What are the purification functions of soil, the purification process of soil, the purification proc

Soil purification refers to the measures and processes to reduce or eliminate pollutants and toxins in the soil through physical, chemical, and biological actions. The process by which the soil itself reduces the concentration of soil pollution and disappears through adsorption, decomposition, migration and transformation.

This is due to the fact that soils play a three-fold role in the environment:

1) Because the soil contains a variety of microorganisms and soil animals, it can decompose and transform all kinds of substances that enter the soil from the outside world.

2) Due to the existence of complex soil organic colloidal and soil inorganic colloidal systems in the soil, through adsorption, desorption, substitution and other processes, it plays an "accumulation effect" on various substances entering the soil from the outside world, so that the pollution changes its morphology.

3) Soil is the base for the growth of green plants, and through the absorption of plants, the pollutants in the soil migrate and transform.

Therefore, some pollutants with different properties can gradually reduce the concentration of pollutants through volatilization, diffusion, decomposition and other actions in the soil, reduce toxicity or be decomposed into harmless substances; Through precipitation, colloidal adsorption and other effects, pollutants can change their morphology, or through biodegradation and chemical degradation, pollutants become less toxic or non-toxic, and even nutritious substances. Some pollutants are also decomposed and vaporized in the soil and migrated to the atmosphere. These phenomena can be understood in a broad sense as the process of soil purification.

As long as the concentration of pollutants does not exceed the self-cleaning capacity of the soil, no pollution will be caused.

In summary, it can be seen that the accumulation and purification of pollutants in the soil are carried out at the same time, which are two opposing processes with opposite effects, and the two are in a state of relative equilibrium.

1.Physical purification effect.

The soil is a multi-phase loose porous body, and the insoluble solid pollutants entering the soil can be mechanically retained by the soil. Soluble pollutants can be diluted by soil moisture to reduce toxicity, or adsorbed by soil solid surfaces, but can migrate with water to surface water or aquifers; Some pollutants can be volatilized or converted into gaseous substances that migrate through soil pores into atmospheric media.

2.Chemical purification effect.

Once a contaminant enters the soil, a series of chemical reactions can occur. Such as condensation and precipitation reactions, redox reactions, complexation-chelation reactions, acid-base neutralization reactions, hydrolysis, decomposition and chemical reactions, or photochemical degradation caused by solar radiation energy and ultraviolet rays. Through the chemical reaction described above, the pollutants are broken down into non-toxic substances or nutrients.

However, it is difficult to chemically purify compounds such as PCBs, fused aromatic hydrocarbons, plastics and rubber. Heavy metals cannot be degraded through chemical purification, but can only change the direction of their migration.

3.Bio-decontamination effect.

There are a large number of microorganisms in the soil that depend on organic matter for survival, and they have a great ability to oxidize and decompose organic matter, which is one of the most important purification methods in the self-purification of the soil environment. The products of the decomposition of various organic pollutants under different conditions are diverse and eventually converted into substances that are non-toxic to living organisms.

1. Willow.

The jasper is made into a tree high, and ten thousand green silk ribbons hang down. These two sentences vividly depict the posture of the green willow, which has a high ornamental value and a wide variety of varieties. In addition to the most common garden ornamental value, it also has a good economic value, wicker because of its unique flexibility, can be made into many handicrafts and daily necessities.

Wood is often used to make paper and artificial cotton.

Scientists who control soil pollution have found that willow can absorb pollutants in the soil well and transform them, so it has a good pollution treatment function and has a certain purification effect on the soil.

2. Poplar. The poplar tree is tall, straight, the tree shape is beautiful, it has a good ornamental value, in many northern areas of our country, the poplar is chosen as the street tree.

In addition to the ornamental value, it has to be mentioned that the ecological protection function of poplar, the famous three-north shelterbelt, is mainly afforested by poplars, the root system of poplars is very developed, can lock water and soil well, and it is precisely because of this characteristic that people have found the role of poplar in windbreak and sand fixation. In addition, poplar can effectively degrade toluene and other harmful substances in the soil, which has a great effect on soil remediation.

3. Sunflowers.

Sunflower's patience is very easy to plant, in addition to the ornamental function we usually know, and the edible value and economic value, the most shocking thing is its purification value, we only know that the sunflower is not high requirements for the soil where it grows, but we did not expect it to have a super purification function on the soil, sunflower can absorb harmful heavy metals in the soil where it is located, and then volatilize and purify, absorb.

There are generally several types of plants that evolve soils, one is to survive in destructive soil species to improve the soil, such as miscanthus, etc., and the other is to survive in poor soil and improve soil (mainly to adsorb soil particles and dead branch decay) such as: bryophytes, and some plants that eat to maintain soil erosion, such as:

Bamao, sedge, etc.

cactus, cactus, tiger tail orchid, spider plant, junzi orchid, crab claw orchid and other orchids; There are also ivy, flowering vines; As well as rich bamboo, fortune tree, etc., can absorb a large number of harmful gases, release oxygen, purify the air, eliminate odors, and beautify the environment.

Well, bamboo, in particular, is really good.

Cactus, bamboo, aspen are fine.

Soil self-purification:The ability of soil to reduce the concentration, reduce or disappear the pollutants entering the environment through complex and diverse physical, chemical and biochemical processes.