What is water pollution?

Water pollution is water that pollutes the environment by reducing or losing the use value of water caused by harmful chemicals. Acids, alkalis, oxidants, as well as compounds such as copper, cadmium, mercury, arsenic, benzene, dichloroethane, ethylene glycol and other organic poisons in sewage will poison aquatic organisms and affect drinking water sources and scenic landscapes. When the organic matter in the sewage is decomposed by microorganisms, the oxygen in the water is consumed, affecting the life of aquatic organisms, and after the dissolved oxygen in the water is exhausted, the organic matter is anaerobic decomposed, producing unpleasant gases such as hydrogen sulfide and mercaptan, which further deteriorates the water quality.

Classification of water pollution

Wastewater is classified differently from different perspectives. According to different sources, it can be divided into two categories: domestic wastewater and industrial wastewater, according to the chemical category of pollutants, it can be divided into inorganic wastewater and organic wastewater, and there are also classified according to industrial sectors or production processes that produce wastewater, such as coking wastewater, metallurgical wastewater, pharmaceutical wastewater, food wastewater, etc.

The main pollutants are: (1) untreated industrial wastewater, (2) untreated domestic sewage, (3) farmland sewage caused by the massive use of chemical fertilizers, pesticides and herbicides, (4) industrial waste and domestic garbage piled up near the river, (5) deforestation and soil erosion, (6) mine sewage due to over-exploitation.

Why does water pollution occur?

Among the water pollution caused by human production activities, the water pollution caused by industry is the most serious. For example, industrial wastewater, which contains many pollutants and complex composition, is not only difficult to purify in water, but also difficult to treat.

Industrial wastewater is the most important cause of water pollution caused by industrial pollution. It accounts for the majority of pollutants emitted by industry. The pollutants contained in industrial wastewater vary greatly depending on the type of plant, and even the quality and quantity of pollutants contained in similar factories with different production processes are different. In addition to the direct injection of wastewater into water bodies to cause pollution, solid waste and exhaust gases will also pollute water bodies.

Agricultural pollution is first caused by the loosening of the land surface by farming or land reclamation, and when the soil and topography are not stable, a large amount of sediment flows into the water, increasing the suspended solids in the water.

Another important reason is the increasing use of pesticides and fertilizers, and only a small amount of pesticides and fertilizers used are attached or absorbed, and most of the rest remain in the soil and float in the atmosphere.

The source of urban pollution is caused by the concentration of urban population, and the pollution of water bodies caused by urban domestic sewage, garbage and exhaust gas. The pollution of water bodies by urban pollution sources is mainly domestic sewage, which is a mixture of various sewage produced in people's daily life, including the sewage discharged from kitchens, washing rooms, bathrooms and toilets.

In the world, as many as 500 cubic kilometers of industrial and domestic wastewater are discharged from urban areas alone in a year, and each drop of sewage will pollute water bodies several times or even dozens of times.

Protection recommendations

1. Strengthen the protection of drinking water intakes:

The departments concerned should demarcate the water source area, set up notices in the area and strengthen the greening of the water intake. Organize personnel to conduct inspections on a regular basis. Eliminate pollution fundamentally and achieve the goal of treating both the symptoms and the root causes.

2. Intensify the treatment of urban sewage and industrial wastewater:

Speeding up the construction of urban sewage treatment plants plays a very important role in improving the water environment in our city. With the increase of urban population and the improvement of residents' living standards, the city's wastewater discharge is increasing, but the urban sewage treatment plant has not increased accordingly, which will inevitably lead to the decline of water environment quality. Therefore, the construction of more sewage treatment plants is urgent.

3. Enhance Citizens' Environmental Awareness:

Improving the environment is not only about remediating it, but more importantly, about enhancing residents' awareness of environmental protection through publicity in all aspects. Residents are more environmentally conscious. Environmentally damaging behaviour is naturally reduced.

4. Realize the resource utilization of wastewater:

With the development of the economy, the discharge of industrial wastewater will increase, if only pay attention to the end of the treatment, it is difficult to achieve the purpose of improving the water pollution situation, so we must realize the resource utilization of wastewater.

5. Purification of household water:

Filtration – precipitation (alum) – deodorization with activated carbon, color removal – disinfection (chlorine, bleaching powder). There is a possibility of secondary contamination during the transfer of tap water, so it is necessary to boil and sterilize when drinking, and also use a clean cup.