CN103920701A - Method for restoring chromium-polluted soil - Google Patents
Method for restoring chromium-polluted soil Download PDFInfo
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- CN103920701A CN103920701A CN201410168206.5A CN201410168206A CN103920701A CN 103920701 A CN103920701 A CN 103920701A CN 201410168206 A CN201410168206 A CN 201410168206A CN 103920701 A CN103920701 A CN 103920701A
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Abstract
The invention discloses a method for restoring chromium-polluted soil. The method comprises the following steps of crushing the chromium-polluted soil to obtain the grain diameter being less than 10cm; adding the crushed chromium-polluted soil into a reducing agent and water, and uniformly mixing to obtain reduced chromium-polluted soil, wherein the molar ratio of the reducing agent to hexavalent chromium in the chromium-polluted soil is (50-400):1, and the water is 5 to 25 percent by mass of the chromium-polluted soil; adding a stabilizer into the reduced chromium-polluted soil, wherein the stabilizer is 0.1 to 20 percent by mass of the chromium-polluted soil, uniformly stirring the stabilizer and the chromium polluted soil, insulating the air, and humidifying and maintaining the mixture for 1 to 3 days. By adopting the method, the restoring cost is low; the restoring speed is high; the restoring effect is good; the restored soil is leached by adopting a strict HJ/T299 sulfuric acid/nitric acid method, and the concentration of the hexavalent chromium in the leached liquid is lower than the fourth category surface water standard; the secondary pollution can be avoided.
Description
Technical field
The invention belongs to environmental technology field, relate to a kind of restorative procedure of chromium-polluted soil.
Background technology
Soil Cr is polluted mainly from industrial wastewater waste residues such as chrome ore, metal smelt, plating, process hides, pigment and chemical industry.Cr VI toxicity is high, animal migration is strong, thereby easily endangers environment, threat human health.Chromic toxicity is low and almost precipitate completely in neutral and weakly alkaline solution, thereby less to environment and the mankind's harm.Chromium also has a great impact the growth of crops.According to test, in water, containing chromium, when 1ppm, can stimulate plant growth, during 1～10ppm, can make plant growth slow down, during to 100ppm, almost make crop stop growing.In recent years, all having there is serious pollution of chromium event in the ground such as Hunan, Henan, Fujian, causes heavy economic losses and personal injury, caused the leaders' of central and local governments great attention.
The technology of improvement chromium-polluted soil has a variety of, mainly contains stabilisation/curing technology, water-washing technique, phytoremediation technology, electric repairing technique etc.Wherein, water-washing technique is mainly for the higher contaminated soil of sandstone content, and by separation, nontoxic or toxicity reduces the treating capacity of contaminated soil compared with low sandstone, and essence does not reduce the toxicity of soil.Phytoremediation technology can reduce soil Cr content, but can be used for that floristics that chromium-polluted soil repairs is less and its growth is affected by environment large.In addition, phytoremediation technology also exists harvesting long, plant repair time to process the problems such as difficult, thereby the application of the engineering of this technology is less.Electric repairing technique is a kind of emerging technology of repairing chromium contaminated soil, can reduce soil Cr content, but has the shortcomings such as energy consumption is high, uncertain factor is many, and engineering application is also less.
Comparatively speaking, stabilisation/curing technology is the most practical technology of repairing chromium contaminated soil.Although this technology does not reduce soil Cr content, can greatly reduce the toxicity of soil, be controlled in a safe range.In addition, this technology has the advantages such as remediation efficiency is high, cost is low, workable, thereby engineering application is more.In the last few years, stabilisation/curing technology had had new development, had formed chemical stabilization technology.This technology is not used curing agent, thereby less to the increase-volume of soil, and the soil texture after processing is approaching with original soil, stability is better, can recycle.
Summary of the invention
The object of the invention is for the deficiencies in the prior art, propose a kind of restorative procedure of chromium-polluted soil.The method cost is low, efficiency is high, workable, there is good practicality.
The inventive method comprises the following steps:
Step (1). chromium-polluted soil is carried out to break process, obtain the chromium-polluted soil that particle diameter is less than 10cm.
Step (2). the chromium-polluted soil after fragmentation adds reducing agent, water, stirs and obtains the chromium-polluted soil after reduction is processed; In reducing agent and chromium-polluted soil, chromic mol ratio is 50～400:1, and water is 5～25 ﹪ of chromium-polluted soil quality;
Described reducing agent is one or more in iron powder, ferrous salt, sulphurizing salt, many sulphurizing salts, sulphite; Reducing agent can directly join in soil with powder type, or reducing agent can first be dissolved in the water, and with solution form, joins in soil;
Described ferrous salt is ferrous sulfate, ferrous nitrate, frerrous chloride or ferrous carbonate;
The cation of described sulphurizing salt, many sulphurizing salts, sulphite is a kind of in sodium, potassium, magnesium, calcium.
