Bottled water is closely monitored by consumer and health authorities to ensure that it reaches the high standards expected for such a product. Among the factors kept under check are the levels of harmful substances, such as asbestos, lead and chlorine, as well as bacteria and pathogens. Bottled water may have various sources, including wells, underground springs and normal municipal supplies. No matter the source, the water must be filtered in a multi-step process, which could include distillation, membrane filtration such as reverse osmosis, and disinfection methods such as UV light or ozone exposure.
Purified water should not be confused with spring water, although the distinction lies mainly in the process that it has undergone, rather than the taste. Any water that goes by the name of spring water must be sourced from a spring. Spring water is typically filtered using a series of filters, running in sequence from 5 micron to 0.2 micron filtration. Ozone treatment generally follows as a disinfection measure.
Drinking Water Process
Purified water is equally potable and has the additional advantage of consistent taste and quality. Water is purified using the primary processes of deionisation and distillation followed by reverse osmosis (RO). Filtration uses the straining principle to remove larger particles from water, but may struggle with smaller particles. The filter’s pore size and the filtering element’s durability are key factors in estimating the life and productivity of a filter. Elements may be made of ceramic, fibreglass, carbon or even compressed surgical paper. A combination including RO is preferred to filtration alone, because RO is cost-efficient, energy-efficient, and may be relied on to remove up to 99% of ions, bacteria and viruses.
Disinfection of Water
Disinfection using chlorine, ultraviolet (UV) light or ozone is a common final step in the process of water purification. UV is recognised as a particularly effective and cost-efficient method, but requires extensive pre-treatment in order to remove larger organic particles which may shield microorganisms from the damaging effects of the UV rays. The presence of these particles in the water is called turbidity. While this state has no effects on health of itself, it may render the disinfection methods ineffective. Turbidity also provides an advantageous environment for the growth of disease-causing organisms such as bacteria and viruses, so the presence of turbidity itself may be an indicator of the need for water disinfection.