695 results about "Cadmium pollution" patented technology

The invention discloses a restoration agent for lowering cadmium/lead effective state content in soil, which is composed of quicklime, calcium sulfate, wood charcoal, iron chloride and water, wherein the weight ratio of the quicklime, calcium sulfate, wood charcoal and iron chloride is (1-2):(1-2):(1-2):(0.5-1), and the water accounts for 30-45 wt% of the soil. The restoration agent can be used for treating heavily polluted soil; and common chemical passivators can only restore lightly polluted soil, and do not have obvious effect on heavy pollution. The restoration agent can be used for treating both acidic soil and neutral soil. The restoration agent has high remediation efficiency for cadmium polluted soil; the reaction mechanisms relate to chemical precipitation and physical adsorption; and when one action fails due to change of the outside conditions, the other action can perform the guarantee function. The restoration agent has certain control actions on the lead effective state content in the polluted soil.

The invention discloses a bacterial strain b capable of resisting the growth of heavy metal Cd and reducing sulfate, and a bacterial strain capable of resisting the growth of the heavy metal Cd and solubilizing phosphate. The classification and name of the bacterial strain b and the bacterial strain are respectively enterbacter ludwigii SRB-2-5U-2 and pseudochrobactrum saccharolyticum LB-4-4-1c, which are already preserved in the Common Microbe Center of the China Committee for Culture Collection of Microorganisms. The bacterial strains disclosed by the invention can be used for simultaneously remediating the surface soil, deep soil and rhizosphere soil of a plant, reducing the pollution of Cd to surface water and underground water, and also improving the activity and fertility of the soil.

The invention provides a composite passivator applicable to rice field soil cadmium pollution. The composite passivator is mainly prepared from chitosan, sodium bentonite, bone meal, lime, charcoal, ZnO and nanometer FeO. The invention further provides a preparation method and application of the composite passivator. By means of the composite passivator, the available cadmium content in rice and the cadmium content in rice can be remarkably reduced, the soil pH value can be improved, vast rice soil polluted by heavy metal cadmium can be treated, the organic matter content is greatly improved, and the soil biology-chemical characteristic is improved.

The invention relates pseudomonas, use thereof and a method for removing cadmium pollution to the environment. The pseudomonas class is named pseudomonas putidaHN103 and the collection number in a collection center is CCTCCNo.M2011184; and the shape and characteristics of the pseudomonas putidaHN103 comprise: 1) on a culture medium, a bacterial colony which used to be colorless and transparent turns white, smooth and convex-like with irregular edges; and 2) according to the result of bacterial microscopic examination, pseudomonas belongs to brevibacterium and is gram negative. The use of the bacteria is the use of the bacteria as a biological repair material for removing cadmium pollution. The method for removing cadmium pollution to the environment comprises the following steps: 1) regulating the cadmium ion concentration in sewage to a range in which pseudomonas can grow normally; 2) placing pseudomonas; 3) keeping the pseudomonas in the sewage for a certain time period; and 4) removing bacterial absorbing cadmium ions. The pseudomonas requires small investment, is low in cost, high in adaptability and capable of effectively removing cadmium, can quickly and obviously lower the concentration of cadmium ions in the environment and is suitable for biological remediation environments polluted by cadmium.

The invention discloses a phytoremediation method for soil with cadmium pollution. The method comprises the following steps: ryegrass is planted in soil with cadmium pollution; organic acid is added before harvest, and the organic acid is one selected from ethylene diamine tetraacetic acid, oxalic acid, glacial acetic acid, propane diacid, tartaric acid or malic acid. In the method, based on ryegrass as a biomass raw material, when the ryegrass is used to restore the soil with cadmium pollution, through activation and induction actions of the organic acid, the bio-availability of heavy metal cadmium is raised, absorption and enrichment of cadmium of plants are promoted, and therefore the phytoremediation speed of soil with heavy metal pollution is raised. In addition, the organic acid can promote increase of amount of dry matter of overground parts and root systems of ryegrass to some extent, and finally, long-term goals of harmony of soil productivity restoration and local landscapes, ecological balance and sustainable development are achieved.

