Shunde's economic development is a miracle, and its economic strength ranks first among the top 111 counties in China for four consecutive years. However, with the rapid development of Shunde's economy and population, some problems have arisen with the continuous development of various industries, such as the pollution of urban waters. Whenever we approach the Yangdahe River near our school, we often see all kinds of garbage floating on the river, and sometimes we smell a burst of stench. We deeply feel that water pollution is getting worse and worse. In order to make people have a correct understanding of urban water pollution, and promote more citizens to participate in environmental protection work, improve environmental awareness, * * * care about the surrounding environment and protect our living space.

Yangdahe is an important river flowing through Lunjiao in Shunde, which runs through Lunjiao street center, Licun, Xiyong, Xiashi and Sanzhou, and mainly provides industrial and agricultural water for the above areas. In recent years, with the development of Shunde's economy and the gradual improvement of people's living standards, Yangdahe is inevitably polluted by all kinds of untreated sewage, which has caused adverse effects on people's production and life.

PH value of sampling point, water temperature (℃), visibility (m) floating objects

Recreation Center 6.1 23.2 turbid, 1.15 oily layer and all kinds of garbage

Ailianqiao 6.3 23.1 turbid, 1.16 small amount of plastic bags and oily layer

Xiyong Bridge 6.8 23 turbid, 1.21 water lily and garbage

.

② The visibility of the four points is low, which is not up to the standard, and there are often floating objects, oil stains, plastics and other garbage on the water surface.

It shows that the river pollution is serious, and the water area at Ailianqiao is the darkest and stinkiest.

by comparing with the data provided by the environmental protection bureau, we can find that our measured data are slightly different, which may be related to the different measurement points and time.

Yangdahe is a confluence of industrial wastewater, agricultural wastewater and domestic wastewater from Sanzhou, Xiashi, Xiyong, Licun and Lunjiao Street Center. Due to the rapid development of Lunjiao in recent years, industrial areas and commercial buildings have mushroomed on the banks of Yangda River. Therefore, the waste water and sewage discharged into Yangdahe gradually increased, so that the Yangdahe river is no longer crystal clear. That is to say, Yangdahe gradually lost its original value and function, and the water body was polluted. According to the monitoring, the main water pollutants in Yangdahe River are as follows:

1. Industrial pollution:

Due to the poor supervision of relevant government departments, some enterprises' sewage discharge equipment is aging, and it is difficult to meet the standards. This type of factory includes Weili woodworking machinery factory, glass factory, auto repair shop, electroplating factory, etc. The pollution of some industries is very serious. There is no sewage treatment plant in Lunjiao area for the time being, which can't make the sewage be treated in time and effectively. Some even directly discharge it to the nearby Yangdahe River through small rivers and branches. Industrial pollutants mainly include (1) oil pollution: oil pollution is not only harmful to the utilization of water, but also affects the oxidation into the water body after forming an oil film on the water surface. Oil is also easy to fill the gills of fish, making it difficult for fish to breathe and even causing fish to suffocate. (2) Mercury pollution: Yangdahe water body is also polluted by mercury, which mainly comes from pesticide production and the use of mercury-containing pesticides. (3) Chromium pollution. Due to the limitation of experimental instruments and other conditions, our group can't accurately measure the contents of mercury and chromium in Yangdahe water. According to the data provided by the Environmental Protection Office, the contents of mercury and chromium in Yangdahe water are low, and our group has doubts about the authenticity and accuracy of the data provided by the Environmental Protection Office.

2. Pollution of the catering industry

There are more than a dozen restaurants along the banks of the Yangda River. Walking along the Yangda River, you can often see confetti, colorful plastic bags and fast food lunch boxes floating on the river. In large and small restaurants along the river, they often pour sewage and even leftovers from guests into the river. In this way, our sheep river has been trampled over and over again.

3. Domestic sewage pollution

Walking along the Yangdahe River, we can see that there are sewage outlets on both sides of the river constantly discharging untreated domestic sewage into the river. We count the number of sewage outlets all the way, and there are more than 41 large and small. Because the sewage discharged from households is mainly all kinds of washing water in people's daily life, which contains a lot of detergents, and the detergents all contain phosphate-based purifying agents, which can lead to eutrophication and deterioration of water bodies.

In order to know the situation of domestic sewage discharge and detergent use, we designed a family questionnaire, and selected 151 students in Grade Two of Senior High School to conduct a questionnaire survey with their parents. We collate, count and analyze every item of data in the questionnaire.

(1) The monthly per capita water consumption is 5.5 tons. The population along the Yangdahe River is about 51,111, and it is estimated that the monthly water consumption of residents in the town center is about 275,111 tons. Since the amount of sewage discharged is roughly equal to the amount of water used, the amount of sewage discharged is about 275,111 tons, which shows that the Yangdahe River is under great pressure.

(2) 82.6% of households use phosphorus-containing washing powder to wash clothes

(3) Most residents have heard of phosphorus-free washing powder, but it is difficult to buy it in the market.

(4) Two-thirds of residents know that the use of phosphorus-containing washing powder will damage the environment, while the use of phosphorus-free washing powder will not damage the environment.

(5) 97% of households use detergent, and the average amount of detergent is 491ml.

from the above data analysis, a large part of the sewage discharged from the sewage outlet is residents' domestic sewage. Because residents use a large number of phosphorus-containing detergents, domestic sewage is rich in substances such as P, which causes eutrophication of the water body, the amount of dissolved oxygen in the water body decreases, and the water body turns black and smelly.

4. Water "green devil"-water hyacinth pollution

Shunde is a part of the land of plenty and is a famous water town. Interwoven vertically and horizontally, the river water network extending in all directions is distributed in every corner of Shunde. Therefore, water hyacinths can also be seen everywhere.

Water hyacinth was planted as pig feed in 1951s and 1961s, and then spread to wild weeds. Up to now, the situation has almost got out of hand. Water hyacinth mostly grows in rivers, ponds and canals. Most of the water hyacinths of Lunjiao grow in rivers or ponds. They can often be seen on the Yangdahe River. Most of these water hyacinths flow from the tributaries of Yangda River.

In that large piece of farmland about 211 meters in front of Xiashi intersection, there is a small tributary connecting Yangda River with a width of 5 meters. If you don't look carefully, you don't know it is a small river at all, but you will mistake it for a green vegetable. It is also difficult to see the shadow of water on the bank of the river. These water hyacinths often drift to Yangdahe with the current. Water hyacinth, a "green devil" on the water, will isolate sunlight, air and water, making other creatures in the water unable to survive, causing a large number of anaerobic microorganisms to breed, but a large number of beneficial microorganisms will die, making the water body black and smelly and polluting the environment. If we don't take measures to prevent the expansion of "green devils" on the water, the consequences will be unimaginable.