State Key Laboratory of Water Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
Sci Total Environ. 2012 Nov 15;439:1-7. doi: 10.1016/j.scitotenv.2012.08.022. Epub 2012 Oct 5.
The sorption behaviors of diuron (DIU), fluridone (FLU) and norflurazon (NOR) by a single-walled carbon nanotube (SWCNT) and three multi-walled carbon nanotubes (MWCNT) samples including MWCNT10 (<10nm, outer diameter), MWCNT20 (10-20 nm), and MWCNT40 (20-40 nm) were investigated. All adsorption isotherms were nonlinear and were well fitted with the Freundlich model and Dubinin Ashtakhov (DA) model. The linear relationships between the organic carbon (OC)-normalized saturated adsorption capacity (Q(0)(OC)) and surface area (SA) suggest that SA is presumably responsible for the adsorption of DIU and NOR on CNTs. While FLU, DIU, and NOR OC-normalized distribution coefficients (logK(OC)) of CNTs increased with increasing their hydrophobicity (logK(OW)) and the positive relationships between the logK(OW)-normalized logK(OC) (i.e., logK(OC)/logK(OW)) of FLU, DIU, and NOR and their hydrogen bonding ability indicate that the adsorption of FLU, DIU and NOR was mainly controlled by the hydrophobic interaction and hydrogen bonding. The higher logK(OC) or Q(0)(OC) values of MWCNT10 and SWCNT relative to other large MWCNTs and carbonaceous adsorbents suggest that MWCNT10 has the potential to serve as an adsorbent used to reduce the mobility of herbicides in agricultural and environmental applications.
单壁碳纳米管（SWCNT）和三种多壁碳纳米管（MWCNT）样品（MWCNT10（<10nm，外径）、MWCNT20（10-20nm）和 MWCNT40（20-40nm））对敌草隆（DIU）、氟草隆（FLU）和氟唑草酮（NOR）的吸附行为进行了研究。所有吸附等温线均为非线性，均与弗伦德利希模型和杜宾纳什托哈夫（DA）模型拟合良好。有机碳（OC）归一化饱和吸附容量（Q(0)(OC)）与比表面积（SA）之间的线性关系表明，SA 可能是导致 DIU 和 NOR 在 CNT 上吸附的原因。而 FLU、DIU 和 NOR 的 OC 归一化分布系数（logK(OC)）随其疏水性（logK(OW)）的增加而增加，FLU、DIU 和 NOR 的 logK(OW)-归一化 logK(OC)（即 logK(OC)/logK(OW)）与氢键能力之间的正相关关系表明，FLU、DIU 和 NOR 的吸附主要受疏水相互作用和氢键控制。MWCNT10 和 SWCNT 的 logK(OC)或 Q(0)(OC)值相对于其他大 MWCNT 和碳质吸附剂较高，表明 MWCNT10 具有作为用于减少农业和环境应用中除草剂迁移性的吸附剂的潜力。
