CN108723074B - Method for stabilizing and repairing heavy metal contaminated soil by using sludge-based carbon ash - Google Patents
Method for stabilizing and repairing heavy metal contaminated soil by using sludge-based carbon ash Download PDFInfo
- Publication number
- CN108723074B CN108723074B CN201810435816.5A CN201810435816A CN108723074B CN 108723074 B CN108723074 B CN 108723074B CN 201810435816 A CN201810435816 A CN 201810435816A CN 108723074 B CN108723074 B CN 108723074B
- Authority
- CN
- China
- Prior art keywords
- sludge
- heavy metal
- soil
- contaminated soil
- ash
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000010802 sludge Substances 0.000 title claims abstract description 78
- 239000002689 soil Substances 0.000 title claims abstract description 64
- 229910001385 heavy metal Inorganic materials 0.000 title claims abstract description 50
- 238000000034 method Methods 0.000 title claims abstract description 32
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 18
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 18
- 230000000087 stabilizing effect Effects 0.000 title claims abstract description 9
- 239000002245 particle Substances 0.000 claims description 28
- 239000000463 material Substances 0.000 claims description 24
- 238000000227 grinding Methods 0.000 claims description 16
- 238000001816 cooling Methods 0.000 claims description 12
- 230000008439 repair process Effects 0.000 claims description 12
- 239000010865 sewage Substances 0.000 claims description 10
- 238000000498 ball milling Methods 0.000 claims description 9
- 239000007787 solid Substances 0.000 claims description 9
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical group O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 8
- 229910052760 oxygen Inorganic materials 0.000 claims description 8
- 239000001301 oxygen Substances 0.000 claims description 8
- 238000002156 mixing Methods 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 7
- 239000002367 phosphate rock Substances 0.000 claims description 7
- 239000000843 powder Substances 0.000 claims description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 239000003623 enhancer Substances 0.000 claims description 6
- 239000010419 fine particle Substances 0.000 claims description 6
- 238000003756 stirring Methods 0.000 claims description 6
- 229910052581 Si3N4 Inorganic materials 0.000 claims description 4
- 230000032683 aging Effects 0.000 claims description 4
- 238000001035 drying Methods 0.000 claims description 4
- 238000011068 loading method Methods 0.000 claims description 4
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims description 4
- 229910052793 cadmium Inorganic materials 0.000 claims description 3
- 229910052804 chromium Inorganic materials 0.000 claims description 3
- 229910052745 lead Inorganic materials 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 229910052725 zinc Inorganic materials 0.000 claims description 3
- PTFCDOFLOPIGGS-UHFFFAOYSA-N Zinc dication Chemical compound [Zn+2] PTFCDOFLOPIGGS-UHFFFAOYSA-N 0.000 claims description 2
- 229910052802 copper Inorganic materials 0.000 claims description 2
- 238000007873 sieving Methods 0.000 claims description 2
- 239000012744 reinforcing agent Substances 0.000 claims 1
- 238000002161 passivation Methods 0.000 abstract description 12
- 230000000694 effects Effects 0.000 abstract description 7
- 230000008569 process Effects 0.000 abstract description 6
- 230000008901 benefit Effects 0.000 abstract description 4
- 230000007613 environmental effect Effects 0.000 abstract description 3
- 238000010276 construction Methods 0.000 abstract description 2
- 239000002994 raw material Substances 0.000 abstract description 2
- 239000002956 ash Substances 0.000 description 39
- 230000006641 stabilisation Effects 0.000 description 9
- 238000011105 stabilization Methods 0.000 description 9
- 239000002028 Biomass Substances 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 5
- 125000000524 functional group Chemical group 0.000 description 5
- 238000012216 screening Methods 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- YWEUIGNSBFLMFL-UHFFFAOYSA-N diphosphonate Chemical compound O=P(=O)OP(=O)=O YWEUIGNSBFLMFL-UHFFFAOYSA-N 0.000 description 3
- 238000005265 energy consumption Methods 0.000 description 3
- 239000003344 environmental pollutant Substances 0.000 description 3
- 238000002386 leaching Methods 0.000 description 3
- 229910052698 phosphorus Inorganic materials 0.000 description 3
- 239000011574 phosphorus Substances 0.000 description 3
- DLYUQMMRRRQYAE-UHFFFAOYSA-N phosphorus pentoxide Inorganic materials O1P(O2)(=O)OP3(=O)OP1(=O)OP2(=O)O3 DLYUQMMRRRQYAE-UHFFFAOYSA-N 0.000 description 3
- 231100000719 pollutant Toxicity 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 238000005067 remediation Methods 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000003723 Smelting Methods 0.000 description 2
