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1.0 Water Issues
Water has always been one of the most important needs of man. It is one thing that man cannot do without. As such, water for drinking and cooking should be safe for drinking. For water to be both potable and good tasting, it should be clear, odorless, and free from any unpleasant taste or odor.
Most Common Uses of Water
- cooking
- drinking
- bathing
- cleaning
- lawn sprinkling
- fighting fires
- flushing toilets
- irrigation
- commercial uses
- industrial uses
Three basic types of water that people need:
- Utility Water
This type of water is used in lawn sprinkling and sanitation. Although this type has to be bacteriologically safe, it does not need to be treated to the highest quality standards.
- Softened Water
This type of water is used for personal grooming, bathing, dishwashing, and laundering. This type is probably most demanded type of water.
- Drinking Water
This type of water must be of the highest quality. It must meet, or even exceed the chemical and bacteriological requirements set for drinking water regulation.
With the high demand for water, the importance of water in the various sectors of the society is not only realized, but felt as well. It is important to know the different types of water and how each type is used in the community.
1.1 Growing Problems of Water In as much as people dreams to partake of water of the highest quality today, it seems not achievable naturally. Growing problems of water cannot be denied. All over the world, many people have been confronted with various kinds of problems with their water. These problems can lead to water pollution and water borne diseases if not dealt with immediately. Thus, it is very important to know and be aware of these growing problems and what cause them.
Fig.1. Potential Sources of Water Contamination
1.2 Categories of Water Impurities
Water can be contaminated in a number of ways. Moreover, water contains some impurities as well. Some of the impurities of water include dissolved gases, suspended solids or dirt, and dissolved solids.
1.2.1 Dissolved Gases Dissolved gases are those that are dissolved in rainwater in the hydrologic cycle as these pass through the atmosphere. These gases include oxygen and carbon dioxide.
- Carbon Dioxide
Carbon dioxide causes the corrosion of stream water and condensate lines in rivers. The river water contains around 50 ppm of carbon dioxide while well water contains 2-50 ppm of carbon dioxide.
- Oxygen
Oxygen causes corrosion and pitting of water lines and boiler exchangers. The amount of dissolved oxygen in water is dependent on water temperature and other solid contents in water.
1.2.2 Suspended Solids Suspended solids are impurities that are not dissolved in water. These include oil, mud, and decaying vegetation. These solids tend to separate from standing water.
Other types of suspended solids:
- Detrimental iron compounds
- Metals
- Algal blooming
Fig.2. Samples of Suspended Solids of 382ppm
1.2.3 Dissolved Solids Some of the most common dissolved solids present in water are calcium, chloride, silica, iron, and magnesium. The kind of dissolved solids present in the water actually depends on the source of the water. For well water, dissolved minerals are picked up as it percolates down the earth’s crust.
Common dissolved solids in water:
IRON
The rusty and metallic taste in water can be attributed to iron. Moreover, the presence of iron can stain clothes. Most ground water has some amount of iron and manganese, as these occur naturally in the earth.
Problems with dissolved solids in water:
- pH
pH stands for potential of Hydrogen. If you want to know if a substance is acidic, natural, or basic, you need to determine its pH. The pH is actually calculated from the number of hydrogen ions present, measured on a scale of 0 to 14. Pure water has a pH of 7. On the other hand, when carbon dioxide is dissolved in water, it produces acid and lowers the pH. The allowable limit for pH in drinking water is between 6.5 and 8.5
- Hardness
Water hardness is caused by dissolved salts of Magnesium and Calcium. The amount of allowable hardness in water is specified by its TDS. Hard water is not really harmful for as long as its TDS is within the limits. Moreover, hard water can be softened by using Sodium as replacement for Magnesium and Calcium.
- Organic Chemicals
The bad taste and bad smell in water is most commonly caused by the presence of organic chemicals. The sources of organic chemicals include petroleum products, pesticides, and other toxic chemicals. While Chlorine is most commonly used for keeping water free of bacteria, it sometimes react with some organic minerals naturally present in water. In effect, harmful chemicals like TMH’s, Chloroform, and Haloacetic Acids are formed.
1.3 Water Contaminants There are four groups of water contaminants. These include microbial pathogens, inorganics, organics, and radioactive elements.
- Microbial Pathogens
These are disease producing micro organisms which are present in drinking water. These micro organisms include parasites, bacteria, and viruses. Water that is contaminated with sewage and animal waste is most likely to be contaminated with pathogens.
Pathogens can cause salmonella infection, abdominal cramps, hepatitis, dysentery, gastroenteritis, shigellosis, and giardiasis among others.
Fig.3. Microbial Pathogens
- Inorganics
These contaminants include toxic metals that can get into drinking water from natural resources and industrial processes. These toxic metals include barium, chromium, arsenic, lead, silver, and mercury. Nitrate is also another inorganic contaminant that may contaminate drinking water.
Toxic metal contamination can cause nausea, cancer, acute poisoning, and other health effects.
- Organics
These include toxic chemicals and metals in water. These include pesticides, Trihalomthanes, and volatile inorganic chemicals.
Toxic chemical contamination can cause nervous system disorders, cancer, kidney and lung damage, birth defects, and reproductive disorders.
- Radioactive Elements
The most common radioactive element which can contaminate water is radon. Radon actually results from the decay of uranium in rocks and the soil. More than anything else, radon is a threat to health when it enters the home as a soil gas rather than as a water contaminant.
Fig.4. Possible Source of Radioactive Contamination
More than just the impurities in water, it is also important to know the contaminants in the water that can cause pollution and pose as threats to human health.
Most Common Toxic Contaminants:
- Mercury
- Arsenic
- Lead
This is also a heavy metal like Mercury. In the same manner, it is also harmful to human health. Older pipes and fittings contain lead. Thus,, it is important to seek water purification process which can remove lead and other heavy metals present in water.
- Fluorides
These are chemicals that contain fluorine. Fluorides occur naturally in many water sources. When in small quantities, fluorides can be beneficial to health. However when it exceeds the tolerable amount of 4 ppm, it is not good for the health anymore.
- Hexavalent Chromium 6
Chromium exists as a safe trivalent known as Chromium 3. However, it also exists in another form known as Chromium 6, which is poisonous. Water can be contaminated with Chromium 6 by the absorption of this chemical from chemical industries. Chemical industries that discharge their water without proper treatment are the main culprits of Chromium 6 contamination.
- Radon
Radon is naturally occurring in the ground and ground waters may be contaminated with it. The only way of knowing if water is contaminated with radioactive minerals like radon is to have the ground or well water tested.
- Nitrates
Nitrates and ammonia easily get into water sources. Leakage or seepage of fertilizers or animal wastes seep into the ground water sources. Nitrates are particularly dangerous to infants under 6 months old. The standard limit for the amount of nitrates in water is 10 ppm.
