Daily wastewater pollutant dynamics with respect to catchment population structure
To relate population structure and activity to wastewater volume and composition, field trials were conducted at the outlets of two urban catchments that have different population structures (residential-only and mixed). Macropollution and metal micropollution were both considered. In the residential-only catchment, a diurnal pattern with a morning peak (at 10:00) and an evening peak (at 20:00, corresponding to dinner) was observed for all seasons. No difference was observed throughout the year; patterns in summer days, in which daily mobility out of the catchments should be reduced, were similar to those observed in other seasons. For both catchments, N-NH4 (from urine) and chemical oxygen demand (from urine and grey water) correlated with Cu, Zn, Al, Fe and Mn but not with alkaline earth metals. The observed diurnal pattern is associated with work and school mobility and with the general lifestyle of the population. Such an approach is useful to model expected domestic pollution patterns, with respect to lifestyle changes in the future.
