人工合成纳米材料在水环境中的聚沉行为研究进展

Research Advances on the Aggregation and Sedimentation of Synthetic Nanomaterials in the Aquatic Environment

随着纳米科技的快速发展,纳米材料的种类和数量呈指数增长。人工纳米材料不可避免地进入水环境并发生复杂的环境行为,可能在水中分散悬浮,也可能发生团聚和沉降,从而影响其迁移、转化和归趋。本文综述了近年来有关人工合成纳米材料在水环境中聚沉行为的研究进展,分析了影响纳米材料团聚与沉降的两个主要因素:自身理化性质(材料形态、颗粒尺寸、化学组成、晶体结构、表面修饰等)和水环境要素(pH、离子种类和离子强度、天然有机质等)及相应的作用机理,剖析了当前研究中存在的问题,指出有关纳米材料与无机胶体等物质间的异团聚、各环境要素间的交互作用、以及纳米材料在接近自然环境的低浓度(<1mg/L)条件下的聚沉行为研究仍需进一步完善。

With the rapid development of nanotechnology,the variety and quantity of nano-materials are exponentially increased. Once inevitably released into the aquatic environment,synthetic nanomaterials will result in complicated environmental behaviors as they could be dispersed and suspended in water,or aggregated into bigger particles and settled down in water,which will inevitably affect the transportation,transformation and fate of themselves. This paper has reviewed the research advances on the aggregation and sedimentation of nanomaterials in aquatic environment in recent years,analyzed two key factors influencing the aggregation and sedimentation of nanomaterials,including the physicochemical characteristics of nanomaterials( such as particle size,chemical composition,particle morphology,crystal structure,surface modification,and nanomaterial concentration) and the hydrochemical characteristics of the aquatic environment( such as pH values,ionic species and strengths,and natural organic matters),and their corresponding mechanisms of action,analyzed the existing problems in current researches,and finally pointed out that future studies on the heteroaggregation between nanomaterials and substances such as inorganic colloids,the interaction between various environmental factors,and the aggregation and sedimentation behaviors of nanomaterials under the condition of low concentration(<1 mg/L),which is close to the natural environment,should be further undertaken and improved.