- 239000002154 agricultural waste Substances 0.000 description 2
- 229910052586 apatite Inorganic materials 0.000 description 2
- 238000009412 basement excavation Methods 0.000 description 2
- 230000006399 behavior Effects 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000011065 in-situ storage Methods 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 238000011835 investigation Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000011707 mineral Substances 0.000 description 2
- OJMIONKXNSYLSR-UHFFFAOYSA-N phosphorous acid Chemical compound OP(O)O OJMIONKXNSYLSR-UHFFFAOYSA-N 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 238000000197 pyrolysis Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000012502 risk assessment Methods 0.000 description 2
- 238000012954 risk control Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 238000009736 wetting Methods 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- WQHONKDTTOGZPR-UHFFFAOYSA-N [O-2].[O-2].[Mn+2].[Fe+2] Chemical compound [O-2].[O-2].[Mn+2].[Fe+2] WQHONKDTTOGZPR-UHFFFAOYSA-N 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 230000009418 agronomic effect Effects 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000001010 compromised effect Effects 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000009713 electroplating Methods 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 229910052587 fluorapatite Inorganic materials 0.000 description 1
- 229940077441 fluorapatite Drugs 0.000 description 1
- 239000010881 fly ash Substances 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- VSIIXMUUUJUKCM-UHFFFAOYSA-D pentacalcium;fluoride;triphosphate Chemical group [F-].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O VSIIXMUUUJUKCM-UHFFFAOYSA-D 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 239000012265 solid product Substances 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C1/00—Reclamation of contaminated soil
- B09C1/08—Reclamation of contaminated soil chemically
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Soil Sciences (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
The invention discloses a method for stabilizing and repairing heavy metal contaminated soil by utilizing sludge-based carbon ash. The method has the advantages of simplicity, practicality, wide raw material source, low price, green and energy-saving process, strong universality, obvious and long-acting passivation effect, no high requirement on equipment in the construction link, contribution to large-scale popularization and obvious economic, social and environmental benefits.
Description
Technical Field
The invention relates to a method for stabilizing and repairing heavy metal contaminated soil by using sludge-based carbon ash, belonging to the technical field of soil improvement and repair.
Background
The situation of heavy metal pollution of soil in China is severe, and the development of prevention, control and repair work of heavy metal pollution of soil becomes a significant practical requirement of China. The method for repairing heavy metals in soil comprises the following steps: 1) the toxicity, the bioavailability and the migration transformation capacity of the heavy metal are reduced by changing the occurrence state or the combination mode of the heavy metal in the soil, so that the ecological and health risks of the heavy metal are reduced (an acceptable level is reached); 2) the risk management is realized by cutting off or blocking the exposure route or mode of the compound and a receptor; 3) the heavy metals are removed from the soil by various technical means or methods, thereby completing the restoration and purification of the soil. The specific technology comprises the following steps: solidification/stabilization, soil leaching, phytoremediation, agronomic improvement, and the like. The passivation stabilization technology based on the chemical process has the advantages of strong universality for various heavy metal elements, good stabilization effect, simple and convenient operation, short period, low cost and the like, and is widely applied to the remediation engineering of heavy metal contaminated soil in China.
Passivation stabilization is not a restoration technology taking reduction of the total amount of pollutants as a starting point, but stabilization materials or agents such as lime, clay ore, iron manganese oxide and the like are added into soil to enable the stabilization materials or agents to generate a series of reactions such as adsorption, precipitation, redox, complexation and the like with heavy metals, and then the physicochemical properties and the environmental behaviors of the heavy metals in the soil are regulated and controlled to realize risk management and control. Therefore, the selection of highly effective stabilizing materials or agents for the source characteristics of the contaminants is critical to the success of this technology.
