Method of detoxifying mud, in particular sea and lagoon sediments, or grounds containing organic and/or inorganic trace pollutants
FIELD: environmental pollution control.
SUBSTANCE: invention relates to industrial process of detoxifying sea and lagoon sediments or grounds polluted by stable organic trace pollutants (e.g., dioxins and furans, polychlorobiphenyls, aromatic polycyclic hydrocarbons) and inorganic trace pollutants (e.g., Hg, Cr, Cu, Zn, Pb, As, Cd, etc.). Detoxification process comprises following stages: (i) thermal desorption of organic pollutants in trace amounts from mud or ground and removal of volatile metals from furnace operated at 300 to 700єC to form first gaseous stream containing removed organic pollutants and volatile metals and stream consisting of remaining solids; and (ii) extracting heavy metals from the stream of remaining solids with the aid of inorganic acids or chelating compounds, in one or more steps, to produce chemically dissolved above-indicated heavy metals and essentially detoxified mud or ground having characteristics allowing thus treated mud or ground to be returned to their original place.
EFFECT: achieved complete detoxification with minimum environmental harm.
16 cl, 1 dwg, 3 tbl, 2 ex
This invention relates to the method of disposal of sludge, in particular marine and lagoonal sediments, and sludge generated during dredging or land contaminated by persistent organic microparasites (for example, dioxins and furans (TO/t), biphenyls (PCBs), polycyclic aromatic hydrocarbons (UPA) and inorganic microparasites (e.g., Nd, CR, cu, Zn, Pb, As, Cd and so on).
The degree of risk for human health and environmental safety, related with the presence of halogenated organic compounds, mainly dioxins, furans and PCBs or heavy metals such as Na, CR, cu, Zn, Pb, As, Ni, Cd, known and documented. It was proved that the chlorinated and brominated organic microparasite constantly present in the environment that cause their accumulation and leads to places with pronounced high levels of pollution.
To date, the most widely used procedure to reduce the effects of contamination of sediments in the lagoons and seas were dredging and final placement digidrirovanny and stable materials in controlled dumps; this method of placement is becoming more and more impractical and is the increasing difficulty of finding the appropriate space; moreover, the problem is not solved completely, but moved to areas where pollution is less danger.
Thus, the necessary technology for removal of these contaminants.
Used methods chosen for each individual case and tailored to the specific situation.
The choice of different working options are usually based on the choice of technology to carry out the task of waste management, with the best engineering and economic guarantees and may provide less impact on the environment; the latter is of most interest to local residents.
Described numerous ways to remove organic and non-organic microcontaminants from contaminated sludge, which mainly belong to the following categories.
Methods biological treatment consists in the decomposition of pollutants by microorganisms. Biological activity leads to the transformation and detoxification of substances present in the original sludge. WO-95/22374 (British Nuclear Fuels) describes the removal of metal particles using microbiologically produced sulphuric acid.
In the case of organic microcontaminants such as BEFORE/f, UPA and PCBs in biological treatment requires precise selection of a specific biomass capable of including the ü in your metabolism these specific substances; in any case, the cleaning capabilities are limited inherent in these compounds toxicity, as well as their low water solubility and affinity to those present in the sludge humic substances.
The simultaneous presence in the sludge organic and non-organic microcontaminants always causes the need to provide the sequence of the individual phases of the biological treatment.
The biological treatment processes applied to these complex matrices, characterized by slow kinetics, they have limited regulatory capacity and low capacity to cleaning.
Inertinite is the process of cleaning applied to the matrices of inorganic nature, which is the result of physical phenomena and chemical reactions cause the solidification and stabilization of contaminated material by imprisonment in the granules contained toxic components, which are fixed and immobilized in the solid mass. Inertial solidified in the water ligands and additives that accelerate the effects of capture, is a method widely used for immobilization of heavy metals contained in the residual fly ash generated in the processes of thermal treatment of waste, as described, for example, IT 21560 A/89 of the same applicant.
Formed as a result of the solid wastes have mass, which is about twice the mass of the source material, which further affects the final cost of accommodation in controlled dumps.
