Ultraviolet light-emitting diodes in water disinfection
Ultraviolet light-emitting diodes in water disinfection
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DOI：
10.1007/s11356-009-0103-y
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发表时间：
2009-06-01
影响因子：
5.8
通讯作者：
Sillanpaa, Mika
中科院分区：
文献类型：
--
作者：
Vilhunen, Sari;Sarkka, Heikki;Sillanpaa, Mika
背景、目标和范围 研究了新型紫外线发光二极管 (UV LED) 系统在水消毒中的应用。传统的紫外线灯，如汞蒸气灯，消耗大量能量，并且在使用后被认为是有问题的废物。 UV LED 节能且无毒。本研究展示了 LED 在消毒中的适用性，并提供了两种发射波长和不同测试介质对大肠杆菌破坏的影响的信息。材料和方法使用常见的实验室大肠杆菌菌株 (K12)，并使用两个均包含 10 个 LED 的光解批量反应器研究了两种发射波长（269 和 276 nm）的影响。用超纯水、营养物和水以及含有腐殖酸的营养物和水检查了测试介质的影响。结果即使发射更高波长的一个反应器的光功率是另一个反应器的两倍，反应器的效率几乎相同。因此，波长的影响很明显，269 nm 发出的辐射更强。此外，还研究了背景的影响，发现只有轻微的恶化影响。在 5 分钟的实验中，在所有情况下，每立方厘米的细菌减少了 3 至 4 个对数菌落形成单位 (CFU)。 讨论 当测试介质的浊度较大时，部分紫外线辐射用于吸收液体上的额外物质并与液体发生反应。腐殖酸还可以覆盖细菌，降低细胞对紫外线的敏感性。当考虑光功率时，尽管波长差异很小，但较低的波长显然更有效。原因可能是 DNA 的吸收量更大，导致更有效地破坏细菌。 结论 UV LED 可以有效地破坏大肠杆菌，即使 LED 被认为具有相当低的光功率。波长的影响很明显，但测试介质没有太大影响。建议和观点 本研究发现 UV LED 是细菌消毒的最佳方法。人们发现发射波长是使用 LED 时的一个重要因素；因此，应谨慎选择合适的 LED 以实现最大程度的消毒。
Background, aim, and scope The novel system of ultraviolet light-emitting diodes (UV LEDs) was studied in water disinfection. Conventional UV lamps, like mercury vapor lamp, consume much energy and are considered to be problem waste after use. UV LEDs are energy efficient and free of toxicants. This study showed the suitability of LEDs in disinfection and provided information of the effect of two emitted wavelengths and different test mediums to Escherichia coli destruction.Materials and methods Common laboratory strain of E. coli (K12) was used and the effects of two emitted wavelengths (269 and 276 nm) were investigated with two photolytic batch reactors both including ten LEDs. The effects of test medium were examined with ultrapure water, nutrient and water, and nutrient and water with humic acids.Results Efficiency of reactors was almost the same even though the one emitting higher wavelength had doubled optical power compared to the other. Therefore, the effect of wavelength was evident and the radiation emitted at 269 nm was more powerful. Also, the impact of background was studied and noticed to have only slight deteriorating effect. In the 5-min experiment, the bacterial reduction of three to four log colony-forming units (CFU) per cubic centimeter was achieved, in all cases.Discussion When turbidity of the test medium was greater, part of the UV radiation was spent on the absorption and reactions with extra substances on liquid. Humic acids can also coat the bacteria reducing the sensitivity of the cells to UV light. The lower wavelength was distinctly more efficient when the optical power is considered, even though the difference of wavelengths was small. The reason presumably is the greater absorption of DNA causing more efficient bacterial breakage.Conclusions UV LEDs were efficient in E. coli destruction, even if LEDs were considered to have rather low optical power. The effect of wavelengths was noticeable but the test medium did not have much impact.Recommendations and perspectives This study found UV LEDs to be an optimal method for bacterial disinfection. The emitted wavelength was found to be an essential factor when using LEDs; thus, care should be taken in selecting the proper LED for maximum disinfection.