CN105598159B - A method of joint repairs DDT-polycyclic aromatic hydrocarbon composite pollution soil - Google Patents

Abstract

A method of joint repairs DDT polycyclic aromatic hydrocarbon composite pollution soil, it is related to a kind of method of repairing polluted soil, this method acts on the efficient degradation of DDT polycyclic aromatic hydrocarbon composite pollution in soil using degradation bacteria, solubilization in combination with rhanolipid as biosurfactant to organic contaminants in soil, and then realize the purpose of DDT and polycyclic aromatic hydrocarbon in efficiently removal soil.Degradation bacteria of the present invention is combined with rhanolipid as biosurfactant repairs DDT polycyclic aromatic hydrocarbon composite pollution soil, it is low with rehabilitation cost, can large-area applications, the particular advantages such as safe and simple, non-secondary pollution, and can realize and be repaired in production, it has a extensive future.

Description

A method of joint repairs DDT-polycyclic aromatic hydrocarbon composite pollution soil

Technical field

The present invention relates to a kind of methods of repairing polluted soil, and the polycyclic virtue of DDT-is repaired more particularly to a kind of joint The method of hydrocarbon combined contamination soil.

Background technology

China's land resource shortage, many place soil are existing to apply a large amount of DDT by different degrees of pollution （DDT）Equal organo-chlorine pesticides cause the history score of Farmland Soil Pollution, and continue on the energy consumptions such as coal and oil and make At PAHs in soil（PAHs）It builds up.China has a large population and a few land, and still needs to produce agricultural product in soil pollution area；It is another Aspect, due to the acceleration of urbanization process, a large amount of industrial enterprises move outside, and leave many high risk industrial pollution place and urgently repair It is multiple, to ensure the Sustainable and highly-efficient use of land resource.Currently, the organic composite pollution of China's soil is extremely serious, and to agricultural production The influence of product and health has started to show.It would therefore be highly desirable to which it is slow to carry out economic, efficient, safety soil organic composite pollution Solution and the practical technique repaired realize Agricultural Clean and land resource to ensure Removed In Soil-crop System ecological environment security Sustainable utilization.

Although DDT-polycyclic aromatic hydrocarbon composite pollution soil has catholicity and seriousness, current research still main In terms of concentrating on the reparation to DDT or polycyclic aromatic hydrocarbon Single Pollution object, there is not yet to the reparation skill of its combined contamination soil Art.Therefore, a low consumption is developed, efficient, environmental-friendly, non-secondary pollution treatment technology is of great significance.

Invention content

The purpose of the present invention is to provide a kind of methods that joint repairs DDT-polycyclic aromatic hydrocarbon composite pollution soil, should Method application rhanolipid as biosurfactant has relatively strong solubilized soil washing to the organic pollution in soil, utilizes it The dissolubility and biological effectiveness of DDT-polycyclic aromatic hydrocarbon in soil are improved, promotes degradation bacteria compound to DDT-polycyclic aromatic hydrocarbon The degradation of contaminated soil improves the remediation efficiency of contaminated soil, it can be achieved that being repaired in production.

The purpose of the present invention is what is be achieved through the following technical solutions：

A method of joint repairs DDT-polycyclic aromatic hydrocarbon composite pollution soil, and the method includes following procedure：

To DDT-polycyclic aromatic hydrocarbon composite pollution soil by the way of in-situ immobilization, used DDT and polycyclic Aromatic hydrocarbons efficient degrading bacteria bacterium solution is Arthrobacter globiformis（Arthrobacter globiformis）, wherein bacterial concentration be 1.0 × 10⁸~10¹⁰CFU/mL；Used biosurfactant is rhamnolipid.It is applied in 0 ~ 20 cm topsoils of contaminated soil Enter the rhanolipid as biosurfactant of a concentration of 5 mg/kg soil, then sprays 500 mL/m of Arthrobacter globiformis bacterium solution², fill Divide mixing, periodically waters, soil moisture content is made to be maintained at the 40% of maximum field capacity；It is DDT in periodic monitoring soil, more The content of cycloaromatics can repeat aforesaid operations after 30 d, until the DDT, polycyclic aromatic hydrocarbon content in soil are reached according to monitoring result To safety of soil environment standard；

Advantages of the present invention is with effect：

It is of the present invention to combine reparation DDT-polycyclic aromatic hydrocarbon with rhanolipid as biosurfactant by degradation bacteria Combined contamination soil, this method act on the efficient degradation of DDT-polycyclic aromatic hydrocarbon composite pollution in soil using degradation bacteria, together When solubilization in conjunction with rhanolipid as biosurfactant to organic contaminants in soil, and then realize efficiently removal soil The purpose of middle DDT and polycyclic aromatic hydrocarbon has rehabilitation cost low, can large-area applications, safe and simple, non-secondary pollution etc. is only Special advantage, and can realize while production while repairs, have a extensive future, the prevention polycyclic aromatic hydrocarbons contaminated to soil DDT-with Crop production safety has most important theories and realistic meaning, instructs the improvement of such soil to provide technology with reparation for China and refers to It leads.

Description of the drawings

Fig. 1 is in soil after rhanolipid as biosurfactant and 30 d of degradation bacteria Combined Treatment, 90 d, 150 d The residual condition of DDT；

Fig. 2 is in soil after rhanolipid as biosurfactant and 30 d of degradation bacteria Combined Treatment, 90 d, 150 d The residual condition of PAHs.

Specific implementation mode

The following describes the present invention in detail with reference to examples.