Alternative accommodation in the dumps is the possibility of production of final products for use in the urban economy, which, however, significantly increases the cost of processing.
The above-described methods passivation, as shown, are insufficient and not very effective in the case of immobilization of contaminants organic nature.
Processing extraction and washing.
This type of processing based on the extraction of chemical or physical methods of harmful substances, using mechanical energy and is suitable fluid and additives for washing.
Extraction techniques allow you to remove various types of organic contaminants: oil, cyanide, polycyclic aromatic hydrocarbons and heavy metals.
Usually, however, the subsequent processing are used in the extraction solvent and the residual traces of solvent in the treated material is difficult. Removing such heavy metals as cu, Fe and Pb, when exposed to acids described, for example, in US-5476994 (Greenfield Environmental) and in EP-853986 (Procter & Gamble).
The heat treatment removes impurities by direct or to svinnogo heating sludge. The heat treatment can be carried out in an oxidizing atmosphere or in the absence of air; at the first stage of the process evaporate the moisture and most volatile organic compounds. Evaporation and/or pyrolysis of the heavier organic compounds occurs at higher temperatures (300-600°). Evaporated impurities are then subjected to a complete oxidation in the process of destruction, which is carried out in an excess of oxygen at temperatures in the range from 850 to 1200° (afterburner) depending on their nature.
In the processes of heat treatment is complete knowledge of the physico-chemical characteristics of raw materials; it defines the technical characteristics of the installation: dimensions, operating temperature, time and method of purging the outgoing gas streams.
The heat treatment process for removal of organic compounds from contaminated materials are described, for example, in WO-90/11475 (T Corporation).
Inorganic compounds such as heavy metals, obviously, are not destroyed during combustion and are in the form of residue in the smoke and liquid effluents after treatment processes formed by the combustion of the smoke.
Treatment by vitrification.
If the sludge simultaneously contaminated with various groups of pollutants, it is usually necessary to apply several techniques of neutralization. For neutralization sludge from gamestorrents and inorganic nature, you should choose treatment, suitable for removal of organic substances, such as, for example, thermal or extraction processing, and the processing suitable for the reduction of toxicity due to the presence of heavy metals, such as, for example, the processes of stabilization, bacterial inoculation and passivation.
These two types of processing are combined in the method of vitrification (glass transition), in which, subjecting the source material to temperatures in excess of the softening temperature (1100-1300° (C)simultaneously carry out the combustion of organic substances and stabilization of the organic fraction to the inert mass of vitreous consistency. Thus, this process allows complete decomposition of the organic fraction with simultaneous passivation of inorganic parts, as described, for example, in DE-3827086. The vitrification process is more energy consumption, it is not possible to return the processed materials to their original spots, but only in controlled landfills, and in the course of processing obtained by the combustion gases are formed remains liquid effluents contaminated with heavy metals.
Now found in the General scheme of the process in which by combining thermal desorption and transfer of heavy metals in a soluble state by a chemical reaction receive the sludge completely cleared from the body, the economic and inorganic pollutants which can be returned to the original place, the smoke cleared at the level of best available technology, chemically inert and stable solid residues, and do not receive a liquid effluent.
This invention is the complete elimination of pollution by organic trace contaminants (e.g., BEFORE/f, PCB, UBA) and inorganic trace contaminants (e.g., Nd, CR, cu, Zn, Pb, As) lagoon and marine sediments and sludge formed as a result of dredging, at the same time allowing you to return the processed materials in their original location.
This process is extremely versatile and allows you to treat the contaminated sludge by simultaneous presence of organic and inorganic material, and one organic material or a single inorganic material.
From an economic point of view, this process compared with traditional combustion has the advantage that the heat treatment is carried out at considerably lower temperatures, 450 - max 700°instead 850-1000°and that the indirect heating is allocated a reduced amount of fumes that need to be cleaned, resulting in reduced size of the equipment as a whole.
