Is there a 700-word comment on the sewage treatment plant?

Water accounts for more than 70% of the human body.

Water, together into a river, together into a river, can carry a boat or capsize it.

Water, flowing from a woman's eyes, can melt an iron man's heart with strength!

Water is the source of our life!

How can you not drink water?

Drinking water can help you concentrate and regain your strength. Fatigue and inability to concentrate are the first signs of water shortage.

You need to drink at least 8 glasses of water every day to replenish the water lost in 24 hours.

Women need more water than men. Because women have more subcutaneous fat, which is like an insulator, it will increase body temperature and thus accelerate water loss, so they should drink more water as a supplement.

However, do you know that pollution is getting worse and worse, our rivers and lakes are moaning, and our only earth is crying? Look at the following information, you will be dumbfounded: At the meeting of academicians of China Academy of Sciences and China Academy of Engineering held in 2004, Professor Liu Hongliang, academician of China Academy of Engineering and chief scientist of lake environment research in China, said that the river basins in China are generally polluted and are developing. The investigation of 55,000 km river sections in China shows that about 23.3% of the river sections are seriously polluted and cannot be used for irrigation, 45% of the river sections are free of fish and shrimp, and 85% of the river sections cannot meet the Class III water quality standard, so the ecological function is seriously degraded.

The monitoring data of the whole country 176 urban sections 1998 rivers show that 52% of the rivers are seriously polluted, and the main pollution indicators are COD, BOD5, ammonia nitrogen, volatile phenol and ancient oil, followed by heavy metals. According to the data of China Environmental Bulletin, the order of water quality of seven major river basins in China from poor to good is Liaohe River Basin, Haihe River Basin, Huaihe River Basin, Songhua River Basin, Yellow River Basin, Pearl River Basin and Yangtze River Basin. Nearly 80% of the tributaries of Huaihe River 19 1 are dark green.

In recent 30 years, lake pollution has shown a rapid growth trend. The pollution degree of large lakes from heavy to light is Dianchi Lake, Chaohu Lake, Nansi Lake, Hongze Lake, Taihu Lake, Dongting Lake and Jingbo Lake. The pollution of nitrogen and phosphorus in Dianchi Lake is serious, the problem of eutrophication is prominent, the water quality of the whole lake is worse than Class V, and the cyanobacteria flooding is getting worse.

The serious marine pollution is manifested in the increase of red tide frequency and the expansion of flood range. There were only a few red tides in China in 1960s, but there were more than 360 in 1990s. The field involved in the 1960s was very small. 1 In July, 1997, an unprecedented red tide broke out in the Bohai Sea, covering an area of 46 square kilometers and lasting nearly1month.

Groundwater 30% of urban water supply in China comes from groundwater, and 89% in northern cities. In recent 20 years, the quality of urban groundwater has generally deteriorated. 1992 survey shows that more than 90% of urban groundwater in the north is polluted, of which 28% is not suitable for drinking.

Drinking water is also polluted. The safety of drinking water is directly related to human health. The pollution rate of water bodies near cities and towns in China has reached 90%, which poses a great threat to the drinking water safety of hundreds of millions of people, leading to diseases, labor loss, disability and even premature death.

At present, there are more than 2000 kinds of organic pollutants detected in water at home and abroad, among which 1 14 kinds have or are suspected to have carcinogenic, teratogenic and mutagenic "three substances". More than 100 kinds of organic pollutants can be detected in water sources all over China, among which "three kinds of pollutants" are often found, which cannot be removed after the top-down traditional water treatment process. On the contrary, chlorinated organics will be formed due to chlorination disinfection.

Pathogenic microorganisms in water will lead to large-scale disease outbreaks and epidemics. In rural areas lacking drinking water treatment facilities, the incidence of intestinal infection is 87% ~ 95%, ranking first among all kinds of infectious diseases.

Water pollution harms the "vegetable basket"

A large amount of untreated sewage was used for irrigation, resulting in more than 6.5438+million mu of farmland being polluted by heavy metals and synthetic organic matter. There are 3.4 million mu of obviously or heavily polluted cultivated land in China, and the cultivated land polluted only by heavy metals accounts for 1/5 of the total cultivated land area in China. According to the sampling survey conducted by the Ministry of Agriculture in 372 representative areas, it was found that110 of the total grain in China did not meet the hygiene standards. The over-standard rates of major agricultural and livestock products in heavily polluted areas are: grain 12% (rice is the highest), vegetables 17.9%, fruits 15%, meat 8.6% (chicken is the highest and beef is the lowest), eggs 19% and fresh milk 2%.

Sewage irrigation will also lead to low grain yield, increased pollution and decreased nutrient content. Due to the pollution of food and vegetables, the daily arsenic intake of Beijing residents has reached the WHO's 120%. Long-term irrigation with polluted water will cause pathogens, mutagenic substances and carcinogens to migrate into the human body through food such as grain, vegetables and fruits, which will lead to a large increase in many diseases in the population.

Water pollution is also very harmful to fisheries. Pathogens, viruses, harmful and toxic substances lead to diseases and mass deaths of aquaculture organisms. 198 In the spring of the Pearl River Estuary, the loss of fishery in Guangdong reached 40 million yuan, and that in Hong Kong was10 million Hong Kong dollars. In eutrophic lakes and reservoirs, due to the proliferation of algae, the dissolved oxygen in the deep layer drops, and fish and shrimp die of suffocation due to lack of oxygen. A large amount of pollution has led to a sharp decline in the number of rare animals such as spotted seals, hawksbill and China baiji. The quality of seawater products declines, and the toxicity of toxins contained in shellfish and heavy metal residues in fish increases.

