16 results about "Soil cadmium" patented technology

This invention belongs to the field of heavy metal pollution remediation technology, and relates to the preparation and application of a cadmium passivating agent for weakly alkaline soil. The weakly alkaline soil cadmium passivating agent mainly comprises the following components by weight: 30-50 parts of a mineral complex, 40-60 parts of a bioactive component, and 5-15 parts of an auxiliary stabilizer. The mineral complex includes natural sepiolite, calcium-based bentonite, and a polyether-polyester diblock copolymer; the bioactive component includes microbial agents, phosphorus-modified biochar, lecithin, and phosphatidylserine; and the auxiliary stabilizer includes nano-hydroxyapatite and a chitosan-grafted polyaspartic acid complex. This weakly alkaline soil cadmium passivating agent exhibits excellent remediation effects on cadmium in contaminated soil, effectively preventing or reducing the entry of cadmium and other heavy metals into the food chain, and has significant market potential.

The application relates to the cross field of photocatalytic composite materials and soil environment remediation technology, and specifically discloses a three-dimensional graphene aerogel loaded cadmium sulfide quantum dot composite material, a preparation method and application of the composite material in soil cadmium pollution remediation, the composite material is composed of a three-dimensional interconnected porous sulfur-doped graphene aerogel skeleton and in-situ anchored cadmium sulfide quantum dots, the cadmium sulfide quantum dots have a particle size of 2-10 nm, a loading amount of 10 wt%-25 wt%, a surface sulfur vacancy density of 5%-8%, the skeleton has a sulfur atom content of 2 at%-5 at%, and the two are connected through a carbon-sulfur-cadmium covalent bridge; the material has a hierarchical porous structure with longitudinal through macropores of 20-80 mu m and intrawall mesopores of 2-20 nm, the material is prepared by adopting a three-stage programmed hydrothermal method, and a sulfur source is released in stages by 30%-50% excess thioacetamide to drive the formation of an epoxy group nucleophilic ring-opening anchor point, in-situ nucleation of quantum dots and generation of surface sulfur vacancies.

This invention discloses a methylbacterium XC1 strain screened from the rhizosphere soil of contaminated paddy fields. Methylbacterium XC1 can stably survive in cadmium-contaminated soil and effectively fix available cadmium in the soil, thereby reducing the content of available cadmium in the soil and achieving effective remediation of cadmium pollution in the soil.

This invention discloses a combined microbial agent and its method for promoting plant growth and soil remediation. The combined microbial agent comprises an inoculum of the arbuscular mycorrhizal fungus *Gloydius juvenilee* and a fermentation broth and / or suspension of *Methylobacterium XC1*. The combined microbial agent can increase rice seedling height, root length, and biomass accumulation, inhibit the migration of cadmium from cadmium-contaminated soil to the aboveground parts of rice seedlings, and simultaneously promote the conversion of soil cadmium to a stable / residual state with low bioavailability.

The present application relates to the field of agricultural ecological monitoring and molecular diagnosis, and specifically discloses a method for rapidly detecting soil cadmium pollution by using plant genetic markers, which aims to solve the problems of complex pretreatment, dependence on large instruments and inability to reflect biological availability in existing soil cadmium detection, selects the cadmium-specific response gene rb_592991 of the super-hyperaccumulator Bidens pilosa as a target, extracts the total RNA of the Bidens pilosa exposed to the soil to be detected, performs one-pot constant-temperature reaction at 60 DEG C by using RT-LAMP combined with CRISPR / Cas12b system, and realizes naked-eye visual interpretation by using a colloidal gold lateral flow test strip. The detection system of the present application has a minimum detection limit (LOD) of 0.2 mg / L in a water culture environment, has strong anti-interference property, does not require expensive instruments, and can rapidly evaluate the biological availability of soil cadmium in situ, thereby providing a simple, efficient and new strategy for early warning of cadmium pollution in farmland and traditional Chinese medicine production areas.

