Question

[~*~Han Min Hee~*~]

Làm một bài thuyết trình về sự ô nhiễm nước (tự viết, không tham khảo trên mạng, làm ơnnnnnn)

Answer 1

[nguyễn hoàng anh]

Water pollution is a change in composition and quality of water that is not suitable for different uses, exceeding permissible standards and adversely affecting human life, health and creatures.

Natural water exists in many different forms: sewage, water in rivers and lakes, exists in the form of vapor in the air. Contaminated water means that its constituent exists in other substances, which can harm humans and the life of creatures in nature. Polluted water is often difficult to overcome but must be avoided from the beginning.

In the daily life, under the current growth rate, people inadvertently pollute water sources with chemicals and waste from factories and enterprises. The individual units use groundwater in the form of drilling wells , after stopping not using it, it is not sealed the holes that make dirty water run in and contaminate groundwater. The factories exhaust fumes industrial dust in the air as air pollution, when it rains , pollutants will be mixed into storm water also contributes to water pollution.Carbohydrates, proteins, fats ... are often present in domestic sewage, urban wastewater, food processing industry wastewater are easily biodegradable organic substances. In domestic water, about 60-80% of organic matter is easily biodegradable. Biodegradable organic substances often adversely affect aquatic resources, because when decomposed These substances will reduce the dissolved oxygen in the water, leading to fish and shrimp death. Many pathogenic microorganisms present in water harmful to use water in daily life . These organisms can transmit or cause disease to humans. These disease-causing organisms do not originate from water, they need a host to live, parasitize, grow and reproduce. Some of these disease organisms can live for quite a long time in water and are a potential risk of disease transmission. These organisms are bacteria, viruses, protozoa, helminths. There are also a number of agents such as colorings, flavoring agents, etc.In the world every year there are about 60,105 tons of synthetic organic substances including fuels, pigments, pesticides, growth stimulants, and additives in food and pharmaceutical products. These substances are often toxic and have a high biological durability, especially aromatic hydrocarbons causing strong environmental pollution, greatly affecting human health.The harmful bacteria in polluted water from human and animal wastes can cause cholera, skin cancer, typhoid and polio.