Reducing agent in step (2) can become trivalent chromium by the hexavalent chrome reduction in soil, and chemical equation is as follows:
Trivalent chromium precipitates in neutrality or weakly alkaline environment, generates chromium hydroxide, and its chemical equation is as follows:
3OH
-+Cr
3+→Cr(OH)
3↓ (4)
Trivalent chromium also can precipitate with iron ion, ferric hydroxide colloid reaction, and its chemical equation is as follows:
xCr
3++(1-x)Fe
3++3OH
-→Cr
xFe
1-x(OH)
3↓ (5)
Cr
3++nFe(OH)
x→Cr
3+-[Fe(OH)
x]
n↓ (6)
Step (3). in the chromium-polluted soil after reduction is processed, add stable pharmaceutical, stable pharmaceutical is 0.1～20 ﹪ of chromium-polluted soil quality, after stirring, isolated air, moisture-keeping maintaining 1～3 day.
Described stable pharmaceutical is one or more in magnesia, magnesium hydroxide, magnesium carbonate, calcium oxide, calcium hydroxide, calcium carbonate;
Stable pharmaceutical reduces the animal migration of chromium by modes such as adsorption, chemical precipitations, thereby reduces the toxicity of soil; The effect that regulates soil pH value is also played in adding of stable pharmaceutical, makes the soil after processing be applicable to plant growth.
The present invention compared with prior art, has following beneficial effect:
(1) rehabilitation cost is low; The medicament that the present invention uses is all common industrial chemical, and price is low, wide material sources; The plant equipment relating to mainly contains excavator, soil breaker and mixer; The rehabilitation cost of every side's chromium-polluted soil is lower, if adopt original position repair mode, cost will be lower;
(2) reparation speed is fast; Chemical stabilization technology is to repair one of fastest soil remediation technology; According to the ability to work of soil breaker and mixer, the soil remediation amount of every cover system is 10～50m
3/ h;
(3) repairing effect is good; Soil after reparation, adopts strict HJ/T299 sulfuric acid nitrate method to leach, and in leachate, hexavalent chromium concentration is lower than IV class surface water standard;
(4) do not produce secondary pollution; In whole repair process, do not produce waste water and waste gas, thereby can not cause secondary pollution to surrounding environment.
The specific embodiment
Below in conjunction with embodiment, the invention will be further described.
Embodiment 1
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 400:1 adds 400mol iron powder on one side.Stir after 2min, add 20L water, stir 3min.Then, by 0.1 ﹪ of chromium-polluted soil quality, add 0.1kg magnesia, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.01mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 2
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 8cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 380:1 adds 380mol ferrous sulfate on one side.Stir after 3min, add 5L water, stir 4min.Then, by 1 ﹪ of chromium-polluted soil quality, add 1kg magnesium hydroxide, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.015mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.Embodiment 3
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 350:1 adds 350mol ferrous nitrate on one side.Stir after 5min, add 25L water, stir 5min.Then, by 5 ﹪ of chromium-polluted soil quality, add 5kg calcium oxide, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.01mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 4
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 300:1 adds 300mol frerrous chloride on one side.Stir after 2min, add 20L water, stir 3min.Then, by 6 ﹪ of chromium-polluted soil quality, add 6kg calcium hydroxide, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 2 days, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.01mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.04mg/L after processing.
Embodiment 5
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 250:1 adds 250mol ferrous carbonate on one side.Stir after 2min, add 25L water, stir 3min.Then, by 8 ﹪ of chromium-polluted soil quality, add 8kg calcium carbonate, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.015mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.05mg/L after processing.Embodiment 6
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 240:1 adds 240mol vulcanized sodium on one side.Stir after 4min, add 15L water, stir 3min.Then, by 4 ﹪ of chromium-polluted soil quality, add 4kg magnesia and add 3kg magnesium hydroxide by 3 ﹪ of chromium-polluted soil quality, stir 5min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 3 days, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.017mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.05mg/L after processing.
