Finite element analysis of flows in secondary settling tanks

The equations governing unsteady flows in secondary settling tanks, a component of the wastewater treatment process, are analysed using the finite element method. The model corresponding to such liquid–solid flows is highly non-linear and coupled, and incorporates the effects of turbulence. The results of numerical simulations are compared against experimental results from tests on full-scale settling tanks, and against results obtained from a finite difference code based on an idealized onedimensional flux theory. The results compare well with the test results, over the range of applicability of the model