Climate change adaptation by solar wastewater treatment (SOWAT) for reuse in agriculture and industry*

Abstract

AbstractAccess to drinking water and sanitation are among the goals adopted by the United Nations in its 2030 Agenda for Sustainable Development. However, in poor and low‐income countries, this goal has not yet been reached. This is caused by several lacks in the technological mastery of water and wastewater treatment processes, fresh water and sanitation networks, and, finally, financial resources. Increasing the success chances to reach this goal should not happen by copying centralized water and sanitation systems used in high‐income countries. Rather efforts need to be made towards energy‐efficient decentralized water and wastewater treatment facilities, using simple and sustainable low‐cost technologies.The present paper suggests solar wastewater treatment (SOWAT) as an easy decentralized and sustainable wastewater treatment. It combines three steps of conventional wastewater treatment (i.e., pretreatment, biological treatment, and disinfection) by using a single treatment step conducted in a single equipment: solar still. It is has been experimentally tested to treat saline, domestic, municipal, and industrial wastewaters. All obtained results have recorded significant removal of inorganic, organic, bacteriologic, and metallic pollution.For community and industrial use, a new design of a hybrid SOWAT micro‐plant proposes the integration of a pretreatment stage and a smart multi‐source heating system. It is decentralized because it is powered by solar energy, other renewable energies, recovered flared gas, or conventional energy. Its continuous operation during the decrease or absence of solar radiation, by night, is expected to increase its daily production from 255% to 1,500%.