Ipclass — an interactive program for calibrating activated sludge systems

Ipclass — an interactive program for calibrating activated sludge systems is formulated and demonstrated. The model involves a heuristic screening algorithm for exploring the system equations structure, analytical computations of the sensitivities of the variables to the model coefficients, analytical computations of the gradients of the objective functions selected for the calibration process, and a gradient interactive steepest descent minimization scheme. The methodology was implemented in an end-user PC program: Ipclass, that uses the TK Solver and Matlab as computational engines, and Visual Basic as the shell. Applications to the activated sludge system models of (Argaman Water Research 29(1) (1995), 137-145) and Argaman et al. (Journal of Environmental Engineering ASCE 125(7) (1999), 608-617) are presented.