Solar Wastewater Treatment: Advantages and Efficiency for Reuse in Agriculture and Industry

Algeria wastewater treatment sector uses weakly sustainable processes as natural lagooning and sand filters. The mainly processes use activated sewage sludge process and aerated lagoons. However these lasts induce high electricity consumption especially due to the daily continuous use of aeration propellers for the biologic treatment. The first part of study evaluated the yearly electricity consumption of an activated sewage sludge process to establish an exhaustive diagnostic of wastewater treatment, energy and environmental nexus. Obtained results showed that the used treatment consumed yearly 1.12 GWh of electricity and emitted 15.91 103 t CO
₂
-eq of Greenhouse Gas emission (GHG). The biological treatment was the intensive-energy part of the process with 78% of electricity consumption. To decrease the negative impacts of the mentioned nexus, the second part of the study proposes Solar Wastewater Treatment (SOWAT) as a new sustainable and easy solar wastewater treatment. It uses one step treatment: the evaporation/condensation process performed in solar still. Comparatively to the conventional treatment, the sustainable process recorded similar efficiency treatment for municipal wastewater. Better yet, it allowed the wastewater disinfection that is not planned in the studied treatment plant. SOWAT is also applied successfully to treat real textile wastewater rejected from Algerian Textiles Company. Results recorded a significant removal of pollution. Treatment results both of real municipal and textile wastewater are conform to standards which allowed their reuse respectively in agriculture and industry.