The invention discloses a remediation method for cadmium-contaminated soil, and belongs to the field of soil remediation. In the remediation method, wood vinegar and biochar are prepared from rice straw and/or oilseed rape straw; paddy rice is planted in the cadmium-contaminated soil from May to October of each year firstly, and biochar is applied before paddy rice planting, so that paddy rice conforming to the national standard can be prepared in the cadmium-contaminated soil (to be specific, the cadmium content conforms to the national standard); oilseed rape is planted in the cadmium-contaminated soil from the time after the harvest of the paddy rice to May of next year, and wood vinegar is applied in a specific period to remove cadmium in the cadmium-contaminated soil safely and effectively, so that cadmium in the soil is effectively removed. Moreover, the method effectively utilizes the whole year, thereby guaranteeing the harvest of cereal crops while realizing the remediation of contaminated soil.

The invention provides a cadmium pollution bioremediation agent which is composed of the following ingredients in parts by weight: 10-20 parts of core rhzomorph, 10-20 parts of a nutritional ingredient, 2-6 parts of an enzyme activity substance and 54-78 parts of an rhzomorph carrier. The invention further provides an application of the cadmium pollution bioremediation agent. The cadmium pollution bioremediation agent is reasonable in microorganism specie collocation and high in comprehensive function. Microorganisms in the core rhzomorph can be planted and grow in soil rapidly to form strong bacterial colonies, and heavy metal ions, namely, cadmium Cd<+1> can be directly absorbed to microbial cell walls or into cells to be cured and passivated. Besides, bacillus cereus and beer yeast in the composition have high absorption and passivation function on heavy metal ions, namely, cadmium Cd<+1>, chromium Cr<+1> and lead Pb<+1>, due to the high comprehensive function, the mobility of the heavy metal ions, namely, cadmium Cd<+1>, is reduced, and the purpose of reducing absorption of crops on the heavy metal ions is achieved.

The invention relates to a method for improving soil, in particular to a method for restoring cadmium pollution of soil in a passivation mode. The method is to add plant residue rich in sulfydryl in the soil and mainly comprises the following steps of: 1, grinding the plant residue rich in the sulfydryl to ensure that the length of the residue is less than 10cm; 2, adding the plant residue obtained in the step 1 into the soil to be restored and mixing the residue and the soil, wherein the weight part ratio of the soil to be restored to the plant residue of fresh plant is 1:0.001; and 3, ensuring that the moisture content of the soil added with the plant residue is maintained over 50 percent of the maximum field moisture capacity within 20 to 40 days, wherein the plant residue rich in the sulfydryl is cruciferae plant residue or liliaceae plant residue. Compared with the prior art, the method has the advantages of environmental friendliness, low restoring cost, no influence on farmland production, and improvement on soil fertility, content of soil organic matter and land productivity.

The invention discloses a water treatment method for removing Tl<+> and/or Cd2<+> by producing nanometer iron and manganese oxides in situ, relating to a water treatment method of thallium and/or cadmium-containing source water and solving the problems of complex process, high running cost and low removing efficiency of thallium and/or cadmium existing in the conventional water treatment technology specific to thallium and/or cadmium-polluted source water. The method comprises the following steps of: adding permanganate and ferrous salt into Tl<+> and/or Cd2<+>-containing water; stirring to obtain a mixed solution; adding a coagulant; and performing conventional water treatment. A nanometer ferric hydroxide-manganese dioxide oxide composite adsorbent which has a large specific surface area and high electronegativity and is easy for precipitation separation is produced in situ by making permanganate react with the ferrous salt, so that Tl<+> and/or Cd2<+> can be removed effectively andspecifications in the national Sanitary Standard for Drinking Water are met. The method has the advantages of high removing efficiency, simple process, flexibility and convenience for operation, no change of the original treatment process of a water plant, low running cost and the like, and can be applied to emergency treatment of a water pollution event.

The invention discloses a lead-cadmium compound conditioner for rice field soil as well as preparation and application methods of the lead-cadmium compound conditioner. The conditioner is composed of the raw materials in mass fractions: 30-50% of calcium carbonate, 5-10% of hydroxyapatite, 20-30% of sepiolite and 20-30% of zeolite; the preparation of the conditioner comprises the following steps of: weighing various raw materials according to the mass fractions of the components of the lead-cadmium compound conditioner; continuously stirring the various raw materials in a stirring device for at least 30 min, and thoroughly stirring and evenly mixing all the materials; and the method of application of the conditioner comprises the following steps of: (1) analyzing the total quantity of lead and cadmium in the rice field and the content of lead and cadmium in exchange state; (2) determining the pollution level of the rice field soil by using an evaluation model; (3) applying the lead-cadmium compound conditioner according to the lead-cadmium pollution level in the rice field, and applying the lead-cadmium compound conditioner to the slightly polluted rice field at 100-150 kg/mu, to the mildly polluted rice field by 150-300 kg/mu and to medium-polluted rice field at 300-600 kg/mu, and balancing and stabilizing for 10-15 days; and (4) analyzing and measuring the content of lead and cadmium in exchange state in the rice field, and if the fixed rate is lower than 90%, additionally applying the conditioner at 100-150 kg/mu.

