Use of a web-based virtual laboratory to introduce mass transfer processes in environmental engineering and science courses

This paper describes the development of a web-based laboratory as a means to introduce advanced mass transfer processes concepts in environmental engineering and science courses. This web-based laboratory is comprised of interactive user-friendly input interfaces, customizable output interfaces, illustrative Help and Tutorial sections, a relational database, and a finite element in space and finite difference in time numerical engine. Architecture used to develop and implement this system is briefly discussed. The virtual laboratory employs spherical particles representative of a number of matrices of interest to environmental engineers, including water treatment systems and subsurface contaminant fate and transport. Users of the laboratory may define physical and chemical characteristics of up to five different particles, including up to five separate reactive regions within each particle. Complex mass transfer processes, including linear and nonlinear sorption and Fickian and non-Fickian diffusion processes, are capable of being modeled for each reactive domain within each particle. Two types of boundary conditions, reflective of completely mixed flow reactors and completely mixed batch reactors, are also included. Illustrations of the education benefits derived from use of the web-based laboratory are demonstrated by two examples.