Al-Gharabli Samer, Engeßer Patrick, Gera Diana, Klein Sandra, Oppenländer Thomas
German Jordanian University, Chemical-Pharmaceutical Engineering Department, School of Applied Medical Sciences, 35247, Amman, 11180, Jordan.
Hochschule Furtwangen University, Campus Villingen-Schwenningen, Jakob-Kienzle-Str. 17, 78054 Villingen-Schwenningen, Germany.
Chemosphere. 2016 Feb;144:811-5. doi: 10.1016/j.chemosphere.2015.09.012. Epub 2015 Sep 27.
Excilamps are mercury-free gas-discharge sources of non-coherent VUV or UV radiation with high radiant power and a long lifetime. The most efficient excilamp that is currently available on the market is a VUV xenon excilamp system (Xe2()-excimer lamp, λ(max) = 172 nm) with a stated radiant efficiency η of 40% at an electrical input power P(el) of 20 W, 50 W or 100 W. In this paper, the use of this highly efficient Xe2()-excilamp (P(el) = 20 W) for water treatment is demonstrated using a recirculating laboratory photoreactor system with negative radiation geometry. The efficiency in the 172 nm initiated bleaching of aqueous solutions of Rhodamine B is compared to that initiated by a common low-pressure mercury (LP-Hg) lamp (185 nm, TNN 15/32). The dependence of the pseudo zero order rate constant k´ of decolorization of RhB on the flow rate and on the initial concentration of RhB was investigated. Both lamps exhibited dependences of k´ on the initial concentration of RhB, which represents a typical saturation kinetical behavior. The saturation kinetics was very prominent in the case of the Xe2()-excilamp. Also, the Xe2()-excilamp treatment exhibited a significant influence on the flow rate of the RhB aqueous solution, which was not the case during the LP-Hg lamp initiated bleaching of RhB. The results of this paper demonstrate that Xe2()-excilamps can be used for VUV-initiated water purification. However, to reach the maximum efficacy of the Xe2()-excilamp for photo-initiated water purification further engineering optimization of the photoreactor concept is necessary.
准分子灯是无汞的气体放电光源，可产生非相干的真空紫外（VUV）或紫外辐射，具有高辐射功率和长寿命。目前市场上最有效的准分子灯是一种VUV氙准分子灯系统（Xe2() - 准分子灯，λ(max) = 172 nm），在20 W、50 W或100 W的电输入功率P(el)下，其辐射效率η据称可达40%。在本文中，使用具有负辐射几何结构的循环实验室光反应器系统，展示了这种高效Xe2() - 准分子灯（P(el) = 20 W）在水处理中的应用。将罗丹明B水溶液在172 nm光引发下的漂白效率与普通低压汞（LP - Hg）灯（185 nm，TNN 15/32）引发的效率进行了比较。研究了罗丹明B脱色的伪零级速率常数k´对流速和罗丹明B初始浓度的依赖性。两种灯的k´均对罗丹明B的初始浓度有依赖性，这代表了典型的饱和动力学行为。在Xe2() - 准分子灯的情况下，饱和动力学非常显著。此外，Xe2() - 准分子灯处理对罗丹明B水溶液的流速有显著影响，而在LP - Hg灯引发的罗丹明B漂白过程中则没有这种情况。本文结果表明，Xe2() - 准分子灯可用于VUV引发的水净化。然而，为了实现Xe2() - 准分子灯在光引发水净化中的最大功效，光反应器概念的进一步工程优化是必要的。
