A highly-accessible introduction to mass transfer problems in environmental engineering and science. Chemical transport processes in environmental systems are exceptionally complex and notoriously difficult to model. Unlike equations derived for homogenous, well-defined environments in chemical production, for example, equations derived for environmental systems rely upon calculations made for highly heterogeneous, often poorly defined environments consisting of a great many phases and chemicals. Unfortunately, texts on chemical transport usually focus on problems related to chemical process engineering, making it exceedingly difficult for environmental engineers to model processes in natural and engineered systems. This book provides practicing engineers and graduate students with a clear, comprehensive introduction to transport processes in environmental systems. Structured to suit a one-semester, introductory course on the subject, it begins with the basics of molecular diffusion and chemical partitioning and then progresses to more advanced topics including dispersion, particle transport, fractals, and biofilms. Throughout, the author places an equal emphasis on both engineered and natural systems. Each chapter draws on realistic examples and problems to reinforce important concepts. Environmental Transport Processes is an ideal first textbook for environmental engineering students who have never studied mass transport, as well as undergraduate and graduate chemical engineering students with little or no experience in environmental topics. It is also a valuable working resource for professionals in those fields, and all researchers interested in transport processes.