An Air Operated Domestic Brackish Water Reverse Osmosis Plant: Economically Sustainable Solution for Safe Drinking Water Supply for Chronic Kidney Disease of Unknown Etiology Affected Areas in Sri Lanka

Chronic Kidney Disease with unknown etiology (CKDu) is one of the crucial health issues in North Central, Uva, North Western, North, Central, and Eastern Provinces of Sri Lanka and incapacitates the kidney function. The main source for the CKDu has not yet been identified, though many scientists believed that the number of certain drinking water quality parameters is changed due to the contamination of water sources by agricultural activities. Hence, the government of Sri Lanka introduces electrically driven Brackish Water Reverse Osmosis (BWRO) plants with a capacity of 10 tones/day to supply safe drinking water for the impacted community though it is an energy-intensive process. Concurrently, a smaller version of an electrically driven BWRO plant was introduced to the rural farming community for their domestic use. However, it was not practically worked out due to various reasons such as high cost, unavailability of electrical power supply for those villages. In this study, an economical air operated domestic use BWRO plant with zero-emission was designed. This anticipated system significantly reduces the government expenditures to subsidize the water purification cost by 50% of the existing expenses. Besides, simple payback time was found to be 2.5 years, and the benefit-cost ratio to be more than 1. Evaluating the performance with the conventional values, it comprehends with more sustainable and economically viable system compared to the existing method of water purification.

Optimum Solution for the Safe Drinking Water Crisis in Tala Upazila, Bangladesh

Coastal areas of Bangladesh are especially vulnerable due to their physiographic location and exposure to natural calamities. Around 35 million people living in coastal areas have no access or limited access to safe drinking water. Contamination of water sources by salinity, arsenic or iron are the principal causes of water scarcity. Rising sea levels and unevenness of climatic events due to climate change will exacerbate the situation in coastal areas, especially in the southwestern coastal zone. This study examines one of the vulnerable coastal upazila Tala at Satkhira(an 'upazila' is a medium level administrative unit in Bangladesh) in the southwestern zone of Bangladesh to understand the gravity of the problems. The study develops a GIS based multi-criteria analysis to identify suitable options and locations of fresh water as part of a current and future solution to the problems and further deterioration. To fulfill the objectives, a questionnaire-based GPS guided field survey was conducted to collect details of field level conditions in order to find a suitable solution. Because aquifers are considered the primary source of drinking water, field data have been analyzed for two distinct aquifers, one relatively shallow and one deeper, to understand aquifer quality. Potentiality of different water sources the socioeconomic status of communities, types of water use and corresponding sources and water demand are also evaluated. The analysis finds that alternative water sources that are safe are difficult to find, because both surface and groundwater-based sources are already contaminated, and there are no nearby, easily accessible safe sources. Groundwater-based sources are contaminated by arsenic, iron or salinity, and surface water-based sources are not in use due to maintenance and management issues. In some cases, surface water sources are polluted by flash flooding of high saline water during storm surges or seepage from saline water-based aquacultures. Multiple limitations identified during field observations and field data analysis were considered as an analytical parameter A GIS based multi-criteria analysis incorporated field data, including Geo-spatial and socioeconomic information for road networks, settlement locations, number of households, quality and quantity of existing water sources, water demand and business opportunities. The analysis found some potential options in distributed locations which are consistent with community demand. Suggested options made use of technologies that are already understood and commonly used by communities, like deep tubewells, PSFs(Pond Sand Filter) and WTPs(Water Treatment Plant). In the study area, PSF is the most commonly used method and to make this surface water-based technology sustainable some precautionary measurements are suggested.