Patent•
Method for treating heavy metal contaminated soil
02 Jul 2014-
TL;DR: In this article, a method for treating heavy metal contaminated soil is proposed. But the method comprises the steps of breaking a contaminated paddy field, irrigating the paddy fields until a water logging layer on a soil layer is 10-15cm deep after breaking the 0.5-0.6m deep soil on the surface layer into soil lumps with sizes less than 2-3mm, adding a modified clay mineral adsorbent, mechanically stirring the adsorbents, standing for 6-8 hours, removing the supernatant, and carrying out solid-liquid
Abstract: The invention discloses a method for treating heavy metal contaminated soil. The method comprises the steps of breaking a heavy metal contaminated paddy field, irrigating the paddy field until a water logging layer on a soil layer is 10-15cm deep after breaking the 0.5-0.6m deep soil on the surface layer into soil lumps with sizes less than 2-3mm, adding a modified clay mineral adsorbent, mechanically stirring the adsorbent, standing for 6-8 hours, removing the supernatant, and carrying out solid-liquid separation; then uniformly adding magnetic nano materials to the soil with adjusted moisture content, mechanically stirring the materials, standing for 3-8 hours, and collecting the magnetic nano materials in the soil by way of magnetic separation, thus achieving solid-solid separation; preparing leachate for leaching, adding carbon microspheres while leaching, and then, leaching 1-3 times by using pure water as an eluent, thus obtaining the treated soil, wherein the amount of water used each time is 0.6-1 times the leachate added for the first time by volume. The method is simple to operate, is low in cost, has high removal efficiency, meets the actual requirements, and has good popularization and application values.
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Patent•
10 Dec 2014
TL;DR: In this article, a leaching method for arsenic polluted soil by using magnetic separation is described, which is characterized by comprising the following steps: pre-treating polluted soil to be treated, entering leaching system, successively adding prepared leacheate and a prepared auxiliary agent, and after thorough mixing leaching, obtaining arsenic pollutants by magnetic separation through powerful magnetic separation equipment in a stirring rolling pattern.
Abstract: The invention discloses a leaching method for remediation of arsenic polluted soil by using magnetic separation. The method is characterized by comprising the following steps: pre-treating polluted soil to be treated, entering a leaching system, successively adding prepared leacheate and a prepared auxiliary agent, and after thorough mixing leaching, obtaining arsenic pollutants by magnetic separation through powerful magnetic separation equipment in a stirring rolling pattern; and performing solid-liquid separation on the remaining soil and leacheate, directly backfilling or using clean soil, after coagulation sedimentation is performed on waste leacheate, recycling the waste leacheate for preparing the leacheate, and performing follow-up treatment on precipitated waste residues and waste residues obtained after magnetic separation together. Through the adoption of the method disclosed by the invention, the problem that heavy metal, especially arsenic, pollutes the soil can be thoroughly solved, the polluted soil can be treated stably, continuously and efficiently, and the method is suitable for remediation of the arsenic polluted soil with different pollution concentrations or other composite polluted soil.
