Huang Ju-Sheng, Chou Hsin-Hsien, Chen Chih-Ming, Chiang Chun-Mao
Department of Environmental Engineering, Kun Shan University, Tainan County 710, Taiwan, ROC.
Chemosphere. 2007 Jun;68(2):382-8. doi: 10.1016/j.chemosphere.2007.01.037. Epub 2007 Mar 6.
A laboratory study using a combined upflow anaerobic sludge bed (UASB)-activated sludge (AS) reactor system was undertaken to explore the effect of recycle-to-influent ratio (R(e)=1, 2, and 3) on the activities of nitrifiers and denitrifiers. Suspended-solids pre-settled piggery wastewater was used as the substrate-feed wastewater. At the R(e) of 1-3, the combined reactor system achieved efficient removal of COD (96-97%), TKN (100%) and total nitrogen TN (54-77%). Methanogenesis occurred with nearly-complete denitrification in the UASB reactor, whereas complete nitrification took place in the AS reactor. A higher R(e) (i.e., accompanied with a shorter solids retention time) resulted in a larger amount of high-activity denitrifiers and thereby achieved a higher TN removal efficiency. Compact granules and a high biomass concentration in the UASB reactor were observed. At the R(e) of 1-3, the maximum specific reaction rate of nitrifiers (0.45-0.49 NH(4)(+)-NmgVSS(-1)d(-1)) and the specific nitrification rates of mixed culture (0.18-0.22mg NH(4)(+)-NmgVSS(-1)d(-1)) in the AS reactor varied slightly; whereas the maximum specific reaction rate of denitrifiers (0.18-0.27mg NO(x)(-)-NmgVSS(-1)d(-1)) and the specific denitrification and COD removal rates of mixed culture (0.025-0.050mg NO(x)(-)-NmgVSS(-1)d(-1); 0.24-0.31mgCODmgVSS(-1)d(-1)) in the UASB reactor increased with increasing R(e). The primary finding of the study is that the combined UASB-AS reactor system should be operated at a higher R(e) to maintain high-activity denitrifiers to remove organic materials and nitrogen from piggery wastewater.
开展了一项实验室研究，采用上流式厌氧污泥床（UASB）-活性污泥（AS）组合式反应器系统，以探究回流比（R(e)=1、2和3）对硝化菌和反硝化菌活性的影响。以预沉淀的猪场悬浮固体废水作为底物进料废水。在R(e)为1至3时，组合式反应器系统实现了对化学需氧量（COD，去除率96 - 97%）、总凯氏氮（TKN，去除率100%）和总氮（TN，去除率54 - 77%）的高效去除。UASB反应器中发生了甲烷生成且几乎完全反硝化，而AS反应器中则实现了完全硝化。较高的R(e)（即伴随着较短的固体停留时间）导致大量高活性反硝化菌的产生，从而实现了更高的TN去除效率。观察到UASB反应器中有致密颗粒和高生物量浓度。在R(e)为1至3时，AS反应器中硝化菌的最大比反应速率（0.45 - 0.49 NH(4)(+)-NmgVSS(-1)d(-1)）和混合培养物的比硝化速率（0.18 - 0.22mg NH(4)(+)-NmgVSS(-1)d(-1)）变化不大；而UASB反应器中反硝化菌的最大比反应速率（0.18 - 0.27mg NO(x)(-)-NmgVSS(-1)d(-1)）以及混合培养物的比反硝化速率和COD去除速率（0.025 - 0.050mg NO(x)(-)-NmgVSS(-)1d(-1)；0.24 - 0.31mgCODmgVSS(-1)d(-1)）随着R(e)的增加而提高。该研究的主要发现是，UASB - AS组合式反应器系统应在较高的R(e)下运行，以维持高活性反硝化菌，从而去除猪场废水中的有机物质和氮。