Embodiment 7
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 220:1 adds 220mol potassium sulfide on one side.Stir after 2min, add 20L water, stir 3min.Then, by 3 ﹪ of chromium-polluted soil quality, add 3kg magnesium carbonate and add 3kg calcium oxide by 3 ﹪ of chromium-polluted soil quality, stir 5min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 3 days, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.011mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 8
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 200:1 adds 200mol magnesium sulfide on one side.Stir after 2min, add 22L water, stir 3min.Then, by 4 ﹪ of chromium-polluted soil quality, add 4kg calcium hydroxide and add 4kg calcium carbonate by 4 ﹪ of chromium-polluted soil quality, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.01mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 9
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 180:1 adds 180mol calcium sulfide on one side.Stir after 2min, add 25L water, stir 3min.Then, by 2 ﹪ (2kg) of chromium-polluted soil quality, add magnesia and add 2kg magnesium hydroxide and add 2kg magnesium carbonate by 2 ﹪ of chromium-polluted soil quality by 2 ﹪ of chromium-polluted soil quality, stirring 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 2 days, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.02mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.05mg/L after processing.
Embodiment 10
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 180:1 adds 180mol sodium polysulfide on one side.Stir after 2min, add 10L water, stir 3min.Then, by 6 ﹪ of chromium-polluted soil quality, add 6kg magnesia, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.01mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 11
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 160:1 adds 160mol potassium polysulfide on one side.Stir after 2min, add 15L water, stir 3min.Then, by 6 ﹪ of chromium-polluted soil quality, add 6kg magnesia, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 3 days, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.01mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 12
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 140:1 adds the many magnesium sulfides of 140mol on one side.Stir after 2min, add 20L water, stir 3min.Then, by 4 ﹪ of chromium-polluted soil quality, add 4kg magnesia and add 4kg magnesium carbonate by 4 ﹪ of chromium-polluted soil quality, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 3 days, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.02mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 13
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 120:1 adds 120mol calcium polysulfide on one side.Stir after 2min, add 25L water, stir 3min.Then, by 3 ﹪ of chromium-polluted soil quality, add 3kg magnesia and add 4kg magnesium carbonate by 4 ﹪ of chromium-polluted soil quality, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.01mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 14
The chromium-polluted soil that to take hexavalent chromium concentration that 100kg is dry be 0.01mol/kg, is controlled at soil block particle diameter in 6cm by roll extrusion fragmentation.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 100:1 adds 100mol sodium sulfite on one side.Stir after 2min, add 24L water, stir 3min.Then, by 6 ﹪ of chromium-polluted soil quality, add 5 ﹪ of 6kg magnesia and chromium-polluted soil quality to add 5kg calcium carbonate, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 2 days, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.02mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.05mg/L after processing.
Embodiment 15
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 80:1 adds 80mol potassium sulfite on one side.Stir after 2min, add 25L water, stir 3min.Then, by 6 ﹪ of chromium-polluted soil quality, add 6kg magnesia, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.01mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 16
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 60:1 adds 60mol magnesium sulfite on one side.Stir after 2min, add 25L water, stir 3min.Then, by 8 ﹪ of chromium-polluted soil quality, add 8kg magnesia, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.01mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 17
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 200:1 adds 200mol calcium sulfite and is that 150:1 adds 150mol magnesium sulfite by reducing agent and chromic mol ratio on one side.Stir after 2min, add 20L water, stir 3min.Then, by 4 ﹪ of chromium-polluted soil quality, add 4kg calcium carbonate and add 2kg magnesia by 2 ﹪ of chromium-polluted soil quality, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 3 days, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.02mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 18
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 200:1 adds 200mol iron powder and is that 100:1 adds 100mol calcium sulfite by reducing agent and chromic mol ratio on one side.Stir after 2min, add 20L water, stir 3min.Then, by 12 ﹪ of chromium-polluted soil quality, add 12kg magnesia, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.01mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 19
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 50:1 adds 50mol iron powder on one side.Stir after 2min, add 20L water, stir 3min.Then, by 10 ﹪ of chromium-polluted soil quality, add 10kg calcium carbonate, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 2 days, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.012mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.05mg/L after processing.
Embodiment 20
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, be 150:1 add 150mol ferrous sulfate, by reducing agent and chromic mol ratio be 150:1 add 150mol iron powder, by reducing agent and chromic mol ratio be 50:1 add 50mol enter ferrous nitrate by reducing agent and chromic mol ratio on one side.Stir after 2min, add 20L water, stir 3min.Then, by 20 ﹪ of chromium-polluted soil quality, add 20kg calcium carbonate, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.01mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 21
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, be 150:1 add 150mol ferrous sulfate, by reducing agent and chromic mol ratio be 150:1 add 150mol iron powder, by reducing agent and chromic mol ratio be 50:1 add 50mol ferrous nitrate by reducing agent and chromic mol ratio on one side.Wherein, ferrous nitrate dissolves in to join after 20L water again and in soil, stirs 3min.Then, by 18 ﹪ of chromium-polluted soil quality, add 18kg calcium carbonate, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.01mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Embodiment 22
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 300:1 adds 300mol frerrous chloride on one side.Wherein, frerrous chloride joins in soil after being dissolved in 20L water again.Stir after 5min, by 10 ﹪ of chromium-polluted soil quality, add 10kg calcium hydroxide, stir 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.01mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.04mg/L after processing.