8 citations
Patent•
13 Mar 2018
TL;DR: In this paper, a preparation method and the application of a biochar-based conditioner for cadmium contaminated soil is described, which includes the following steps: first, mixing biologic materials with sludge, or separately using the sludge and adjusting the moisture content to 10 to 90 percent; adding calcareous materials, carrying out high-temperature carbonization in the oxygendeficit or oxygen-free environment to obtain calcium-loaded biochar; secondly, adding a zeolite powder into a soluble phosphorus solution and carrying out soaking treatment, standing and
Abstract: The invention relates to a preparation method and the application of a biochar-based conditioner for cadmium contaminated soil The preparation method comprises the following steps: firstly, mixing biologic materials with sludge, or separately using the sludge and adjusting the moisture content to 10 to 90 percent; adding calcareous materials, carrying out high-temperature carbonization in the oxygendeficit or oxygen-free environment to obtain calcium-loaded biochar; secondly, adding a zeolite powder into a soluble phosphorus solution, carrying out soaking treatment, standing and carrying outair drying to obtain phosphorus modified zeolite; thirdly, uniformly mixing the calcium-loaded biochar obtained in the first step with the phosphorus modified zeolite obtained in the second step according to the ratio of 2-5 to 1, moisturizing, aging and drying, so as to obtain a finished product The preparation method disclosed by the invention has the advantages of simple technology, low energyconsumption and no pollution discharge in the processing process The biochar-based conditioner for the cadmium contaminated soil is mixed with the soil for use according to a certain proportion, sothat the absorption of plants to heavy metal cadmium can be reduced by 30 to 50 percent
6 citations
Patent•
21 Oct 2015
TL;DR: In this article, a purification method for removing active heavy metals from soil is proposed, which consists of soaking heavy metal polluted soil with heavy metal-free water, repeatedly plowing the soaked soil to achieve a muddy state, standing the plowed soil for 3-48 h, placing the clarified water at the upper layer of the stand soil into a sammns heavy metal removing device to remove heavy metals, and soaking the soil in the step 1 with the water being subjected to the heavy metal removal step, and repeatedly performing the steps 2-4 until 80% of the
Abstract: The invention relates to a purification method for removing active heavy metals from soil. The purification method comprises: 1, soaking heavy metal-polluted soil with heavy metal-free water; 2, repeatedly plowing the soaked soil to achieve a muddy state; 3, standing the plowed soil for 3-48 h; 4, placing the clarified water at the upper layer of the stand soil into a sammns heavy metal removing device to remove heavy metals; and 5, soaking the soil in the step 1 with the water being subjected to the heavy metal removing step, and repeatedly performing the steps 2-4 until 80% of the heavy metals in the soil is removed. According to the present invention, the whole treatment process does not affect the structure and the characteristic of the soil, the normal farming and the normal planting of the soil are not hampered, the heavy metal removing is permanent, and the method can be widely used for heavy metal polluted farmland and soil restoration.
4 citations
Patent•
23 Sep 2015
TL;DR: In this article, a method for removing lead and zinc in the contaminated soil by leaching with biologic materials was proposed, where distilled water was used for the vibration digestion on air-dried plant powders, and the filter liquor was added into the soil, then the pH value of mixed solution was adjusted using dilute nitric acid and sodium hydroxide solution, and finally lead in the soil are vibrated and leached out.
Abstract: The invention relates to the technical filed of restoring of contaminated soil in the environment, and in particular relates to a method for removing lead and zinc in the contaminated soil by leaching with biologic materials. According to the method, distilled water is used for the vibration digestion on air-dried plant powders, the filter liquor is added into the soil, then the pH value of mixed solution is adjusted using dilute nitric acid and sodium hydroxide solution, and finally lead and zinc in the soil are vibrated and leached out. According to the method for removing lead and zinc in the contaminated soil by leaching with biologic materials, coriaria sinica maxim, pistacia weinmannfolia, castor-oil plant or euphorbia helioscopia are used as flushing agent, the cost is low, the source is wide, the leaching effect on the soil is obvious, and the secondary pollution does not occur on the environment.
3 citations
Patent•
07 Jul 2017
TL;DR: In this article, a method for reducing accumulation quantity of arsenic in crops and belongs to the fields of heavy metal pollution remediation and agricultural product safety is presented, where deep ploughing is performed on soil before crops are planted, soil moisture content is reasonably controlled, and an appropriate amount of clay minerals and an arsenic precipitate adsorbent are added into arsenic-polluted surface soil to improve soil; surface soil and an improver are turned over and are uniformly mixed, and are aged for 20 days.
Abstract: The invention provides a method for reducing accumulation quantity of arsenic in crops and belongs to the fields of heavy metal pollution remediation and agricultural product safety. According to the technical scheme adopted by the invention, deep ploughing is performed on soil before crops are planted, soil moisture content is reasonably controlled, and an appropriate amount of clay minerals and an arsenic precipitate adsorbent are added into arsenic-polluted surface soil to improve soil; surface soil and an improver are turned over and are uniformly mixed, and are aged for 20 days; and a base fertilizer is added and crops are planted, and a leaf phosphorus fertilizer is sprayed after crops normally grow to reduce arsenic accumulation of the crops and increase the crop yield. The method is strong in operability, is environmentally friendly, and can realize continuous and safe planting of crops on medium-light arsenic polluted soil.
