A kind of heavy-metal contaminated soil renovation agent and its preparation method and applicationTechnical field
The present invention relates to heavy-metal contaminated soil based technique for in-situ remediation field, specifically discloses a kind of heavy-metal contaminated soilRenovation agent and its preparation method and application.
Background technology
Announced according to Environmental Protection Departments in 2014 and Ministry of Land and Resources《National Soil Pollution Investigation publication》, the whole nationThe total exceeding standard rate of soil is 16.1%, and based on inorganic type, organic type takes second place pollution type, and compound pollution proportion is less, inorganicExceeded digit of pollutant accounts for the 82.8% of all super punctuation bits.Cadmium, mercury, arsenic, copper, lead, chromium, zinc, 8 kinds of inorganic pollution object points of nickelPosition exceeding standard rate is respectively 7.0%, 1.6%, 2.7%, 2.1%, 1.5%, 1.1%, 0.9%, 4.8%.From in terms of pollution distribution situation, south soilEarth pollution overweights the subregion soil contamination problems such as the north, Yangtze River Delta, the Delta of the Pearl River, Northeastern rust belt moreProminent, southwest, variable charge soil heavy metals exceeding standard scope are larger；Level of inorganic contaminants distribution in cadmium, lead, mercury, arsenic 4 is presentedThe situation gradually risen from northwest to the southeast, from northeast to southwestward.
The enrichment of heavy metal in soil can work the mischief to plant and human health, and heavy metal pollution of soil source mainly hasAtmospheric sedimentation of irrigation, agricultural chemicals and Term Fertilization and pollutant etc..Cadmium and lead are the environmental pollutions of the extremely strong accumulation of toxicityThing, can in people's cylinder accumulation, so as to cause acute and chronic poisoning, and mammal is had stronger carcinogenic, teratogenesis andMutagenesis.
At present, heavy metal pollution of soil recovery technique is conventional physical restoration, thorugh biologic engineering method, chemical restoration etc.,Physical restoration mainly includes soil moved in improve the original, digs, adsorbs fixation, Electroremediation method etc., and it has strange land pollution, engineering greatly, throwsThe problems such as providing big, it is inapplicable for large-area Farmland contamination；Thorugh biologic engineering method includes microorganism, phytoremediation etc., is repaiiedThe cycle of answering length, biomass are little and floristics is limited the problems such as lacking, and popularization and application are difficult to for the moment；Chemical method includes leaching, complexingMethods such as extraction, in-situ chemical reparation etc..In numerous renovation agent technologies, in-situ chemical reparation is considered as a kind of effectiveAnd lower-cost method, the technology it is critical only that the suitable chemical redemption medicament of selection, traditional reparation medicament mainly withBased on lime, phosphate and biosolids, repair mechanisms are single, easily affected by environmental pH change, and treatment effect is not dashed forwardGo out.
The content of the invention
The purpose of the present invention is the deficiency for existing heavy-metal contaminated soil in-situ immobilization agent technology, there is provided a kind of efficientHeavy-metal contaminated soil in-situ immobilization agent, while provide above-mentioned heavy-metal contaminated soil in-situ immobilization agent preparation method and shouldWith.
The technical solution used in the present invention is：
A kind of heavy-metal contaminated soil renovation agent, is made up of following component by mass percentage：Dolomite 25-40%, three siliconSour magnesium 30-50%, potassium dihydrogen phosphate 10-15%, vermiculite 3-5% and calcium-base bentonite 10-15%.
The preparation method of above-mentioned heavy-metal contaminated soil renovation agent, comprises the steps：
（1）Each raw material is weighed respectively by above-mentioned mass percent；
（2）Calcined after dolomite is crushed；
（3）The grinding of magnesium trisilicate, potassium dihydrogen phosphate, vermiculite and calcium-base bentonite is uniform, and add the dolomite after calcining to enterRow stirring, directly dress wraps or compresses granulation dress bag after stirring.
Further, the particle diameter after dolomite is crushed is 0.1-0.3mm.
Further, calcining heat is 700-900 DEG C, and calcination time is 3-4h.
Further, the particle diameter after the grinding of magnesium trisilicate, potassium dihydrogen phosphate, vermiculite and calcium-base bentonite is 0.05-0.3mm。
Application of the above-mentioned heavy-metal contaminated soil renovation agent in soil remediation, comprises the steps：
Apply above-mentioned heavy-metal contaminated soil renovation agent in heavy-metal contaminated soil, plough and be well mixed, renovation agent consumption rootAdjust according to pollution level, preferably 100 ~ 300,000 grams/acre of renovation agent consumption, apply renovation agent and planted after 10 ~ 20 days.
The beneficial effects of the present invention is：
The present invention heavy-metal contaminated soil renovation agent main component be natural mineral matter, non-secondary pollution；Formula components are takenWith reasonable, each component can be cooperateed with and played a role, and make full use of the compensatory of heavy metal ion and with valency substitutability, mineral matterThe mode curing heavy metals such as lattice Inter layer adsorption, surface complexation and formation precipitation, can effectively reduce heavy metal in soil ionTransfer ability and biological effectiveness, so as to reduce agricultural product in content of beary metal.
The present invention not only has the function of heavy metal in curing soil, and can also supplement nutrient for soil in time, improvesSoil texture, increases soil fertility, and increases the yield and quality of crops.
The heavy-metal contaminated soil renovation agent product form variation of the present invention, for different applying environments, may be selectedGraininess or powder renovation agent.For example for the agricultural land soil reparation of heavy metal pollution, graininess renovation agent is may be selected, hadThe airborne dust solved the problems, such as in application of effect.
