anaerobic process when treated with protease. Correspondingly, the protein-like substances in the DOM increased rapidly from 1 to 6d, and decreased to the lowest level after 12d for the protease treatment.
在我们之前的研究中，已经提出通过水解酶可以增强废活性污泥（WAS）的水解。在这项研究中，使用三维激发-发射矩阵（EEM）荧光光谱法研究了厌氧消化过程中外源聚合物物质（EPS）和溶解有机物（DOM）的荧光光谱特征，以探索通过额外酶（蛋白酶、α-淀粉酶和混合物）增强 WAS 的破坏机制。在 EPS 的 EEM 荧光光谱中，在 1 和 6d 后鉴定出与蛋白质类荧光团（芳香族和色氨酸蛋白类物质）相关的两个单独荧光峰，并且在所有处理中，在 12d 的厌氧消化后仅观察到芳香族蛋白类物质。对于 DOM，鉴定出三个单独的荧光峰，但在 12d 后与可见腐殖酸类荧光团相关的峰消失了。在整个厌氧过程中，EPS 的 EEM 荧光强度降低，而 DOM 的 EEM 荧光强度在 1d 时增加，然后一直降低到结束。在整个厌氧过程中，在用蛋白酶处理时，EPS 中残留的蛋白质类物质最低。相应地，在蛋白酶处理时，DOM 中的蛋白质类物质从 1 天迅速增加到 6 天，然后在 12 天后降低到最低水平。