The biochar is a solid product obtained by pyrolyzing biomass residues at high temperature, has the characteristics of large specific surface area, rich functional groups, strong ion exchange capacity, high pH value and the like, and is very suitable for improving and repairing heavy metal contaminated soil. The regulation and control of pyrolysis temperature and the selection of biomass precursors are two key factors influencing the physical and chemical properties and the interface behavior of the biochar. Generally speaking, the biochar prepared at high temperature (600-900 ℃) has high aromatizing degree, large specific surface area and high alkalinity, but the yield is relatively low and the energy consumption is high; the biochar prepared at low temperature (250-400 ℃) has high yield and low energy consumption, and can also retain more oxygen-containing functional groups and soluble minerals on the surface of the material, thereby being beneficial to the passivation and repair of heavy metals; the performance of the prepared biochar is compromised in a medium-temperature (400-600 ℃) environment. Most of heavy metal contaminated soil in China is (weakly) acidic, and the alkaline environment is particularly critical to the passivation process of heavy metals. Increasing the basicity of the biochar by increasing the pyrolysis temperature on the one hand weakens the bonding effect of the oxygen-containing functional groups and is obviously too costly. In addition, the long-term effect of biochar to passivate heavy metals is another bottleneck problem which greatly limits the large-scale application of biochar.
Disclosure of Invention
Aiming at the technical bottleneck of repairing heavy metal contaminated soil by biochar passivation, the invention provides the technical scheme that ash residues generated by burning biomass are used for replacing ash residues in high-temperature biochar, so that the alkaline environment required by the repairing process is ensured, and the resource utilization of the ash residues is realized; a small amount of phosphate rock powder is introduced through ball milling, so that the specific surface area of the repair material is improved, and the problems of stability and long-acting property of heavy metal passivation are solved; and a new method for stabilizing and repairing heavy metal contaminated soil based on biomass heat treatment (side product) is further constructed.
In order to achieve the purposes, the invention discovers that alkaline environment, large specific surface area and rich oxygen-containing functional groups are three major factors for realizing efficient passivation by developing biochar passivation repair research on several typical heavy metal contaminated soils in China. Although the low temperature (250-400 ℃) is beneficial to the biochar to retain more oxygen-containing functional groups, the biochar prepared at the high temperature (600-900 ℃) is better in stabilizing effect. Comparing the compositions of 2 biochar, we find that the high-temperature biochar has higher ash content, and the contribution of the ash to the increase of the pH value and the specific surface area greatly improves the passivation capability of the biochar on heavy metals. In the research of screening biomass precursors, the biochar prepared from sludge of a sewage plant is high in yield, the ash content is much higher than that of other agricultural biomass, and the mineral composition is richer. In 2018, the sludge output of domestic sewage plants in China exceeds 5000 million tons, about 10 percent of sludge is incinerated, and about 50 million tons of sludge incineration ash are generated every year. The composition of the sludge incineration ash is analyzed, and the sludge incineration ash is found to be very similar to the sludge-based biochar ash and is alkaline, and the main component of the sludge incineration ash is SiO2、Al2O3And Fe2O3Besides large specific surface area and porosity, the material also has potential gelling activity. Therefore, we propose to prepare a novel passivation repair material by replacing high-temperature biochar ash with sludge incineration ash, and further construct a novel repair method.
The specific technical scheme is as follows:
a method for stabilizing and repairing heavy metal contaminated soil by using sludge-based carbon ash is characterized by comprising the following steps: the method comprises the following steps:
(1) drying the dewatered sludge at 105-110 ℃, cooling, crushing and sieving to obtain sludge particles;
(2) pyrolyzing part of sludge particles obtained in the step (1) for 2-4 hours at 270-350 ℃ in an oxygen-limited environment, cooling, and collecting a solid carbonized product, namely low-temperature sludge-based biochar;
(3) burning the other part of sludge particles obtained in the step (1) for 1-3 h in an oxygen-rich environment at 850-900 ℃, cooling, and collecting solid ash residues remained on the grate, namely sludge burning ash residues;
(4) mixing the low-temperature sludge-based biochar obtained in the step (2), the sludge incineration ash obtained in the step (3) and an enhancer according to the mass ratio of 20: 5-40: 0.1-1, adding the mixture into a ball milling cavity, grinding for 1-6 hours at the rotating speed of 100-500 rpm, and separating grinding media to obtain a sludge-based carbon ash repairing material; the enhancer is industrial grade phosphate rock powder, and the main component is fluorapatite (chemical formula, Ca)10(PO4)6F2) 22-32% of total phosphorus (phosphorus pentoxide);
(5) and (3) crushing the heavy metal contaminated soil into soil fine particles, mixing the soil fine particles with the sludge-based carbon ash repairing material obtained in the step (4) according to the dry-basis mass ratio of 100: 1-15, adding water to adjust the humidity of the soil fine particles to saturation, stirring uniformly, and then aging and maintaining for 7-21 d to finish the repairing of the sludge-based carbon ash repairing material on the heavy metal contaminated soil.
