81 results about "Soil washing" patented technology

The invention discloses a soil washing restoration system based on a reduction concentration design concept and a method thereof. The washing restoration system comprises the following four module units which are sequentially connected with one another: a feeding and screening unit, an ore washing unit, a sludge dewatering unit and a tail-end sewage treatment recycling unit. The pollutants on the surface of coarse particles are eluted, transferred and concentrated into the filter-pressed mud cake by virtue of washing, so that pollutant-containing fine particles in contaminated soil can be effectively separated from crude particles such as gravel and grit. The repaired and discharged clean gravel and grit can be directly recycled to serve as building material. According to the system, purified water serves as a washing solution, so that secondary pollution caused by addition of a chemical washing agent is avoided, and the washing solution is treated by a tail-end sewage treatment system so as to be recycled. The reduction of remediation of contaminated soil is realized, the comprehensive repair cost is greatly reduced, the washed and discharged materials can be recycled, the contaminated soil is repaired, and a novel profit point is created.

The invention discloses a vehicle-mounted integrated soil washing and restoring device which comprises a vehicle-mounted conveying system, a screening and breaking module, a stirring centrifugal machine module and an energy supply module. The screening and breaking module, the stirring centrifugal machine module and the energy supply module are all integrally installed in a carriage of a transport vehicle. All the soil washing and restoring devices including the vehicle-mounted conveying system, the screening and breaking module, the stirring centrifugal machine module and the energy supply module are integrated in the carriage of one transport vehicle, the function of the conveying system and the functions such as screening and breaking, chemical washing and energy supply in the soil restoring process are integrated to one platform, and the soil washing and restoring device which is highly integrated and is independent and complete is formed. The device can be driven to a site with the soil restoring requirement at any time according to requirements. Due to the fact that the device is provided with the high-power energy supply module, no extra energy is needed, and soil restoration treatment can be conducted in any place where the vehicle can reach.

The invention provides a heavy metal contaminated soil washing method. The method comprises the following steps: compounding organic acid and aids into a washing solution; fully mixing the washing solution and heavy metal contaminated soil in a stirring reactor for a long time, removing heavy metals in the washed liquid waste by virtue of an adsorbent, and recycling the residual liquid waste which serves as a washing solution. According to the method, desorption and solubilization of the heavy metals in the soil can be facilitated by compounding the organic acid and aids, the application range of the washing solution is widened, and secondary pollution to the environment is avoided. The heavy metal contaminated soil washing method disclosed by the invention has the advantages of simple process, simplicity in operation, environment friendliness, high removal efficiency, washing solution recyclability, agent and water resource conservation, and the like.

The invention relates to a combined type soil washing and desorption method and device. The method comprises the steps of spraying polluted soil, using a wet type multilevel vibratory screen for screening the soil, and removing large-particle-size stones or coarse sand which can be directly backfilled; conducting washing and desorption treatment on fine soil particle suspending liquid, and separating small-particle-size clay pollutants through hydrocyclones which are connected in series and provided with a solid-liquid mixer and a micro rotational flow sequencer respectively; conducting washing and desorption treatment and hydrocyclone separation on residual intermediate-particle-size sandy soil, and recycling washing liquid through a precision filter; conducting clear water washing treatment and hydrocyclone separation on soil obtained after filtration, conducting dehydration through a centrifugal machine, and finally achieving deep separation of waste water and soil particles. By means of the method and device, the purposes of soil backfill, tap water reutilization and washing agent recycling are achieved. Device parameters can be adjusted and optimized according to actual conditions, pollutants containing heavy metal, pesticide and the like can be effectively removed, and the deficiency that current soil washing cannot be industrialized is overcome.

A soil washing process includes mixing water and contaminated soil in a log washer, separating the soil and water mixture into a first stream of wet soil and a second stream of water and floating organic materials, dewatering the first stream of wet soil to form a cleaned soil stream, dewatering the second stream to separate out the organic materials and form a water stream, separating the water stream into a stream of non-colloidal particulates and a stream of colloid-containing water, dewatering the stream of non-colloidal particulates, and adding the stream of colloid-containing water to the soil and water mixture. The method may further include returning a first portion of the colloid-containing water to the log washer, and drawing off a second portion of the colloid-containing water to filter out the colloids before returning a clean water stream to the log washer.