This invention discloses a method for selecting Rhododendron and a soil remediation method for remediating low-concentration cadmium-contaminated soil in phosphate mine waste sites, belonging to the field of contaminated soil remediation technology. It aims to solve the problems of low biomass and low cadmium accumulation rates of herbaceous plants in the high-phosphorus and alkaline environment of phosphate mining areas. This invention selects Rhododendron as the core remediation plant, and seedlings are planted after soil evaluation; soil moisture is maintained through quantitative irrigation, and nitrogen and potassium fertilizers are supplemented to optimize nutrients; the above-ground parts are mechanized and the underground roots are regularly cleaned 8-10 months after planting, followed by harmless disposal. By adopting the above technical solution, this invention utilizes the high biomass and strong stress resistance of Rhododendron to achieve efficient extraction and stripping of low-concentration cadmium, reducing cadmium pollution in the soil while increasing vegetation coverage in the mining area, demonstrating excellent ecological benefits.

This invention belongs to the field of biotechnology, specifically relating to the plant growth-promoting properties of two alkali-producing strains, *Rhizobium miltiorrhiza* and *Pseudomonas mossae*, and their applications in soil cadmium fixation and fertilization. This invention provides a multifunctional alkali-producing bacterium, which is any one of the following strains: *Rhizobium miltiorrhiza* (… Rhizobium miluonense WW22, accession number: CGMCC No. 27718; *Pseudomonas molluscum* ( Pseudomonas mohnii WW2, accession number: CGMCC No. 27716. This invention also provides the use of the above-mentioned strain: cadmium fixation and fertilization. The strain of this invention can promote the reduction of cadmium availability in the soil and increase the nutrient content in the soil, providing a technical basis for ensuring the safe production and utilization of crops in cadmium-contaminated farmland, and has broad application prospects.

The application discloses a method for reducing cadmium in wheat in medium and light cadmium contaminated soil, and belongs to the technical field of safe production of crops. In view of the problem that the effect of existing single planting or single cadmium reduction technology is limited and easy to affect the yield of wheat, a four-dimensional combined scheme combining soil passivation, screening of low-cadmium varieties, foliar control and agronomic regulation is adopted, the soil cadmium activity is reduced by applying a composite passivation agent, a low-cadmium high-yield variety is screened, a negative load foliar control agent is sprayed to inhibit the transportation of cadmium to grains, and scientific agronomic management is combined, so that the reduction of cadmium in wheat and high yield are realized. The method is simple in operation, controllable in cost, has a cadmium reduction efficiency of more than 35%, and can reduce the cadmium content in wheat grains to within the national food safety standard, is suitable for the safe production of wheat in medium and light cadmium contaminated farmland, and has good popularization and application value.

This invention discloses a method for safe and efficient production of crops in acidic cadmium-contaminated farmland using a silicon-calcium-based soil composition. The method includes: S1 preparing the silicon-calcium-based soil composition; S2 applying the composition to the soil surface 1-3 days before plowing and mixing it evenly, maintaining a field water holding capacity of 30%-70%, and statically maintaining this position for 10-20 days; S3 flooding the soil to a field water holding capacity of 120%-200%, maintaining this position for 15-25 days, and then allowing it to dry to 20%-30%; S4 sowing crops after plowing and managing the harvest. This invention can rapidly improve strongly acidic soils, significantly alleviate aluminum toxicity, reduce soil cadmium activity, avoid soil structure damage and nutrient loss, and achieve safe and efficient crop production. Furthermore, it uses industrial and agricultural waste as raw materials, making it low-cost, easy to apply, and in line with the concept of green and sustainable development.

