A kind of farmland pollution soil heavy metal passivant and its preparation and applicationTechnical field
Technical field of the invention for heavy metal pollution soil remediation, more particularly to a kind of farmland pollution heavy metal-polluted soil are bluntThe method of preparation and use of agent.
Background technology
Because atmospheric sedimentation, sewage irrigation, medicine fertilizer are excessively used, the pollutant containing heavy metal enters agriculture by all meansField, farmland soil heavy metals are caused to pollute getting worse.Because heavy metal can not be degraded by microorganisms, it is difficult to eliminate, it is in soilMurder by poisoning will be produced to soil-plant system to a certain extent by being accumulated in earth, cause assessing index, crop yield and productMatter reduces, and deteriorates hydrological environment, and as the phenomenon amplified step by step is presented in food chain, and then jeopardize health.On southern groundArea, acid rain can increase dissolution of the heavy metal from soil, increase the validity of heavy metal.
Cultivated area about 2,000 ten thousand hm of the current China by heavy metal pollutions such as cadmium, mercury, arsenic, lead2.Account for total area under cultivation20%, the whole nation every year because of heavy metal pollution and the grain of the underproduction more than 10,000,000 t, the grain by heavy metal pollution is annualReach 12,000,000 t.Heavy metal pollution can influence crop yield and quality, and can be detrimental to health by food chain.CloselyNian Lai, Hunan rice heavy metals exceeding standard event, causes Hunan rice unsalable, and rice production enterprise operation is difficult.
At present, countries in the world mainly include physics, chemistry, biotechnology to farmland soil heavy metals pollution remediation technologyDeng.Peripheral doses can efficiently remove removing heavy metals, but quantities is big, cost is high, be not suitable for large area soil pollution reparation.Chemistry is repaiiedInclude chemical leaching and chemical property again to improve etc., chemical leaching complex procedures, soil texture and physicochemical property are destroyed it is serious,It is also easy to produce secondary pollution；And chemical property improvement then mainly adds organic matter, passivator etc. into soil, the life of heavy metal is reducedThing validity, this method economy is easy to operate, has been widely applied at present, but the stability of regulation effect and secondary pollutionThe problem of do not solved effectively yet.Biological prosthetic mainly to include phytoremediation and microorganism remediation etc., biological prosthetic effect is steadyFixed, reliable, non-secondary pollution, but generally repairing efficiency is long, efficiency is low, is also not suitable for serious pollution soil.
Heavy metal has in soil：It is exchangeable species, carbonate combine state, iron and manganese oxides reference state, organically combine state, residual5 kinds of forms of slag state, in general its Phyto-availability taper off trend.Chemical passivation recovery technique, by heavy metal-pollutedAddition passivator makes each occurrence patterns of the heavy metal in soil change in dye soil, and main purpose is by giving birth to by heavy metalThe high exchangeable species of thing validity and carbonate combine state convert to the low organically combine state of biological effectiveness and residual form, reduceIts biological effectiveness is one of effective way for administering heavy-metal contaminated soil, and the technology has processing time is short, economyInexpensively, the advantages that applied widely.
The content of the invention
It is an object of the invention to provide a kind of farmland pollution soil heavy metal passivant and its preparation and application, soilThe physical-chemical reactions such as absorption, complexing and co-precipitation occur between heavy metal and the passivator in earth to adjust and change a huge sum of moneyBelong to the existing forms in soil, reduce the biological effectiveness of heavy metal, and then reduce the biology such as heavy metal on plants and human bodyThe toxicity of acceptor, reach the purpose of repairing polluted soil.
To achieve the above object, the present invention provides following technical scheme：
A kind of farmland pollution soil heavy metal passivant, calcium oxide 20%-50%, sulfide 3%-10%, ferrous salt 3%-15%, vegetationGrey 5%-10%, volcanic rock 5%-10%, natural silicate clay mineral 10%-30%, nanometer hydroxyapatite 15%-30%.
As the further scheme of the present invention, described calcium oxide is the calcium oxide of active ingredient 90%.
As the further scheme of the present invention, described sulfide is the sulfide of active ingredient 60%.