The invention discloses a vehicle mobile soil washing and repairing device. The device comprises a vehicle mobile platform, and a soil collection system, a power conveying system, a soil crushing and washing system, a treated soil output system and an agent filling system which are arranged on the vehicle mobile platform. The device is small in floor space, has mobility, and is capable of flexibly and conveniently treating a plurality of polluted areas according to the difference of the polluted areas, so that the secondary pollution to the local soil can be avoided; and furthermore, after the device is used, the soil is continuously mixed with a treating fluid, and the contact area between the treating fluid and the polluted soil can be enlarged under the action of a mixing structure in a wash trough, so that the treatment efficiency is improved.

The invention relates to a pretreatment method and device for improving the washing and desorption performance of soil. The pretreatment method comprises the following steps that vortex desorption pretreatment is completed through the combination of a jacket type spiral feeding screen and a hydrocyclone; the screened polluted soil is stirred in stirring tanks, an eluting agent is added, and / or ultrasonic equipment is adopted for cleaning; and after sufficient mixing and reaction, the soil enters the jacket type spiral feeding screen inclining by a certain angle, large particles are screened in a cylinder under spiral driving, middle and small particles penetrate through a screen, flow downwards along with water or a mixed solution of water and the eluting agent and return to the stirring tanks, then under the separation action of the hydrocyclone, small particles are discharged out of an overflow port, middle-sized particles are discharged out of an underflow port, and therefore classification of the large particles, the middle-sized particles and the small particles is achieved. Differential treatment is achieved, the vortex desorption performance of the soil is improved, and the pretreatment method is excellent. The pretreatment method has the advantages of being simple, convenient, efficient, capable of saving energy, fast, small in side effect, and free of secondary pollution. Parameters of the pretreatment device can be adjusted and optimized according to actual conditions, pollutants containing heavy metal, pesticides and the like are effectively removed, and the defects of the industrialized technology of current soil washing and desorption pretreatment are overcome.

The invention provides a soil heavy mental eluant, a preparation method, an application method and a waste liquid treatment method. The eluant is a humic acid leaching reagent prepared from raw materials such as coal, and is applied to management and remediation of heavy metal contaminated farmlands and industrial and mining sites through a soil washing mode. The soil eluant has the advantages that the heavy metal removal efficiency is high, a new pollutant is not introduced and secondary pollution is not caused. Active humic acid is extracted from the materials such as decomposed coal rich in humic acid as the washing agent for soil heavy metals, the heavy metals in a waste liquid are effectively removed and recovered by using cheap and available quick lime, slaked lime or waste rich in calcium hydroxide, the soil heavy mental eluant has the advantages of being good in washing effect, small in side effect, low in cost and free of secondary pollution, and the practicability of a washing technology is improved.

The invention relates to a cyclone type soil washing method with undercurrents connected in series. The cyclone type soil washing method with the undercurrents connected in series comprises the steps that screened micro soil particle suspension liquid is stirred and washed; the micro soil particle suspension liquid flows through two or multiple segments of hydrocyclones with the undercurrents connected in series, and a solid-liquid mixer group is installed in front of a cyclone system, so that the purposes of enhancing desorption of small-particle-size cohesive soil pollutants in the soil slurry, improving the desorption capacity and conducting densification on the undercurrents are achieved; and in each segment, corresponding structures are designed according to actual working conditions to achieve the best operation condition so that cost can be lowered, and efficiency can be improved. By the adoption of the cyclone type soil washing method with the undercurrents connected in series, deep separation between waste water and large-particle soil in the soil slurry is achieved, and the purpose of recycling detergent is achieved; and device parameters can be adjusted and optimized according to actual conditions, pollutants containing heavy metal, organic matter and the like are effectively eliminated, and the defects of existing methods for soil washing, desorption and densification are overcome.

