Abstract
Water is one of the most important natural resources supporting the diverse array of life present on earth. Rapid diminution of fresh potable water reserves, contamination of existing ones, and generation of large amount of wastewater due to anthropogenic activities have compelled the scientists to develop methods to treat the contaminated water. Across the globe, millions of people are inaccessible to fresh drinking water. Multiple health issues are linked with the purification of drinking water supplied through different ways including bottled water, tap water, and borewells. The drinking water is most often contaminated with pathogenic microbes including bacteria, viruses, and protozoa beyond the recommended limits causing serious human health hazards. The pathogenic microbes commonly detected in water supplies include those related to dysentery, typhoid fever, vomiting, and cholera. Therefore, removal of human pathogens from drinking water is essential for health security. Numbers of physical and chemical techniques have been developed to make available the pathogen free drinking water. Techniques employing membranes for trapping hazardous biological contaminant are currently gaining momentum worldwide. This chapter deals with the sources of pathogens in drinking water, important waterborne diseases, and different aspects of nanofiltration techniques over other commercially used methods for removal of pathogens.