Water Supply Networks

A water supply network is an arrangement developed through the t echnologies of hydrology that includes the watershed where the water is collected, a water reservoir for storage of water, a water treatment plant, and a transmission system for piping to the storage of treated water. Water supply networks are a component of the master plan of municipalities and other government bodies and are designed considering factors of existing and future requirements, pressure, and leakage. The water supply networks are normally owned and operated by the local governments, municipalities, or other public organizations, and rarely by commercial enterprises. One of the major factors that made urbanization feasible was the introduction of water supply networks, since the quality of water has always been a source of serious concern for humans.

A water resource is a source of water that is essentially required by human, agricultural, industrial, and environmental activities. Fresh water on the earth is only 3%, and most of this fresh water is frozen in glaciers and polar ice caps. A small percentage of the residual fresh water is above the ground, and the remainder is groundwater. Water resources are gradually decreasing as population increases at a faster rate than the increase in water resources. In many parts of the globe, the supply of water is less than the requirement due to which there are serious concerns for the population of the area. In countries like Australia water rationing is strict and it is illegal to water your lawn except during the time and days allotted. In Dubai, the flush water and bath water is thoroughly treated and then used for watering plants and the road side greenery. Therefore, there is an increasing requirement for a global awareness regarding the preservation of water for water supply networks.

The quality of water depends upon geology and the environment. Treatment is required before it reaches the consumer, so as to ensure the provision of clean and pure drinking water. Water treatment ensures the removal of all contaminants including microorganisms, inorganic contaminants, organic contaminants from industrial processes, and radioactive contaminants. The process of water treatment commences with clarification that is the removal of dirt particles and the addition of chemicals to sediment the particles, filtration to remove fine particles, and disinfection normally by the addition of chlorine that destroys bacteria and almost all viruses. Treatment of water is strictly controlled by various regulatory agencies since the health of humans is concerned and since the use of contaminated water may cause serious diseases.

Osmosis is the movement of water or solvent from one side of a solution having greater concentration of solute through a semi-permeable membrane to the other side where the concentration is low. The aim of the transfer is to equalize the concentrations of the solute on both sides. This flow will continue without the input of any outside energy till both the solutions are of equal concentration. The semi permeable membrane permits the flow of water but not particulate matter like urea, bacteria, etc. Reverse osmosis is a process in solution flows in reverse to the phenomenon. It is the movement of water through the membrane, from a lesser concentration towards a higher concentration with the help of pressure. An outside pressure of 30 bars is supplied to special semi permeable membrane and clean water is utilized and the dirty component is rejected. The advantages of reverse osmosis include that is the most effective and economical technique for the purification of tap water and that it removes most forms of contaminants and requires minimum maintenance. A disadvantage is that the flow rate is slow since the membranes are extremely restrictive.