Beijing Water Quality Monitoring Center: "Nancheng City is worse than Beicheng City" does not exist

Recently, some media reported that the person in charge of the Urban Water Supply Quality Monitoring Center of the Ministry of Housing and Urban-Rural Development said that a new sample survey showed that the water quality standards for tap water in China were 83%.

The number quoted Ms. Lee's question: Beijing has always been saying that North City “applies to the upper reaches of the water”. Does the water quality of Nancheng County fall below the unqualified level of 17%?

Thousands of tests a day to control water quality safety

Are there any doubts that the quality of water in East and West Town is better than that in the suburbs?

“This situation does not exist!” said Lin Aiwu, director of the Beijing Water Group Water Quality Monitoring Center. “We have the same requirements for all the water plants, and the urban water supply network is connected, and it is impossible to divide it into administrative regions. The water quality is in line with the national standard."

The water quality monitoring center of the Beijing Water Group is independent of the waterworks. In 2007, the center was able to acquire 106 inspection capabilities that were implemented in 2012 in the New National Standards for Sanitary Drinking Water (abbreviated as “the New National Standard”). At present, three levels of water quality testing have been established, and "daily" testing has reached more than 1,000 times.

For example, at the working team level, each class will have a dedicated monitoring and inspection system.

Lin Aiwu said that at present, there are 243 water quality monitoring sites in schools and social units to conduct regular inspections of the user's tap water in the pipe network.

Nancheng scale is mostly due to groundwater

From July 1 this year, the new national standard will be enforced. Lin Aiwu said: "The new national standard 42 test items have been enforced on July 1, 2007, and 64 items have been postponed until July 1, this year.

In 2007, the Center tested 106 city water quality standards.

However, Ms. Li, who lives in Nancheng, discovered that scales may appear intermittently in the kettle. Lin Aiwu said that Beijing’s water supply is generally divided into two types of water sources: groundwater and surface water. Nanchang's water plants use more groundwater. Groundwater is more alkaline and has higher hardness, so the water that is burned out tends to have water and alkali. "As long as the hardness is controlled below 380 mg/l, it complies with national regulations and is harmless to the human body."

Micro Water Plant Advances the South-to-North Water Diversion Test

At present, Hebei aids the Beijing water standard, but chloride and other indicators are high. In this way, the scale adhered to the pipe may react with the acidic substance and may fall off, and the water may be yellowish.

At present, the Beijing No. 9 Water Plant has adjusted the local water and Hebei water, reducing the chloride and other indicators.

However, with the coming of water from the South-to-North Water Diversion Project, the difficulty of water distribution will increase. In response, this year, the Water Group has reconstructed a total of more than 300 kilometers of pipelines including Yongdingmennei Street and Taijichang Avenue. It is necessary to reconstruct approximately 2,000 kilometers before 2015.

Not only that, the Water Group also established a “minor” water plant near the Danjiangkou Reservoir, the water source of the South-to-North Water Transfer Project, and water pipes dug from different parts of Beijing were pulled here. Field inspection of the existing water supply pipe network for adaptation to water from the South-to-North Water Transfer Project.

- Secret

As the Beijing No. 9 Water Plant of the Nominating Water Plant in Beijing, more than half of urban water is supplied daily. A few days ago, this reporter went deep into the factory area to treat the water of Miyun Reservoir, one of the important water sources in Beijing, as an example to reveal the entire process of tap water treatment for readers.

1 Water source

The source is loaded with "telescope"

Miyun Reservoir is one of the important water sources for the Ninth Water Plant. The water at Miyun Reservoir is transported here through 78 km of pipelines.

On the computer screen of the central control room of the water plant, multiple parameters of the water quality of Miyun Reservoir are displayed in real-time - total algae, green algae concentration, turbidity, nitrate ammonia, total organic carbon, etc., and each parameter comes in red, yellow, and green. Indicated.

Green indicates that the water quality is qualified. Once problems are found, such as excessive turbidity, the system will initiate red and yellow warnings according to the severity. The monitoring system will immediately activate the alarm and issue a warning sound.