Further, in the step (1), the dewatered sludge is sludge produced by treating domestic sewage in an urban sewage plant; the water content of the dewatered sludge is between 55 and 75 percent.
Further, in the step (1), the particle size of the sludge particles is less than 2 mm.
The sludge incineration ash residue is solid ash residue remained on a grate, and comprises furnace slag discharge and ash falling between grates; the residue collected in the flue gas cleaning system, i.e. fly ash, is not included.
Further, in the step (4), the grinding medium is zirconia balls or silicon nitride balls with the diameter of 1-30 mm.
Still further, in the step (4), the loading amount of the grinding medium is 20-70% of the volume of the ball milling cavity.
Further, in the step (4), the grain size of the reinforcer is 80-120 meshes.
Further, in the step (4), the particle size of the sludge-based carbon ash repair material is 20-500 meshes.
Further, in the step (5), the particle size of the soil fine particles is less than 2 cm.
And (5) further, the heavy metal elements in the heavy metal contaminated soil are one or more of Cd, Cr, Cu, Ni, Pb and Zn, and the total content of 6 heavy metal elements in the heavy metal contaminated soil is not more than 4000 mg/kg.
Furthermore, in the step (5), in the heavy metal contaminated soil, the content of Cd (II) or Cr (VI) is not more than 200mg/kg, the content of Cu (II), Ni (II) or Pb (II) is not more than 1000mg/kg, and the content of Cr (III) or Zn (II) is not more than 2500 mg/kg.
The pH value of the heavy metal contaminated soil is 4.5-8.0.
The beneficial effects are that:
1. the invention adopts the sludge incineration ash instead of the function of high-temperature preparation of biochar ash in heavy metal stabilization, greatly reduces the energy consumption cost, finds a new outlet for resource utilization of the sludge incineration ash, and has remarkable economic, social and environmental benefits.
2. The technical method is simple and practical, the raw materials are wide in source and low in price, the process is green and energy-saving, the passivation effect is obvious and long-acting, the construction link has no high requirement on equipment, and the large-scale popularization is facilitated.
3. The technical method has strong universality, is suitable for repairing the soil with different pollution loads of 6 heavy metal elements, can be used for improving and repairing the soil heavy metal pollution derived from main industrial sources in China, such as picking, smelting, electroplating, tanning, battery manufacturing, electronic component manufacturing and the like, can be used in combination with other technologies, and has wide market prospect.
4. The technical idea of the method can be further expanded from sludge to other types of biomass, such as: various agricultural wastes and the like, and further provides a new way for reducing and recycling the agricultural wastes.
Detailed Description
The present invention is further illustrated by the following examples, which are provided for the purpose of illustration only and are not intended to limit the scope of the invention.
Example 1
A. Preparation of sludge-based carbon ash repairing material
The dewatered sludge is taken from a domestic sewage plant of a certain city in Central China, and the sewage treatment process of the plant is A2And O, the water content of the dewatered sludge is 60 percent. And (3) blowing and drying the dewatered sludge at 105 ℃, and crushing the dewatered sludge through a 10-mesh standard sieve after cooling to obtain sludge particles.
And pyrolyzing part of sludge particles for 3h in an oxygen-limited environment at 300 ℃, cooling and collecting a solid carbonized product, namely the low-temperature sludge-based biochar.
Burning the other part of sludge particles for 3h in an oxygen-rich environment at 850 ℃, cooling and collecting solid ash residues remained on the grate, namely sludge burning ash residues.
The industrial grade phosphate rock powder is purchased from a certain chemical industry enterprise in Shandong, and mainly comprises fluorine-apatite with the main component of 22-32 percent of total phosphorus (phosphorus pentoxide) and the particle size of 80-120 meshes.
Mixing the obtained low-temperature sludge-based biochar, sludge incineration ash and an enhancer of phosphorite powder according to the mass ratio of 40: 20: 1, adding the mixture into a ball milling cavity, grinding for 4 hours at the rotating speed of 400rpm, wherein a grinding medium is zirconia balls with the diameter of 8mm, the loading amount of the zirconia balls is 35% of the volume of the ball milling cavity, and separating the grinding medium after grinding to obtain the sludge-based carbon ash repairing material.
