Advantages and characteristics of land treatment system

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3 Advantages and characteristics of land treatment system

The land treatment system is based on the interaction of soil, plants, microorganisms, etc.
, forming aerobic, anoxic and anaerobic systems from the surface of the soil to the interior of the soil, which helps various pollutants to act in different environments.
, And finally achieve the purpose of removing or reducing pollutants
.

Generally, the main pollutants are removed in a well-structured soil layer 30-50cm below the surface

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1 Removal of nitrogen and phosphorus

Research results show that the form of nitrogen is inorganic and organic
.

The number of ammonifying bacteria, nitrosating bacteria, nitrifying bacteria, and denitrifying bacteria in the sewage land system are all at a high level.

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2 Removal of organic matter

The land treatment system has a good ability to purify organic matter, especially degradable organic matter.
After the organic matter in the sewage enters the soil, it is first intercepted by filtration and adsorption, and then degraded by biological oxidation.
Most of the BOD removal reaction Generally occurs at 50cm on the surface
.

The results of experiments conducted by Li Haijun and the Australian Science and Industry Organization (CISCO) on the new FILTER land treatment system show that the FILTER system enables the removal rate of COD to reach more than 70% through the biological, physical, and chemical effects of the soil

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3 Purification of SS

The removal of SS by the land treatment system mainly relies on precipitation, adsorption and interception of plants and organisms
.

Generally, the suspended solids in sewage can be almost completely removed by the land treatment system

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4 Purification of other pollutants

The sewage land treatment system can also remove pathogenic microorganisms, bacteria, parasites and viruses.
They are removed through filtration, adsorption, drying, irradiation, biological predation, and exposure to adverse conditions
.

Trace organic matter in water can also be removed by the effects of volatile luminescence decomposition, adsorption and biodegradation

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5 Features of land treatment system

①Low capital construction costs
.

Land treatment can be based on the specific terrain, choose those sites that are not suitable for other developments, use some low-cost land such as wasteland as treatment sites, and select the appropriate type.

②Low energy consumption
.

The land treatment system makes full use of the chemical energy of solar energy and substances in sewage

③High recovery rate of reclaimed water
.

The land treatment system can process 80% of industrial water and 60% of domestic water into relatively clean water quality.

④Ecological and social benefits are significant
.
Land treatment utilizes the regulation function of its soil-plant system to receive the shock load of sewage and has a strong buffering effect, thereby protecting and receiving water bodies and groundwater, and preventing secondary pollution
.
Compared with the traditional two-stage biochemical treatment method, when the water quality changes, the sludge swells and the effluent water quality deteriorates, which has obvious advantages
.
Compared with the direct discharge model of sewage treatment plants, land treatment realizes the recycling of nutrients and water resources of sewage at the same time.
In suburbs or rural areas, sewage treatment can also increase soil fertility and grow cash crops.
At the same time, it realizes the material and energy cycle from the ecological point of view
.
The quality of the forage grass in the land treatment system is guaranteed, and the output is increased by more than 60%; the silage output of the 200hm ² area of ​​the demonstration project can meet the winter feeding needs of 1,000 dairy cows.
It is estimated that the annual net income of each herder is more than 10,000 yuan
.
The gas generated by the operation of the land treatment system has little negative effect on the surrounding environment
.
Preliminary research on the emission laws of methane and CO ₂ during the operation of the land treatment system shows that the operation of the land treatment system produces a certain amount of greenhouse gases, but through the corresponding emission reduction measures, the sewage land can be improved.
The greenhouse gas generated during the operation of the treatment system is greatly reduced so that it does not have a negative effect on the surrounding ecological environment
.
In addition, because the land treatment system places the main structures underground, it not only does not affect the ground landscape, but also uses the advantages of green plants to achieve the dual effects of purifying sewage and beautifying the green environment, thereby saving some large cities from beautifying the city.
Investment costs to increase the greening rate
.
Research on the ecological effects of the Huolin River sewage land treatment project by Tai Peidong and others in Inner Mongolia showed that the urban sewage land treatment system in arid areas can change the ecological environment in a local area, improve the monotonous natural landscape of the grassland area, and give full play to its environmental protection, tourism, and ecological construction.
And other functions
.

Related Links: Overview and Types of Wastewater Land Treatment System (2)