Specific embodiment
Below will the present invention is described further by instantiation.
Embodiment 1
Pot experiment
A kind of heavy-metal contaminated soil renovation agent, each Ingredient percent is as follows：
| Raw material | Mass percent（%） |
| Dolomite | 35 |
| Magnesium trisilicate | 40 |
| Potassium dihydrogen phosphate | 10 |
| Vermiculite | 5 |
| Calcium-base bentonite | 10 |
Above-mentioned heavy-metal contaminated soil renovation agent, its preparation method is as follows：
（1）Each raw material is weighed respectively by the mass percent in upper table；
（2）Dolomite ore is crushed, the sieve of 0.3mm is crossed after crushing, then calcined, calcining heat is 800 DEG C,Calcination time is 4h, standby；
（3）Magnesium trisilicate, potassium dihydrogen phosphate, vermiculite and calcium-base bentonite are ground, the sieve of 0.3mm is crossed after grinding, it is standbyWith；
（4）The raw material of above-mentioned preparation is proportionally stirred, appearance is pressed into after stirring the particle of coarse screw thread, that is, makeInto heavy-metal contaminated soil renovation agent.
Experimental design：The present embodiment adopts pot experiment, soil to take from xiangtan, hunan province county, and pedotheque picks up from farmingLayer, sampling depth is 0-20cm, and soil pH value is about 6.2, and potted plant ladle sample adopts polyethylene（PE）Material, pedotheque table in bucketArea is 0.4m2, depth is 20cm.Test arranges three process：（1）CK, does not apply heavy-metal contaminated soil renovation agent（Numbering1）；（2）Apply 150,000 grams/acre of soil-repairing agent of the present invention（Numbering 2）；（3）Apply 200,000 grams/acre of soil-repairing agent of the present invention（Numbering 3）；With the effect of heavy-metal contaminated soil renovation agent relatively more of the present invention.Each is processed in triplicate, random packet arrangement,Rice varieties select Y two excellent 9918.
Product application process：Heavy metal soil-repairing agent of the present invention is uniformly sprinkling upon into pedotheque surface, is then fully stirredMix, rice transplanting after standing 15 days, cultivation management measure is consistent with field management during test.
Detection project and method：Soil available Cd and lead according to《Soil quality Available Lead and Cadmium detrmination》GB/T 23739-2009, the lead in brown rice according to《The measure of Pb in food》GB 5009.12-2010, the cadmium in brown rice according to《The measure of cadmium in foods》GB 5009.15-2014.
Result of the test shows, compared with blank CK, applying heavy-metal contaminated soil renovation agent of the present invention can reduceThe content of soil available Cd and lead, while the content of cadmium and lead in rice can be reduced.Apply 150,000 grams/acre of present inventionHeavy-metal contaminated soil renovation agent, soil available Cd and Available Lead content reduce respectively 62.4% and 33.1%；RiceThe content of middle cadmium and lead reduces respectively 52.8% and 34.8%.Apply 200,000 grams/acre of heavy-metal contaminated soil reparations of the present inventionAgent, soil available Cd and Available Lead content reduce respectively 63.2% and 36.8%；The content difference of cadmium and lead in riceReduce 55.6% and 39.1%.Apply in the case of heavy-metal contaminated soil renovation agent of the present invention containing for cadmium and lead in riceAmount is below national standard limit.
Embodiment 2
A kind of heavy-metal contaminated soil renovation agent, each Ingredient percent is as follows：
| Raw material | Mass percent（%） |
| Dolomite | 30 |
| Magnesium trisilicate | 45 |
| Potassium dihydrogen phosphate | 15 |
| Vermiculite | 5 |
| Calcium-base bentonite | 5 |
Above-mentioned heavy-metal contaminated soil renovation agent, its preparation method is same as Example 1.
The present embodiment adopts field plot trial, and in Lengshuijiang, Hunan, test arranges 3 process to test site,（1）CK, does not apply renovation agent（Numbering 4）；（2）Apply 150,000 grams/acre of renovation agent of the present invention（Numbering 5）；（3）Apply the present invention to repair200,000 grams/acre of agent（Numbering 6）；Three repetitions, random district's groups arrangement.Each Rice Cropping plot area is 22.5m2（4.5m×5m）, with the ridge of 0.3m wide thick plastic film parcel between each process（Buried depth 0.4m）Separate.Rice varieties are excellent from Y two9918, Fertilization Level and other field management measures, it is each process it is completely the same.
Product application process：Heavy metal soil-repairing agent of the present invention is uniformly spread fertilizer over the fields in experimental plot, is then ploughed a fieldWith the work that harrows a field, rice transplanting after 20 days.
Detection project and method are same as Example 1.
Result of the test shows：Compared with blank CK, 150,000 grams/acre of heavy-metal contaminated soil reparations of the present invention are appliedAgent, soil available Cd and Available Lead content reduce respectively 68.4% and 30.1%；The content difference of cadmium and lead in rice73.1% and 47.6% is reduced, rice yield volume increase 3.6%.200,000 grams/acre of heavy-metal contaminated soil renovation agents of the present invention are applied,Soil available Cd and Available Lead content reduce respectively 69.1% and 32.7%；The content of cadmium and lead is reduced respectively in rice80.8% and 57.1%, increasing production of rice 4.8%.Apply in the case of heavy-metal contaminated soil renovation agent of the present invention in riceThe content of cadmium and lead is below national standard limit.