The invention discloses an efficient dehydration system and a dehydration method of soil washing slurry. The method comprises the following steps: conveying the slurry enriched with pollutants after soil washing and reducing to a closed pipeline mixer by a slurry pump and adding flocculating agents to the pipeline mixer at the same time; pumping the washing slurry subjected to flocculation reaction into geotextile pipe bags on a dehydration platform in the end; achieving efficient slurry-water separation and dehydration volume reduction in the geotextile pipe bags by the gravity and the pumping pressure; collecting the water removed from the bag bodies in a diversion trench around the dehydration platform and carrying out two-stage precipitation on water, thus achieving recycling of the water as process water; dehydrating and solidifying the washing slurry in the geotextile pipe bags, transporting the mud bodies obtained after dehydration and recycling or finally disposing the mud bodies according to the pollution properties of the mud bodies. The system has the positive effects that the geotextile pipe bags are applied to dehydration of the soil washing slurry for the first time; compared with systems adopting traditional mechanical dehydration (such as plate-frame pressure filtration), the system not only adopts a simple process, has high slurry handling capacity and high dehydration efficiency but also has the effect of greatly reducing electricity and manpower and is low in cost.

The invention discloses a method for restoring moderately Cd-contaminated soil by using vine and melon vegetables and a light eluting agent. According to the invention, plantation of vine and melon vegetables and application of the light eluting agent are employed, vegetable cultivation and soil washing are combined together, so heavy metals in soil are allowed to be removed from surface soil posing harm to crops, only a small destructive effect is exerted on soil, and agricultural production can be continued during restoration of heavy metal pollution, which enables production and restoration to be realized at the same time. When the light eluting agent is added into soil, Cd in a cultivation soil layer can be eluted to a deep layer where the root of a crop cannot reach and can be adsorbed by soil. The roots of vine and melon vegetables absorb Cd activated by the eluting agent in contaminated soil; however, activated Cd is generally intercepted by long stems and considerable leaves, little Cd can be delivered to edible parts, i.e., fruits, so harvested fruit vegetables are safe to eat. Harvested stems and leaves of the vegetables can be used as an organic fertilizer, and the content of heavy metals in the stems and leaves accords with standards of an organic fertilizer, thereby causing no secondary pollution.

The invention belongs to the field of treatment and regeneration of polluted soil, in particular to a soil restoring method by damp and hot pollution removal, and equipment thereof. A system for treating organic pollution soil comprises soil washing equipment, slurry extraction equipment, slurry settling equipment and sludge heating equipment and tail gas treatment equipment. The treatment method comprises the following steps of (1) washing the organic pollution soil with the soil washing equipment to prepare slurry, (2) conveying the slurry into the slurry settling equipment with the slurry extraction equipment, allowing the slurry to settle to form sludge, recycling water on a sludge layer for washing the organic pollution soil again, and (3) transferring the sludge obtained in Step (2) to the sludge heating equipment, allowing moisture and organic pollutants in the sludge to be evaporated into gas to be separated from the sludge, and backfilling after reducing the sludge. According to the system and the method, the treatment cost can be lowered, the treatment effect is improved, the treatment capacity is increased, the application scope is wide, and the secondary pollution rate is reduced to the maximum extent.

The invention discloses a root washing machine for washing soil at plant roots. The root washing machine comprises a machine body, wherein a soil washing barrel is arranged in the machine body; a plurality of dehydrating holes are formed in the soil washing barrel in a penetrating mode; a screen is arranged inside the soil washing barrel; a root washing barrel surrounds the outer side of the soil washing barrel; a gap is separately formed between the soil washing barrel and the screen or between the soil washing barrel and the root washing barrel; stirring claws are arranged in the screen; the bottom of the soil washing barrel is equipped with a water draining barrel in a penetrating mode; a water drainage solenoid valve is arranged in the water draining barrel; a motor is arranged below the root washing barrel; the motor is connected with the stirring claws through a reduction clutch; a cover plate is arranged on the top of the machine body; a joint of the cover plate and the machine body is further equipped with a safety switch; a control panel is arranged on the machine body; the control panel is connected with a water level controller; the water level controller is connected with a gas storage chamber arranged on the outer part of the root washing barrel through a pressure hose; a water inlet joint is arranged on the upper part of the machine body; and a water filling valve is arranged in the water inlet joint. The root washing machine is used for cleaning plant roots, and saves manpower and time.

