Arsenic-free water

AsFreeH2O: Suitability and social acceptance of water purification technologies under the influence of future sea water level rises.

(Research project 2016 - 2018, funded within HeiKa Explore by the Universities of Heidelberg and Karlsruhe).

Changes in sea water levels affect water quality and thus available freshwater resources in many areas of the world. Arsenic-contaminated and increasingly saline groundwater - in contrast to microbially contaminated surface water - poses a special challenge that also requires intensive consideration of the social environment of those affected. Treatment of visibly polluted surface water makes more sense, both technologically and energetically, than the less obvious arsenic contamination of groundwater. However, too little has been done to date to introduce the population to this alternative and lower arsenic water resource. This project will use the example of Bangladesh to lay the groundwork for understanding the challenge of arsenic contamination through intensive collaboration and to develop an approach that can be applied to such a problem.

Fig 1: Simple household filters are already in use in northwestern Bangladesh to remove iron.

Figs. 2 and 3: Initial and very low-cost prototypes, developed at the Institute for Geosciences Heidelberg (GEOW), use indigenous technology and combine it with a filter material that adsorbs arsenic (in the cloth bag on the left picture).

• Technological: Two typical arsenic removal technologies, adsorption (Heidelberg) and membrane technology (Karlsruhe) are being evaluated due to changing water quality caused by seawater levels.
• Social: In two different districts in Bangladesh (Pabna & Sylhet), the factors of the socio-cultural environment are evaluated by a local NGO from Heidelberg (AGAPE e.V.) with regard to the changing resource water due to sea water levels.
• With the help of the NGO AGAPE e.V., an ethnological approach from other regions of Southeast Asia will be adapted to the local conditions in Bangladesh in order to understand and consider the mindset and needs of Bangladeshis regarding the use of filtration technologies.
• Technologies for water treatment and storage will be integrated in terms of decision-making processes, acceptance, and parameters of technology adaptation (operation, energy use, water quality, distance, etc.).
• Public understanding of imperceptible chemical water contaminants will be investigated and communicated through understandable data. The extent to which this knowledge can influence the decision to use or not use technology will be investigated.

Figs. 4 and 5: Various technologies are to be tested for suitability and social acceptance. Community filters, e.g. Dadpur Primary School photo right) and small filters for household use (left) are used.