There are many ways of purifying water, but below are just a few ways, which sound familiar yet most of us may not be exactly sure what is involved. Read on and decide which way you want your water treated.
Distilled Water
Distillation heats water until it vaporizes as steam. Minerals, bacteria and other substances are left behind when the steam re-condenses into relatively pure water. Distillers remove bacteria, minerals, trace metals, many volatile organic chemicals and nitrates. The distillation process is very slow. Approximately five gallons of tap water are required to produce one gallon of distilled water.
Contaminants removed: Bacteria, lead, nitrates, sodium chloride, organic chemicals, many pesticides.
Reverse Osmosis
Osmosis is why drinking salty water (like ocean water) will kill you. When you put salty water in your stomach, osmotic pressure begins drawing water out of your body to try to dilute the salt in your stomach. Eventually, you dehydrate and die.
In reverse osmosis, the idea is to use a membrane to act like an extremely fine filter to create drinkable water from salty (or otherwise contaminated) water. The salty water is put on one side of the membrane and pressure is applied to stop, and then reverse, the osmotic process. It generally takes a lot of pressure and is fairly slow, but it works.
Reverse osmosis (RO) units remove substantial amounts of most inorganic chemicals (such as salt, metals and minerals), most micro-organisms, and many organic chemicals. They do not effectively remove some organic compounds. Mechanical filters and activated carbon filters are almost always used with a RO unit.
Contaminants removed: Lead, sulfates, calcium, magnesium, sodium, potassium, manganese, aluminum, Chloride, Nitrates, Fluoride Boron, Most micro-organisms, organic chemicals
Mechanical Filters
Mechanical filters, or micro-filtration, remove suspended material from water including sand, silt, clay or organic matter. These filters do not remove dissolved or very fine particles and are often used in combination with other equipment. Filters are commonly made of fabric, fibre, ceramics or other screening material.
Contaminants removed: sediment, dirt, rust, algae, and other suspended solids
Activated Carbon
Activated carbon filters absorb impurities from water as they pass through a carbon cartridge. Such filters are used to eliminate or remove undesirable odours, tastes, organic compounds and residual chlorine. Carbon filters also remove some potentially hazardous contaminants such as radon gas, hydrogen sulfide, many dissolved organic chemicals and trihalomethanes. Most inorganic chemicals are not removed by these filters.
Contaminants removed: Hydrogen sulfide, radon, chlorine, volatile organic compounds, pesticides, benzene, colours and odours.
