Assessment of Groundwater Quality in CKDu Affected Areas of Sri Lanka: Implications for Drinking Water Treatment

Abstract

This study investigated the water quality of the groundwater that was collected from the chronic kidney disease of unknown etiology (CKDu) prevailing areas in the dry zone of Sri Lanka to assess its suitability for drinking purposes, and for the first time a Water Quality Index (WQI) with emphasis on proposing appropriate drinking water treatment method was developed. A total of 88 groundwater samples were collected in dry (December 2016) and wet (May 2017) seasons; high concentrations of water hardness, fluoride, salinity, dissolved organic carbon (DOC), and the general alkaline nature of water were the main issues that were observed for disease incidence. The chemical weathering of the underlying bedrock, followed by ion exchange and precipitation processes, primarily controlled groundwater geochemistry. During the 1985–2017 period, the variations of the annual rainfall and temperature were minimal, which suggests no evidence for major climatic changes within the study areas. Almost all of the samples from the CKDu regions show a low alkali hazard and most of the samples show a medium to high salinity hazard. The DOC of the studied samples was mainly composed of the organic fractions in the following order, as fulvic acids > humic acids > aromatic protein II > soluble microbial by-products, and the molecular weights (MW) of these fractions ranged from 100–3000 Da. Based on the water quality index (WQI) calculations, it was found that only 3.8% in the wet season and 2.6% in the dry season of total water samples were categorized as the “excellent” type, and all other water sources require a further treatment before consumption. As there is an urgent need for establishing proper long-term drinking water treatment technology for the CKDu affected area, these findings can be used as benchmark of raw water quality in the design processes of treatment plants.

Impact of water quality on Chronic Kidney Disease of unknown etiology (CKDu) in Thunukkai Division in Mullaitivu District, Sri Lanka

“…Similarly, uoride levels were relatively high in Thunukkai compared to those of the dry zone of Sri Lanka, reported by Chandrajith et al, [25]. Water hardness and the conductivity levels in Thunukkai were compatible with those of the high and moderately prevalent areas [24].…”

“…Nevertheless, in compliance with the present study, Wickramarathna et al, [10] reported insigni cant levels of Cd and As in ground water of Girandurukotte, Wilgamuwa and Nikawewa areas. Chloride ion content in the groundwater of Thunukkai was exponentially high compared to the groundwater in CKDu high prevalent areas such as Padaviya, Kebithigollawa, Medawachchiya, & Kahatagasdigiliya, and moderate prevalence areas such as Mihintale, Talawa, and Nochchiyagama of the dry zone of Sri Lanka [24]. Similarly, uoride levels were relatively high in Thunukkai compared to those of the dry zone of Sri Lanka, reported by Chandrajith et al, [25].…”

Impact of water quality on Chronic Kidney Disease of unknown etiology (CKDu) in Thunukkai Division in Mullaitivu District, Sri Lanka

“…However, the heavy metals such as As and Cd in the water of Thunukkai were significantly low compared to the levels detected in the North Central province (Jayasumana et al, 2013(Jayasumana et al, & 2015. Chloride ion content in the ground water of Thunukkai was exponentially high compared to the ground water in CKDu high prevalent areas such as Padaviya, Kebithigollawa, Medawachchiya, & Kahatagasdigiliya, and moderate prevalence areas such as Mihintale, Talawa, and Nochchiyagama of the dry zone of Sri Lanka (Cooray et al, 2019). Water hardness and the conductivity levels in Thunukkai were compatible with those of the high and moderately prevalent areas (Cooray et al, 2019).…”

Drinking-Water Supply for CKDu Affected Areas of Sri Lanka, Using Nanofiltration Membrane Technology: From Laboratory to Practice

“…However, the studies toward the effect of water consumption on the incidence rate of CKDu is scarce to date. We examined the chemical quality of groundwater from different CKDu affected zones [12,13] and developed an integrated water quality index (WQI) [13] to demarcate water with high TDS, DOC, and fluoride in CKDu areas that requires treatment [14].…”

“…In this study, a decentralized automated NF-membrane-based pilot drinking-water treatment plant was fabricated to meet the stringent water requirements in a CKDu-affected zone in Sri Lanka. Based on our previous data [14], a suitable NF membrane was selected out of ten commercial brands with the highest TDS and DOC rejection. Then, a drinking-water treatment plant equipped with the selected NF membrane was fabricated and installed in a CKDu-prevalent area of Sri Lanka, and its performance was investigated for one year.…”