Curbing water pollution is imminent.

Water pollution poses an unprecedented challenge to the original water treatment process.

Academician Liu Hongliang analyzed the causes of water pollution in China, such as population and economic growth, extensive development mode, unorganized large-scale discharge of pollutants, low sewage treatment rate, and sacrificing environment and resources to pursue immediate interests.

In order to basically control the water pollution in China in 20 10, improve the water environment quality in 2030 and greatly improve the water environment quality in 2050, there are two basic countermeasures: increasing the planned urban sewage treatment rate; Strengthen the implementation of water-saving and pollution-reducing cleaner production, and further reduce industrial water consumption, wastewater volume and pollution load.

Therefore, at 9: 30am-11:00am on October 27th, 2005, I was fortunate to participate in the "Environmental Protection Series Activities-Visiting Nanshan Sewage Treatment Plant" organized by Nanshan Volunteer Union. Now let me show you my handwriting:

Nanshan Sewage Treatment Plant is located at Moon Bay Avenue 16. We were received by Mr. Zhao, who loves environmental protection and is knowledgeable (Mr. Zhao on the right is explaining the sewage system in Shenzhen). Under his leadership, we first learned the general situation of Shenzhen sewage treatment plant. At present, there are four major sewage treatment plants in Shenzhen: Yantian sewage treatment plant, Luofang sewage treatment plant, Binhe sewage treatment plant and Nanshan sewage treatment plant. The sewage discharge modes of each sewage treatment plant are deep water sewage discharge, clean water sewage discharge and seawater sewage discharge. Ladies and gentlemen, I must declare here. These are unheard of. Today, I heard for the first time that my little daughter is an errand boy. No, so I have to go online for help.

First stop: pumping station, which is the first process of sewage treatment. When you enter this room, you can only use one word to describe "smelly". It really stinks. Everybody cover their noses with their hands at once. Because this station is the first pass for industrial, domestic and domestic wastewater to enter, two large-scale filtration devices are working here, which are used to simply treat sewage, that is, salvage solid substances such as plastic bags and paper from the discharged sewage. Look at this disgusting sewage, and then look at Mr. Zhao, who is in a normal state, and listen to his explanation: "These equipments are all imported from abroad, but at present our domestic technology can't reach it. Do you know that many sewage treatment plants are losing money, and our employees only get 150 yuan subsidy more than other employees every month under such conditions? " I am deeply touched, because our technology is underdeveloped, for the asymmetric welfare of our country to the front-line staff, and for the sacrifice spirit of our front-line staff!

Second station: take sewage sand, that is, preliminarily separate the sand in sewage; Step 3: pumping sewage treatment equipment; Step 4, clean the dirt on the equipment with a fine grid decontamination machine; The fifth sand scraper removes sand from sewage and plays a role in precipitation; Step six, separate the other rubbish, ok? A 65,438+05-ton truck can be separated here for a week. These wastes can't be used with the current technology, but they are seriously polluted, so the sewage treatment plant pays the garbage treatment station to burn them at the price of 40 yuan per vehicle. Step 7: sedimentation tank, which mainly precipitates sludge in sewage. Nanshan Sewage Treatment Plant has six such ponds, each with a depth of 8 meters, which are mainly treated by BOD. These equipments are also imported from abroad. Step 8, a sludge treatment workshop; The ninth step is the sludge dewatering machine room, where the sludge precipitated by filtration is treated by large instruments and chemicals. The treated sludge only contains 70% water, but it can't be recycled because it contains too many heavy metals and too few inorganic substances. These sludge are transported to Qingshui River for treatment by more than 65,438+00 trucks (more than 65,438+00 tons of trucks) every day.

The above is a brief process of pollution control in Nanshan Sewage Treatment Plant. The audience can't stand your perspective. Because of my limited writing ability, I can only write this kind of diary for your reference. Up to now, everyone may have a question, "What about the treated water?" Don't worry, because of a series of problems such as funds, equipment and technology, the second phase of our Nanshan sewage treatment plant has not been completed. After the second phase is completed and put into use, the treated water can be treated again, so the treated water is biological treated water, which can be used for daily life, but it is not drinking water, so the treatment cost is more expensive. Guess what? At present, the water we drink in Shenzhen is bought from Dongjiang Group. According to Mr. Zhao, it costs more than one yuan per cubic meter if it is not purified. Then after a series of work such as purification, the cost of a cubic meter of water is expensive, and the hard work of the staff and the high investment cost can be imagined.

Unconsciously, it has arrived at 1 1: 20, and our visit is over. Ladies and gentlemen, it's really shocking to look at it. If I realized the importance of environmental protection by publicizing environmental protection and doing questionnaires before, today's visit to the sewage treatment plant really gave me a vivid lesson, which really touched my understanding and recognition of environmental protection in the depths of my soul and really realized that the earth on which we human beings depend has really been scarred by our so-called civilized, advanced and high-tech products. She's crying. Water has sounded the alarm for mankind again and again. In order to make us have a safe and prosperous future, let each of us take action to protect the most precious biological resource on earth-water, starting from scratch!