Yao C, Lei G, Cathles LM, Steenhuis TS (2014) Pore-Scale Investigation of Micron-Size Polyacrylamide Elastic Microspheres (MPEMs) Transport and Retention in Saturated Porous Media. Environ Sci Technol 48: 5329–5335. Available: http://dx.doi.org/10.1021/es500077s.
We thank Douglas Caveney for help with constructing the transparent micromodel. This research was supported by Program for Changjiang Scholars and Innovative Research Team in University (IRT1294), the China Scholarship Council for Chuanjin Yao (Grant No. 201306450015), and the Fundamental Research Funds for the Central Universities of China (Project No. 11CX06025A).