水沙体系中碳纳米材料和抗生素复合污染对藻类的毒性效应及机制

In recent years, the ecological risk and environmental safety of nanomaterials (NMs) have drawn great concern with their increasing application. Many studies have investigated the toxicity of NMs. However, the effect of sediments on the toxicity of NMs was rarely reported. Suspended sediments and varieties of pollutants are ubiquitous in natural rivers. Recently, researchers began to examine the combined toxicity of NMs and pollutants. However, the effect of sediments on the combined toxicity of NMs and pollutants remains unknown. Therefore, in this study, carbon-based NMs (CNMs) and antibiotics were selected as target pollutants, the toxicity of CNMs and/or antibiotics on algae was investigated in a water and sediment system. Metabolomics studies combined with multiple statistics and metabolic pathway analysis were performed to reveal the molecular responses of algae to CNMs and antibiotics. The effects of salinity and nutrients on the toxicity of CNMs and/or antibiotics were also investigated. Moreover, the contents, particle size and components of sediments on the toxicity of CNMs and/or antibiotics to algae were determined. The results are important to reveal the behaviors, toxicity, ecological and environmental risks of CNMs and pollutants.

近年来，随着纳米材料的广泛应用，其潜在生态风险和环境安全问题引起了国内外政府和研究者的高度关注。有关纳米材料毒性效应的研究很多，但已有研究很少考虑泥沙对纳米材料毒性效应的影响。实际的水体是水沙多介质的体系，也是多种污染物复合污染的体系。最近，人们开始关注纳米材料和其他污染物复合污染的毒性效应，但有关泥沙对复合污染毒性效应影响的研究鲜有报道。本项目以碳纳米材料（CNMs）和抗生素为目标污染物，以藻类为研究对象，探讨水沙介质中CNMs和抗生素单一和复合污染对藻类的毒性效应；建立藻类代谢组学分析技术，通过统计分析和代谢通路分析，阐释藻类对CNMs和抗生素毒性的分子响应机制；探讨水体盐度和营养物质对CNMs和抗生素毒性效应的影响；分析水沙体系中泥沙含量、粒径和组成对CNMs和抗生素毒性效应的影响及机理。研究对揭示天然水体中CNMs和污染物的环境行为、毒性效应、潜在生态危害和环境风险具有重要意义。

纳米材料和抗生素都是典型的新污染物。近年来，随着纳米材料和抗生素的广泛应用，二者在自然环境中不断被检出，其生态风险和环境安全问题引起了各国政府和学者的高度关注。然而，目前有关纳米材料和抗生素毒性效应的研究多局限于单一类污染物，很少关注二者复合污染的联合毒性效应，更鲜少关注天然水体中泥沙颗粒对污染物毒性效应的影响。本研究以典型碳纳米材料（碳纳米管和氧化石墨烯）和抗生素为目标污染物，以水生生态系统的初级生产者——蓝藻（Synechocystis sp. PCC 6803）为模式生物，系统研究了典型碳纳米材料和抗生素对蓝藻的联合毒性效应，并进一步选用环境中普遍存在的天然碳材料溶解性腐殖酸和颗粒态黑炭，探讨了腐殖酸、黑炭和抗生素对蓝藻的毒性效应及机理，剖析了天然矿物胶体（氧化铝和氧化硅）对碳材料和抗生素联合毒性效应的影响及机理。研究从细胞和分子水平上揭示了碳材料和抗生素对蓝藻的毒性机理，发现了碳材料对抗生素的吸附作用是决定二者对蓝藻联合毒性效应的重要因素，并建立了碳材料和污染物联合毒性效应的预测模型，为评价和预测水体碳材料和污染物联合毒性效应提供了重要方法与手段。揭示了天然水体中不同矿物胶体通过改变碳材料和污染物的相互作用而影响其联合毒性，为评价和预测实际水体中不同污染物的联合毒性效应提供了新见解。研究成果对揭示天然水体中碳材料和污染物的环境行为及其毒性效应具有重要意义，并为碳材料和抗生素应用的潜在生态危害和环境风险评价提供理论依据。