The Modern Chemistry Of Drinking Water Filtration

35 Pages 8642 Words

The Modern Chemistry of Drinking Water Treatment
Dory Green
Introduction
Ever since the first days of dysentery and diarrhea, the world has recognized the all-importance of clean drinking water. They have not, however, come to recognize how it is brought to them on a daily basis. The water treatment industry is taken for granted right up until the moment a problem arises. Immeasurable amounts of water are wasted every day without even a single thought to how difficult a process it is to provide that water in the first place.
Probably the oldest method of drinking water treatment is simple distillation. The water is boiled and the steam is captured. The minerals are meant to be left in the boiling chamber, while only the pure water is turned to steam. Bacteria, viruses and cysts are killed by the heat, and heavy metals, organics, radionuclides, inorganics, and particulates are left behind. This is a relatively effective procedure in a perfectly sterile still, however it cannot remove volatile organic chemicals (VOC’s), like benzene, which have a lower boiling point than water and can vaporize and mix with the steam, causing undue troubles to the drinker (Tuttle). Obviously, over the course of history, there has been a need for advancement in the area of drinking water treatment, and the modern techniques have come quite a long way.
Raw water can usually be classified into one of two groups: surface water or ground water. Surface water is found in lakes, rivers, ponds, essentially any above-ground area (EPA 1999 (2)). It is generally relatively low in mineral content, yet it is exposed to numerous contaminants such as animal wastes, pesticides, industrial wastes, algae and more. Ground water is found trapped below the surface of the earth, a product of rain, melted snow, underground rivers, and similar sources. Because of the way that the water travels below the ground, it may contain all of the contaminants of surf...