The invention relates to the technical field of environment protection and greening of side slopes, and provides a spray seedling matrix for regreening of bare side slope adapted to soil in arid and semi-arid zones and a preparation method of the spray seeding matrix. The spray seedling matrix provided by the invention is prepared from the following raw materials in parts by weight: 25 to 40 parts of composted organic wastes, 30 to 40 parts of side slope loess, 5 to 15 parts of kaolin, 0.5-0.8 part of potassium fulvate, 5 to 15 parts of bentonite clay, 3 to 4 parts of flour sticky glue and 5 to 10 parts of plant fibers. According to the spray seedling matrix, intensive aboveground parts and developed root systems of plants can be quickly formed on the long-term arid and bare side slope, regreening of the side slope can be effectively carried out, the soil is consolidated, and surface runoff and soil washing can be prevented and controlled. The preparation method provided by the invention comprises the steps of mixing the composted organic wastes, the side slope loess, the kaolin, the potassium fulvate and the bentonite clay and pulverizing into particles; then mixing the particles with the plant fibers to obtain a mixture; successively, adding water and stirring the mixture to form a viscous state; then mixing the viscous product with the flour sticky glue. The preparation method has the advantages of simple technology, strong operability and benefit to industrial production.

The invention relates to a method for overflow-serial cyclone soil washing. The method comprises the following steps: carrying out stirring and washing treatment on a sieved fine soil particle suspension; enabling the sieved fine soil particle suspension to pass through two or more stages of overflow-serial hydrocyclones which are equipped with solid-liquid mixers in front of inlets respectively, so as to achieve fine separation for small-particle-size clay pollutants and improve a desorption capacity; and designing a corresponding structure for each stage according to an actual working condition to achieve the optimal operation conditions, thus lowering the cost and increasing the efficiency. The method realizes deep separation for waste water and the fine soil particles, and achieves a purpose of recycling a detergent. Parameters of the device disclosed by the invention can be adjusted and optimized according to the actual condition, effective removal for pollutants containing heavy metals, organic matters and the like is realized, and deficiencies in a present method for reinforcing desorption in soil washing are made up.

The invention provides a treating system and method for waste liquid generated in washing of soil polluted by polycyclic aromatic hydrocarbons. The treating system comprises a pretreatment unit, a coagulation and sedimentation unit, an ozone oxidation unit, an effluent reusing unit, a tail gas treatment unit and a sludge disposal unit in sequential connection. A water distributing system used in the invention is of an umbrella shape. An aeration system employed in the invention is a microporous titanium aerator. An ozone generator utilized in the invention comprises an air compressor set, a lyophilizer, an oxygen making set and an ozone generating unit. According to the invention, waste liquid generated in washing of soil polluted by polycyclic aromatic hydrocarbons is the target of the invention; based on the characteristic that the waste liquid contains fine soil particles and a great amount of polycyclic aromatic hydrocarbons, coagulation and sedimentation as well as ozone oxidation are used as main treating techniques to rapidly and effectively remove polycyclic aromatic hydrocarbons in the waste liquid, and treated liquid can be recycled in a soil washing system, thereby realizing zero discharge of waste water in the technology of soil washing.

The invention discloses a method for recovering a thiacalix[4]arenetetrasulfonate (TCAS) soil washing agent and relates to a contaminated soil remediation technology. The method comprises the following steps of: soaking an anion exchange resin which is taken as an adsorbent in water so as to ensure the resin is fully swollen, and washing by using deionized water until the resin is neutral, wherein the ratio of the weight of the anion exchange resin to the volume of a contaminated soil eluent is 10:1; pumping the contaminated soil eluent into an ion exchange column by using a peristaltic pump,collecting a desorption solution after the entire contaminated soil eluent passes through the anion exchange column, adding analytical pure sodium chloride, and salting out to ensure that the TCAS washing agent is precipitated; putting an obtained solution into a centrifuge tube, centrifuging at the rate of 5,000rpm for 10 minutes, and dumping to remove supernatant; and putting a TCAS precipitateinto a baking oven, and oven-drying at the temperature of 80 DEG C for 2 hours to obtain TCAS. By the method, the high-efficiency recovery of the TCAS washing agent in the contaminated soil eluent can be realized, and the recovery rate of the TCAS washing agent in the contaminated soil eluent can reach over 96 percent; and operation steps are simple, convenient and easy.

