Method for restoring sludge land heavy metal contaminated soil

Abstract

The invention provides a method for restoring sludge land heavy metal contaminated soil. The method comprises the following steps: applying charcoal base fertilizer in the soil, uniformly mixing the soil with the charcoal base fertilizer, carrying out ageing, after the ageing, putting earthworms in the soil for cultivation, after introducing the earthworms in the soil normally, planting castor-oil plant and applying the charcoal base fertilizer in the soil simultaneously, after a certain period of time, removing the castor-oil plant overall, putting earthworms in the soil for cultivation, after introducing the earthworms in the soil normally, planting willows and applying the charcoal base fertilizer in the soil simultaneously, after a certain period of time, removing the willows overall, and repeating the steps in a circulating manner until content of heavy metal in the soil reaching the safe standard. With adoption of the method, the restoring treatment effect to the sludge land heavy metal contaminated soil is ideal, the treatment time is short, the territory applicability is wide, and secondary pollution to the soil can be avoided.

Description

technical field [0001] The invention relates to the field of contaminated soil treatment, in particular to a method for repairing heavy metal contaminated soil in sludge. Background technique [0002] With the gradual increase of my country's sewage treatment plants and the development of sewage treatment technology, the sludge generated during the sewage treatment process is also gradually increasing. Due to its large size, complex components, high moisture content, low strength, and a large amount of Harmful substances such as pathogenic microorganisms, parasite eggs, and heavy metals, accompanied by stench, these unfavorable factors have brought a lot of inconvenience to its transportation, storage, and subsequent resource utilization. At present, many factories still dump sludge at will. transport, simply landfill or stack, causing damage to the environment. [0003] Heavy metal pollution in sludge has become an environmental problem of worldwide concern. Heavy metals in...

AI Technical Summary

Problems solved by technology

Fixing method to deal with heavy metal pollution in sludge is one of the widely used technologies at home and abroad, but the existing gelling materials for solidification not only have a single source, but also the cost is too high, and at the same time, the pH value of the leachate of the solidified sludge will be too high , in the process of solidified sludge reuse, the strong alkalinity produced by the solidified body in contact with groundwater or surface water will endanger the water quality in the ecosystem; the dissolution of microorganisms to heavy metals in sludge is through the bacteria's dissolution of iron and sulfur in sludge Oxidation increases the oxidation-reduction potential in the sludge and lowers the pH value, thereby dissolving the heavy metals, and leaching the dissolved heavy metals can reduce the content of heavy metals in the sludge. The effect of heavy metals is good, but how to properly deal with high-concentration heavy metal leachate is still a thorny problem; sludge incineration can effectively decompose toxic and harmful components in sludge, enrich heavy metals, and facilitate centralized treatment. However, sludge The slime incineration process will produce secondary pollution, including harmful gases, harmful waste residues, etc.

Images