Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2013-09-24, 11:56:35 | version 1.25.20
107 Dipl.-Ing. (FH) Hendrik Schikora Phone +49 711 970-4144 hendrik.schikora@igb.fraunhofer.de Dr. Michael Haupt Phone +49 711 970-4028 michael.haupt@igb.fraunhofer.de References [1] Malik, M.A. (2010) Water purification by plasmas: Which reactors are most energy efficient?, Plasma Chem Plasma Proc. 30: 21–31 [2] Siemens Industry (2011) New actinometry procedure for industrial UV applications, http://www.industry.siemens.com/ topics/global/en/fairs/siww/water-convention/Documents/09_ Poster_New-Actinometry-Procedure.pdf [3] Valsero, M. H.; Molina, R.; Schikora, H.; Müller, M.; Bayona, J. M. (2013) Removal of cyanide from water by means of plasma discharge technology, Water Research 47: 1–7 Funding We would like to thank the European Union for funding the pro- ject “Water decontamination technology for the removal of re- calcitrant xenobiotic compounds based on atmospheric plasma technology” in the Seventh Framework Programme (FP7/2007- 2013), grant agreement no. 262033. Project partners and further information www.waterplasma.eu Energy-efficient and effective degradation A method for comparing the efficiency of advanced oxidation processes is the measurement of the energy input that is re- quired to decolor methylene blue by one order of magnitude [1]. Using the plasma process 4 g/kWh (Fig. 4) is achieved. This value is nearly one order of magnitude better than the energy efficiency measured with a UV H2O2 treatment of methylene blue [2]. In another application of the water plas- ma method the project showed that cyanide (Fig. 5) is broken down by 90 percent within 2 minutes [3]. Outlook Unlike well-established advanced oxidation processes the plas- ma process for water decontamination has no barrier between the plasma and the medium that is to be purified. It therefore requires almost no maintenance and is characterized by a long life. A very high degree of efficiency is achieved even without the introduction of hazardous substances such as hydrogen peroxide or ozone. As a result of the project a demonstrator is now available that is suitable for purifying substantial quanti- ties of contaminated water (240 L/h). At the moment further possible applications for the procedure are being examined. 1 Schematic view of a plasma reactor for water purification. 2 Experimental setup of a plasma reactor for water purification. 3 Hydroxyl radicals formed in the plasma decompose the dye methylene blue. 4 Degradation kinetics of 1 mg/L methylene blue (efficiency90 % reduction of 4 g/kWh). 5 Degradation of 0.8 mg/L cyanide in water using plasma treatment. 0 5 10 15 20 Opticalabsorption[relativeunits] Treatment time [min] Helium Oxygene Process gas: 0.4 0.2 0 0.8 0.6 1 Degradation[%] Treatment time [s] 40 20 0 20 40 60 80 100 1200 140 80 60 100 4 5 Contacts