Energy China Gezhouba Group started with "water treatment", and in recent years it has expanded its business in environmental protection business areas such as sewage and soil treatment. The treatment of the black and odorous water body of Yawei Creek in Hainan is a typical case. After the treatment, the Yawei River not only bid farewell to the black and odor of the past, but also became the first demonstration base for comprehensive treatment of black and odor water established by the Ministry of Water Resources in Haikou. In 2018, the typical experience and practices found by the State Council in the general inspection were given a circular.

From the "Smelly Ditch" butterflies with piles of garbage and black and smelly waters to the "Net Red River" with clear water and rippling blue waves. In just three years, what magical technology has the China Energy Construction Gezhouba Group used to achieve a breakthrough in turning decay into a miracle? Let's get to know it together~

Yawei Creek is a branch on the left bank of Henggou River in the middle of Haidian Island, Meilan District, Haikou City. It is 2.3 kilometers long and runs across Haidian Island from east to west. Standing next to the Yawei Creek, the green water is covered with green trees, and the beautiful scenery is unobstructed. The picturesque Yawei Creek landscape belt has become the landmark of Haidian Island. As a typical case of odorous water treatment, Yawei Creek has received extensive media attention.

It is hard to think of a river that was once exposed by CCTV as a typical black and smelly water body. In order to completely solve the problem of black and smelly water body, it will reproduce the "green water and green mountains". Energy China Gezhouba Group has set up a special class to study the main reasons for the black and odor of water bodies, and uses the "four major technologies" to work together to ensure that the water quality meets the standards.

Breakthrough One · Source control and pollution interception

As the saying goes, “black and odor is in the water, the source is on the shore, the key lies in the outlet, and the core is in the pipe network.” The root of the black and odor control of urban water bodies lies in the treatment of excessive sewage discharge. Only when the sewage does not enter the river, the water quality will gradually recover. It's like treating a disease in the human body. Only when the virus or bacteria in the body is controlled can we gradually recover through our immunity.

"At that time, we had hundreds of workers dispatched at the same time to investigate hundreds of kilometers of municipal pipe network one by one, and to investigate the source of sewage from every sewage outlet that enters the river. When the source of sewage was clear, we began to transform the pollution source and directly build a new interception. The sewage pipe network sends the sewage to the newly built integrated sewage treatment equipment to be treated and discharged into the water body.” said Xu Zhong, the chief engineer of the Haikou Water Treatment Project of China Energy Construction Gezhouba No. 1 Company at the time.

In the process, the integrated sewage treatment equipment is also selected to adopt the MBBR process. By adding suspended fillers in the biochemical reaction tank, the sewage is effectively biochemically treated, and the method of dynamic filtration is adopted to achieve continuous sewage treatment; and remote monitoring is used to achieve People are on duty, technical management is simple, labor costs are low, and operation is stable.

Breakthrough II·Internal source cleanup

Internal source cleaning is to dredge the entire river section and quickly remove pollutants that have been deposited for a long time in the river. Internal source dredging is the fastest way to get results. However, the amount of dredging works is huge, and the Yawei River alone needs to remove 145,000 cubic meters of silt.

The traditional construction method of interception, excavation and drying takes a long time, affects the construction period, and also interferes with the lives of surrounding citizens. So I inquired about and found a crawler filter press to completely solve this series of problems. The crawler-type filter press can dry and deodorize the sludge with high water content in the river, which not only solves the problem of unpleasant smell during cleaning, but also solves the problem of easy pollution of the road during the sludge transportation process, which becomes the bottom sludge of the river. The main force of treatment has greatly reduced the secondary pollution of silt.

Breakthrough three: Improve hydrodynamics

Standing by the Ducktail Creek, you can see from time to time there are splashes on the water "grumbling", resembling a spring, and there are many white balls floating on the water. This is a kind of hydrodynamic force. Those bubbling splashes are actually produced by the super-large flow aeration and flow-making integrated machine installed in the water body, which can bring more dissolved oxygen to the microorganisms in the water, and promote the formation of an internal circulation mode in the river water body, so that the living water does not rot. Effect.

In addition, in some water bodies, the method of widening the box culvert through the road was also adopted. Yawei River is a tidal channel. The bottom slope of the river is flat and the flow rate is slow. The inland water body reciprocates with the rise and fall of the tide, which makes the water body poorly fluid. In order to effectively solve this problem, the project department directly widened the box-through culvert, rebuilt the shoreline, improved the hydrodynamic conditions, and improved the self-purification capacity of the water body.

Breakthrough Four·Water Ecological Restoration

Ecological restoration is another new idea of using the concept of ecological chain to absorb water pollution. "The main function of aquatic plant technology is to purify micro-polluted water bodies, while at the same time providing places and food for the survival and reproduction of other organisms." Xu Zhong said.

Now you can see a circle of wooden piles on the shore of the lake, which are treated by carbonization anticorrosion process, after pile sinking construction, soil covering, gravel backfilling, etc., emergent plants are planted between the wooden piles and the shore. These plants include salt-tolerant reeds, Zaili flowers, yellow iris, water onions, etc., which are an important step in the establishment of a water ecological restoration system. Use biotechnology to restore and improve the operation capacity of the ecosystem in the water body, and improve the water body's "immunity".

At the beginning of 2019, Haikou City built a new Yawei River Wetland Ecosystem Project to activate waterfront space and introduce slow-moving systems; restore ecological corridors and build biological habitats; improve water security, build urban sponges, etc., and strive to build wetland parks. Returning water to the people and sharing the effectiveness of water treatment... "Heishui River" has become a thing of the past.

Today's Yawei Creek, with clear waters and green banks, and a shallow bottom of Yuxiang, makes people walking by the babbling creek, as if they have entered a paradise. In the evenings and weekends, many citizens and tourists can always see leisure and recreation by the Yawei Creek, which has become the "net celebrity check-in point" on Haidian Island. According to a survey conducted by the Haikou City Social Situation and Public Opinion Survey Center, the surrounding people’s satisfaction with the water treatment carried out by the Yawei Creek continues to reach more than 90%.

Keywords: engineering news, engineering construction information

"Green water and green mountains are the golden mountains and silver mountains." Under the governance of China Energy Construction Gezhouba Group, Haikou regained its nearly 4 million square meters of blue wave lake. On the road of pursuing a dream for environmental protection, Energy China Gezhouba Group has strengthened the confidence of Haikou citizens in pursuing the harmony and unity of man and nature, and has added a rich touch to the picture of ecological beauty of "mountains and rivers". Editor/Sang Xiaomei