Passivator for alkaline soil and application of passivator

Abstract

The invention discloses a passivator for alkaline soil. The passivator is prepared with a method including preparation steps as follows: A), biochar is placed in a mixed solution of sodium sulfide and sulfuric acid to be soaked for 3-5 h; B), a reactant is ultrasonically washed for 30 min and then put in a microwave chemical reactor to react for 10 min; C), the reactant is subjected to suction filtration, the biochar is washed with deionized water to be neutral and dried, and the passivator for the alkaline soil is obtained. The passivator for the alkaline soil can adsorb cadmium ions in the alkaline soil, reduces the content of cadmium in the soil and has the advantages of high repairing rate, good long-term stability, low cost, simplicity in application and the like; besides, the modified biochar contains a large quantity of organic matters and other nutrient elements, rich nutrition is provided for plant growth, and the passivator has huge application and popularization value.

Description

technical field [0001] The invention relates to the field of soil heavy metal pollution control, in particular to an alkaline soil cadmium passivator and application thereof. Background technique [0002] Soil is the natural environment on which human beings depend and an important resource for agricultural production. However, environmental pollution and ecological damage are becoming more and more serious, seriously affecting human health and survival. Among them, heavy metal elements are particularly serious in polluting and damaging the environment. It is one of the most extensive and harmful environmental problems that human beings face, and which needs to be solved urgently. [0003] For large areas of heavy metal-contaminated soil, especially moderately and slightly polluted soil, the in-situ chemical passivation repair technology has the advantages of simple implementation, low cost and fast treatment speed. For the in-situ fixed passivation restoration technology ...

AI Technical Summary

Problems solved by technology

Meng Lingyang used greenhouse pot experiments and soil culture experiments to study the effects of adding peat, activated carbon, and weathered coal to cadmium-contaminated soil (pH=5.5) on the occurrence and bioavailability of cadmium in the soil, and explored its role as a heavy metal cadmium-contaminated soil. The feasibility of the remediation agent, the research results show that: the three organic carbon materials all reduce the soil pH value, after adding different inert organic carbon remediation agents to the cadmium-contaminated soil, the content of extractable cadmium in the soil does not change significantly, and the three remediation agents On the contrary, it increases the cadmium content in crops ("The influence of inert organic carbon materials on the form and bioavailability of cadmium in soil", Meng Lingyang et al., Journal of Agricultural and Environmental Sciences, 2011). The core of in-situ chemical fixation and repair is the passivation agent Selection, it is particularly important to select a suitable passivator for the soil type. At present, there are a large number of passivators that can achieve the adsorption and passivation of effective heavy metals in acidic and neutral cadmium-contaminated soils, but they are not effective for soil cadmium pollution under alkaline conditions. incomplete application

In my country, the alkaline farmland polluted by heavy metal cadmium also accounts for a very high proportion, but there has been no long-term effective passivator that can passivate and fix cadmium. chemical agent appears to be extremely urgent

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