Effects of phosphate on the transport of graphene oxide nanoparticles in saturated clean and iron oxide-coated sand columns  

作　　者：Jiuyan Chen Weifeng Chen Taotao Lu Yumeng Song Haojing Zhang Mengjie Wang Xinhai Wang Zhichong Qi Minghua Lu 

机构地区：[1]Henan International Joint Laboratory of Medicinal Plants Utilization,Henan Joint International Research Laboratory of Environmental Pollution Control Materials,Engineering Research Center for Industrial Recirculation Water Treatment of Henan Province,College of Chemistry and Chemical Engineering,Henan University,Kaifeng 475004,China [2]Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria,Nankai University,Tianjin 300350,China [3]Ministry of Education Key Laboratory of Humid Subtropical Eco-geographical Process,Fujian Provincial Key Laboratory for Plant Eco-physiology,College of Geographical Science,Fujian Normal University,Fujian 350007,China [4]Department of Hydrology,University of Bayreuth,Bayreuth D-95440,Germany

出　　处：《Journal of Environmental Sciences》2021年第5期80-92,共13页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.21707081);the Opening Foundation of Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria(No.2018-06);Science and Technology Major Project of Henan Province,Henan,China(No.CX0001F01800);the College Students’Innovative Training Program of Henan Province(No.202013501013);the Project Management of Innovation and Entrepreneurship Training Program for Minsheng College Students(No.MSCXSY2019013);the China Scholarship Council(No.201708420145)。

摘　　要：In this study, transport behaviors of graphene oxide(GO) in saturated uncoated(i.e., clean sand) and goethite-coated sand porous media were examined as a function of the phosphate. We found that phosphate enhanced the transport of GO over a wide range of solution chemistry(i.e., pH 5.0–9.0 and the presence of 10 mmol/L Na^(+) or 0.5 mmol/L Ca^(2+)). The results were mainly ascribed to the increase of electrostatic repulsion between nanoparticles and porous media. Meanwhile, deposition site competition induced by the retained phosphate was another important mechanism leading to promote GO transport. Interestingly, when the phosphate concentration increased from 0.1 to 1.0 mmol/L, the transportenhancement effect of phosphate in goethite-coated sand was to a much larger extent than that in clean sand. The observations were primarily related to the difference in the total mass of retained phosphate between the iron oxide-coated sand and clean sand columns, which resulted in different degrees of the electrostatic repulsion and competitive effect of phosphate. When the background solution contained 0.5 mmol/L Ca^(2+), phosphate could be bind to sand/goethite-coated sand surface by cation bridging;and consequently, promoted competition between phosphate and nanoparticles for deposition sites, which was an important mechanism for the enhanced effect of phosphate. Moreover, the DLVO theory was applicable to describe GO transport behaviors in porous media in the absence or presence of phosphate. Taken together, these findings highlight the important status and role of phosphate on the transport and fate of colloidal graphene oxide in the subsurface environment.

关 键 词：Graphene oxide PHOSPHATE GOETHITE TRANSPORT Sand 

分 类 号：X131[环境科学与工程—环境科学]