3 citations
References
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Patent•
04 Jul 2012
TL;DR: In this paper, a preparation method for magnetic nano biological microspheres for remedying soil polluted by organic chloride durably is proposed, which includes the following steps of: (1) preparing nano Fe3O4 particles with the surfaces adsorbing amino by a coprecipitation method; (2) dissolving chitosan into an acetic acid solution to form a homogeneous transparent colloidal solution, and mixing and stirring the solution and the nano particles to obtain the magnetic nano-particles; (3) adding the prepared magnetic nanoparticles into a
Abstract: The invention relates to a preparation method for magnetic nano biological microspheres for remedying soil polluted by organic chloride durably. The preparation method comprises the following steps of: (1) preparing nano Fe3O4 particles with the surfaces adsorbing amino by a coprecipitation method; (2) dissolving chitosan into an acetic acid solution to form a homogeneous transparent colloidal solution, and mixing and stirring the solution and the nano Fe3O4 particles to obtain the magnetic nano-particles; (3) adding the prepared magnetic nano-particles into a buffering solution of citric acid and performing ultrasonic dispersion to obtain magnetic fluid; and (4) adding the magnetic fluid into a bacterial solution, adding cross-linked fluid dropwise, performing adsorption-cross-linking, and performing solid liquid separation under the action of an external magnetic field to obtain the magnetic nano biological microspheres. The method is quick, simple, convenient and low in cost. The prepared magnetic nano biological microspheres have the characteristics of homogenous shape, large specific surface area, high microbial activity and the like and are applicable to degradation of organic chloride pollutant and in-situ remediation of polluted soil.
18 citations
Patent•
08 Jan 2003
TL;DR: In this article, a method for purifying a layer of contaminated soil is provided, including the following steps: (a) preparing an injection well for injecting a fluid which has a purification capability utilizing one of physical action, chemical reaction, metabolism of microbes and promotion thereof and highly pressurized washing into the layer and (b) injecting the fluid under a high pressure at which one of the physical actions, chemical reactions, metabolism, and promotion of microbes can be controlled, through injection nozzles provided on a first wall or a first bottom of the injection well.
Abstract: A method for purifying a layer of contaminated soil is provided, including the following steps: (a) preparing an injection well for injecting a fluid which has a purification capability utilizing one of physical action, chemical reaction, metabolism of microbes and promotion thereof and highly pressurized washing into the layer and (b) injecting the fluid under a high pressure at which one of the physical action, chemical reaction, metabolism of microbes and promotion thereof and highly pressurized washing can be controlled, through injection nozzles provided on a first wall or a first bottom of the injection well. The method has features that the injected fluid stirs and washes the layer to separate or decompose contaminants and the contaminants axe eliminated by collecting the fluid containing an undecomposed portion of the contaminants in the layer through a plurality of collection wells.
4 citations
Patent•
24 Feb 2014
TL;DR: In this paper, a method for reducing a heavy metal content in heavy metal polluted soil by using a ferritization treatment, which can improv a reuse rate of treated soil within a site and reduce a final disposal amount by reducing the heavy metal contents in the soil.
Abstract: PROBLEM TO BE SOLVED: To provide a method for reducing a heavy metal content in heavy metal polluted soil by using a ferritization treatment, which can improv a reuse rate of treated soil within a site and reduce a final disposal amount by reducing the heavy metal content in the heavy metal polluted soil.SOLUTION: A method for reducing a heavy metal content in heavy metal polluted soil consists of: a step to slurry the heavy metal polluted soil by adding water thereto; a step to accelerate elution of heavy metals in the soil by adding at least one selected from a group including sodium hydroxide or the like to the slurried heavy metal polluted soil and alkalizing the soil; a step to generate finely pulverized ferrite with the heavy metals captured therein by adding ferrous sulfate to the soil from which elution of the heavy metals is accelerated and stirring the mixture at normal temperature; and a step to reduce a heavy metal content in the heavy metal polluted soil by classifying and separating only a finely pulverized portion including ferrite with the heavy metals captured therein from the ferritized soil.
3 citations