Scholarly article on topic 'Development of Multibarrier Systems Consisting of Nano-Enhanced Membranes and UV-LEDs for Water Purification Applications'

Development of Multibarrier Systems Consisting of Nano-Enhanced Membranes and UV-LEDs for Water Purification Applications Academic research paper on "Chemical engineering"

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Procedia Engineering
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{"Nano enhanced membranes" / Microfiltration / "Metallic microsieves" / wastewater}

Academic research paper on topic "Development of Multibarrier Systems Consisting of Nano-Enhanced Membranes and UV-LEDs for Water Purification Applications"

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Procedía Engineering 44 (2012) 544 - 545

Procedía Engineering

www.elsevier.com/1ocate/procedia

Euromembrane Conference 2012 [0D17]

Development of multibarrier systems consisting of nano-enhanced membranes and UV-LEDs forwater purification applications

V. Keuter*, I. Gehrke et al

Fraunhofer Institute UMSICHT, Germany

Introduction

In 2030, about 47% of world population will be living in areas of high water stress. From the global water shortage an emerging need for more efficient and cost saving water purification methods is resulting. In both developing and industrialized countries a growing number of contaminants like micro-pollutants (e.g. endocrine disruptors) are entering the water bodies. Conventional decontamination processes e.g. using oxidizing chemicals like ozone or chlorine consume a high amount of chemical agents and, furthermore, can produce toxic by-products. A promising method is represented by the membrane technology with less use of chemicals and retention of contaminants. However, membrane processes are characterized by a high tendency to fouling resulting in drastically performance decrease.

Approach

The adaption of highly advanced nanotechnology to traditional process engineering offers new opportunities for the intensification of water processes. In our approach we focus on the application of nanocoating procedures to membrane processes in order to reduce e.g. the fouling potential of membranes. Combined with advanced UV light sources this will result in the development of novel multibarrier systems. Nanocoating methods based on biocide and photocatalytic substances like Ti02 and/or Ag are applied in order to functionalize membranes. Specific experimental set-ups at laboratory scale for measuring permeate flux, pressure loss and photocatalytic activity as well as biocide effects has been applied.

Fig. 1: Concept of advanced multibarrier system

1877-7058 © 2012 Published by Elsevier Ltd. doi: 10.1016/j.proeng.2012.08.481

V. Keuter and I. Gehrke /Procedia Engineering 44 (2012) 544 - 545

Novel metallic microsieves at CD-scale, including a homogeneous pore size distribution and higher robustness, have been developed and tested applying novel molding processes. They feature an enormous permeate flux. In order to maintain the permeate capacity, currently, photocatalytic nanocoatings are applied to the surface. The coatings are characterized by a high adhesion to the metallic membranes. The coating process can be exactly controlled, so the very precise pore geometry is preserved and the holes are kept unblocked from coating material. The novel fouling repellent microsieves are to be implemented in compact and flexibly adjustable multibarrier modules particularly for producing potable water but also for the post-treatment of wastewater.

First results

Applying Sol/Gel or CVD processes resulted in stable and photocatalytic active coatings. Photoactivity is analyzed via degradation of methylene blue and methanol as well as lab trials with real and doped wastewater to control reduction of microorganism and organic pollutants. Further R&D is ongoing to increase the photoactivity and to design a compact multibarrier system. From a wide range of different UV-LEDs types for direct disinfection and activation of Ti02 have been characterized. A new module for the application of the UV-LEDs has been designed. The systems will be demonstrated in water and wastewater applications in a technical scale.

Wellenlänge [nm]

Fig. 2: Emission spectra of different UV-LEDs

Acknowledgements: Results of the presentation are based on projects partly funded by the German Federal Ministry of Education and Research (BMBF).

Keywords: Nano enhanced membranes, Microfiltration, Metallic microsieves, wastewater