Fig. 1 rhanolipid as biosurfactant and DDT in soil after 30 d of degradation bacteria Combined Treatment, 90 d, 150 d Residual condition.Rhanolipid as biosurfactant and PAHs in soil after 30 d of degradation bacteria Combined Treatment, 90 d, 150 d Residual condition see Fig. 2.In control group without any processing（CK）In, PAHs natural degradations are very slow, in 150 d Degradation 3.04%；In degradation bacteria system for handling, PAHs residual quantities are reduced in 30 d rapidly, in 30 subsequent d- in soil It is very slow that rate is reduced in 150 d, is tended towards stability.When being not added with rhanolipid as biosurfactant, after handling 150 d The degradation rate of PAHs is up to 19.83%.Add rhamnolipid concentration range be 5 ~ 20 mg/kg dry ground when, PAHs degrade situation with DDT is similar, and declines instead with the increase of concentration for the treatment of.After handling 150 d, a concentration of 5 mg/ of rhamnolipid is added The PAHs degradation rates that kg soil, 10 mg/kg soil, 20 mg/kg soil are handled respectively reach 35.64%, 28.33%, 24.80%.Therefore, Rhanolipid as biosurfactant is more suitable in 5 mg/kg soil using concentration, also can reach and efficiently repairs PAHs Polluted Soils Earth.

Fig. 2 rhanolipid as biosurfactant and PAHs in soil after 30 d of degradation bacteria Combined Treatment, 90 d, 150 d Residual condition, it is dirty to DDT in soil and PAHs to consider rhanolipid as biosurfactant and degradation bacteria Combined Treatment The repairing effect and cost of dye, it is final to determine that rhanolipid as biosurfactant is more suitable in 5 mg/kg soil using concentration. In the present embodiment, after 150 d reparation phases, rhanolipid as biosurfactant is using concentration in 5 mg/kg soil, biological surface Activating agent rhamnolipid can respectively reach 63.74% and 35.64% with degradation bacteria to the degradation rate of DDT in soil and PAHs.

Embodiment：It tests field plot

Specific implementation step is as follows：

1) degradation germ liquid is cultivated, used DDT and polycyclic aromatic hydrocarbon-degrading bacteria are Arthrobacter globiformis （Arthrobacter globiformis）, wherein bacterial concentration is 1.0 × 10⁸~10¹⁰ CFU/mL。

2) rhanolipid as biosurfactant, used rhanolipid as biosurfactant concentration difference are configured For 5 mg/kg soil, 10 mg/kg soil, 20 mg/kg soil.

3）It tests in the greenhouse that place is Shenyang City Shenbeixin District industrialized agriculture, by the fresh soil of 0 ~ 20 cm in experimental plot Sample after discarding the impurity such as weeds, stone, plastics, is sufficiently mixed and arranges smooth, soil physico-chemical property is after measured：Organic matter Content is 54.37 gkg^-1, cation exchange capacity (CEC) is 13.09 cmolkg^-1, pH value 7.17, clay, powder and sand grains Proportion is respectively 26.11 %, 72.82%, 1.07%.Experimental field is divided into 15 cells, the area of each cell is 1.0 The m of m × 1.0, set blank control respectively（CK）, degradation bacteria+5 mg/kg soil rhamnolipid, the mouse of degradation bacteria+10 mg/kg soil Lee's glycolipid, rhamnolipid dry+20 mg/kg of degradation bacteria spray processing, and wherein degradation germ liquid additive amount is 500 mL, concentration It is 1.0 × 10⁸CFU/ mL periodically water, so that soil moisture content is maintained at the 40% of maximum field capacity, opened respectively in experiment DDT, the content of polycyclic aromatic hydrocarbon in 30 d, 90 d, 150 d periodic monitoring soil after beginning.

Rhanolipid as biosurfactant in soil after 30 d of degradation bacteria Combined Treatment, 90 d, 150 d DDT it is residual Condition of showing mercy is shown in Fig. 1.In control group without any processing（CK）In, DDT natural degradations are very slow, just degrade in 150 d 3.59%；In degradation bacteria system for handling, DDT residual quantities reduce rapidly in 30d in soil, the drop in 30 ~ 150 subsequent d Low rate is very slow, tends towards stability.When being not added with rhanolipid as biosurfactant, DDT degradation rates after 150 d are handled Up to 51.32%.When it is 5 ~ 20 mg/kg soil to add rhamnolipid concentration range, DDT degradation rates are anti-with the increase of concentration for the treatment of And decline.After handling 150 d, a concentration of 5 mg/kg soil of addition rhamnolipid, 10 mg/kg soil, 20 mg/kg soil are handled DDT degradation rates respectively reach 63.74%, 59.78%, 58.99%.Therefore, rhanolipid as biosurfactant uses concentration 5 Mg/kg soil is more suitable, can reach and efficiently repairs DDT contaminated soils.

Claims (1)

1. it is a kind of joint repair DDT-polycyclic aromatic hydrocarbon composite pollution soil method, which is characterized in that the method includes with Lower process：

It is multiple in reparation DDT and polycyclic aromatic hydrocarbon to DDT-polycyclic aromatic hydrocarbon composite pollution soil by the way of in-situ immobilization It is Arthrobacter globiformis to close the efficient degrading bacteria used in contaminated soil（Arthrobacter globiformis）, wherein bacterium solution is dense Degree is 1.0 × 10⁸~10¹⁰CFU/mL；The biosurfactant used is rhamnolipid, on the surface layers 0-20cm of contaminated soil The rhanolipid as biosurfactant of a concentration of 5mg/kg soil is applied in soil, then sprays Arthrobacter globiformis bacterium solution 500ml/ m², mix well, periodically water, soil moisture content is made to be maintained at the 40% of maximum field capacity；Drop is dripped in periodic monitoring soil The content of tears, polycyclic aromatic hydrocarbon can repeat aforesaid operations after 30d, until the DDT, polycyclic aromatic hydrocarbon in soil contain according to monitoring result Amount reaches safety of soil environment standard.