Exploratory experiments to determine the effect of alternative operations on the efficiency of subsurface arsenic removal in rural Bangladesh

Technological innovations for societal change : Arsenic mitigation technologies for safe drinking water in rural Bangladesh

“…The collected groundwater samples were examined in the laboratory to understand whether the concentration of arsenic and iron (and other elements such as silica, bicarbonate, phosphate, and manganese) comply with the optimal hydro-geochemical conditions determined in the laboratory for SAR experiments. It is worth mentioning that the availability of iron is a prerequisite for arsenic retention in the subsurface during SAR operation (Rahman et al, 2014). Figure 5.2: Prototype of Sub-surface Arsenic Removal Technology (Freitas et al, 2014;Rahman et al, 2014) The research team selected Payob Secondary High School as a location that matches water quality parameters for installing this prototype SAR unit.…”

“…It is worth mentioning that the availability of iron is a prerequisite for arsenic retention in the subsurface during SAR operation (Rahman et al, 2014). Figure 5.2: Prototype of Sub-surface Arsenic Removal Technology (Freitas et al, 2014;Rahman et al, 2014) The research team selected Payob Secondary High School as a location that matches water quality parameters for installing this prototype SAR unit. Equally important, the school authorities (the owners of the spot) and local community representatives gave consent to the research team to utilize the school as a temporary laboratory.…”

“…An inline monitoring system was also established. In order to extract ground water, two electrical suction pumps with a generator were used (for detailed discussion of the SAR prototype, see Rahman et al, 2014).…”

“…SAR operation involves the following consecutive steps: extraction of anoxic groundwater from the aquifer with arsenic and iron, aeration of the extracted water in a tank, re-injection of the aerated water into the same aquifer and lastly, extraction of larger volume of water with lower arsenic concentrations (van Halem, 2010;Rahman et al, 2014;Freitas et al, 2014). Several research and policy documents (GoB, 2011;Ravenscroft et al, 2009) strongly endorsed the desirability of researching and developing SAR, the idea of which builds on the extensive practical experience with (similarly designed) sub-surface iron and manganese removal technologies in Germany and Netherlands (van Beek, 1985;Appelo et al, 1999;Mettler, 2002;van Halem et al, 2010).…”

“…Even though it relies on the existing infrastructure of a shallow tube well, it does require adoption of new water use practices and does not fit directly into the existing socio-technical safe drinking water system in rural Bangladesh. This technology was incubated in the laboratory and then deployed for purposes of experimentation in rural Bangladesh by a research team from the Netherlands and Bangladesh (van Halem, 2010;Rahman et al, 2014;Freitas et al, 2014). This paper conceptualizes this as "real world experiments" (Gross & Hoffmann-Riem, 2005), and uses a transition theory lens to understand the transformative potential of such experimentation.…”