Embodiment 23
Take the chromium-polluted soil that 100kg hexavalent chromium concentration is 0.01mol/kg, by roll extrusion fragmentation, soil block particle diameter is controlled in 6cm.Soil after fragmentation is packed in mixer, stir on one side, by reducing agent and chromic mol ratio, be that 250:1 adds 250mol ferrous carbonate on one side.Wherein, ferrous carbonate joins in soil after dissolving in 25L water again, stirs after 8min, by 14 ﹪ of chromium-polluted soil quality, adds 14kg calcium carbonate, stirs 3min.Soil after processing is in a huddle, with waterproof cloth, hide.After maintenance 1 day, to the soil sampling after processing, do Leaching and detect, adopt HJ/T299 sulfuric acid nitrate method to leach.Testing result shows: the 20mg/L of Cr VI leaching concentration from processing drops to the 0.014mg/L after processing; The 25mg/L of total chromium leaching concentration from processing drops to the 0.06mg/L after processing.
Although openly preferred embodiment of the present invention; but they are not for limiting the present invention; any those skilled in the art; in not departing from the scope of the present invention; various changes can be made and adjust, so being as the criterion of should being defined with the application's claim protection domain of protection scope of the present invention.
Claims (6)
1. a restorative procedure for chromium-polluted soil, is characterized in that the method comprises the following steps:
Step (1). chromium-polluted soil is carried out to break process, obtain the chromium-polluted soil that particle diameter is less than 10cm;
Step (2). the chromium-polluted soil after fragmentation adds reducing agent, water, stirs and obtains the chromium-polluted soil after reduction is processed; In reducing agent and chromium-polluted soil, chromic mol ratio is 50～400:1, and water is 5～25 ﹪ of chromium-polluted soil quality;
Step (3). in the chromium-polluted soil after reduction is processed, add stable pharmaceutical, stable pharmaceutical is 0.1～20 ﹪ of chromium-polluted soil quality, after stirring, isolated air, moisture-keeping maintaining 1～3 day.
2. the restorative procedure of a kind of chromium-polluted soil as claimed in claim 1, is characterized in that reducing agent is one or more in iron powder, ferrous salt, sulphurizing salt, many sulphurizing salts, sulphite.
3. the restorative procedure of a kind of chromium-polluted soil as claimed in claim 1, is characterized in that stable pharmaceutical is one or more in magnesia, magnesium hydroxide, magnesium carbonate, calcium oxide, calcium hydroxide, calcium carbonate.
4. the restorative procedure of a kind of chromium-polluted soil as claimed in claim 1, is characterized in that reducing agent is that reducing agent directly joins in soil with powder type, or reducing agent is first dissolved in the water, and with solution form, joins in soil.
5. the restorative procedure of a kind of chromium-polluted soil as claimed in claim 2, is characterized in that ferrous salt is ferrous sulfate, ferrous nitrate, frerrous chloride or ferrous carbonate.
6. the restorative procedure of a kind of chromium-polluted soil as claimed in claim 2, the cation that it is characterized in that sulphurizing salt, many sulphurizing salts, sulphite is a kind of in sodium, potassium, magnesium, calcium.