As the further scheme of the present invention, described ferrous salt is the ferrous salt of active ingredient 85%.
As the further scheme of the present invention, described natural silicate clay mineral is the natural silicon of active ingredient 70%Silicate clay mineral, from the one or more in kandite, smectite, vermiculite, illite, sepiolite, particle diameter 60-100 mesh.
It is quick by nitrate and hydroxy acid in-situ oxidation as the further scheme of the present invention, described nanometer hydroxyapatiteSynthesis, 20-30 DEG C of oxidizing temperature.
The present invention farmland with heavy metal be passivated concentrate, calcium oxide, sulfide, ferrous salt heavy metal passivation mechanisms withBased on chemical precipitation.Silicate clay mineral particle diameter is 60-100 mesh, because it has larger specific surface area and pore volume, counterweightThe passivation mechanisms of metal with adsorb with surface complexation based on.Volcanic mud has very strong suction-operated, and the main component of plant ash isCarbonate, carbanion are easily combined with heavy metal ion, by heavy metal precipitation, nanometer hydroxyapatite have it is stronger fromSub- exchange capacity, the calcium ion on surface are easy to by Cd2+、Pb2+、Hg2+Deng toxic heavy metal ion exchange, and displacement canComplete within a short period of time.Therefore the passivator effectively can play passivation to the heavy metal ion in soil, reach quickThe effect of rehabilitating soil.
Present invention also offers the preparation method of the farmland pollution soil heavy metal passivant, step are as follows：(1) weighThe natural silicate clay mineral of prescription quality percentage, crush, it is standby that ball milling is screened to fineness 60-100 mesh；(2) nitrate1 is pressed with hydroxy acid:1 mass ratio is mixed, and is placed in reactor, and temperature is kept for 20-30 DEG C react 1 hour, is filtered after reaction, and spendIon water washing, 80 DEG C of sediment dry 2-3 hours, obtain nanometer hydroxyapatite；（3）Weigh the oxidation of prescription quality percentageCalcium, sulfide, ferrous salt, plant ash, volcanic mud, it is well mixed, does with natural silicate clay mineral, nanometer hydroxyapatiteDry 24 hours, it is sealed.
As the further scheme of the present invention, drying temperature is 40-50 DEG C.
Farmland pollution soil heavy metal passivant of the present invention is used to reduce heavy metals in farmland content, repairs Polluted SoilEarth.
As the further scheme of the present invention, application method comprises the following steps：（1）Topsoil soils monitor：By topsoil soilPave flat post-sampling of earth carries out Speciation Analysis of Heavy Metals；
（2）Topsoil soils pre-process：Physiochemical properties of soil is adjusted, regulation soil moisture content is 20-30%, soda acidSpend for 6-8, reach the use standard of heavy metal deactivator.
（3）Heavy metal deactivator is applied：Before agro-farming or after crop harvesting, by the way of manually adding, with 2-5t/ musIn agricultural land soil surface applied passivator, agricultural land soil is crushed using rotary cultivator, soil and passivator is admixed uniformly,Heavy metal-polluted soil is reacted with passivator, and the reaction time is 5 days, and ground grading reaches the requirement of arable land plantation, and passivator is everyYear applies 1-2 times.
（4）Land reclamation：Before reclaiming, the fertility of soil is detected, nursed one's health by applying Organic Manure on Soil,Reclaim and select the variety of crops of local general planting.
（5）Effect monitoring：After proportion of crop planting, plot is selected to be tracked monitoring, to eating part after crops harvestingIt is monitored, is contrasted with expected target of repairing.
As the further scheme of the present invention, step（3）The rotary cultivator used is tilling depth up to 20~25 centimetres of heavy typeHorizontal shaft type rotary cultivator.
Compared with prior art, the beneficial effects of the invention are as follows：
1st, heavy metal deactivator processing time is short of the present invention, it is quick, it is strong to soil remediation ability, repair the medicament time than conventionalShorten half, 1-2 days curing times.
