Cd pollution and passivation repair agent for farmlands and cultivated lands and repair method

Abstract

The invention discloses a Cd pollution and passivation repair method for farmlands and cultivated lands. The method comprises the following steps: (1) detecting Cd pollutant indexes; (2) preparing a repair agent; (3) spreading the repair agent; (4) applying a base fertilizer after irrigation; (5) performing flooding maintenance management on the lands in the whole rice planting process; (6) planting the rice, detecting Cd content in the rice and Cd pollutant indexes in the soil, and judging whether the indexes are qualified. The invention further discloses a Cd pollution and passivation repair agent for farmlands and cultivated lands. The repair agent is composed of thiol clay mineral, carbonate, silicate and phosphorus based compounds. According to the Cd pollution and passivation repair agent for farmlands and cultivated lands and the repair method provided by the invention, the content of Cd bio-available form in the soil can be rapidly reduced, the fertility of the soil can be well prevented from being lost so as not to reduce the yield of grains, and the Cd content in the grains can be controlled, so that the Cd content in the grains reaches the national relevant regulations.

Description

technical field [0001] The invention relates to the field of Cd pollution treatment, in particular to a Cd pollution passivation restoration agent and restoration method for farmland and arable land. Background technique [0002] Today's society is facing more and more serious pollution problems. With the development and progress of society, natural resources such as water, land, and air that people rely on for survival are being polluted to varying degrees. In order to better protect the environment, people not only pay more and more attention to the indicators of production emissions, but also need to further process the polluted resources so that they can be used again by people. [0003] Cadmium pollution in farmland is a kind of land pollution. There are four methods to control cadmium (Cd) polluted farmland, namely physical method, leaching method, chemical stabilization method and biological method. [0004] The above four methods use different means to remediate the...

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Problems solved by technology

[0005] (1) Physical method: mainly through soil dumping, guest soil and deep plowing to make farmland return to production. Its advantage is that it can completely eradicate land pollution. The source of soil and the destination of polluted soil are difficult to solve, and it takes a long time to restore soil structure and fertility

[0006] (2) Leaching method: mainly through irrigation or precipitation, the Cd in the topsoil layer is washed to the bottom soil layer, so that the soil in the cultivated layer is purified, so that it can be restored to cultivation. Its advantage is that it will not change the way of cultivated land utilization, but The leaching process will wash out the soil fertility of the farmland, and the soil needs to be re-fattened. The soil after leaching will take a long time to restore cultivation and the project cost will be high

[0007] (3) Chemical stabilization method: mainly by reducing the amount of Cd dissolved in water to prevent plants from absorbing water-soluble cadmium, reduce soil biotoxicity, and avoid accumulation in plants. The advantage is that the investment is low and the effect is quick , the bioavailable content of Cd can be reduced by this method, but in the prior art, only 15-20% of the heavy metal bioavailable content can be removed, and the qualified rate of planting crops on the removed land can only reach 70% about

[0008] (4) Biological method: mainly using hyperaccumulative plants to absorb Cd in the farmland soil to achieve the purpose of reducing the Cd content in the farmland. Its advantage is that it can completely restore the farmland and will not cause side effects on the farmland soil. Find plants with large biomass, strong ability to super-accumulate Cd, and fast life cycle conversion; thus leading to a long recovery period for the overall biological method

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