ABSTRACT
Engineering is essentially an economic optimization problem, "best" being defined as fulfilling the treatment objectives at the lowest possible total cost. The quantities that must be optimized are the process variables, defined as any quantity that is under the direct control of the process designer and operator. To establish the optimum values of these process variables, the engineer has three tools: experience, experiment, and mathematical modelling. Close collaboration between microbiologists and engineers is essential for the development of innovative bioremediation processes, and the earlier this collaboration begins the better. Too many promising developments have been hindered by microbiologists who thought they could do engineering and engineers who thought they could do microbiology. The chapter examines some differences between modem bioremediation problems and conventional applications to sewage and industrial wastewater treatment and discusses some of the necessary changes in bioreactor design.
