A kind of broad spectrum type heavy-metal contaminated soil stabilization agentTechnical field
The present invention relates to a kind of contaminated site to repair medicament, in particular it relates to which one kind can be applied to heavy-metal contaminated soilStabilize the broad spectrum type stabilization agent repaired.
Background technology
With developing rapidly for industrial or agricultural, and in evolution corresponding environmentally friendly technical measures and management means missing,A large amount of pollutants are caused to enter soil environment system.Once the amount of pollutant into soil exceedes the self-purification capacity of soil in itself,Soil function and structural damage will be caused, poisonous and harmful substance will accumulate in soil, and can by certain direct orIndirect approach enters human body, is detrimental to health.
The heavy metal pollution of soil is widely present in China to a certain extent.There is common heavy metal contaminants in soilMercury, cadmium, lead, arsenic, copper, nickel, zinc, antimony and Cr VI etc..Heavy metal pollution of soil has cumulative bad and irreversibility etc. prominent specialSign, selectable recovery technique is accordingly less, and stabilization technology particularly dystopy stabilization technology is at present both at home and abroad for weightOne main recovery technique of metallic pollution soil.
The stabilisation reparation of heavy-metal contaminated soil refers to add appropriate targetedly heavy metal stabilization in contaminated soilChemical drug agent, by the way that absorption, precipitation, complexing, ion exchange and redox etc. one occurs between medicament and heavy metal pollution of soil thingSeries effect, by physics, chemistry or it is physicochemical in the form of change existing forms of the heavy metal contaminants in soil, reduceToxicity, dissolubility, transportable property and the bioavailability of heavy metal contaminants, so as to reach reduction health risk and realizeThe purpose of repairing effect.It is heavy metal-polluted at home in the case of existing soil restoring technology level and recovery project practical experienceDye soil stabilization recovery technique is used widely because of its low, efficiency high of input, the reparation advantage such as quick, simple to operate.
In view of will exist in the diversity of heavy metal pollution of soil species, or even same plot contaminated soil it is a variety of notSame heavy metal contaminants；In addition the earth volume of heavy-metal contaminated soil is often also relatively large, and stabilize needs in repair processLarger amount of stabilization agent is wanted to add.Therefore, for it is a kind of it is cheap and easy to get, safe and reliable, easy to use, can be directed to it is a variety of heavyThe demand that metallic pollution carries out the effective broad spectrum type heavy-metal contaminated soil stabilization agent for stabilizing and repairing is more urgent.
The content of the invention
It is an object of the invention to provide a kind of the medicament repaired, cheap and easy to get, peace are stabilized for heavy-metal contaminated soilIt is complete it is reliable, easy to use, can carry out effective stabilizing reparation for various heavy pollution.
In order to achieve the above object, the invention provides a kind of broad spectrum type heavy-metal contaminated soil stabilization agent, wherein,Described medicament includes following components by mass percentage：Double superhosphate 20~40%, ferrous sulfate heptahydrate 0~30%,Diatomite 0~10%, concave convex rod 0~10%, montmorillonite 10~20%, kaolin 5~15%, talcum powder 5~10%, magnalium waterTalcum 0-10%, bentonite 5~15%.
The Compositional type stabilization agent is mainly made up of clay mineral, phosphate and ferrous salt.Select clay pit ownerIf there is absorption and the stable mechanism of ion exchange of broad spectrum activity feature using it；Further to increase its universality, selectionA variety of clay minerals cheap and easy to get, nontoxic are compounded, include diatomite, concave convex rod, montmorillonite, kaolin,Talcum powder, magnalium hydrotalcite and bentonite etc., there is preferable stabilization effect to heavy metals such as cadmium, lead, copper, nickel, zinc.Phosphoric acidSalt is respectively provided with preferably precipitation stabilization effect to heavy metals such as lead, antimony, cadmium, copper, nickel, zinc, and available phosphorus is have selected in the present inventionContent is higher and same cheap and easy to get and calcium superphosphate with preferable soil fertility is as in Compositional type stabilization agentA kind of main formula composition.Ferrous sulfate has stronger reproducibility, and direct stabilized Cr VI can will be difficult in soilEither quinquevalence antimony, which is reduced into, facilitates stabilized trivalent chromium or trivalent antimony, and this kind of heavy metal in soil can be helped to realize stabilizationChange；Simultaneously for arsenic etc., the heavy metal of coprecipitation reaction can occurs in some with molysite, and ferrous sulfate equally has certain stabilizationChange effect, therefore also select ferrous sulfate heptahydrate as a kind of formula components in formula.
Above-mentioned broad spectrum type heavy-metal contaminated soil stabilization agent, wherein, described medicament, its in the preparation, firstThe solid powder of each component is weighed respectively by the formula rate of setting, then respectively by the further powder of the solid powder of each componentIt is broken, finally each component after crushing is uniformly mixed again.
