Water pollution caused by human activities is an important environmental phenomenon, starts from the first attempts of industrialization, to become a widespread problem, since the industrial revolution began in the early nineteenth century.
Industrial production processes initiated at this time require the use of large volumes of water for the processing of raw materials, being the effluent of such production processes, discharges into the natural channels of water (rivers, lakes) with contaminated waste.
Since then, this situation is repeated in all countries that have developed industrialization, and even though the technology has somehow managed to reduce the volume and type of pollutants discharged into the natural channels of water, this has not occurred or the form or the amount necessary for the problem of water pollution is solved.
Water pollution occurs through direct or indirect introduction into streams or aquifers of solid, liquid, gas and heat energy, among others. This contamination is causing damage to living organisms in the aquatic environment and also represents a danger to the health of people and animals.
There are two ways through which water may be contaminated. One is by means of natural contaminants, that is, the natural cycle of water may come into contact with certain constituents pollutants discharged into water, atmosphere and crust. For example, mineral and organic substances dissolved or suspended, such as arsenic, cadmium, bacteria, clay, organic materials, etc.
Another way is through the pollution generated by man or man, and are products of liquid and solid wastes discharged directly or indirectly in the water. For example, health sinks substances, substances from industrial waste and substances used in agricultural pest control and / or vectors of disease.