The invention provides an improvement agent used in cadmium-polluted soil, which includes following components, in proper ratio: agricultural rare earth nitrates, waste catalyst, medical stone, humic acid mineral powder, sepiolite, plant ash, kaolin and zeolite. When the improvement agent is applied in heavy metal-polluted soil, heavy metal in soil is effectively passivated and immobilized under a synergistic effect of the components above, and meanwhile, the polluted soil is effectively repaired, so that activity of the heavy metal in soil is significantly reduced and adsorption of crops to the heavy metal is effectively reduced, thereby reducing heavy metal content in crops significantly. The improvement agent is excellent in stability and environment-friendly property, is free of secondary pollution, is low in cost and is easy to popularize in large scale. When the fertilizer is applied in heavy metal-polluted soil, the use quantity is only 10-200 kg/hm<2>. The composite fertilizer can significantly reduce the heavy metal content in crops, so that the heavy metal content in crops reaches national food safety standard.

The invention belongs to the fields of soil heavy-metal pollution treatment in environment protection and agricultural product safety, and relates to a preparation for reducing accumulation of cadmium in crops and an application method thereof. The preparation for reducing accumulation of cadmium in crops comprises the compositions with the following concentration: 50-80 g/L of reduced glutathione, 15-30 mg/L of sodium selenite and 2.0-3.0*10<3> mg/L of zinc sulfate. The crops mean paddy rice or barley. The preparation has the advantages of preparing simpliness, usage convenience, no toxic and side effects, low cost and the like. The preparation is used by spraying on leaf surfaces, the operation is similar to operation of spraying pesticides, the application method is simple and easy to operate, and the preparation is also capable of improving the content of zinc, selenium and other nutritional elements in the crops. The preparation is applicable to paddy rice, barley and other crops for producing low-cadmium products, and is suitable for popularization application in moderate/mild cadmium-pollution regions.

The invention discloses a method for the preparation and use of a slow-release iron-based biochar soil heavy metal passivator. The slow-release iron-based biochar soil heavy metal passivator of the present invention is prepared by an one-step method, wherein iron-based biochar, kaolin and a biological starch are mixed into a core material in a specific ratio; an acidic silica sol and a chitosan solution are prepared, under the effects of an alkaline catalyst and an emulsifier, as a chitosan and silica-sol composite material as a coating, and the iron-based biochar is coated with the alkaline coating material, with the core material and the coating material being controlled at a certain volume ratio. The passivator has a wide raw material source, a simple and convenient preparation process, easy industrialized production, and can passivate the heavy metal arsenic and cadmium efficiently and inhibit the absorption and accumulation of arsenic and cadmium. The passivator prepared by the present invention can last for 4 growing seasons and has a higher passivation efficiency and a longer action time than common iron-based biochar passivators. The passivator can be widely used in the control of arsenic and cadmium pollution farmland.

The invention discloses a combined prevention and control method for cadmium exceeding of rice in medium-light cadmium-polluted soil. The method comprises the following steps of: uniformly spreading a soil passivant onto the surface of medium-light cadmium-polluted soil before ploughing and fertilizing the medium-light cadmium-polluted soil; uniformly stirring; balancing for over three days, and applying a basic fertilizer; transplanting low-cadmium-absorption paddy rice onto soil to which the basic fertilizer is applied; and adopting a flooding irrigation management measure at the infertility period of the low-cadmium-absorption paddy rice to complete combined prevention and control of cadmium exceeding of rice. The method disclosed by the invention has the advantages of low cost, environment friendliness, saving in resources, easiness in operating, and the like, the biological effectiveness of cadmium in acid heavy metal-polluted soil can be effectively lowered, and cadmium accumulation of rice is reduced.

