Modelling pollution transport dynamics and mixing in square manhole overflows

Detailed knowledge of the dynamic interactions between incoming sewerage and an overflowing manhole, resulting pollutant concentrations from manhole flooding, are critical for robust design operations wastewater infrastructures, especially during extreme climatic events. This study investigates mixing dispersion solute in square overflow using laboratory tracer experiment analytical modelling. Tests conducted with three flow rates to examine characteristics over a wide range operational conditions. Two scenarios including blocked pipe exit, combination exit studied. The Residence Time Distributions (RTD) longitudinal coefficients determined understand transport. analysis fluorometric data show appropriateness robustness deconvolution model adopted this determining RTDs (R2 > 0.95). Similarly, Taylor's was shown be capable predicting advective dispersive mechanisms within conditions tested study. New empirical predictive formulae derived characterize manholes under different