Composite passivator for heavy metals in soil and using method of composite passivator

Abstract

The invention relates to a composite passivator for heavy metals in soil and a using method of the composite passivator and belongs to the technical field of soil treatment. The composite passivator for heavy metals in soil is prepared from the following components in percentage by mass: 30%-50% of phosphate ores, 15%-25% of calcium hydrogen phosphate, 15%-25% ofcalcium magnesium phosphate fertilizer and 5%-20% of sintered red mud. The using method disclosed by the invention comprises the steps: mixing the composite passivator for heavy metals in soil with soil polluted by heavy metals according to a proportion of (1-5):100, adding water to keep the soil water content be 75% of the maximum water holding capacity of a field, and keeping the soil water content at normal temperature for 40 days. The soil polluted by the heavy metals is passivated and remediated by utilizing cheap ores and wastes, controlling pollution by using the wastes is realized under the condition that the cost is relatively low, and dverse effects to the soil environment cannot be caused. In addition, an adding method disclosed by the invention is relatively simple and capable of adapting to the large-scale remediation of soil polluted by the heavy metals.

Description

technical field [0001] The invention belongs to the technical field of soil treatment, and in particular relates to a soil heavy metal composite passivator and a use method thereof. Background technique [0002] At present, the restoration of heavy metal pollution in soil mainly has the following two methods: one is to change the occurrence form of heavy metals in the soil to reduce their mobility, bioavailability and environmental risks in the soil, that is, to stabilize heavy metals; the other is to stabilize heavy metals. Heavy metals are removed from the soil so that the soil heavy metal content approaches or reaches the soil background value. The stabilization technology has attracted extensive attention due to its advantages of short treatment time, low cost, wide application range, and small impact on the ecological environment. At present, the commonly used passivation fixatives include inorganic passivation agents and organic passivation agents. Inorganic passivat...

AI Technical Summary

Problems solved by technology

However, the organic remediation agent is expensive, and the existing soil heavy metal passivation agent is generally added in a large amount, and the cost is too high, so it is difficult to apply in practice

In addition, organic polymers are used as soil heavy metal passivators for soil remediation, but there is a risk of decomposition of this passivator, and heavy metals may be released again, causing harm to the soil environment

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