Water contaminants are natural or foreign substances that pollute water. Water containing high concentration of these substances is unsafe for human consumption. They may be visible or microscopic and vary from soluble to insoluble. Water contaminants are grouped into six main categories.
Microorganisms are microscopic organisms commonly referred to as germs. They are naturally present in water or in the environment. However, humans and animals contribute greatly to water micro organic contamination. This is common along lakes and rivers where there is human activity. Animal and human fecal wastes constitute most of microscopic contaminants. Water runoff has also been noted to cause water contamination. The level of contamination is determined by the measure of turbidity. Normally, high turbidity is associated with high levels of contamination by microorganisms.
Examples of microorganisms include bacteria, viruses, fungus and protozoa.
Microscopic organisms cause many water borne diseases such as cholera, typhoid, dysentery and most gastrointestinal disorders.
Disinfectant by-products are elements or compounds that arise as a result of water purification using chemicals. Examples include chlorite, bromate haloacetic acid and total trihalomethanes. Disinfectant by-products are carcinogenic in nature. Most of them are closely associated with liver, kidney and central nervous system disorders. Reliable sources indicate that infants suffer from anemia when they drink water contaminated by these byproducts.
Disinfectants are chemicals added to water to eliminate microorganisms. There are three harmful compounds in disinfectants. These are: chlorine, chloramines and chlorine dioxide. Disinfectants cause irritation in the nose and eyes. They also cause anemia, renal conditions, liver problems, stomach discomfort and nervous system problems in infants.
Inorganic chemicals are synthetic or natural chemicals that do not contain carbon elements. They come from erosion of natural deposits, oil refineries, electronic factories and asbestos cement decay. They also originate from mines, corroded galvanized pipes or household plumbing systems. Fertilizers contain a considerable amount of inorganic chemicals.
Examples of inorganic contaminants include: barium, asbestos, cadmium, arsenic, copper, lead, mercury, zinc, and beryllium. Ailments related to inorganic water contaminants are hypertension, renal, dermatological, intestinal and endocrine disorders.
Radio-nuclides are radioactive elements. Their presence in drinking water will cause cancer and kidney toxicity. Radio-nuclides come from erosion of man-made or natural mineral deposits. Examples are; uranium, alpha and beta particles.
Organic chemicals are compounds that contain carbon elements. The main sources of organic chemical contaminants are sewages, herbicides and incinerators. Industrial discharge may contain unacceptable levels of organic chemicals. Insecticides used to control plant insects leach from soils to water bodies making them unsafe for drinking.
Majority of the hydrocarbons are considered water contaminants. Benzene compounds and chloride alkanes, alkynes and alkenes are the main organic contaminants. Reliable sources indicate that systemic disorders are caused by most organic chemicals found in water. Cataract and some reproductive illnesses are caused by organic contaminants.
Scientist and researchers have come up with ways of purifying water depending on the nature of contaminants or levels of contamination. These methods are either biological or chemical.