However, the biggest advantage of this process is limited impact on the environment, because it allows, in addition to the lower volume of the emitted fumes, to operate at low temperatures and the natural characteristics of solid matrices remain unchanged, which, consequently, allows you to return them to their original location.
The precipitate is the same as it was originally (Il, not cement block or vitrified product), but it is completely free of organic and inorganic pollutants.
This process does not work any liquid runoff; flow remains inert solids, in which toxic metals, separated from the original sediment/sludge in accordance with the process of passivation, already patented by the applicant (IT 21560 A/89), stably immobilized in the cement matrix.
According to this invention a method of disinfection of sludge or soil containing organic and/or inorganic microparasite, characterized in that it essentially consists of the following steps:
thermal desorption of sludge or soil organic microcontaminants and volatile metals in a furnace at a temperature in the range from 300 to 700°obtaining a gaseous stream containing the removed organic contaminants and volatile metals, and thread the remaining solids;
- extraction of heavy metals from the stream remaining solids with inorganic acids or chelat forming compounds in the aquatic RA the creators in one or more stages by means of chemical dissolution of these heavy metals with obtaining essentially neutralized sludge or land, having the capability to return them to their original location.
The method according to this invention may also include known traditional methods of treatment recommended to complete the cycle of disinfection, such as:
thermal drying of materials to be processed;
- the oxidation of desorbed gases/cleaning of the smoke produced by burning;
- flocculation for the deposition of metals in the liquid phase;
- dehydration of sludge obtained from the treatment;
- inertial fine powder and is obtained when the sludge.
Consider where and how you can apply these steps in this process.
Thermal desorption may be preceded by a stage of thermal drying is preferably carried out by indirect heating or heating using heat-conducting oil or steam, for concentration of sludge or soil to dry residue or at least up to 80 mass%.
For thermal drying can be followed by stage one-stage screening and/or crushing.
The gaseous stream containing organic contaminants and volatile metals, obtained by thermal desorption, processed by thermal oxidation with subsequent dedusting and removing acids and, possibly, treatment of demercurization.
Thermal regeneration and/or fast the e-cooling (quenching) of the fumes, water may immediately follow the treatment system.
The above process may also include the additional step of processing the water coming from the stage extraction of heavy metals and drying stage of removal of the acid, if present, and water effluent of the process of obtaining a fully refundable in the process water and the final sludge, which is concentrated heavy metals, and which can be processed by initiala, preferably together with powders obtained by dust, obtaining stable and chemically inert solid residue.
Treatment for mercury removal can be carried out in a wet scrubber, and out of the water stream contaminated with mercury, sent directly to the stage of water treatment or subjected to special treatment on demercurization in which is formed the water stream is returned to the step of extraction of heavy metals, and the flow of mercury-containing sludge.
The modular concept allows the processing of different types of source material with different pollutant concentrations, except for some of the above stages, as in the case of stage thermal drying, which can be excluded in the case of treatment of sediments with low humidity.
These different stages are illustrated in more detail below.>
Thermal desorption can be held in a rotating drum furnace with indirect heat and conduct it at a lower temperature than the normal value used when burning, usually between 300 and 700°C, preferably between 400 and 650°C. in This way, the organic components are isolated in the form of vapor, and, depending on their nature and content of O2in the reaction atmosphere, they can pass into the secondary combustion chamber or in an unchanged form, or partly in the form of pyrolysis products, or as gaseous products of combustion. The carrier gas (nitrogen, air, diluted air or the gas obtained by heating desorber) serves preferably with a relatively low speed so as to obtain a linear gas flow rate (2-50 cm/sec, sufficient to move the desorbed vapors and minimize the capture of fine powders. The length and speed of rotation of the furnace is adjusted to obtain the residence time of the processed material is preferably in the range from about 20 minutes to 90 minutes depending on the type of conditioning, which was already subjected to this material (particle size) and extent of contamination.
When working with indirect heating heating stream is separated from the stream, the resulting desorption, thus minimizing the costs associated with the level at the roar, and requirements associated with the processing of exhaust gases.