2nd, heavy metal deactivator recovery technique of the present invention, is not take up ploughing, and does not influence agricultural production and income, and costIt is low, effect on environment is small, does not destroy soil environment, be especially suitable for for handling farmland soil of the large area by heavy metal pollutionEarth.
3rd, heavy metal deactivator of the present invention overcomes single to having passivation every, the various heavy such as lead, copper, zincOrganic passivation agent or inorganic passivant repairing effect are undesirable, only have the shortcomings that passivation to a certain or several heavy metal species.
4th, heavy metal deactivator of the present invention is mainly made up of alkaline material, is widely used in southern acid heavy metal pollution agricultureRepair in field.
5th, heavy metal deactivator of the present invention is using raw material that is common, easily obtaining, relatively cheap, suitable popularization.
Embodiment
Embodiment 1
A kind of farmland pollution soil heavy metal passivant, is made up of following each component and its percentage by weight：Active ingredient 90%Calcium oxide 40%, the sulfide 10% of active ingredient 60%, the ferrous salt 15% of active ingredient 85%, plant ash 5%, volcanic mud 5%, haveImitate the natural silicate clay mineral of composition 70%（Kandite and smectite）10%, nanometer hydroxyapatite 15%.
Preparation method：(1) kandite and the smectite mixing of the active ingredient 70% of prescription quality percentage are weighedThing, crush, it is standby that ball milling is screened to fineness 60-100 mesh；(2) nitrate and hydroxy acid press 1:1 mass ratio mixes, and is placed in reactorIn, temperature is kept for 20 DEG C react 1 hour, is filtered after reaction, and is washed with deionized, and the drying 2 hours of 80 DEG C of sediment, must be receivedRice hydroxyapatite；（3）Calcium oxide, sulfide, ferrous salt, plant ash, the volcanic mud of prescription quality percentage are weighed, it is and naturalSilicate clay mineral, nanometer hydroxyapatite are well mixed, and are dried 24 hours, are sealed.
Embodiment 2
A kind of farmland pollution soil heavy metal passivant, is made up of following each component and its percentage by weight：Active ingredient 90%Calcium oxide 20%, the sulfide 8% of active ingredient 60%, the ferrous salt 12% of active ingredient 85%, plant ash 10%, volcanic mud 10%, haveImitate the natural silicate clay mineral of composition 70%（Vermiculite, illite and sepiolite mixture）20%, nanometer hydroxyapatite20%。
Preparation method：(1) vermiculite, illite and the sepiolite mixing of the active ingredient 70% of prescription quality percentage are weighedThing, crush, it is standby that ball milling is screened to fineness 60-100 mesh；(2) nitrate and hydroxy acid press 1:1 mass ratio mixes, and is placed in reactorIn, temperature is kept for 30 DEG C react 1 hour, is filtered after reaction, and is washed with deionized, and the drying 3 hours of 80 DEG C of sediment, must be receivedRice hydroxyapatite；（3）Calcium oxide, sulfide, ferrous salt, plant ash, the volcanic mud of prescription quality percentage are weighed, it is and naturalSilicate clay mineral, nanometer hydroxyapatite are well mixed, and are dried 24 hours, are sealed.
Embodiment 3
A kind of farmland pollution soil heavy metal passivant, is made up of following each component and its percentage by weight：Active ingredient 90%Calcium oxide 20%, the sulfide 5% of active ingredient 60%, the ferrous salt 15% of active ingredient 85%, plant ash 7%, volcanic mud 8%, effectivelyThe natural silicate clay mineral of composition 70%（Kandite, smectite, vermiculite, illite, the mixture of sepiolite）30%, nanometer hydroxyapatite 15%.
Preparation method：(1) the natural silicate clay mineral of the active ingredient 70% of prescription quality percentage is weighed（KaoliniteStone race mineral, smectite, vermiculite, illite, the mixture of sepiolite）, crush, it is standby that ball milling is screened to fineness 60-100 mesh；(2) nitrate and hydroxy acid press 1:1 mass ratio is mixed, and is placed in reactor, and temperature is kept for 25 DEG C react 1 hour, is filtered after reaction,And be washed with deionized, the drying 2.5 hours of 80 DEG C of sediment, obtain nanometer hydroxyapatite；（3）Weigh prescription quality percentageCalcium oxide, sulfide, ferrous salt, plant ash, volcanic mud, mixed with natural silicate clay mineral, nanometer hydroxyapatiteUniformly, dry 24 hours, be sealed.