B. Stabilization and restoration of heavy metal contaminated soil
Taking the surface layer contaminated soil remediation of a certain metal smelting site in the Hunan area as an example, the site detailed investigation and risk assessment result shows that: the type of the polluted soil is red soil, and the main pollutants are heavy metals Pb, Cd and Zn. In-situ excavation of polluted soil in a to-be-repaired area of a field, stirring and crushing the soil by using a screening and crushing bucket to enable the particle size of more than 90% of soil particles to be less than 2cm, adding a repairing material according to the dry basis mass ratio of the soil to the repairing material of 10: 1 after watering and wetting the soil, adding water to adjust the soil humidity to be saturated, and aging and maintaining for 14d after uniform stirring. And (3) evaluating the repairing effect by adopting an SPLP leaching experiment, completing repairing after compacting a backfilling field after meeting the risk control requirement, wherein detailed parameters are shown in an attached table 1.
Example 2
A. Preparation of sludge-based carbon ash repairing material
The dewatered sludge is obtained from a domestic sewage plant in a certain city in east China, and the sewage treatment process of the plant is A2And O, the water content of the dewatered sludge is 62%. And (3) blowing and drying the dewatered sludge at the temperature of 110 ℃, and crushing the dewatered sludge after cooling and screening the dewatered sludge by a standard sieve of 10 meshes to obtain sludge particles.
And pyrolyzing part of sludge particles for 2 hours in an oxygen-limited environment at 350 ℃, cooling and collecting a solid carbonized product, namely the low-temperature sludge-based biochar.
Burning the other part of sludge particles for 2h in an oxygen-enriched environment at 900 ℃, cooling and collecting solid ash residues remained on the grate, namely sludge burning ash residues.
The industrial grade phosphate rock powder is purchased from a certain chemical industry enterprise in Shandong, and mainly comprises fluorine-apatite with the main component of 22-32 percent of total phosphorus (phosphorus pentoxide) and the particle size of 80-120 meshes.
Mixing the obtained low-temperature sludge-based biochar, sludge incineration ash and an enhancer of phosphorite powder according to the mass ratio of 30: 20: 1, adding the mixture into a ball milling cavity, grinding for 6 hours at the rotating speed of 350rpm, wherein a grinding medium is silicon nitride balls with the diameter of 6mm, the loading amount of the silicon nitride balls is 50% of the volume of the ball milling cavity, and separating the grinding medium after grinding to obtain the sludge-based carbon ash repairing material.
B. Stabilization and restoration of heavy metal contaminated soil
Taking the example of the remediation of the surface contaminated soil of a land left by a certain surface treatment plant in Zhejiang, site detailed investigation and risk assessment results show that: the type of the polluted soil is red soil, and the main pollutants are heavy metals Cr and Ni. In-situ excavation of polluted soil in a to-be-repaired area of a field, stirring and crushing the soil by using a screening and crushing bucket to enable the particle size of more than 90% of soil particles to be less than 2cm, adding a repairing material according to the dry basis mass ratio of the soil to the repairing material of 12: 1 after watering and wetting the soil, adding water to adjust the soil humidity to be saturated, and aging and maintaining for 18d after uniform stirring. And (3) evaluating the repairing effect by adopting an SPLP leaching experiment, completing repairing after compacting a backfilling field after meeting the risk control requirement, wherein detailed parameters are shown in an attached table 2.
Claims (10)
1. A method for stabilizing and repairing heavy metal contaminated soil by using sludge-based carbon ash is characterized by comprising the following steps: the method comprises the following steps:
(1) drying the dewatered sludge at 105-110 ℃, cooling, crushing and sieving to obtain sludge particles;
(2) pyrolyzing part of sludge particles obtained in the step (1) for 2-4 hours at 270-350 ℃ in an oxygen-limited environment, cooling, and collecting a solid carbonized product, namely low-temperature sludge-based biochar;
(3) burning the other part of sludge particles obtained in the step (1) for 1-3 h in an oxygen-rich environment at 850-900 ℃, cooling, and collecting solid ash residues remained on the grate, namely sludge burning ash residues;
(4) mixing the low-temperature sludge-based biochar obtained in the step (2), the sludge incineration ash obtained in the step (3) and a reinforcing agent according to the proportion of 20: 5-40: mixing the materials in a mass ratio of 0.1-1, adding the mixture into a ball milling cavity, grinding for 1-6 h at a rotating speed of 100-500 rpm, and separating grinding media to obtain a sludge-based carbon ash repair material; the enhancer is industrial grade phosphate rock powder;
(5) crushing the heavy metal contaminated soil into fine soil particles, and mixing the fine soil particles with the sludge-based carbon ash repairing material obtained in the step (4) according to a dry-basis mass ratio of 100: 1-15, adding water to adjust the humidity of the fine particles of the soil to saturation, stirring uniformly, and aging and maintaining for 7-21 d to finish the repair of the sludge-based carbon ash repair material on the heavy metal polluted soil.
