解磷真菌复合骨炭材料修复铅污染土壤的机制研究.

[Objectives] This paper was aimed to study the remediation effects of phosphate-solubilizing fungi and bone char in different soils. [Methods] Three different types of lead-contaminated soils (neutral yellow brown soil, alkaline sand soil and acidic red soil)were mixed with the bone char sintered at different temperatures. We measured the contents of phosphorus and lead, and the remediation differences of different soils. The Pb bioavailability of lead-contaminated soil was then determined by planting non-heading Chinese cabbage. The application potential of compound remediation materials was confirmed by adding compound remediation agents to the soil with the best remediation effect. [Results] The bone char had the best effect of promoting the release of phosphorus in yellow brown soil, and the available phosphorus content was 64 times higher than that of the control, showing a high potential of lead remediation. The pH of yellow brown soil was neutral, and the available P in the soil would not be fixed by Ca, Fe, Al, etc., thus increasing the probability of its reaction with Pb. When bone char was solely used, the material treated at 200-300 ℃ had qualified remediation effect. We planted non-heading Chinese cabbage to verify the bioavailability of lead in yellow brown soil after bone char application. It was observed that addition of a certain proportion of bone char to yellow brown soil (the initial mass ratio of bone char to lead was over 0.5:1) could not only increase the absorption of phosphorus by 2.0 to 3.5 times, but also reduce the absorption of lead by non-heading Chinese cabbage(content of lead in pakchoi leaves was reduced by 70% to 80% compared with blank treatment). A composite of bone char and Aspergillus niger was further applied to yellow brown soil, and the effective lead was reduced to 14.36 mg·kg-1. In particular, the growth of the A. niger proved the remediation potential of the composite. [Conclusions] The composite of bone char and A. niger was suitable for lead remediation in neutral soils, and the suitable heating temperature for preparing bone char was 200-300 ℃. [ABSTRACT FROM AUTHOR]