Method for safely utilizing heavy metal polluted cultivated land based on combination of charcoal in-situ passivation and sweet sorghum planting

Abstract

The invention discloses a method for safely utilizing heavy metal polluted cultivated land based on combination of charcoal in-situ passivation and sweet sorghum planting. Results show that after 0.5%of coconut shell charcoal, 0.2% of lime and 1% of coconut shell charcoal and 0.4% of lime are treated, the effective cadmium content and the effective lead content of soil are both reduced by 50% orabove, and 0.5% of coconut shell charcoal and 0.2% of lime are treated ideally in combination with cost consideration; the four sweet sorghum varieties all show good heavy metal tolerance. After passivating agent treatment, the content of cadmium and lead in the sweet sorghum stems is remarkably reduced. The result shows that the low-absorption strain is suitable for stable restoration and energyutilization of heavy metal polluted areas. Besides, the content of cadmium and lead in the sweet sorghum grains is hardly detected within the feed standard, which indicates that the grains are safe and can be used as a feed raw material. The method is simple and convenient in technology and easy to implement and has an extremely wide application prospect in vast heavy metal polluted areas.

Description

technical field [0001] The invention relates to a method for safely utilizing heavy metal polluted cultivated land based on biochar in-situ passivation combined with sweet sorghum planting. Background technique [0002] In recent years, my country's industrialization and urbanization process has been accelerating, and a large number of pollutants have been discharged randomly, which has made soil heavy metal pollution increasingly serious, and the polluted area is also expanding year by year. The heavy metals cadmium and lead are enriched, stay in the soil for a long time, are easy to accumulate in the topsoil, and can be absorbed by plants. They are the main heavy metal pollution in the soil-plant ecosystem in China. According to statistics, the area of ​​cultivated land polluted by heavy metals in my country has reached 20 million hectares. Every year, 12 million tons of grains are polluted and heavy metals exceed the standard, causing direct economic losses of 20 billion ...

AI Technical Summary

Problems solved by technology

Studies have shown that sorghum is a crop that can effectively absorb heavy metals, but the ability of different sorghum lines to absorb heavy metals varies greatly

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