Above-mentioned broad spectrum type heavy-metal contaminated soil stabilization agent, wherein, described medicament, the solid powder of its each componentMaterial is further crushed to the mesh of particle diameter 200.That is, reagent combination ratio is adjusted according to heavy metal pollution of soil type first, and passed throughLaboratory lab scale determines end formulation；Then each component, and consolidating each component respectively are weighed respectively by the formula rate of settingBody powder is crushed to 200 mesh or so in mechanical crusher；The last component after all kinds of crushing is placed in agitator again is stirredUniformly, and packed for standby use is carried out.
Above-mentioned broad spectrum type heavy-metal contaminated soil stabilization agent, wherein, described medicament, counterweight first when in useMetallic pollution soil carries out necessary quenched pretreatment, adjusts the physicochemical properties such as moisture content, pH value and the viscosity of soil；Throw againAdd stabilization agent into contaminated soil and be well mixed, finally adjust soil moisture content, then conserved.
Above-mentioned broad spectrum type heavy-metal contaminated soil stabilization agent, wherein, described pretreatment, comprising：As neededThe quality of the heavy-metal contaminated soil of processing, the quick lime or dry wood chip for adding 0.5~2.0% mass ratio adjust the aqueous of soilRate.
Above-mentioned broad spectrum type heavy-metal contaminated soil stabilization agent, wherein, described medicament, its dosage is located with needingThe mass ratio of the heavy-metal contaminated soil of reason is 2~6%.
Above-mentioned broad spectrum type heavy-metal contaminated soil stabilization agent, wherein, described medicament, pass through water spray etc. after addingForm adjusts soil moisture content to 25~30%.
Above-mentioned broad spectrum type heavy-metal contaminated soil stabilization agent, wherein, described maintenance, its time is 3~7 days.
Broad spectrum type heavy-metal contaminated soil stabilization agent provided by the invention has advantages below：
(1) broad spectrum activity of target contaminant, there is good stabilisation to a variety of common heavy metal contaminants in soilRepairing effect.
(2) medicament stock is the common raw material of industry, construction material or agricultural fertilizer, cheap and easily-available, nontoxic,It is small to soil adverse effect after addition, have substantially no effect on soil fertility or even soil fertility can be increased.
(3) stabilization agent preparation and use it is simple and convenient, chemical stabilization repairing effect is good, the maintenance after dispensingTime is short.
Embodiment
The embodiment of the present invention is further described below.
Broad spectrum type heavy-metal contaminated soil stabilization agent provided by the invention, include by mass percentage with the following groupPoint：Double superhosphate 20~40%, ferrous sulfate heptahydrate 0~30%, diatomite 0~10%, concave convex rod 0~10%, montmorillonite10~20%, kaolin 5~15%, talcum powder 5~10%, magnalium hydrotalcite 0-10%, bentonite 5~15%.
The Compositional type stabilization agent is mainly made up of clay mineral, phosphate and ferrous salt.Select clay pit ownerIf there is absorption and the stable mechanism of ion exchange of broad spectrum activity feature using it；Further to increase its universality, selectionA variety of clay minerals cheap and easy to get, nontoxic are compounded, include diatomite, concave convex rod, montmorillonite, kaolin,Talcum powder, magnalium hydrotalcite and bentonite etc., there is preferable stabilization effect to heavy metals such as cadmium, lead, copper, nickel, zinc.Phosphoric acidSalt is respectively provided with preferably precipitation stabilization effect to heavy metals such as lead, antimony, cadmium, copper, nickel, zinc, and available phosphorus is have selected in the present inventionContent is higher and same cheap and easy to get and calcium superphosphate with preferable soil fertility is as in Compositional type stabilization agentA kind of main formula composition.Ferrous sulfate has stronger reproducibility, and direct stabilized Cr VI can will be difficult in soilEither quinquevalence antimony, which is reduced into, facilitates stabilized trivalent chromium or trivalent antimony, and this kind of heavy metal in soil can be helped to realize stabilizationChange；Simultaneously for arsenic etc., the heavy metal of coprecipitation reaction can occurs in some with molysite, and ferrous sulfate equally has certain stabilizationChange effect, therefore also select ferrous sulfate heptahydrate as a kind of formula components in formula.
Medicament in the preparation, weighs the solid powder of each component respectively by the formula rate of setting first, then respectively willThe solid powder of each component is further crushed to the mesh of particle diameter 200, is finally again uniformly mixed each component after crushing.That is,Reagent combination ratio is adjusted according to heavy metal pollution of soil type first, and end formulation is determined by laboratory lab scale；ThenEach component is weighed respectively by the formula rate of setting, and is respectively crushed to the solid powder of each component in mechanical crusher200 mesh or so；The last component after all kinds of crushing is placed in agitator again stirs, and carries out packed for standby use.
