Fulvic acid-potassium chloride combined eluant, and preparation method and application thereof

Abstract

The invention discloses a fulvic acid-potassium chloride combined eluant, and a preparation method and application thereof, relating to the technical field of restoration of heavy metal pollution in soil. According to the invention, humic acids with different qualities for restoring heavy metal cadmium polluted soil are dissolved in a 0.1m / L potassium chloride solution, a 0.1m / L sodium hydroxide solution is utilized to regulate the pH value to 11 or so to prepare a 0.05-1.00% humic acid solution, centrifugation is performed, and the separated solution is a fulvic acid-potassium chloride mixed solution; and the fulvic acid-potassium chloride mixed solution can be used as a combined eluant to elute the cadmium polluted soil. The chemical eluant used in the invention has the advantages of simple formula, obvious effect, strong operability, low application cost, high elution rate and high removal effect for cadmium ions in soil. The test indicates that the elution rate is optimal when the concentration of the eluate is 0.05%, the pH value is 4, the volume ratio of the eluant to the cadmium polluted soil is 10:1 and the elution time is 2 hours; and the eluate can not generate secondary pollution to the soil, and has an obvious supplementation action on potassium lost in the elution process.

Description

technical field [0001] The invention discloses a combined leaching agent of fulvic acid and potassium chloride and its preparation method and application thereof, and relates to the technical field of remediation of heavy metal pollution in soil, in particular to a leaching agent for repairing soil cadmium (Cd) pollution and its application . Background technique [0002] Soil heavy metal pollution is one of the serious environmental problems facing the world today. At present, phytoremediation is mostly used to control soil cadmium pollution. However, because the recommended heavy metal-enriched or hyper-accumulated plants often have the characteristics of low biomass, long remediation period, and easy to be affected by climate, the remediation benefits are low. [0003] The soil leaching method belongs to the heavy metal chemical remediation method, that is, the use of chemical or biological leaching agents to enhance the mobility of heavy metals in the soil, so as to ef...

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Problems solved by technology

[0004] Humic acid is a polymer aggregate composed of a variety of functional groups, and it exists widely in the soil environment. Current research focuses on the adsorption and desorption characteristics of humic acid on heavy metals in the water environment or the auxiliary function of humic acid in phytoremediation. However, there are few reports on the leaching method of various components in humic acid, especially the combination of fulvic acid and other reagents, on soil cadmium pollution, and the current leaching agents do not consider the loss of soil potassium nutrients by leaching agents. In addition, most of the heavy metals in the soil are combined with the solid phase, which limits the leaching effect of the leaching agent on heavy metals, and the leaching efficiency is not high.

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