Assessment of the effectiveness of riverbank filtration in a selected reach of Bharathapuzha River basin, Kerala, India
摘要
In most developing countries, the rivers are contaminated with municipal, industrial, and agricultural waste. A suitable cost-effective method for treating polluted rivers is very much essential for sustainable development. Riverbank filtration (RBF) is a nature-based water treatment technique that utilizes induced infiltration from rivers into adjacent alluvial aquifers. A number of physical, chemical, and biological activities occur underground that improve the water quality. It helps in reducing conventional drinking water treatment costs. RBF has become common in northern parts of India and around the world, but it is still not familiar in southern India, especially in Kerala. The main aim of the present study is to find a suitable location for Riverbank filtration (RBF) in the Bharathapuzha River basin, Kerala, India. Three-dimensional groundwater flow model was developed using MODFLOW to simulate river--aquifer interactions, while pathogen transport was assessed using RT3D. A trial-and-error approach was used to determine the optimum location of pumping wells for RBF. The modelling results indicated that four wells could be constructed at an optimum distance of 130 m parallel to the river. It was also found that the pumping rate required per well is 125 m3/day for an effective RBF system. The results demonstrate that RBF is a technically viable and economically attractive drinking water supply option for monsoon-dominated coastal river basins of Kerala and offer a transferable framework for RBF site selection in similar tropical environments.