Maïga Ynoussa, Denyigba Kokou, Wethe Joseph, Ouattara Aboubakar Sidiki
Université de Ouagadougou, UFR SVT, Centre de Recherche en Sciences Biologiques, Alimentaires et Nutritionnelles (CRSBAN), Laboratoire de Microbiologie et de Biotechnologie, 03 BP 7131, Ouagadougou 03, Burkina Faso.
J Photochem Photobiol B. 2009 Feb 9;94(2):113-9. doi: 10.1016/j.jphotobiol.2008.10.008. Epub 2008 Nov 5.
Experiments on sunlight inactivation of Escherichia coli were conducted from November 2006 to June 2007 in eight outdoors microcosms with different depths filled with maturation pond wastewater in order to determine pond depth influence on sunlight inactivation of E. coli. The long-term aim was to maximize sunlight inactivation of waterborne pathogens in waste stabilization ponds (WSPs) in sahelian regions where number of sunny days enable longer exposure of wastewater to sunlight. The inactivation was followed during daylight from 8.00 h to 17.00 h and during the night. Sunlight inactivation rates (K(S)), as a function of cumulative global solar radiation (insolation), were 16 and 24 times higher than the corresponding dark inactivation (K(D)) rates, respectively in cold and warm season. In warm season, E. coli was inactivated far more rapidly. Inactivation of E. coli follows the evolution of radiation during the day. In shallow depth microcosms, E. coli was inactivated far more rapidly than in high depth microcosms. The physical chemical parameters [pH, dissolved oxygen (DO)] of microcosms water were higher in shallow depth microcosms than in high depth microcosms suggesting a synergistic effect of sunlight and these parameters to damage E. coli. To increase the efficiency of the elimination of waterborne bacteria, the use of maturation ponds with intermediate depths (0.4m) would be advisable in view of the high temperatures and thus evaporation recorded in sahelian regions.
2006年11月至2007年6月，在八个装有熟化池废水、深度不同的户外微观世界中进行了大肠杆菌阳光灭活实验，以确定池塘深度对大肠杆菌阳光灭活的影响。长期目标是在萨赫勒地区的废物稳定塘（WSPs）中最大限度地利用阳光灭活水生病原体，该地区晴天数量多，使废水能更长时间暴露在阳光下。在白天8.00至17.00以及夜间对灭活情况进行跟踪。阳光灭活率（K(S)）作为累积全球太阳辐射（日照）的函数，在寒冷和温暖季节分别比相应的黑暗灭活（K(D)）率高16倍和24倍。在温暖季节，大肠杆菌灭活得更快。大肠杆菌的灭活随白天辐射的变化而变化。在浅深度微观世界中，大肠杆菌的灭活比在深深度微观世界中快得多。浅深度微观世界中水的物理化学参数[pH值、溶解氧（DO）]高于深深度微观世界，这表明阳光和这些参数对破坏大肠杆菌有协同作用。鉴于萨赫勒地区记录的高温以及由此产生的蒸发情况，为提高消除水生细菌的效率，建议使用中等深度（0.4米）的熟化池。