This invention discloses a soil cadmium passivating agent, its preparation method, and its application, belonging to the field of soil heavy metal pollution remediation technology. The preparation method includes the following steps: screening and removing impurities from calcium-phosphorus-silicon industrial waste residue, crushing and sieving to obtain pretreated calcium-phosphorus-silicon industrial waste residue; mixing the pretreated calcium-phosphorus-silicon industrial waste residue with residual raffinate and adjusting the solid-liquid ratio, stirring and acid-hydrolyzing to obtain a slurry; drying the slurry to constant weight and crushing to obtain the soil cadmium passivating agent. This invention also discloses the soil cadmium passivating agent prepared by the above method and its application. This invention uses three phosphorus chemical solid wastes—phosphorus tailings, yellow phosphorus slag, and residual raffinate—as raw materials, selecting and proportioning them, and preparing the soil cadmium passivating agent through acid hydrolysis activation and low-temperature drying and shaping. This solves the problems of poor passivation effect, poor stability, and long preparation cycle of existing passivating agents, and has good practical value.

This invention relates to the field of planting environment monitoring technology, specifically to a data analysis-based method for detecting anomalies in Sichuan pepper planting environments. The method includes: obtaining soil root coupling characterization values ​​based on the time span differences between the same-order subsequences in the soil cadmium ion concentration fluctuation sequence and the soil pH fluctuation sequence, as well as the time span differences between the same-order subsequences in the Sichuan pepper root cadmium ion concentration fluctuation sequence and the Sichuan pepper root pH fluctuation sequence; obtaining soil root propagation direction characterization values ​​based on the differences in start time and range between the soil cadmium ion concentration fluctuation sequence and the Sichuan pepper root cadmium ion concentration fluctuation sequence; adjusting a fixed empirical lag order based on the soil root coupling characterization values ​​and the soil root propagation direction characterization values ​​to obtain an optimized lag order; and using an ARMA model with the optimized lag order to detect anomalies in the soil cadmium content of the Sichuan pepper planting area. Furthermore, this invention can improve the accuracy of detecting anomalies in Sichuan pepper planting environments.

This invention provides a method for remediating cadmium-contaminated farmland soil using a multifunctional slow-release granule combined with EDDS-enhanced Bidens trifoliata. Before sowing, the multifunctional granules are applied to the cadmium-contaminated soil, followed by irrigation with calcium nitrate solution after sowing Bidens trifoliata. On day 40, a melatonin aqueous solution is applied as a top dressing; and on days 50-60, a mixed aqueous solution of EDDS and CaCl2 is sprayed. The multifunctional granules, from the inside out, consist of an alkali-modified biochar-supported iron-based oxide core, a urea-formaldehyde-PASP functional layer, and a calcium alginate shell. This invention achieves highly efficient remediation of cadmium-contaminated farmland soil by Bidens trifoliata through the temporal coupling of cadmium pre-fixation and slow-release nitrogen supply by the multifunctional granules, melatonin-promoted growth, and synergistic activation by EDDS / CaCl2. It is simple to operate, highly efficient, and can effectively shorten the remediation cycle of moderately and severely cadmium-contaminated farmland soil in arid and semi-arid regions, showing promising prospects for widespread application.

This invention discloses the application and method of green manure return to the field in the remediation of cadmium pollution in red soil, belonging to the field of agricultural heavy metal pollution remediation technology. This method addresses the problems of high cost, potential secondary pollution, and difficulty in coordinating with agricultural production associated with chemical passivating agents in the remediation of cadmium-contaminated farmland in red soil. It utilizes a crop rotation system combining continuous planting and incorporation of milkvetch with rice planting and fertilization to simultaneously regulate and significantly increase soil microbial biomass carbon and amorphous iron oxide content, synergistically driving the transformation of soil cadmium from a highly active, weakly acidic extractable state to a more stable iron-manganese oxide-bound and organically bound state. This method achieves long-term, stable reduction of soil cadmium bioavailability without the need for additional chemical passivating agents, realizing a green, low-cost, and in-situ synergistic approach to cadmium pollution remediation and agricultural production, and has significant application value.