Couples receive for heating, are clean and do not require further purification; in addition, when used at the stage of thermal recycling significantly reduces the problems of interaction with the materials of the equipment.
Pollutants that are contained in the load, such as, for example, dioxins, furans, (f), polychlorobiphenyls (PCBs), polycyclic aromatic hydrocarbons (UPA) and mercury, thermally desorbers, forming a gas flow (smoke) and the flow of solids, free from organic impurities and volatile metals.
The gas stream can be subjected to further heat treatment (oxidation) for complete decomposition of organic compounds and subsequent energy recovery using heat-conducting oil, which is used for heat transfer at the stage of thermal drying of sludge; the following directly behind the stage thermal utilization stage of rapid quenching water slows down the possible effects of repeated formation of dioxins and furans.
For final purification obtained by the combustion of the fumes, you can include the following sequence of stages: filtering powders and washing smoke on the acid-base column with a double loop.
At the output of the installation is obtained superb smoke cleared, ofleverage significantly more stringent requirements, than the designated European and international rules.
Mercury concentrates in the liquid flow coming from the stage leaching of smoke as a result of condensation; this flow may be subjected to special treatment for mercury removal in accordance with known processes: deposition using sulfur compounds or capture the layer of ion exchange resins or activated carbon. Purified from mercury runoff fully use recycled as process water in the extraction step for translation of metals in solution.
The flow of solids produced in the process of thermal desorption and contains at this moment only heavy metals, can be subjected to the extraction process for transfer to the solution of metals through chemical action undertaken by the applicant.
Extraction of metals can occur in reactors/tanks ideal mixing, in which the aqueous leach solution is in contact with the sludge within a certain interval of time depending on the size of the particles preferably varies from 1 to 20 hours, more preferably from 1 to 4 hours.
Preferred acids are HCl and H2SO4; NGO3and a mixture of HCl and NGO3equally applicable, as well as neutral solutions containing hepatoblastoma is soedineniya, for example, such as ethylenediaminetetraacetic acid (add, EDTA) or citrate.
The choice of reagent is mainly associated with the type and levels of heavy metals present. In particular, for example, observed that while the presence of Zn, Cr, cu, As, Ni, Pb, Cd the most suitable acid is Hcl; H2SO4more effective than Hcl, removing Ni, Zn and mn, but practically ineffective with respect to Pb. Hepatoblastoma agents, such as add, in particular the pH intervals are more effective than acid in the removal of some divalent heavy metals, such as Pb, but complicate the plot of water treatment due to the stage of re-deposition of metals and regeneration etc. If pollution with heavy metals due to the presence of IG, removing much more effectively, if you enter preliminary oxidation in the aqueous phase hydrogen peroxide followed by treatment with acid.
When selected the most suitable reagent for this type of pollution load, the ratio of liquid/solid is determined depending on the desired characteristics of the treatment, can preferably be changed within 3-10, more preferably from 4 to 8: the higher the ratio, the greater will be the effect of removal that can be achieved.
An aqueous solution in which the ohms were dissolved metals, can be separated from the solids by decantation and direct an ordinary node physico-chemical treatment for re-deposition/concentration of metals in the form of sludge.
The solid is preferably subjected to washing to remove dissolved metals, which remained in the dissolved solution in the mud; for this purpose use water recycled from the process of re-deposition of metals.
The solid residue, digidrirovanny and purified from organic microcontaminants (by thermal desorption)and heavy metals (by extraction with chemical reaction), after neutralization can be returned to its original place, or it may be sent for publication in controlled dumps for inert materials or, in extreme cases, for special waste.
As mentioned, stage of water treatment in the process for re-deposition of metals extracted from contaminated solids, and for the treatment of condensation water from the dryer, together with a plot of mercury removal from wastewater coming from leaching columns of smoke generated during combustion, includes the well-known conventional physico-chemical treatment.
No liquid effluent is of particular importance in the present method; in fact, all water treatment is made at the site of extraction of heavy metals at the site and the cooling and final purification obtained by the combustion of smoke, fully refundable in the process.