The invention discloses an ex-situ soil washing solid-liquid separation process. The process takes loading flocculation as a core, and the produced floc is compact in structure, void water content, fast in settling and excellent in uniformity and is applicable to solid-liquid separation of ex-situ soil washing mixed solutions. The mixed solution enters a loading flocculation area in main equipmentfor flocculating under the pressure effect, then floc enters a settling zone and a sludge thickening area, the sludge is concentrated and discharged and is treated by a subsequent dehydration processfor backfill. Clean water enters a settling section and a sloping plate zone and outflows via an orifice master gully and a water collection tank, and the effluent is discharged or recycled. During process operation, for a superposed layer nearby a water outlet of the flocculation zone, small floc and one part of soluble organic matters can be removed. The process integrates multiple process units such as a loading flocculation unit, a settling unit, a clarifying unit, and a sludge thickening unit, and the integration level of the main equipment is improved; the degree of automation is high,the application range is wide, the capital investment and operation cost is low, the floor space is small, and the operation is simple.

The invention relates to a method for recovering a surfactant from soil washed liquid. The method comprises the steps of: 1) standing the soil washed liquid, wherein the soil washing liquid is the liquid waste recovered from the surfactant-containing cleaning liquid subjected to soil washing, 2) uniformly mixing the stood soil washed liquid with a flocculant to form sediments, standing, removing sludge after standing to obtain a solution A, 3) filtering the solution A with active carbon, wherein the obtained filtrate is a solution containing the surfactant. The method has the advantages of small occupied area, simplicity for operation, short system operation time, goodeffect of separating surfactant and polyaromatic hydrocarbon, and high recovering efficiency, and the recovered cleaning liquid can be reused for soil washing.

The invention discloses a vehicle-mounted integrated soil washing and restoring device which comprises a vehicle-mounted conveying system, a screening and breaking module, a stirring centrifugal machine module and an energy supply module. The screening and breaking module, the stirring centrifugal machine module and the energy supply module are all integrally installed in a carriage of a transport vehicle. All the soil washing and restoring devices including the vehicle-mounted conveying system, the screening and breaking module, the stirring centrifugal machine module and the energy supply module are integrated in the carriage of one transport vehicle, the function of the conveying system and the functions such as screening and breaking, chemical washing and energy supply in the soil restoring process are integrated to one platform, and the soil washing and restoring device which is highly integrated and is independent and complete is formed. The device can be driven to a site with the soil restoring requirement at any time according to requirements. Due to the fact that the device is provided with the high-power energy supply module, no extra energy is needed, and soil restoration treatment can be conducted in any place where the vehicle can reach.

The invention discloses a washing method for heavy metal contaminated soil. According to the washing method, two stages of smashing devices are arranged, collected soil is preliminarily smashed through the first-stage smashing device, and then the soil is finally smashed through the second-stage smashing device; the soil is thoroughly smashed through the two stages of smashing devices, thus, the soil and a detergent are mixed conveniently, and the washing efficiency is greatly improved; the detergent is atomized through a spray head on a washing mixing mechanism, resources are saved, resourceconsumption is reduced, the purification and washing cost is reduced, the contact area of the detergent and the smashed soil is increased, and thus the washing efficiency is improved; the soil is guided into equipment in batches through a batch loading mechanism, and thus the equipment is prevented from being blocked and damaged; meanwhile, the soil is smashed more easily and purified more easily,the purification time is shortened, and the soil washing efficiency is improved; and when the soil is guided out of the equipment through a solid-liquid separation and conveying device, water stainsand chemical agents left after washing in the soil are separated from the soil, and thus secondary pollution of the soil is avoided.

