Small-scale piped water supply: end-user inclusive water research in arsenic affected areas in India and Bangladesh (DELTAP)

DELTAP is s multi-disciplinary research project, where geologists, water treatment scientists and industrial design engineers join forces to develop an integrated approach towards small-scale piped water supply (SPWS) systems in the arsenic-affected Ganges-Brahmaputra-Meghna Delta. The project has started in 2016 with a field study in Bihar (India) with a focus on water quality mapping with mobile crowd participation. The coming years the research will continue with 3 PhD candidates, both in India and Bangladesh, with the ultimate aim to develop blueprints for end-user inclusive SPWS systems

Decision-support for arsenic- and salt- mitigation in Bangladesh: the ASTRA approach

Bangladesh faces a growing water crisis. Limitations to safe water access arise from the widespread pathogenic contamination of its surface waters, the severe arsenic contamination of its aquifers and the growing salinity in the country’s coastal regions. Appropriate water supply methods are identified for some of these contexts, it is challenging to select resilient water supply solutions for the low-income, rural areas of Bangladesh. The ASTRA tool is developed to support the identification of potentially appropriate drinking water methods and to aid their implementation in this context. It can be seen as the combination of a multidisciplinary sourcebook and a decision-support instrument. This paper outlines the main mitigation routes as the (i) targeting of contamination-free groundwater, (ii) treatment of arsenic- and salt-contaminated aquifers and (iii) utilization of non-groundwater sources. The paper also describes the tool-inventory and the context factors applied to determine functional ranges of the included water supply methods

Ceramic Water Filter for Point-Of-Use Water Treatment in Developing Countries: Principles, Challenges and Opportunities

Drinking water source contamination poses a great threat to human health in developing countries. Point-of-use (POU) water treatment techniques, which improve drinking water quality at the household level, offer an affordable and convenient way to obtain safe drinking water and thus can reduce the outbreaks of waterborne diseases. Ceramic water filters (CWFs), fabricated from locally sourced materials and manufactured by local labor, are one of the most socially acceptable POU water treatment technologies because of their effectiveness, low-cost and ease of use. This review concisely summarizes the critical factors that influence the performance of CWFs, including (1) CWF manufacturing process (raw material selection, firing process, silver impregnation), and (2) source water quality. Then, an in-depth discussion is presented with emphasis on key research efforts to address two major challenges of conventional CWFs, including (1) simultaneous increase of filter flow rate and bacterial removal efficiency, and (2) removal of various concerning pollutants, such as viruses and metal(loid)s. To promote the application of CWFs, future research directions can focus on: (1) investigation of pore size distribution and pore structure to achieve higher flow rates and effective pathogen removal by elucidating pathogen transport in porous ceramic and adjusting manufacture parameters; and (2) exploration of new surface modification approaches with enhanced interaction between a variety of contaminants and ceramic surfaces

Sex Differences in the Brain: A Whole Body Perspective

Most writing on sexual differentiation of the mammalian brain (including our own) considers just two organs: the gonads and the brain. This perspective, which leaves out all other body parts, misleads us in several ways. First, there is accumulating evidence that all organs are sexually differentiated, and that sex differences in peripheral organs affect the brain. We demonstrate this by reviewing examples involving sex differences in muscles, adipose tissue, the liver, immune system, gut, kidneys, bladder, and placenta that affect the nervous system and behavior. The second consequence of ignoring other organs when considering neural sex differences is that we are likely to miss the fact that some brain sex differences develop to compensate for differences in the internal environment (i.e., because male and female brains operate in different bodies, sex differences are required to make output/function more similar in the two sexes). We also consider evidence that sex differences in sensory systems cause male and female brains to perceive different information about the world; the two sexes are also perceived by the world differently and therefore exposed to differences in experience via treatment by others. Although the topic of sex differences in the brain is often seen as much more emotionally charged than studies of sex differences in other organs, the dichotomy is largely false. By putting the brain firmly back in the body, sex differences in the brain are predictable and can be more completely understood

Ceramic silver impregnated pot filters for household drinking water treatment in developing countries

Civil Engineering and Geoscience

Water research for the world

Let’s start with the United Nations Millennium Development Goals Report 2012. Remember the target? Halve, by 2015, the proportion of the population without sustainable access to safe drinking water and basic sanitation. Thanks to China and India the world has met the drinking water target in 2010, but the work is not done yet. The poorest lag behind, especially in Sub-Saharan Africa (Figure 1). Over 40 per cent of all people without improved drinking water live in sub-Saharan Africa. The gap between urban and rural areas still remains wide, with the number of people in rural areas without an improved water source five times greater than in urban areas. Ruralurban disparities in access to sanitation are even more pronounced than for access to drinking water. The number of people forced to resort to open defecation remains a widespread health hazard and a global scandal. Nearly 60 per cent of those practicing open defecation live in India. In sub-Saharan Africa, 75 per cent of the households have to collect water from some distance. The time and energy devoted to this manner of water collection is considerable. For 25 sub-Saharan countries combined, it is estimated that 26 million hours are spend per day, which equals the working hours of the lifetimes of 300 people. An important note: water quality is not accounted for in United Nations report – so results may well be overestimated. But isn’t that what it’s all about? Providing improved water sources, not just any source.Water ManagementCivil Engineering and Geoscience

Subsurface iron and arsenic removal for drinking water treatment in Bangladesh

Arsenic contamination of shallow tube well drinking water is an urgent health problem in Bangladesh. Current arsenic mitigation solutions, including (household) arsenic removal options, do not always provide a sustainable alternative for safe drinking water. A novel technology, Subsurface Arsenic Removal, relies on the existing technology of Subsurface Iron Removal. The principle of this technology is that aerated water is periodically injected into an anoxic or anaerobic aquifer through a tube well. The injection water partially displaces the original iron and arsenic containing groundwater. The oxygen-rich injection water oxidized adsorbed iron on the soil grains around the tube well. Once the flow direction is reversed, the oxidized iron (precipitated as iron (oxy)hydroxides) provides adsorption sites for soluble iron and arsenic. Subsequently groundwater with reduced iron and arsenic concentrations can be abstracted. This technology has the potential to be an affordable, robust and chemical-free arsenic removal solution for decentralized application. In this PhD study a combination field and laboratory research, in Bangladesh and the Netherlands, has resulted in better understanding of the subsurface processes determining the sustainable operation in diverse geochemical settings.Water MangamentCivil Engineering and Geoscience

Influence of particle properties on iron flocculation

In this study, the importance of charge interactions during flocculation of Fe3+ in the presence of particles and anions/cations at various pH values was investigated. SiO2, (s) and ZnO(s) were dosed as particles to promote charge interactions and/or serve as a nucleus to accelerate floc formation. In the pH range 6–9, SiO2, (s) is negatively charged, while ZnO(s) carries a positive charge. Ca2+ and HPO4 2- were selected to investigate charge interactions in the water phase. A significant delay in floc growth due to charge repulsion between negatively charged iron species was observed at pHini 9. For positively charged species at pHini 6, a delay in floc growth was observed as well, but to a lesser degree. These effects could be neutralized by either dosing (positively charged) ZnO(s) or Ca2+ at pHini 9, or (negatively charged) SiO2, (s) at pHini 6. The addition of phosphate did not hinder floc growth at pHini 6. While phosphate completely inhibited floc growth at pHini 7–9 in the presence of negatively charged SiO2, (s), the presence of positively charged ZnO(s) partly neutralized the detrimental influence of phosphate on floc growth. Similarly, dosing Ca2+ partly neutralized the effect of phosphate.Sanitary Engineerin