The sludge obtained from the treatment of liquid effluent is in the form suitable for thermal processing for allocating relatively clean of heavy metals for reuse or, together with the powders collected on the device for dedusting, you can apply for a special installation for passivation, a process which has already been patented by the applicant.
The preferred embodiment of the present invention is illustrated further by means of the drawing, which, however, in no way should be considered as limiting the scope of the invention.
The contaminated sludge (1) direct thermal drying (E)produced indirectly by using thermal (heat conducting) oil or steam, followed by sieving (V), where the average fraction of the product (4) serves on stage thermal desorption in a rotary drum furnace with indirect heating (D); a large fraction (2) is served on the grind (F), and then again at screening (V), while a small fraction of the sifted product (5) again served in the upper part of the dryer (S), to control and to regulate the level of moisture contaminated sludge at the entrance.
The gas flow (6), containing organic contaminants and deleted volatile metals, enters from stage (D) VM is the extent with the flow of residual solids (7), which is sent to the phase extraction (S), where the contained heavy metals dissolved chemically, with subsequent dehydration (M) for separating excess water (8) from the stream of residual solids and neutralization (N) to obtain bacteria-free stable sludge (9).
Smokes (10) from the stage of drying (E) partially condense in (C) obtaining a gaseous stream (11) and water flow (12).
The gas stream (11) is fed to the afterburner (R) (which also serves the gas flow (6)out of desorber (D)) for the destruction of the desorbed impurities with subsequent thermal utilization of gases subjected to combustion in (R)rapid cooling of the smoke through water extinguishing (Q), filtering (G) for the Department of powders (13) and the acid-alkaline leaching (L) smoke (14) in the wet scrubber for separating acid gases and mercury.
Fully cleaned gas stream (20), which is subjected to additional heating in (C) before releasing it into the atmosphere (21), exits the scrubber (L) together with the water flow (22), significantly contaminated with mercury and acid gases, which are sent to special processing on demercurization (N), whence comes the acidic stream (23), again supplied to the phase extraction (S), and stream silt (24), containing the bulk of the mercury, which is sent to the stage of dehydration (U).
Water n the current (8), coming out (M), serves on the stage of physico-chemical water treatment (T) together with the water flow (12)emerging from the condenser, to precipitate heavy metals.
Out (T) out of two streams: a stream of solids (15) (sludge obtained from the treatment of water), which can be subjected to dehydration in (U) and then submit for processing passivation (Z) together with powders (13)coming from the filter (G), before placing them in heaps; and the stream (16), which is partially (17) is recycled to the wet scrubber (L), partial (18) serves to rapid cooling (Q), and partially (19) serves at the stage of extraction of metals (S).
The following examples better illustrate the invention, but in no case should not be considered as limiting its scope.
Table I lists the three types of precipitation, which can be neutralized by the method according to this invention, with their relative physical and chemical characteristics.
In this table I, the difference with the residue at 105°With an indication of the degree of moisture of the sludge, and the values shown in italics are calculated dried at 105°the product of the data analysis of sediments as such (TQ).
It is shown that the analyzed sediments especially contaminated with organochlorine microparasites, mainly PCBs and UP/f, and Nd, Pb, si and Zn.
The precipitate (F6) was processing the method according to this invention, including thermal desorption and extraction of heavy metals with two different types of treatment conditions.
From examples 1 and 2, you can see that the proposed method of disinfection allows to obtain a solid material with physical and chemical characteristics by which it can be attributed to making the most stringent requirements of the group And in accordance with the Protocol 93 (L.360/91), related to the lagoon of Venice, and, therefore, it is completely reusable for the reconstruction of the sandy shallows of the lagoon.
Table II shows the result of combined effects of desorption and transfer into a solution of metals loading F6. described in table I.
Specifically, the desorption was performed in a rotary drum furnace having a length of about 3 m and a diameter of 26 cm, with a rotation speed of 2.5 rpm gradient along the axis of 1.95%. The furnace was heated in an indirect way, to the sludge at a distance of approximately 70 cm from the exit of the furnace had a temperature of 450°and created a counter-current of air. At the entrance of the furnace filed 40 kg of sludge for 5 hours and 15 minutes, and on the output side gave 7 normm3/h of air.
