As we all know, water is a resource for human survival. With the development of industry, rivers and lakes have become more and more polluted, and urban landscape water bodies have begun to change. The water bodies are enriched with nutrients such as nitrogen and phosphorus, causing abnormal proliferation of algae and producing "water blooms". "Or "Lake Indigo", the transparency of the water body decreases, the dissolved oxygen decreases, and the water quality deteriorates seriously, that is, the eutrophication of the water body.
1. Causes of water pollution
1. Poor water source conditions
Landscape water mainly comes from tap water, river water, and groundwater. With economic development, water pollution has become more and more serious and the ecological environment has been destroyed. The country has begun to focus on improving the water quality of rivers and lakes.
2. Many sources of pollution
Including decomposition products of aquatic organisms, corrosive products of flowers and trees, chemicals, etc.
3. Man-made destruction
Human littering is one of the causes of river pollution.
4. Unreasonable design
If the design is unreasonable, the artificial lake water lacks fluidity, and pollutants will accumulate and spread, leading to final deterioration. Second, the hardening of lakes leads to the imbalance of the ecosystem, and the water quality is severely affected.
5. Pollution of groundwater
With the development of industry and agriculture, more pollutants (such as nitrogen, phosphorus, heavy metal ions, etc.) seep into the ground and pollute groundwater. Most of the landscape water is connected to the groundwater, which pollutes the landscape water.
6. Invasion of blue-green algae
The invasion of blue-green algae is also one of the causes of water pollution.
2. Treatment methods of water pollution
1. Physical Law
1.1 Water diversion method
When the suspended matter (such as mud and sand) in the water body increases and the water body becomes muddy, the concentration of impurities in the water can be diluted by diversion and water exchange to reduce the concentration of impurities.
1.2 The way of circulating filtration
In the initial stage of the design, according to the size of the water body, a matching filter sand tank and a circulating blower are designed, and the circulating pipes are buried for daily water quality maintenance in the future.
2. Physical and Chemical Law
2.1 Coagulation sedimentation method
The processing objects of the coagulation sedimentation method are suspended solids and colloidal impurities in the water.
2.2 medicated air floatation
Adding chemicals can kill algae. The water quality becomes clear in a short time, and drug-resistant algae will appear after a long time.
Cause secondary pollution.
3. Biochemical treatment method
The principle of the biochemical treatment method is to use the life activities of cultivated organisms or cultivated and inoculated microorganisms to transfer, transform and degrade pollutants in the water so as to restore the water body. It can also be called biological-ecological water body restoration technology.
3.1 Biological contact oxidation
Biological contact oxidation is widely used in the treatment of micro-polluted source water. If the initial injection water and the later supplementary water of the landscape water body have a high organic content, the biochemical treatment process can be used to remove such pollutants.
3.2 Membrane Bioreactor
In the reactor, the inlet water is separated from the outlet water with a microfiltration membrane or an ultrafiltration membrane, and activated sludge is cultivated in the inlet part or put into the cultivated activated sludge, and aerated.
3.3 PBB method
The PBB method is an in-situ physical, biological, and biochemical remediation technology, which is mainly to increase oxygen into the water body and regularly inoculate compound microorganisms that have the effect of purifying water.
3.4 Biological filter method
The biological filter method is a combined treatment method that combines the traditional sand and gravel filtration with the wetland pond bed. It uses a multi-stage water drop aeration method. It can effectively control the odor of the effluent, the ammonia nitrogen value and improve the removal effect of organic matter.
4. Bionics processing method
Combining the aeration method, filtration method, purification method, and biological method organically, and then make a fundamental change, the treatment of landscape water in such a link will make the landscape water always clear, fresh, and never degenerate.