Membrane fouling characteristics and cleaning strategies for rural decentralized nanofiltration drinking water station based on groundwater source.

Groundwater is an important source of drinking water in rural areas. In this study, the performance of water purificat ion in a rural water station equipped with nanofiltration (NF) membranes based groundwater source was investigated, as well as the contamination morphology, foulant composition and distribution characteristics of NF membrane. Results showed that significant differences of membrane foulants were observed in different sections of NF membrane.

Hydrological interactions between surface water and groundwater in ancient manmade village tank cascade systems (VTCSs) in the dry zone of Sri Lanka.

Sri Lanka, a tropical island, confronts climate-driven water scarcity and is of great concern to building climate-resilient water management to achieve UN SDGs 6 and 13. This study explores the dynamic interaction between surface water (SW) and groundwater (GW) in the dry zone of Sri Lanka, employing a multi-tracer of dual stable isotopes (O and H) and chloride. Two basins, Mahakanadarawa (MK) basin with numerous village tanks and tank cascade systems (VTCSs/TCSs) and Kawudulla (KW) basin serving as a control with a lack of tanks, were selected in this study.

Chemical characteristics and water stability evaluation of groundwater in the CKDu Zone of Sri Lanka.

Groundwater is the main source of drinking water for the rural population in the chronic kidney disease of unknown etiology (CKDu) zone of the North Central Province (NCP) in Sri Lanka. In this study, a total of 334 groundwater samples (311 dug wells, 21 tube wells and 2 springs) during the wet season from two aquifers in the NCP were collected, and investigated their chemical characteristics and evaluate their water quality, including groundwater chemistry, main ion sources, the corrosion and scaling potential of groundwater. The results showed that the two hydrochemical types of groundwater in the NCP were mainly of the Ca-HCO, Na·Ca-HCO types, with the main HCO, Na and Ca ions in both types of groundwater originating from silicate and evaporite salt dissolution and influenced by alternating cation adsorption, while the presence of NO was mainly anthropogenic.

Modeling the spread of COVID-19 in spatio-temporal context.

This study aims to use data provided by the Virginia Department of Public Health to illustrate the changes in trends of the total cases in COVID-19 since they were first recorded in the state. Each of the 93 counties in the state has its COVID-19 dashboard to help inform decision makers and the public of spatial and temporal counts of total cases. Our analysis shows the differences in the relative spread between the counties and compares the evolution in time using Bayesian conditional autoregressive framework.

Fluorescence characteristics and source analysis of DOM in groundwater during the wet season in the CKDu zone of North Central Province, Sri Lanka.

The dissolved organic matter (DOM) should be purified for safe drinking water due to disinfection by-products (DBPs) produced by disinfectants reaction with DOM. Current research on groundwater in the chronic kidney disease with unknown etiology (CKDu) zone of the North Central Province (NCP) in Sri Lanka has focused mainly on aquatic chemistry, with limited attention paid to the spatial distribution, compositional sources and factors of DOM. Therefore, the structure, composition, source and spatial distribution of the DOM of two kinds of groundwater samples collected from dug well and tube well in the NCP during the wet season were determined, compared and analyzed by analytical tools such as parallel factor analysis (PARAFAC).