Using EEFM (Excitation emission fluorescence matrix) to differentiate the organic properties of the effluents from the ozonated biofilters

作者：Lai Wen Liang^*; Chen Lih Fu; Liao Shao Wei; Hsu Shu Lin; Tseng Li Ho; Miaw Chang Ling

来源：Water, Air, and Soil Pollution, 2007, 186(1-4): 43-53.

DOI：10.1007/s11270-007-9461-6

• TBC (total bacterial count)
• NPDOC (non-purgeable dissolved carbon)
• EEFM (excitation emission fluorescence matrix)
• SMPs (soluble microbial products)

This study conducted a two-stage experiment. The first stage attempted to establish biostable filter beds. Two parameters, total bacterial count (TBC) and non-purgeable dissolved carbon (NPDOC), measured by passing through a 0.2 mu m membrane filter, were selected to compare the difference of biostability of a filtration system with recirculation with different O(3)-to-NPDOC ratios of filtered water. The excitation emission fluorescence matrix (EEFM) was used as an effective tool for understanding information regarding organic characteristics by comparing source filtered water before and after ozonation and the effluent during biostablizing filter. During the second stage, a biostable filter was used to compare differences in biodegradability of ozonated products sodium oxalate and sodium acetate. Experimental results demonstrate that both parameters, NPDOC removal and TBC, can be utilized to evaluate the biostabilty of a filter bed. With each parameter, a plateau was reached in roughly 20 days. The source water from Chen Ching Lake (CCL) contained a protein-like substance determined by the EEFM. This protein-like substance was also destroyed by O(3)/ NPDOC= 1.1. Soluble microbial products (SMPs) released from the biostablizing filter into the effluent have two peaks in the EEFM, identified as protein-like and humic-like acid. The NPDOC removal for the biostabilizing filter using O(3)/NPDOC= 1.7 was less than that using O(3)/NPDOC= 1.1. Bacterial counts in the effluent from the biostabilizing filter using O(3)/ NPDOC= 1.1 was better than that of O(3)/NPDOC= 1.7. This difference can be explained by the high ratio of O(3)/NPDOC producing by-products of ozonation that were easily utilized by microorganisms; however, filter bed also released relatively more SMPs owing to increased proliferation of microorganisms attached to glass pellets in the filter. Regarding the differences in decomposition of the by-products of ozonation by the biostable filter, such as sodium oxalate, the NPDOC removal at O(3)/NPDOC= 1.1 was better than that at O(3)/DOC= 1.7. This phenomenon can be explained as previously mentioned.

• 出版日期2007-11