2. The method of claim 1, wherein: in the step (1), the dewatered sludge is sludge generated by treating domestic sewage in an urban sewage plant, and the moisture content of the dewatered sludge is 55-75%.
3. The method of claim 1, wherein: in the step (1), the particle size of the sludge particles is less than 2 mm.
4. The method of claim 1, wherein: in the step (4), the grinding medium is zirconia balls or silicon nitride balls with the diameter of 1-30 mm; the loading amount of the grinding medium is 20-70% of the volume of the ball milling cavity.
5. The method of claim 1, wherein: in the step (4), the grain size of the enhancer is 80-120 meshes.
6. The method of claim 1, wherein: in the step (4), the particle size of the sludge-based carbon ash repair material is 20-500 meshes.
7. The method of claim 1, wherein: in the step (5), the particle size of the soil fine particles is less than 2 cm.
8. The method of claim 1, wherein: in the step (5), the heavy metal elements in the heavy metal contaminated soil are one or more of Cd, Cr, Cu, Ni, Pb and Zn, and the total content of 6 heavy metal elements in the heavy metal contaminated soil is not more than 4000 mg/kg.
9. The method of claim 8, wherein the first and second light sources are selected from the group consisting of,the method is characterized in that: in the step (5), Cd in the heavy metal contaminated soil2+Or Cr6+Is not more than 200mg/kg, Cu2+、Ni2+Or Pb2+Has a content of not more than 1000mg/kg, Cr3+Or Zn2+The content of (A) is not more than 2500 mg/kg.
10. The method of claim 1, wherein: in the step (5), the pH value of the heavy metal contaminated soil is 4.5-8.0.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810435816.5A CN108723074B (en) | 2018-05-04 | 2018-05-04 | Method for stabilizing and repairing heavy metal contaminated soil by using sludge-based carbon ash |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810435816.5A CN108723074B (en) | 2018-05-04 | 2018-05-04 | Method for stabilizing and repairing heavy metal contaminated soil by using sludge-based carbon ash |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108723074A CN108723074A (en) | 2018-11-02 |
| CN108723074B true CN108723074B (en) | 2021-04-06 |
Family
ID=63938084
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810435816.5A Active CN108723074B (en) | 2018-05-04 | 2018-05-04 | Method for stabilizing and repairing heavy metal contaminated soil by using sludge-based carbon ash |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108723074B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110240386B (en) * | 2019-07-11 | 2023-11-17 | 中国科学院城市环境研究所 | Straw and sludge cooperative treatment device and method |
| CN110976498A (en) * | 2019-12-20 | 2020-04-10 | 纳琦绿能工程有限公司 | Leaching remediation method for heavy metal contaminated soil |
| CN112275788A (en) * | 2020-09-27 | 2021-01-29 | 东华大学 | Method for solidifying and stabilizing heavy metal ions in soil by using sludge-based biochar |
| CN113321390B (en) * | 2021-06-18 | 2022-09-27 | 清远绿由环保科技有限公司 | Full-resource treatment method of iron-containing municipal sludge |
| CN113582452A (en) * | 2021-08-04 | 2021-11-02 | 苏州旭东环保科技有限公司 | Method for recycling reclaimed water in printing and dyeing wastewater |
| CN115709980B (en) * | 2022-11-23 | 2024-06-28 | 浙江工业大学 | Biochar material rich in microporous structure and adjustable in pore volume, and preparation method and application thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20140115019A (en) * | 2013-03-20 | 2014-09-30 | 강원대학교산학협력단 | Manufacturing method of biochar using sewage sludge and its effect on Pb immobilization in soil |
| CN104190698A (en) * | 2014-08-21 | 2014-12-10 | 中国科学院南京土壤研究所 | Method for restoring clayed soil of high-load heavy metal polluted site |
| CN106082255A (en) * | 2016-06-22 | 2016-11-09 | 河北大学 | A kind of method utilizing waterworks sludge efficiently to prepare permutite and application thereof |