Originally, in order to realize the quality of incoming water, the water plant set up a water source early warning system and installed a variety of water quality on-line inspection equipment in Miyun Reservoir to transmit water quality information in real time through a remote wireless data transmission system. The sudden change in water quality and the adjustment of the follow-up process took time.

In addition, in order to facilitate the treatment of the incoming water from the Miyun Reservoir water source, a pre-oxidation process is used at the water intake of the Miyun Reservoir to kill some microorganisms in the water and prevent the growth of microorganisms during the long pipeline transportation process, which will affect the water quality and the normal water transport of pipelines. At the same time, a powdered activated carbon feed device was set up at the intake of the Miyun Reservoir to deal with seasonal odor problems and to cope with possible raw water organic pollution.

2 Odor removal

Activated carbon to color and taste

In the complicated process of the ninth water plant, the carbon filter can be said to be the "biggest person" after the ride, and it is also not available at many domestic and foreign water plants.

At the side of the charcoal filter pools, pools of water as large as a swimming pool were filled with water. The bottom of the pool was dark, and it seemed to be far from bottoming. Chen Kecheng, director of the Ninth Water Plant, told reporters that each pool is filled with 1.5 meters of activated carbon, a total of 5,400 tons, used to remove the color and smell of water.

"There are many tiny carbon holes in the activated carbon. When the water flows out, some impurities will remain in the carbon holes. We must regularly check the degree of filling of the carbon pores in the activated carbon to determine whether or not to replace it." Chen Kecheng introduced, generally every three years Have to replace or pull back to the factory for "regeneration."

The cost of the carbon filter process is very high, with a price of 11,000 yuan per ton of activated carbon. This is the reason why only a few water plants in China use this process.

3 To impurities

Fine sand sediment impurities

The tap water that flows into residents' homes is clean and free of impurities such as sand and dirt, so you may not even think that the use of water to remove impurities is actually sand!

“This is not an ordinary sand,” said Chen Kecheng, the director of the Ninth Water Plant. It requires high stability, high strength, and a diameter that meets standards.

How does sand work? Originally, adding sand can make the glue in the water adhere to the sand, and then settle down, which is more efficient than simply adding coagulant to the water.

The effect of sand water purification is also good. The instrumentation next to the processing facilities shows that after the sedimentation of Gaza, one of the main indicators of water, the turbidity is only 0.8 degrees, which is already in line with the new standard of drinking water hygiene and the turbidity cannot be higher than 1 degree. Provisions. After the subsequent filtration process, the turbidity of the factory water is controlled below 0.3 degrees, which is also the corporate standard of the Water Group.

These sands are not cheap, and the waterworks will buy 1700 yuan per ton of sand from Xiamen. Before use, the sand will be sanitized and can be almost finished as a mask. Every day there is about 1 ton of sand.

However, the sedimentation of sand is not always there. As the water in Miyun Reservoir decreases year by year, impurities in the water increase. In 2007, this Gaza settlement was added.

4 Waste change treasure

Membrane filter discharge water for 70,000 tons

There is also a “secret weapon” at the Ninth Water Plant, which can reuse the water discharged from the water plant and become qualified tap water.

In 2010, the peak of summer water use in Beijing reached 2.884 million tons of water per day, close to the water supply limit. How can the water supply be increased if the water supply is limited? In the process of water treatment, water plants will generate some waste water. Can they turn waste into treasure and use these waters? The Ninth Water Plant invested 70 million yuan to establish an ultrafiltration membrane treatment process that allows these wastewaters to pass through a membrane with a pore size of only 0.01 micron, which is equivalent to a 5,000-thousandth of the diameter of ordinary humans. After the water passes through the membrane, all the diameters are larger than Subtle impurities in the pore size of the membrane have been removed, and the daily water supply capacity has increased by 70,000 tons, which is equivalent to providing 700,000 people with daily water.

However, Chen Kecheng revealed that the price of the membrane processing equipment is as high as 24 million yuan, and it needs to be replaced every 5-8 years.

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