Yilu XuUniversity of Newcastle
I am studying as a Ph. D. candidature of soil remediation of University of Newcastle. With a background in environmental science and ecology, my research interests include soil carbon sequestration and microbial carbon use efficiency, and heavy metal contaminated soil quality assessment and remediation. I have been working on ‘Soil Carbon Assimilation and Dynamics in Relation with Microbial Carbon Use Efficiency’ as part of my Ph.D. program.
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Abstract
Heavy metal speciation and availability on soil microorganism activities.
The heavy metal(loid)s contamination is pronounced in soils adjacent to mine sites. As an important habitat to thousands of organisms, soil health condition is crucial to their actives. Consequently, soil microbial functioning exposed to long-term contamination by heavy metals affects the role of soils as a carbon sink. Heavy metal toxicity to soil microorganisms are highly depends on their (potential) availability. Therefore, a thorough research on understanding the relation between heavy metal(loid)s and microorganisms will help to detect soil fertility and contribute to soil organic remediation.
We studied the effects of heavy metal speciation and availability on soil microorganism activities at different cadmium and lead contamination gradients, separately as well as jointly. Soil microbial respiration, microbial biomass carbon were investigated. Microbial PLFAs were also extracted and analysed by gas chromatography combined with GC‒MS, HP 5973. Potential and bio-available heavy metal concentration were extracted by 0.05 M EDTA and 0.1 M CaCl2, respectively. Results showed that depending on the solubility and mobility of the heavy metals, the potential bioavailable heavy metal concentration varied between Cd and Pb. In addition, microbial activity and biomass were both reduced because of metal toxicity.
Heavy metal speciation and availability on soil microorganism activities.
The heavy metal(loid)s contamination is pronounced in soils adjacent to mine sites. As an important habitat to thousands of organisms, soil health condition is crucial to their actives. Consequently, soil microbial functioning exposed to long-term contamination by heavy metals affects the role of soils as a carbon sink. Heavy metal toxicity to soil microorganisms are highly depends on their (potential) availability. Therefore, a thorough research on understanding the relation between heavy metal(loid)s and microorganisms will help to detect soil fertility and contribute to soil organic remediation.
We studied the effects of heavy metal speciation and availability on soil microorganism activities at different cadmium and lead contamination gradients, separately as well as jointly. Soil microbial respiration, microbial biomass carbon were investigated. Microbial PLFAs were also extracted and analysed by gas chromatography combined with GC‒MS, HP 5973. Potential and bio-available heavy metal concentration were extracted by 0.05 M EDTA and 0.1 M CaCl2, respectively. Results showed that depending on the solubility and mobility of the heavy metals, the potential bioavailable heavy metal concentration varied between Cd and Pb. In addition, microbial activity and biomass were both reduced because of metal toxicity.
