Wastewater modification processes in a stabilization reservoir: a new mathematical model

The paper presents a mathematical model for the simulation of the ecology of a wastewater stabilization reservoir (WSR). WSRs are hypertrophic aquatic systems devoted to water storage in warm countries where shortage conditions are often encountered. Several factors that affect the stabilization reservoir’s effluent quality were taken into account: hydraulics and hydrology, solar radiation, reaeration, algae, zooplankton, organic matter, pathogens, and sediment-water interactions. The model quantifies the specific influence of each factor on effluent quality, and evaluating the correlation between the different factors. State variables included in the model were: algae, dissolved oxygen, organic matter, zooplankton and indicator bacteria. The model was applied to an Italian stabilization reservoir located in the south part of Sardinia: Simbirizzi lake. The model generated satisfactory results and can be employed as a useful tool for environmental water quality management of stabilization reservoirs.