Method for removing input cadmium in air and irrigation water in paddy fields

Abstract

The invention discloses a method for removing input cadmium in air and irrigation water in paddy fields. The method particularly includes steps of 1), selecting natural biological crusts which are excellently developed and acquiring crust layers of surface layers by means of shoveling; 2), drying the acquired biological crusts in the shade, removing sundries, then smashing the biological crusts, and sufficiently stirring and uniformly mixing the biological crusts with one another to obtain biological crust seed sources; 3), proportionally mixing the prepared biological crust seed sources and fine soil with one another to obtain mixtures, uniformly spreading the mixtures to to-be-inoculated soil surfaces, then watering fields and keeping the field water-holding capacity of 70-80% unchanged;4), controlling appropriate conditions and promoting growth of biological crusts; 5), allowing crusts to naturally float up under the condition of sun illumination after the crusts are mature, draining water at the moment and allowing the crusts to flow out of the paddy fields along with water flow. The method has the advantages that the biological crust seed sources are artificially inoculated in the paddy fields, the biological crusts are cultivated and can quickly grow, the heavy metal cadmium can be absorbed, water flooding is kept in growth and mature later periods, and accordingly the crusts can naturally float up and can be shifted out of farmlands by means of fishing; the biological crusts formed by the aid of the method have obvious functions of absorbing and immobilizing the cadmium in the paddy fields.

Description

technical field [0001] The invention relates to a method for removing heavy metals in a water body environment, in particular to a method for removing cadmium from air and irrigation water input in rice fields by using rice field biological crust biological communities. Background technique [0002] Due to the long-term input of heavy metal pollutants into the cultivated land system by mine smelting and chemical enterprises in various forms, coupled with the entry of heavy metals in fertilizers, a large area of ​​cultivated land in my country has been polluted by heavy metals, which has seriously threatened the safety of my country's food and other agricultural products. According to statistics, the area of ​​cultivated land polluted by heavy metals in my country is nearly 20 million hm 2 , accounting for about 1 / 5 of the total cultivated land area (Luo Yongming, 2006). Among them, cadmium has a strong ability to migrate in the soil, easily enters the food chain, and can ca...

AI Technical Summary

Problems solved by technology

These technologies can effectively reduce the cadmium content in paddy soil, but cannot remove the cadmium continuously input by atmospheric deposition and farmland irrigation water in time

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