Granulated product (PG) were analyzed, and the results are shown in table II. The number of deleted substances referred to the dry product with 33% humidity equal to the moisture load.
These results show is live high degree of removal of organic microcontaminants, almost complete with respect to polycyclic aromatic hydrocarbons (APA), above 99% for PCBs and above 97% for dioxins (UP/f). The mercury content is reduced almost to less than 2 mln (ppm) relative to residual (measured relative to the sludge as such when 88,9% of dry residue), while other heavy metals remain more or less unchanged. Of some interest is the fact that when carrying out heat treatment with air, but at a low temperature part of the CR (VI), already present in the original sludge, does not increase (if valuation is done in the calculation for the same dry residue).
Granulated product (containing 10% moisture) was subjected to a further process of translation in a solution of heavy metals by processing at room temperature for 3h. HCl at a ratio of liquid/solid is equal to 8, and the time of contact of the suspension with mild stirring for 4 hours. The contact time is chosen based on the change of pH. It is shown that after 4 hours it is already stabilized. At the end of processing an aqueous solution in an excessive amount relative to the amount absorbed by the sludge is separated and analyzed, and then recalculate the part of the heavy metals removed from the original granular product. The results listed in table II in the column of S8 show the destruction of more than 50% of almost all anal is projected metals for values greater than 80%, for example, Nd, cu, and As.
Table III shows the result of combined effects of desorption and transfer into a solution of metals loading F6, described in table I.
In particular, the desorption was performed as described in example 1, but with nitrogen as the carrier gas. At the entrance of the furnace was applied 50 kg of sludge in the course of 7 hours, while 7 of the regulations. m3/h of nitrogen was applied from the output.
The granular product was subjected to analysis, and the results are shown in table III, column P7. These results show a high degree of removal of organic microcontaminants, almost full for polycyclic aromatic hydrocarbons (ASD), more than 98% for PCBs and more than 96% of dioxins (UP/f).
To obtain a higher degree of removal of heavy metals in comparison with example 1, the granular product (containing 10% moisture) was subjected to a further translation into a solution of heavy metals by processing at room temperature for 3h. HCl at a ratio of liquid/solid is equal to 8, and the contact time of the suspension, supported with mild stirring, for 4 hours, followed by rinsing in an hour an equal volume of water. At the end of the second treatment aqueous solution in an excessive amount relative to the amount of solution absorbed by the sludge was separated and analyzed, and then counted the proportion of heavy m is the metal, remote from the source of granulated product. The results are shown in table III, columns (S8+S9, unexpectedly show almost complete removal of all analyzed metals. Residual levels comparable with the lower levels of the standards for the environment.
|Air conditioning||TQ 105°||TQ 105°C||TQ 105°C|
|the residue at 105°,% of the mass.||34,0 100||35,9 100||43 100|
|the residue at 900°,% of the mass.||23,1||21,4||31,3|
|The ability to melt in an oxidizing atmosphere|
|latest t/m 3||1,23||1,32|
|Analysis of organic microcontaminants|
|TO/f ng/kg||5584||293 816||252 583|
|Chlorinated solvents, ppm||63,5||69,8|
|With %||7,3||5,3 13,3||4,0 7,4|
|N %||0,6||7,7 1,3||6,1 0,6|
|N %||0,4||<0,5 <0,5||<0,5 <0,5|
|S %||11||0,25 0,32||0,54 0,88|
|Organic Cl %||0,85 2,37||0,55 1,28|
|Total Cl %||1,67 4,65||1.55V to 3.58|
|Nd ppm||19 56||27 75||69 160|
|Pb ppm||244||84 234||91 211|
|Cd ppm||3,6||1,2 3,3||1 2|
|C R is m||121||71 198||53 123|
|CR ppm||96||32 89||37 86|
|Zn ppm||541||460 1281||270 625|
|Ni ppm||48||18 50||35 81|
|As ppm||22||10 28||8,6 20|
|Air conditioning||TQ||TQ conversion||TQ|
|The residue at 900°% mass.||31,3||88,9 33,0||33,0|
|Analysis of organic microcontaminants|
|PCB ppm||10,4||0,10 0,037||100%|
|TO/f ng/kg||252||17 6,4||97%|
|With %||4,0||0,9 0,33|
|S %||0,54||0,70 0,26|
