Journal of Hazardous Materials：氧化石墨烯纳米片在模拟土壤中的浸出及其对微生物群落的影响

南开大学环境科学与工程学院周启星教授团队对氧化石墨烯纳米片在模拟土壤中的浸出及其对微生物群落的影响进行了研究。相关成果发表于Journal of Hazardous Materials（IF=9.038）。

Highlights

•Soil porosity and soil adsorption affect leaching and migration of rGO.

•The physicochemical properties of rGO−Pd nanosheets changed by leaching processes.

•rGO increases microbial species richness and community diversity of soil.

•rGO regulates the use of carbon sources by microorganisms in soil.

Abstract

With the wide use of graphene-like nanosheets, especially in agriculture, their release into the environment, it is crucial to grasp the fate of nanosheets in soil and minimum ecological risks. The present work discovered that leaching and migration of nanosheets (rGO) in soil is affected by soil porosity and adsorption processes. And the contents of rGO−Pd in soil layers and leachate increased and then decreased with the decreased of soil porosity. Moreover, physicochemical properties of rGO−Pd nanosheets changed by leaching processes, especially the changes of morphology, thickness and oxygen functional groups. Leaching of rGO−Pd also interfered the soil microbial homeostasis accompanied by the increase of microbial species richness and community diversity. In addition, rGO−Pd altered the usage of carbon sources by edaphon. The utilization of carbon sources by soil microbes, such as polymers, sugars, phenolic acids, carboxylic acids, amino acids, and amines, was also reduced by nanosheets. These findings provide new insights into environmental behaviors of nanomaterials and nanogeochemistry.

随着石墨烯类纳米片的广泛使用，特别是在农业中的使用，其被释放到环境中，因此，掌握这些纳米片在土壤中的归宿，并降低其生态风险至关重要。研究发现，土壤中的纳米片（rGO）的浸出和迁移受土壤孔隙率和吸附过程的影响。随着土壤孔隙度的降低，土壤层和渗滤液中rGO-Pd的含量先升高后降低。此外，rGO-Pd纳米片的理化性质通过浸出过程而改变，尤其是形态、厚度和氧官能团发生了改变。rGO-Pd的浸出还伴随着微生物物种丰度和群落多样性的增加而干扰了土壤微生物的动态平衡。另外，rGO-Pd通过土壤微生物群落改变了碳源的使用。纳米片还减少了土壤微生物对碳源的利用，例如聚合物、糖、酚酸、羧酸、氨基酸和胺。这些发现为纳米材料的环境行为和纳米地球化学提供了新的见解。