The invention relates to a nutritional agent for improving saline-alkali soil, and a preparation method of the nutritional agent; the nutritional agent is prepared by calcium carbonate, humic acid and bentonite; the preparation method comprises the steps of: crushing the calcium carbonate to be 200 meshes, crushing the humic acid to be 120 meshes and crushing the bentonite to be 100 meshes; mixing the crushed calcium carbonate, humic acid and bentonite according to the proportion of 1: 1: 1 and evenly stirring; and finally, pelleting to obtain the nutritional agent. The prepared nutritional agent comprises the components by weight percent: 12% of N, 6% of P2O5, 5% of K2O, 8% of Si, 5% of TDC, 3% of humic acid, 0.2% of ZN, 23% of SL, 13% of CA, 15% of organic matter, 4% of K2O4 and the balance of impurities. When in use, operations of soil washing and the nutritional agent is not needed to be washed, applied with pulverized fuel ash application and the like according to the conventional method are not needed, so that secondary emission pollution to the product can be completely avoided. The invention is simple and convenient in using method, time-saving, labor-saving and low in cost, so that the soil is completely improved fundamentally.

The invention relates to soil washing using acidogenic leachate. A plant and a method for soil washing using acidogenic leachate are described. Preferably the plant is arranged to be transported to the site where the contaminated soil is located so that the soil washing can be performed on site.

The invention discloses a feeding, slurry making and grading recovery system for soil washing remediation and belongs to the technical field of soil remediation. The feeding, slurry making and grading recovery system for soil washing remediation comprises a crushing and screening module, a feeding and slurry making module and a washing and particle diameter classifying module in sequence. A crushing and screening device of the crushing and screening module is arranged in a feeding workshop with a tail gas treatment function. The feeding and slurry making module is provided with a rod grinding roller mud dissolving machine internally provided with steel rods. The washing and particle diameter classifying module is provided with a double-layer grading vibrating screen composed of a vibrating motor, a double-layer screen and a high-pressure spraying system. By adopting the feeding, slurry making and grading recovery system for soil washing remediation, the defect that a screen is likely to be blocked due to non-uniform feed particle diameters in the prior art is overcome, and the problems of matching of the washed soil particle diameter and equipment and secondary pollution in the polluted soil pretreatment process are solved.

The invention discloses an environment-friendly and safe soil remediation device capable of enhancing the soil remediation effect, relates to the technical field of soil remediation, and solves the problem that an existing device cannot prevent secondary pollution of soil caused by an extracting agent used in the leaching process through a combined remediation technology. The environment-friendly and safe soil remediation device capable of enhancing a soil remediation effect comprises a front frame; the rear end of a rear bracket is fixedly connected with a rear frame; side tracks are arranged at the bottom of the rear frame; a fixing bin is arranged behind the inner side of the rear frame; and a heat treatment structure is arranged in the fixing bin. Through synchronous transmission of two bevel gear sets, a movable screen hopper can be shaken, blocky soil can be rapidly shaken into scattered particles, and the soil can be conveniently and evenly heated; and a heat treatment technology is matched with a soil washing technology, an eluting agent containing volatile pollutants in the soil can be rapidly evaporated through heating, and secondary pollution to the soil caused by an extracting agent used in the eluting process can be prevented.

The invention belongs to environmental protection equipment, particularly relates to a soil cleaning device for environmental protection, aims to provide the soil cleaning device for environmental protection, and the soil cleaning device is capable of purifying the soil, protecting the environment and protecting the health of human bodies. The soil cleaning device for environmental protection comprises a bottom plate, a 7-shaped plate, a blanking hopper, supporting rods, a cleaning box, third water outlet pipes, third valves and the like, wherein the 7-shaped plate is welded to the left-most side of the top of the bottom plate; the blanking hopper is welded to the 7-shaped plate; the supporting rods are connected to the left side of the middle of the top of the bottom plate and the right side of the middle of the top of the bottom plate symmetrically through bolts; the cleaning box is welded to the tops of the supporting rods; the three third water outlet pipes are uniformly welded tothe upper portion of the right side of the cleaning box at intervals; and the third valves are arranged on the third water outlet pipes. According to the soil cleaning device, the soil is cleaned through a cleaning device and the petroleum is recycled, so that the soil is purified, the environment is protected and the health of the human bodies is protected.

