Sulfide Formation And Its Impacts On A Developing Country: A Case Study In Maputo, Mozambique

Wastewater undergoes physical, chemical and biological changes while flowing along sewer systems. For the past decades, awareness of the effects of such changes on the performance of the sewer systems has steadily increased. For countries with high average temperatures and low per capita water consumption, such as Mozambique, these changes are particularly important due to the potential increase of sulphide formation and the consequent release of hydrogen sulphide and other malodorous or toxic gases to the atmosphere. A major expansion of the sewer systems in the main cities of Mozambique is expected in the near future, with the associated longer wastewater travel times and increasing problems of septicity and hydrogen sulfide gas impacts. In order to better understand the in-sewer processes under local conditions, evaluate risks and exemplify how to support general drainage systems planning, two different approaches for modeling the performance of a Maputo separate sewer system were applied, based on: AEROSEPT, an empirical formulation, and WATS, a conceptual and more complex approach.