| CN106675568A (en) * | 2016-12-15 | 2017-05-17 | 北京高能时代环境技术股份有限公司 | Passivator for repairing compound heavy metal polluted farmland and preparation and application thereof |
| CN107335405A (en) * | 2017-09-01 | 2017-11-10 | 深圳市海源能源科技有限公司 | A kind of sludge organism charcoal soil-repairing agent and preparation method thereof |
| CN107555743A (en) * | 2017-10-31 | 2018-01-09 | 江苏和合环保集团有限公司 | A kind of stabilizer of Solid Waste Treatment containing heavy metal |
-
2018
- 2018-05-04 CN CN201810435816.5A patent/CN108723074B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20140115019A (en) * | 2013-03-20 | 2014-09-30 | 강원대학교산학협력단 | Manufacturing method of biochar using sewage sludge and its effect on Pb immobilization in soil |
| CN104190698A (en) * | 2014-08-21 | 2014-12-10 | 中国科学院南京土壤研究所 | Method for restoring clayed soil of high-load heavy metal polluted site |
| CN106082255A (en) * | 2016-06-22 | 2016-11-09 | 河北大学 | A kind of method utilizing waterworks sludge efficiently to prepare permutite and application thereof |
| CN106675568A (en) * | 2016-12-15 | 2017-05-17 | 北京高能时代环境技术股份有限公司 | Passivator for repairing compound heavy metal polluted farmland and preparation and application thereof |
| CN107335405A (en) * | 2017-09-01 | 2017-11-10 | 深圳市海源能源科技有限公司 | A kind of sludge organism charcoal soil-repairing agent and preparation method thereof |
| CN107555743A (en) * | 2017-10-31 | 2018-01-09 | 江苏和合环保集团有限公司 | A kind of stabilizer of Solid Waste Treatment containing heavy metal |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108723074A (en) | 2018-11-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108723074B (en) | Method for stabilizing and repairing heavy metal contaminated soil by using sludge-based carbon ash | |
| Chiou et al. | Lightweight aggregate made from sewage sludge and incinerated ash | |
| CN104190698B (en) | The restorative procedure of a kind of high load capacity heavy metal pollution place clayed soil | |
| DE102011008008B4 (en) | Low-metal, modifiable, phosphate-containing, fertilizer-active soil substrate | |
| CN101598339B (en) | Resource disposal method by conditioning and incinerating crop straw and sewage sludge | |
| CN103880472A (en) | Sludge porous material and preparation method thereof | |
| CN109603752A (en) | The method for preparing heavy metal-polluted soil curing materials using oil shale semi-coke | |
| CN114751766A (en) | Light ceramsite fired by solid waste and method thereof | |
| KR100927255B1 (en) | Artificial reef and its manufacturing method | |
| Zheng et al. | Environmental hazards and comprehensive utilization of solid waste coal gangue | |
| CN107739219A (en) | A kind of method that potash fertilizer raw material is prepared with house refuse burning flying dust | |
| CN108435126A (en) | A kind of dregs composite decoloration dephosphorization material and its forming method | |
| CN117505469A (en) | Harmless safe treatment method for coal gangue | |
| CN112225499A (en) | Method for making brick by using tailings and furnace slag | |
| Wainwright et al. | The production of synthetic aggregate from a quarry waste using an innovative style rotary kiln | |
| JP5319254B2 (en) | Method for firing sludge granulated product and method of using the same | |
| Lehmusto et al. | Ashes from challenging fuels in the circular economy | |
| EP2628715A2 (en) | A method for high-temperature utilization of phosphogypsum | |
| JP4529174B2 (en) | Soil improvement material | |
| JP5131750B2 (en) | Granulated body, sintered body, and production method thereof | |
| Wang | A research on ceramsite obtained from blast furnace slag and sewage sludge | |
| CN1318435A (en) | Comprehensive innocuous utilization technique of lake and city sludge | |
| JP3261604B2 (en) | Waste treatment method | |
| Kumar et al. | Utilization of incineration ash as a construction material: A review | |
| JP6672052B2 (en) | Manufacturing method of molten product |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |