cho mình bài writing unit 7 tiếng anh lớp 8 nhé k chép mạng nha

Currently, the water environment in many urban areas, industrial zones and craft villages is increasingly seriously polluted by wastewater, emissions and solid waste. In big cities, hundreds of industrial production facilities are polluting the water environment due to the absence of waste treatment facilities and facilities. With rapid industrialization, urbanization and population growth are the main causes of increasing pressure on water resources.

The level of water pollution in industrial parks, export processing zones and industrial clusters is very large. In recent years, in the whole country, the phenomenon of water pollution has caused the phenomenon of unusual mass fish deaths. Although all levels and sectors have made great efforts in implementing policies and laws on environmental protection, water pollution is a very worrying issue.

Water pollution comes from the fact that ponds, lakes and rivers receive a variety of waste sources, and the surface water environment is in a polluted state in many places. However, the main source of wastewater affecting the surface water environment in our country is agricultural, industrial and domestic wastewater. The rate of increase of wastewater sources is now increasingly large with a large scale in most regions of the country. In the process of industrialization and modernization of the country, many industries have expanded their production scale as well as distribution scope. Along with that is a large increase in the amount of wastewater, while the investment level for the wastewater treatment system has not met the requirements.

Domestic wastewater accounts for more than 30% of the total amount of wastewater directly discharged into rivers, lakes or canals leading to rivers. According to calculations by the environment agency, the Southeast and the Red River Delta are the two regions with the highest concentration of domestic wastewater in the country. The Southeast region with all the provinces in the southern key economic region, where large industrial zones are concentrated, is the region with the largest amount of industrial wastewater in the country. The number of IPs with wastewater treatment systems is still at an average level (50-60%), moreover, 50% of them are still not operating efficiently.

According to environmental impact studies of the Vietnam Environment Administration, it is found that:

In the textile industry, pulp and paper industry, wastewater usually has an average pH of 9-11; index of biochemical oxygen demand (BOD: Biochemical oxygen Demand - is the amount of oxygen required by microorganisms to oxidize organic substances), chemical oxygen demand (COD: Chemical oxygen Demand - is the amount of oxygen). consumption per 1 liter of wastewater) can be up to 700mg/1 and 2,500mg/1; suspended solids content… many times higher than the allowable limit. The wastewater content of these industries contains cyanide (CN-) exceeding 84 times, H2S 4.2 times, NH3 content exceeding 84 times the allowable standard, so it has caused heavy pollution to surface water sources in the region. residential.

Besides the above-mentioned waste sources, agricultural wastewater is also a matter of concern today. That is the main cause affecting water resources in localities with a strong agricultural economy such as the Mekong Delta. Wastewater from agricultural activities contains pesticides or pesticides that are toxic to the environment and human health. In particular, in these areas, people's lives are still attached to river water sources, used as domestic water or used for aquaculture.

There are many objective and subjective causes leading to water pollution such as population growth, the negative side of the process of industrialization and modernization, weak and outdated infrastructure: awareness People's awareness on environmental issues is still not high… Notably, there is the inadequacy in environmental protection and management activities. Awareness of many levels of authorities, management agencies, organizations and individuals responsible for the task of protecting the water environment is not deep and complete; It is not clear that water pollution is a type of pollution that poses a direct, daily and difficult to overcome danger to human life as well as to the sustainable development of the country.

In addition, the regulations on management and protection of water environment are still lacking, the mechanism of assignment and coordination among agencies, sectors and localities is not synchronized, overlaps, and has not clearly defined responsibilities. clear. There is no strategy, planning for exploitation, use and protection of water resources according to basins and large territories. There are no reasonable regulations on financial contributions to the management and protection of the water environment, causing financial shortages and insufficient revenues and expenditures for water environment protection.

Currently, Vietnam has nearly 76% of the population living in rural areas where the infrastructure is still outdated, most of the wastes of humans and animals are not treated, so they seep into the ground or are washed away. , making water pollution in terms of organic and microbiological increasing. In agricultural production, due to the abuse of pesticides, water sources in rivers, lakes, canals and ditches are polluted, greatly affecting the water environment and people's health.

Due to massive aquaculture, lack of planning, not following the process technology has caused many negative impacts on the aquatic environment. Along with the excessive and improper use of chemicals in aquaculture, the residual food settles on the bottom of ponds, lakes and river beds, making the water environment polluted with organic substances, causing a Some species of organisms cause diseases and appear some toxic algae, there are even signs of red tide in some coastal areas of our country.