Department of Economics and Trade, Hunan University, Changsha 410082, China.
College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China.
J Environ Sci (China). 2018 Aug;70:166-174. doi: 10.1016/j.jes.2017.11.027. Epub 2017 Dec 8.
Biochar is regarded as a promising new class of materials due to its multifunctional character and the possibility of effectively coupling different properties. With increasing introduction into the environment, environmental chemicals such as surfactants will load onto the released biochar and change its physicochemical characteristics and adsorption behavior toward pollutants. In this study, sodium dodecyl sulfate (SDS), as one type of anionic surfactant, was coated onto biochar with different loading amounts. The influence of SDS loading onto biochar's physicochemical properties were investigated by Fourier transform infrared (FT-IR) spectroscopy, elemental analysis, zeta potential and Brunauer-Emmett-Teller (BET) surface area and pore size distribution analysis. Results showed that the pore size of the biochar decreased gradually with the increase of SDS loading because of the surface-adsorption and pore-blocking processes; the pH of the point of zero charge (pH) decreased with increasing SDS loading. Although surface-coating with SDS decreased the pore size of the biochar, its adsorption capacity toward Methylene Blue (MB) significantly increased. The biochar-bound SDS introduced functional groups and negative charges to the biochar surface, which could thus enhance the adsorption of MB via hydrogen bonding and electrostatic interaction. The results can shed light on the underlying mechanism of the influence of anionic surfactants on the adsorption of MB by biochar.
生物炭因其多功能特性和有效耦合不同性质的可能性而被视为一类很有前途的新材料。随着生物炭不断被引入环境，环境化学品如表面活性剂将负载在释放的生物炭上，并改变其对污染物的物理化学特性和吸附行为。在本研究中，十二烷基硫酸钠（SDS）作为一种阴离子表面活性剂，被负载在不同负载量的生物炭上。通过傅里叶变换红外（FT-IR）光谱、元素分析、动电位和 Brunauer-Emmett-Teller（BET）表面积和孔径分布分析，研究了 SDS 负载对生物炭物理化学性质的影响。结果表明，由于表面吸附和孔阻塞过程，生物炭的孔径随着 SDS 负载量的增加而逐渐减小；零电荷点（pH）的 pH 值随着 SDS 负载量的增加而降低。尽管 SDS 的表面涂层减小了生物炭的孔径，但它对亚甲基蓝（MB）的吸附容量却显著增加。生物炭结合的 SDS 为生物炭表面引入了官能团和负电荷，从而可以通过氢键和静电相互作用增强对 MB 的吸附。研究结果可以揭示阴离子表面活性剂对生物炭吸附 MB 的影响的潜在机制。