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|---|---|---|---|
| CN201410168206.5A CN103920701B (en) | 2014-04-24 | 2014-04-24 | A kind of restorative procedure of chromium-polluted soil |
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| CN106984644A (en) * | 2017-05-10 | 2017-07-28 | 青岛科技大学 | The preparation of calcium polysulfide renovation agent and its application in pollution law |
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| CN109954745A (en) * | 2017-12-26 | 2019-07-02 | 光大绿色环保管理（深圳）有限公司 | It is a kind of for handling the reagent and method of heavy metal contaminants in flying dust |
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| CN104307868A (en) * | 2014-09-16 | 2015-01-28 | 青海省环境科学研究设计院 | Method for removing hexavalent chromium from polluted soil |
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| CN104841693A (en) * | 2015-05-29 | 2015-08-19 | 北京大学 | Hexavalent chromium contaminated soil in-situ remediation method |
| CN104841693B (en) * | 2015-05-29 | 2017-05-31 | 北京大学 | A kind of hexavalent chromium polluted soil in-situ restorative procedure |
| CN105215051A (en) * | 2015-11-10 | 2016-01-06 | 辽宁石油化工大学 | A kind of reduction-stabilisation two-period form restorative procedure of chromium-polluted soil |
| CN105215051B (en) * | 2015-11-10 | 2018-06-26 | 辽宁石油化工大学 | A kind of reduction of chromium-polluted soil-stabilisation two-period form restorative procedure |
| CN105499262A (en) * | 2016-01-22 | 2016-04-20 | 户园凌 | Alkaline chromium-contaminated soil solidifying, stabilizing and repairing method |
| CN105499262B (en) * | 2016-01-22 | 2018-08-31 | 户园凌 | A kind of basic chromium Polluted Soil consolidates steady restorative procedure |
| CN105694894A (en) * | 2016-03-18 | 2016-06-22 | 济南大学 | Preparation method and application of hexavalent chromium contaminated soil conditioner |
| CN105880277A (en) * | 2016-06-27 | 2016-08-24 | 安徽金联地矿科技有限公司 | Chromium-contaminated soil remediation method |
| CN106623402A (en) * | 2016-12-07 | 2017-05-10 | 云南大地绿坤环保科技有限公司 | Method for remedying chromium-polluted soil by inorganic hydrazine |
| CN106391695A (en) * | 2016-12-07 | 2017-02-15 | 云南大地绿坤环保科技有限公司 | Remediation method for chromium-contaminated soil |
| CN106825032A (en) * | 2017-03-22 | 2017-06-13 | 中国石油大学(华东) | Chromium-polluted soil humic acid is segmented clean and effective prosthetic device |
| CN106984644A (en) * | 2017-05-10 | 2017-07-28 | 青岛科技大学 | The preparation of calcium polysulfide renovation agent and its application in pollution law |
| CN107486468A (en) * | 2017-08-15 | 2017-12-19 | 北京高能时代环境技术股份有限公司 | One kind is used for hexavalent chromium polluted soil heterotopic repairing method of microorganism |
| CN109954745A (en) * | 2017-12-26 | 2019-07-02 | 光大绿色环保管理（深圳）有限公司 | It is a kind of for handling the reagent and method of heavy metal contaminants in flying dust |
| CN108793909A (en) * | 2018-08-15 | 2018-11-13 | 程钰 | A kind of aluminium smelting waste residue special curing agent and its preparation method and application method |
| CN109985898A (en) * | 2019-04-01 | 2019-07-09 | 常熟理工学院 | A kind of restorative procedure of hexavalent chromium polluted arable soil |
| CN110076188A (en) * | 2019-04-03 | 2019-08-02 | 北京高能时代环境技术股份有限公司 | A kind of long-acting reparation medicament and restorative procedure of severe chromium-polluted soil |
| CN110079323A (en) * | 2019-04-30 | 2019-08-02 | 湖南省和清环境科技有限公司 | A kind of arsenic, nickel combined pollution place soil remediation stabilizer and its processing method |
| CN111185474A (en) * | 2020-01-16 | 2020-05-22 | 招商局生态环保科技有限公司 | Chromium-contaminated soil in-situ remediation composite reagent and use method thereof |
| CN111607401A (en) * | 2020-05-27 | 2020-09-01 | 重庆大学 | Repairing agent for in-situ repairing hexavalent chromium pollution and preparation method and application thereof |
| CN111659726A (en) * | 2020-06-29 | 2020-09-15 | 西南大学 | Ectopic remediation method for chromium-contaminated soil |
| CN112916607A (en) * | 2021-01-26 | 2021-06-08 | 广东中科碧城环境技术有限公司 | Stabilization restoration method for heavy metal contaminated soil |
| CN114314898A (en) * | 2021-12-06 | 2022-04-12 | 北京首钢吉泰安新材料有限公司 | Method for reducing hexavalent chromium in iron-chromium-aluminum annealing cooling wastewater |
| CN114570758A (en) * | 2022-02-24 | 2022-06-03 | 河北华勘地质勘查有限公司 | Method for repairing hexavalent chromium contaminated soil and repairing agent |
| CN116174464A (en) * | 2023-03-06 | 2023-05-30 | 核工业北京化工冶金研究院 | Secondary restoration stable solidification method for 'yellowing' chromium-polluted soil |
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