Distinguishable co-transport mechanisms of phenanthrene and oxytetracycline with oxidized-multiwalled carbon nanotubes through saturated soil and sediment columns: vehicle and competition effects.
To date mechanisms underlying co-transports of engineered nanomaterials (ENMs) with contaminants have not been adequately explored, which involve complex interactions among ENMs, contaminants, and soils. This study investigated co-transport behaviors of 3 oxidized-multiwalled carbon nanotubes (o-MWCNTs) with phenanthrene (PHE) and oxytetracycline (OTC) in soil and sediment columns. Sorptions and desorptions of PHE and OTC by the o-MWCNTs were examined to facilitate the discussion of co-transport mechanisms. The results showed that mobilities of PHE and OTC in the columns were significantly enhanced by the presences of o-MWCNTs in the influents; the eluted o-MWCNTs were positively correlated to the eluted total PHE but negatively correlated to the eluted total OTC; the eluted PHE was mainly in the o-MWCNTs-associated form, while it was mainly the dissolved OTC breaking through the columns. It was thus concluded that the o-MWCNTs acted as vehicles facilitating the PHE transport, while besides the vehicle effect the o-MWCNTs also competed for the adsorption sites on soil particles with OTC and thereby enhancing the OTC mobility. These findings provide new insight into the mechanisms regulating co-transports of ENMs and contaminants in porous media.
School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, PR China.
Jing
J
Fang
School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, PR China; Department of Environmental Science, Zhejiang University, Hangzhou 310058, PR China.
Minhao
M
Wang
School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, PR China; Department of Environmental Science, Zhejiang University, Hangzhou 310058, PR China.
Bing
B
Shen
Department of Environmental Science, Zhejiang University, Hangzhou 310058, PR China.
Luqing
L
Zhang
Department of Environmental Science, Zhejiang University, Hangzhou 310058, PR China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou 310058, PR China. Electronic address: lindaohui@zju.edu.cn.
Daohui
D
Lin
D000327:Adsorption; D037742:Nanotubes, Carbon; D010118:Oxytetracycline; D010616:Phenanthrenes; D012987:Soil; D027981:Symporters
D037742:Nanotubes, Carbon; D010616:Phenanthrenes; D012987:Soil; D027981:Symporters; D010118:Oxytetracycline
Competitive sorption; Nanomaterial; Organic contaminant; Retention; Transport