The invention discloses an immobilized Bacillus having phosphate dissolving and heavy metal passivation functions and a preparation method and an application thereof, which belong to the technical field of cadmium pollution soil biological restoration. The immobilized Bacillus comprises biological carbon and Bacillus cereus B19, can be used for restoring the soil with severe cadmium pollution, and has better restoration effect. The composite microbe fertilizer contains the immobilized Bacillus, an organic fertilizer and an inorganic nutrient having the phosphate dissolving and heavy metal passivation functions. The composite microbe fertilizer has the advantages that cost is low, soil available nutrient content is increased, yield increase is achieved, the soil with cadmium pollution is effectively repaired, introduction of heavy metal cadmium in human body with crops can be effectively controlled, agricultural product safety is guaranteed; in addition, the composite microbe fertilizer cannot change a farmland utilization mode without secondary pollution, is conveniently used, and is economic and feasible.

The invention discloses a passivating agent for reducing the cadmium activity of acidic vegetable soil and a use method thereof. The passivating agent contains the following components by weight: 31.3-46.2% of lime, 26.7-39.0% of potassium humate, and 25.0-37.8% of rice husk carbon. The use method consists of: subjecting the passivating agent to basal application totally according to a dose of 150-450kg per 667 square meters, then conducting plowing and uniform raking to make the passivating agent and contaminated soil mixed uniformly, spraying water, performing balancing for 1-3 days, and then carrying out sowing or transplanting. Through the synergistic effect of various components, the passivating agent involved in the invention can reduce the cadmium activity of the soil and the heavy metal content of vegetables, and improve the crop yield and quality, thus being able to be widely applied to remediation of acidic vegetable soil suffering moderate and mild cadmium pollution or severe pollution.

The invention discloses a method for recovering plants in soil subjected to heavy metal cadmium pollution, and belongs to the field of soil pollution control in environmental protection. The method comprises the following steps: (A) periodically measuring the content of cadmium in the soil, and grafting willow; and (B) after the willow is grafted for two months, adding chemical enhancer consisting of ethyl lactate and ethylene diamine tetraacetic aid into the soil. In the step A, the willow is selected from Jiangsu willow clone J1011, and the planting density of the willow is between 4 and 6 strains every square meter when the content of the cadmium in the soil is 6 milligrams in every kilogram of soil. The method can overcome the defects of short and small strains, low growth rate, small amount of ground biology, and the like during recovery of the plants polluted by the heavy metal cadmium, improve recovery efficiency by singly using organic ligand as a chelate extracting agent to recover the heavy metals, has lower recovery cost, and reduces the use level of synthetic chelating agent such as EDTA by using the ethyl lactate so as to reduce environmental risk for recovering the heavy metal cadmium in the soil by extracting the plants.

The invention relates to a chemical enhanced phytoremediation method of polycyclic aromatic hydrocarbon-cadmium pollution soil, belonging to the field of soil pollution regulation; the method comprises the following steps: (A) the content of cadmium, polycyclic aromatic hydrocarbon, phenanthrene and pyrene in the soil is measured, and willow sowing is carried out; (B) chemical enhancer constitutedby ethyl lactate and ethylene diamine tetraacetic acid is added after the willow is sewed for four months. The willow is golden silk willow J1022, and the planting density of the willow is respectively 4-6 per square meter in the soil which has 5mg phenanthrene, 50mg pyrene and 6mg cadmium in one kilogram. The method avoids the disadvantages of short and small plant, slow growing speed, and low living weight at the upper part of the soil in the phytoremediation, reduces the environment risk of heavy metal cadmium in the plant extraction soil remediation; the adding of the chemical enhancer improves the remediation efficiency that an organic ligand is singly used as chelating solvent extraction agent to remediate the heavy metal, and the remediation effect of polycyclic aromatic hydrocarbon of organic pollutants in the soil is enhanced at the same time, and the remediation of cadmium and polycyclic aromatic hydrocarbon combined pollution in the soil is realized at the same time.

The invention provides a compound fertilizer for repairing cadmium contaminated soil. The compound fertilizer comprises nitrogen, phosphorus and potassium nutrition components and appropriate proportions of agricultural nitric acid rare earth, waste catalyst agent, humic acid mineral powder, meerschaum, plant ash, kaolin and zeolite components. When the compound fertilizer is applied to the cadmium contaminated soil, under the synergistic action of the components, the cadmium in the soil is effectively passivated and fixed, and meanwhile the contaminated soil is effectively repaired, so that the activity of the cadmium in the soil is significantly reduced, the compound fertilizer is beneficial for reducing the absorption of cadmium by crops, and then the cadmium content in the crops is significantly reduced. The compound modifier provided by the invention is relatively good in stability and environment-friendliness, does not generate secondary pollution, and is low in cost and easy to popularize in a large area, and when applied to the cadmium contaminated soil, the applied amount is only 10-200kg/hm<2>, and the cadmium content in the crops can be significantly reduced to reach a national edible safety standard.

