In-depth understanding of transport behavior of sulfided nano zerovalent iron/reduced graphene oxide@guar gum slurry: Stability and mobility  

作　　者：Yuheng Ma Wenhui You Zijiang Yang Zhongyu Ren Qi Jing 

机构地区：[1]Faculty of Architecture,Civil and Transportation Engineering,Beijing University of Technology,Beijing 100124,China

出　　处：《Journal of Environmental Sciences》2024年第10期1-14,共14页环境科学学报（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(No.41907176).

摘　　要：Nanoscale zero-valent iron(NZVI),which has the advantages of small particle size,large specific surface area,and high reactivity,is often injected into contaminated aquifers in the form of slurry.However,the prone to passivation and agglomeration as well as poor stability andmobility of NZVI limit the further application of this technology in fields.Therefore,sulfided NZVI loaded on reduced graphene oxide(S-NZVI/rGO)and guar gum(GG)with shearthinning properties as stabilizers were used to synthesize S-NZVI/rGO@GG slurries.SEM,TEM,and FT-IR confirmed that the dispersion and anti-passivation of NZVI were optimized in the coupled system.The stability and mobility of the slurry were improved by increasing the GG concentration,enhancing the pH,and decreasing the ionic strength and the presence of Ca^(2+)ions,respectively.A modified advection-dispersion equation(ADE)was used to simulate the transport experiments considering the strain and physicochemical deposition/release.Meanwhile,colloidal filtration theory(CFT)demonstrated that Brownian motion plays a dominant role in themigration of S-NZVI/rGO@GG slurry,and the maximummigration distance can be increased by appropriately increasing the injection rate.Extended-Derjaguin-Landau-Verwey-Overbeek(XDLVO)theory showed that the excellent stability and migration of S-NZVI/rGO@GG slurry mainly came from the GG spatial forces.This study has important implications for the field injection of S-NZVI/rGO@GG slurry.According to the injection parameters,the injection range of S-NZVI/rGO@GG slurry is effectively controlled,which lays the foundation for the promotion of application in actual fields.

关 键 词：S-NZVI rGO Guar gum Transport STABILITY 

分 类 号：X703.5[环境科学与工程—环境工程]