Embodiment 4
A kind of farmland pollution soil heavy metal passivant, is made up of following each component and its percentage by weight：Active ingredient 90%Calcium oxide 30%, the sulfide 3% of active ingredient 60%, the ferrous salt 3% of active ingredient 85%, plant ash 7%, volcanic mud 7%, effectivelyThe natural silicate clay mineral of composition 70%（The mixture of kandite, sepiolite）20%, nanometer hydroxyapatite30%。
Preparation method：(1) the natural silicate clay mineral of the active ingredient 70% of prescription quality percentage is weighed（KaoliniteStone race mineral, the mixture of sepiolite）, crush, it is standby that ball milling is screened to fineness 60-100 mesh；(2) nitrate and hydroxy acid press 1:1Mass ratio is mixed, and is placed in reactor, and temperature is kept for 25 DEG C react 1 hour, is filtered after reaction, and is washed with deionized, and is sunkThe drying 2.5 hours of 80 DEG C of starch, obtains nanometer hydroxyapatite；（3）Weigh the calcium oxide, sulfide, Asia of prescription quality percentageMolysite, plant ash, volcanic mud, it is well mixed, dries 24 hours with natural silicate clay mineral, nanometer hydroxyapatite, it is closeEnvelope preserves.
The application method and test data of farmland pollution soil heavy metal passivant prepared by above-described embodiment：（1）PloughLayer soil monitoring：Pave flat post-sampling of topsoil soils is subjected to Speciation Analysis of Heavy Metals, it is as a result as follows：
（2）Topsoil soils pre-process：Physiochemical properties of soil is adjusted, regulation soil moisture content is 20-30%, soda acidSpend for 6-8, reach the use standard of heavy metal deactivator；（3）Heavy metal deactivator is applied：Before agro-farming or after crop harvesting,By the way of manually adding, with 3t/ mus in agricultural land soil surface applied passivator, using tilling depth up to 20~25 centimetres of heavy typesHorizontal shaft type rotary cultivator crushes to agricultural land soil, soil and passivator is admixed uniform, heavy metal-polluted soil and passivator progressReaction, reaction time are 5 days, ground grading, reach the requirement of arable land plantation, for the low Polluted Soil of heavy metal biological usabilityEarth applies passivator progress soil remediation once a year before spring ploughing may be selected, for the higher pollution agriculture of heavy metal biological usabilityAnnual administration twice, ensures the passivation effect of heavy metal-polluted soil before spring ploughing and autumn ploughing may be selected in field；（4）Land reclamation：Heavy metalAfter passivator addition, reclaiming for contaminated land can be carried out, the variety of crops of local general planting may be selected in crops.ReclaimBefore, the soil fertility factors of soil should be detected, include the bioavailability of macronutrient, and the micro member of partElement.If soil quality deteriorates, should be by applying organic fertilizer（Farm manure）Etc. being nursed one's health；（5）Effect monitoring：Proportion of crop plantingAfterwards, selection plot is tracked monitoring, and edible part is monitored after crops harvesting, is carried out pair with expected reparation targetThan.
It can be seen that farmland pollution soil heavy metal passivant of the present invention can be by heavy metal by the high exchangeable species of biological effectivenessConverted with carbonate combine state to the low organically combine state of biological effectiveness and residual form, reduce its biological effectiveness, can be effectiveAdminister heavy-metal contaminated soil.After testing, in the paddy of production lead and every content be respectively 0.08mg/KG and 0.01mg/KG, reach《National food safety standard pollutants in food is limited the quantity》（GB 2762-2012）Limit value requirement.
The better embodiment of this patent is explained in detail above, but this patent is not limited to above-mentioned embodiment partyFormula, can also be on the premise of this patent objective not be departed from one skilled in the relevant art's possessed knowledgeMake a variety of changes.