A process for eliminating the pollution of Pb, Zn and Cd to said and water by use of arabis paniculata features that the Arabis paniculata is planted in the polluted sol or water for absorbing Pb, Zn and Cd. When their concentrations in the plant reach a certain value, the plant on the ground is cut out and its root is retained for growing the plant no the ground and further cutting it out.

The invention discloses a remediation method for heavy metal cadmium pollution of orchard soil based on galinsoga parviflora. The remediation method comprises the following steps: preparing galinsoga parviflora seedlings in a direct transplanting mode or a direct seeding mode; watering to guarantee the water-holding capacity of soil in a field and performing daily management on the galinsoga parviflora; performing harvesting treatment, i.e., harvesting the aboveground part of the galinsoga parviflora. The galinsoga parviflora has resistance and hyperaccumulation feature to cadmium heavy metal, the seedlings absorb and accumulate the cadmium heavy metal in the contaminated soil of the orchard, and the cadmium is transferred to the aboveground part to reduce the cadmium content in the orchard soil, so that the purpose of reducing the cadmium content in the contaminated soil of the orchard is achieved. In addition, the galinsoga parviflora has strong reproductive capacity, grows quickly and is shade-tolerant, the base part has strong branching capacity and can sprout after being harvested; the galinsoga parviflora can be planted almost all the year round in southern China and can grow in extremely barren land, the cost is low, the operability is high, and a new plant genetic resource is developed for phytoremediation of the heavy metal cadmium contaminated orchard soil.

The invention relates to trichoderma asperellum and an application thereof in remediation for heavy metal pollution. The trichoderma asperellum HD228 is separated from cadmium-containing soil in Hengdong County, Hunan, and the preservation number of the trichoderma asperellum HD228 is CGMCC No.12870. The strain (the trichoderma asperellum HD228) has a high cadmium adsorbing capacity, and meanwhile, the strain has a growth promoting effect on rice and has a detoxifying effect on cadmium-stressed rice. Therefore, the trichoderma asperellum HD228 has a potential of developing double functions in a process of conducting soil remediation on cadmium-contaminated rice fields, and a good strain is provided for cadmium-contaminated soil microbial remediation engineering. The application provided by the invention has theoretical and realistic significance for the remediation of cadmium pollution of the cadmium-contaminated rice fields.

The invention relates to a method for comprehensively controlling cadmium pollution of rice by utilizing a modifier and an agricultural technology. The method comprises the steps of irrigating a rice field at the final booting phase of the rice, keeping a water layer of 2-3 cm on a field surface, broadcasting 60 Kg quicklime per mu into water uniformly, and keeping a waterflooding state of the field till the field is dried or drained by nature transpiration and evaporation 5 days before harvesting. With the adoption of the method, Cd elements in soil are gathered at inedible parts of the rice, such as a root, a stem and a leaf, so that the Cd accumulation amount at a grain part is reduced significantly; the Cd elements are effectively prevented and controlled from migrating to the rice; and the Cd content in the rice is reduced.

The invention belongs to the field of soil heavy metal restoration, and concretely discloses a soil restoring agent for cadmium pollution paddy field and application. The soil restoring agent provided by the invention is prepared from the following ingredients in parts by weight: 40 to 70 parts of tobacco stem charcoal, 10 to 20 parts of sepiolite, 10 to 20 parts of kieselguhr, 5 to 10 parts of light burning powder, 5 to 10 parts of lime, 5 to 20 parts of calcium magnesium phosphate fertilizers, 0.5 to 2 parts of zinc fertilizers and 1 to 5 parts of microbial agents. The soil restoring agent is uniformly spread on the soil surface; then, turning is performed so that the soil restoring agent and the polluted soil are sufficiently mixed; the application quantity is 100 to 300kg/mu. The soil restoring agent belongs to the composite restoration; the application is simple; the cost is low; the efficiency is high; the environment is protected.