Heavy metal contaminated soil carries out necessary quenched pretreatment to medicament first when in use, adjusts the aqueous of soilThe physicochemical properties such as rate, pH value and viscosity；Pretreatment includes the quality of the heavy-metal contaminated soil handled as needed, addsThe moisture content of the quick lime of 0.5~2.0% mass ratio or dry wood chip regulation soil.Stabilization agent is added again into contaminated soilAnd be well mixed, added amount of chemical is 2~6% with needing the mass ratio of heavy-metal contaminated soil to be processed.Finally adjust soilMoisture content, pass through the form such as spray water after adding of agent and adjust soil moisture content to 25~30%.Then conserved, curing timeFor 3~7 days.
Specifically, broad spectrum type heavy-metal contaminated soil stabilization agent provided by the invention, specifically used method are as follows：
(1) necessary quenched pretreatment is carried out to the heavy-metal contaminated soil excavated first, by adding 0.5-2.0%The quick lime of mass ratio or dry wood chip and be sufficiently mixed the mode of stirring with contaminated soil adjust the moisture content of soil,The physicochemical property such as pH value and viscosity.Quick lime or dry wood chip also have certain to heavy metals such as the mercury in contaminated soil, zincStabilization processes effect.
(2) small-scale experiment is stabilized by heavy-metal contaminated soil and determines that the specific of stabilization agent adds ratio, according toContaminated soil amount calculate and weigh respective amount stabilization agent it is quantitative add into polluted soil, and mixed with special-purpose machineryConjunction stirs.The addition mass ratio of general stabilization agent is 2~6%.
(3) moisture content is adjusted by forms such as water sprays while stabilization agent is added to contaminated soil side, or steadyDetermine by adjusting soil moisture content to forms such as soil heap body waterings after the completion of chemical drug agent is added, to ensure stabilization agent and soilTarget contaminant has a good reaction environment in earth.Soil moisture content is adjusted to 25~30% or so, with mixed soilHeap moistens but still shaping is advisable.
(4) soil after above-mentioned processing will be completed to conserve 3 to 7 days, sampling analysis stabilizes repairing effect.
Broad spectrum type heavy-metal contaminated soil stabilization agent provided by the invention is done further with reference to embodimentDescription.
Embodiment 1.
Certain is by heavy metal lead and antimony pollution soil, and the wherein concentration of lead is in 1000mg/kg or so, and the concentration of antimony is in 20mg/Kg or so.The average leaching concentration of antimony and lead (leaching of nitric acid-sulfuric acid method) is respectively 0.056mg/ in contaminated soil before repair processL and 0.012mg/L, after processing to be repaired the reparation target of heavy metal in soil leaching concentration be respectively 0.01mg/L and0.005mg/L.Repair process is carried out to above-mentioned heavy-metal contaminated soil using dystopy Stabilization Remediation Technology, according to soil stabilizationChange the result for repairing lab scale, the formula rate of the stabilization agent of use is as follows：Double superhosphate 25%, ferrous sulfate heptahydrate25%, montmorillonite 15%, kaolin 10%, talcum powder 10%, bentonite 15%.
Stabilize quick lime when repairing first by 2% mass ratio and quenched pretreatment, Ran Houxiang are carried out to contaminated soilThe stabilization agent of 4% mass ratio is uniformly added in contaminated soil and is stirred using mechanical agitation facility, then it is equal to mixingSprinkled water after even in soil and adjust soil moisture content to 25% or so, finally conserved 5 days.Conserve after terminating through detection, Polluted SoilThe leaching concentration of lead is respectively less than 0.0006mg/L in earth, and the leaching concentration of antimony is respectively less than 0.0037mg/L, meets that repairing target wantsAsk.
Broad spectrum type heavy-metal contaminated soil stabilization agent provided by the invention, it is that one kind is cheap and easy to get, safe and reliable, makesWith it is convenient, can carry out the effective broad spectrum type heavy-metal contaminated soil stabilization chemical drug for stabilizing reparation for various heavy pollutionAgent, there is good stabilisation repairing effect to a variety of common heavy metal contaminants in soil, raw material is cheap and easily-available, nontoxic nothingEvil, it is small to soil adverse effect after addition, have substantially no effect on soil fertility or even soil fertility, chemical stabilization reparation can be increasedEffect is good, and the curing time after dispensing is short.
Although present disclosure is discussed in detail by above preferred embodiment, but it should be appreciated that above-mentionedDescription is not considered as limitation of the present invention.After those skilled in the art have read the above, for the present invention'sA variety of modifications and substitutions all will be apparent.Therefore, protection scope of the present invention should be limited to the appended claims.