Carbon Nanotube-impeded Transport Of Non-steroidal Anti-inflammatory Drugs In Xiangjiang Sediments

In recent years,with the development of nanotechnology,carbon nanotubes(CNTs)are considered as a kind of new nano-material,which are extensively used in electronics,pharmaceuticals and optic fields.In addition,CNTs are expected to ultimately released to the environment through their manufacturing,usage,and eventual disposal,which will influence the environmental safety and human health.Nonsteroidal anti-inflammatory drugs(NSAIDs)are one of the most prescribed pharmaceuticals,which can be released to the environment with the medical production,human medical treatment and medical waste treatment.With a superior affinity with organic chemicals,CNTs can be carriers for pollutants,thus influencing the environmental behavior of pollutants.As a result,the movement of NSAIDs can be influenced,and then result in environmental risks.The primary target of this study was to research the adsorption of the NSAIDs on Xiangjiang sediments and CNTs,with which we can study the influence of CNTs on the movement of NSAIDs in Xiangjiang sediments.In this study,batch and column experiments were performed to examine the effects of two kinds of multi-walled carbon nanotubes(MWCNTs: MWCNT2040,MWCNT0815)and one kind of single-walled carbon nanotubes(SWCNTs)on the environmental fate of two NSAIDs,paracetamol(PA)and diclofenac sodium(DS).Impact ways of CNTs including addition in inflow and mixing with sediments were investigated.The adsorption capacity of NSAIDs on Xiangjiang sediments increased with increasing CNTs/sediments ratios and in an order of MWCNT2040 ? MTWCNT0815? SWCNT.In column tests,PA showed a higher mobility than DS.With CNTs in inflow,the amounts of NSAIDs leached from sediment columns reduced because of the association with CNTs.For the sediment columns mixed with CNTs,breakthrough of the two NSAIDs was dramatically retarded,and the NSAIDs were hard to separate from CNT-polluted sediments.Our work provides useful insights into fate,transport and risk assessment of NSAIDs in the presence of CNTs.