|Organic CL %||0,55||0,0 0,0|
|Total CL %||1,55||2,30 0,85|
|Air conditioning||TQ||TQ conversion||TQ|
|The residue at 900°||wt. -%||31,3||88,9 33,0||33,0|
|Analysis of organic microcontaminants|
|Organic CL||%||0,55||0,0 0,0|
|General CL||%||1,55||2,80 1,06|
1. The method of disposal of sludge or soil containing organic and/or inorganic micropollutants, characterized in that it essentially comprises the following stages:
thermal desorption of sludge or soil organic micropollutants and volatile metals in a furnace at a temperature in the range from 300 to 700°obtaining a gaseous stream containing the removed organic pollutants and volatile metals, and flow residual solids;
- extraction of heavy metals from a stream of residual solids by using inorganic acids or chelat forming compounds in aqueous solution in one or more stages by chemical dissolution of these heavy metals with obtaining essentially neutralized sludge or land that has features that allows you to return them to their original location.
2. The method according to claim 1, characterized in that subject neutralization of Il represents the sediments of seas and lagoons.
3. The method according to claim 1 or 2, characterized in that thermal desorption carried out in a rotating drum furnace with indirect heating.
4. The method according to claim 1 or 2, characterized in that the desorption is carried out at a temperature limit is 400 to 650° C.
5. The method according to claim 1 or 2, characterized in that the extraction with inorganic acids or chelat forming compounds are one or more washing water.
6. The method according to claim 1 or 2, characterized in that the inorganic acid is hydrochloric acid.
7. The method according to claim 1 or 2, characterized in that thermal desorption is preceded by a stage of thermal drying for concentration of sludge or the earth to the content of dry residue, at least 80 wt.%.
8. The method according to claim 7, characterized in that the stage of drying is carried out by indirect heating using heat-conducting oil or steam.
9. The method according to claim 1 or 2, characterized in that thermal drying stage should sieving or grinding.
10. The method according to claim 1 or 2, characterized in that the gaseous stream containing organic pollutants and volatile metals, obtained by thermal desorption, processed by thermal oxidation with subsequent dedusting and removing acids.
11. The method according to claim 10, characterized in that in addition to dust removal and destruction acids are also demercurization.
12. The method according to claim 10, characterized in that it directly for processing thermal afterburning conduct heat regeneration and/or rapid cooling (“quenching”) of smoke is water.
13. The method according to claim 1 is 2, characterized in that there is an additional processing stage water coming from the stage extraction of heavy metals, and in the presence from the stage of drying according to claim 7 and with the stage of removal of the acid of claim 10, and wastewater process, with the production of water, which is fully refundable in the process, and the final sludge, which is concentrated heavy metals.
14. The method according to item 13, characterized in that the sludge obtained from the treatment of water sent for treatment initiala with stable and chemically inert solid residue.
15. The method according to 14, characterized in that the final sludge is sent for processing by initiala together with powders obtained by treatment in the dust.
16. The method according to claim 11, characterized in that the processing of demercurization of conduct in the wet scrubber and out of the water stream contaminated with mercury, is fed directly to the stage of water treatment according to item 13 or subjected to special treatment for mercury removal from which it receives water flow returned to the stage extraction of heavy metals, and the flow of mercury-containing sludge.
FIELD: environment protection.
SUBSTANCE: method involves introducing into soil contaminated with oil or oil products ameliorant, such as complex of aluminosilicate mineral and nitrogen-phosphate fertilizer; plowing soil to depth of at least 25-30 cm.
EFFECT: reduced soil recultivation time and decreased consumption nitrogen-phosphate additives.