The invention discloses a preparation method of modified micron zero-valent iron and an application method of the modified micron zero-valent iron in remediation of heavy metal contaminated soil. The preparation method of the modified micron zero-valent iron comprises the steps of cleaning of iron raw materials, preparation of micro iron, ultrafine grinding and modifying treatment. A modifying agent composed of water, xanthan gum, sulfide, a stabilizing agent, zeolite and blast furnace slag is adopted in the step of modifying treatment. The preparation method of the modified micron zero-valent iron has the beneficial effects that the production process of the modified micron zero-valent iron is simple, and the effect similar or superior to micron zero-valent iron is achieved while the cost is reduced; and in addition, the reaction activity is controlled, the oxidation rate is decreased, excellent stability is obtained, and the acting time of the micron zero-valent iron is longer. By the adoption of the application method of the modified micron zero-valent iron, the remediation cost of heavy metal contaminated underground water is further reduced. According to the preparation method of the modified micron zero-valent iron and the application method of the modified micron zero-valent iron in remediation of heavy metal contaminated soil, organic fertilizer is added in the soil treatment process so that the fertility of soil can be improved, the structure of soil can be improved through humic acid produced by the organic fertilizer, heavy metal elements, such as lead, chromium and arsenic, in underground water can be removed, and the concentration of pollutants such as nitrate and perchlorate can be reduced.

Preparation method of modified micron zero-valent iron and application method of modified micron zero-valent iron in remediation of heavy metal contaminated soil

The invention belongs to the field of heavy metal pollution remediation in polluted environment, the invention discloses a method for improving stabilization efficiency of nanometer zero-valent iron in a heavy metal composite polluted soil. The method comprises the following steps of (1) preparing for the modified nanometer zero-valent iron; (2) stabilizing treatment of the modified nanometer zero-valent iron on the heavy metal composite polluted soil; and (3) evaluating a stabilization effect; the method is characterized in that sodium carboxymethylcellulose is adopted to modify the nanometerzero-valent iron, the agglomeration of the nanometer zero-valent iron is reduced through utilizing a steric hindrance effect and an electrostatic steric effect to increase the dispersity of the nanometer zero-valent iron and the mobility of the nanometer zero-valent iron in the soil. According to the method, the stabilizing efficiency of the modified nanometer zero-valent iron to heavy metals inthe heavy metal composite polluted soil is improved; and the method is simple to operate, high in repairing efficiency, low in repairing cost and free of secondary pollution to the environment.

Method for improving stabilization efficiency of nanometer zero-valent iron in heavy metal composite polluted soil

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.

Leaching method for remediation of arsenic polluted soil by using magnetic separation

The invention provides a method for remedying Cd-As-Cu heavy metal polluted soil The method comprises the following steps: step 1, uniformly mixing hydrogen peroxide, oxysophocarpine, phosphoric acid, citric acid, palmitic acid, Tween 80 and deionized water to obtain a solution M, uniformly mixing bismuth phosphate, sodium sulfite, ferrous oxide, hydroxypropyl methyl cellulose and deionized water to obtain a solution N, and uniformly mixing bromelain, amylase, glucono-delta-lactone and deionized water to obtain a solution K; step 2, pulverizing the polluted soil, and performing cyclic leaching on the pulverized polluted soil by adopting the solution M; step 3, adding the solution N into the leached soil for uniform mixing; step 4, adding the solution K for uniform mixing and step 5, adding calcium molybdate, calcium oxalate, silkworm shell powder, chicken manure and fly ash for uniform mixing, and performing conservation According to the method provided by the invention, the remedying effect on the Cd-As-Cu heavy metal polluted soil and the market prospect are good

Method for remedying Cd-As-Cu heavy metal polluted soil

The invention discloses a soil heavy metal chromium pollution repairing material. The soil heavy metal chromium pollution repairing material comprises the following materials by weight percent: 10%-30% of stabilizing and solidifying adhesive, 30%-50% of a composite adsorbent, and the balance of water. The invention also discloses a preparation method of the repairing material. The repairing material adsorbs the Cr material in the soil, is favorable for recycling of the material, realizes the efficient repairing, can be recycled for multiple times, and reduces the repairing cost.

Soil heavy metal chromium pollution repairing material and making method and application of soil heavy metal chromium pollution repairing material

The invention discloses a method for carrying out three-level remediation on 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, fishing out the adsorbent which floats on water and completes adsorption, and simultaneously discharging the supernatant, thus completing first-level remediation; then uniformly adding magnetic nano materials to the soil with adjusted moisture content, mechanically stirring the materials, standing for 3-8 hours, and collecting part of heavy metals in the soil by way of magnetic separation; preparing leachate for leaching, adding nano iron powder while leaching, and then, leaching 1-3 times by using pure water as an eluent, thus completing third-level remediation, 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 actual requirements, and has good popularization and application values.

Niu Xiaojun

Papers

Method for carrying out three-level remediation on heavy metal contaminated soil