Slow release organic fertilizer for passivation repairing of heavy metal polluted soil and preparation and application thereof

Abstract

The invention primarily relates to a multifunctional slow release organic fertilizer containing a heavy metal passivator and a preparation method. The fertilizer comprises the main components: thoroughly decomposed compost, a chemical nitrogen fertilizer, a biochemical inhibitor, a soil heavy metal passivating material, plant growth beneficial elements, a water retaining material and a coating liquid for coating the periphery of the organic particles. The proportion of the thoroughly decomposed compost, the chemical nitrogen fertilizer, the biochemical inhibitor, the soil heavy metal passivating material, the plant growth beneficial elements, the water retaining material and the coating liquid is 1: (0.1-0.3):(0.05-0.1):(0.01-0.2):(0.001-0.02):(0.04-0.08):(0.05-0.1). The fertilizer can reduce bio-availability of heavy metals in the heavy metal polluted soil and reduce adsorption of the heavy metals by crops and increase the content of organic matters in soil and improve the soil fertility, can promote crop growth and enhance water and fertilizer-retaining abilities of the soil, and enhance various functions of crops, for example, disease resistance, drought resistance and the like.

Description

technical field [0001] The invention belongs to the field of remediation of soil heavy metal pollution by organic passivators, and relates to a method for realizing remediation of soil heavy metal pollution by utilizing organic fertilizers. Specifically, it is a slow-release organic fertilizer that can not only reduce the bioavailability of heavy metals in the soil, but also promote crop growth and enhance soil water and fertilizer retention capacity, so as to realize resource recycling. Background technique [0002] With the rapid development of industrialization and urbanization, soil heavy metal pollution is becoming more and more serious. The 2014 my country Soil Pollution Survey Bulletin shows [Reference 1: National Soil Pollution Survey Bulletin [EB / OL].2014-04-17], my country 19.4% of farmland soil pollution points exceeded the standard, especially heavy metal polluted soil, and the excessive use of chemical fertilizers aggravated the pollution of heavy metals to the s...

AI Technical Summary

Problems solved by technology

Soil pollution remediation generally reduces the bioavailability of heavy metals through complexation, adsorption, precipitation, redox, etc. The remediation technologies for heavy metal-contaminated soil mainly include electrodynamic remediation technology, leaching method, phytoremediation, microbial remediation, and plant-microbial joint remediation. technology, etc., but these technologies have disadvantages of varying degrees, such as high cost, complex operation, low repair efficiency, poor long-term stability and single repair pollution

[0003] Passivating agent remediation is a method that can reduce the absorption of heavy metal ions by plants. It can be divided into inorganic and organic passivating agents. As an organic passivating agent, organic fertilizer has a passivating effect on heavy metals and is an effective method for repairing heavy metal-contaminated soil. Means, organic and inorganic passivators can reduce the effective concentration of pollutants in the soil through processes such as adsorption, co-precipitation, and complexation. Although these two types of passivators have the advantages of low cost, simple process, and reduced plant toxicity of heavy metals, etc. , but have the disadvantages of low repair efficiency, poor stability, and easy to produce secondary pollution [Reference 2: Mahar, A., Ping, W.A.N.G., Ronghua, L.I., & ZHANG, Z. (2015). Immobilization of lead and cadmium incontaminated soil using amendments: a review. Pedosphere, 25(4), 555-568.]

At the same time, if the soil is barren and under water stress conditions, coupled with the coexistence of various heavy metal pollution ions in the polluted soil, the soil environmental conditions will be worse, and the interaction between pollutants will also aggravate the toxicity, inhibit soil animals and The growth and reproduction of microorganisms, as well as the growth of plants, is not conducive to the improvement and stability of the restoration effect

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