The invention discloses soil cleaning equipment and a soil remediation technology and relates to the technical field of soil remediation. The soil cleaning equipment comprises a tank body, a stirringshaft, a spiral stirring paddle and a driving motor, wherein the spiral stirring paddle is provided with a plurality of water outlets; a discharge opening is formed in one end, away from a feeding hopper, of the tank body; a material receiving box is arranged at the discharge opening formed in the tank body; the discharge opening faces the material receiving box; the plurality of water outlets inthe spiral stirring paddle all spray soil, so that the soil is conveniently cleaned while the soil and leacheate are sufficiently mixed. The soil remediation technology comprises the following steps:step one, sampling; step two, sieving; step three, spraying of leaching pesticide; step four, standing and drying; step five, wastewater treatment; step six, secondary sampling; step seven, backfilling; step eight, remediation of all the soil. After secondary sampling, soil subjected to primary treatment is back filled and marked, so that the soil is easily distinguished.

The invention belongs to the technical field of ex-situ cleaning treatment of petroleum-contaminated soil, and particularly relates to a material balance method based on a cleaning treatment process of oil-contaminated soil and application of the material balance method. The method comprises the following steps: detecting the occurrence content of the total amount of sump oil and the content of group parts in various materials in a petroleum-contaminated soil cleaning system to obtain the distribution state of the content of the sump oil and the content of the group parts of the sump oil under different cleaning cycle conditions aiming at soil with different particle size grades; a material balance calculation method and a material balance relation of the sump oil content in the multi-stage multi-time cleaning process are established; the method comprises the following steps: establishing elution efficiency evaluation parameters by using sump oil material balance data, analyzing the total amount elution effect of sump oil, residual characteristics of biochemical parts such as saturated hydrocarbon, aromatic hydrocarbon and colloid, and the residual amount of sump oil in fine-particle soil, so as to compare, evaluate, regulate and control the design and cleaning effect of a petroleum-contaminated soil cleaning process. And parameter optimization of the optimal cleaning technology and efficient treatment of the oily soil are assisted.

A soil washing process includes mixing water and contaminated soil in a log washer, separating the soil and water mixture into a first stream of wet soil and a second stream of water and floating organic materials, dewatering the first stream of wet soil to form a cleaned soil stream, dewatering the second stream to separate out the organic materials and form a water stream, separating the water stream into a stream of non-colloidal particulates and a stream of colloid-containing water, dewatering the stream of non-colloidal particulates, and adding the stream of colloid-containing water to the soil and water mixture. The method may further include returning a first portion of the colloid-containing water to the log washer, and drawing off a second portion of the colloid-containing water to filter out the colloids before returning a clean water stream to the log washer.

The invention provides soil washing liquid which comprises a solute and a solvent. The solute comprises p-methoxyphenol, potassium persulfate and oxalic acid, and the solvent is water. According to the mass percent, the p-methoxyphenol ranges from 5.4% to 5.8%, the potassium persulfate ranges from 2.2% to 2.8%, and the oxalic acid ranges from 1% to 2%. According to the soil washing liquid, the p-methoxyphenol is used for absorbing organic contaminants in soil through a chemical reaction and is combined with a brand-new, efficient and full-function soil remediation agent through chemical bonds,the contaminants are removed, effective organic matter in the soil is increased, and the p-methoxyphenol can be utilized by probiotics in the soil; meanwhile, the potassium persulfate and the oxalicacid can absorb heavy metal in the soil, the oxalic acid can be used for adjusting the pH value of the soil washing liquid, and the p-methoxyphenol can be combined with the organic contaminants more easily so as to achieve the optimal effect; and in addition, the excessive part can be used as nutritional ingredients to improve the fertility of the soil, and the defects that existing soil washing liquid is narrow in treatment application range, and soil with the soil washing liquid recycled cannot be used for cultivating are overcome.