Assessment of quality and potential reuse of wastewater treated with conventional activated sludge

Abstract

Climate change and the increasing scarcity of water resources have placed the water sector in Morocco at the centre of the public authorities' interests, because of its decisive role in the country's water security and in supporting its development, particularly irrigated agriculture. This has prompted the scientific community and national authorities to move towards an alternative resource to promote the reuse of treated wastewater in irrigation, which could alleviate this water crisis. This study evaluates the performance of the Al-Hoceima city's low-load activated sludge type wastewater treatment plant by analyzing the quality of raw and treated (domestic) wastewater. Indeed, the analysis of the evolution of the pollution parameters between the entry of the station and its exit, shows average reductions of 99% for BOD5, 97% for COD, 96% for TSS, and for the reduction of heavy metals was as follows: Ba < Co < Mn < Pb < Cu < Zn < As < Ni < Cr < Fe < Cd < Hg. Based on the results of the analyses, all of which comply with the discharge standards, Al-Hoceima WWTP is considered a leader in the field of wastewater treatment. A comparison with the recommendations of Morocco and the international community reveals that the results of on-site parameters such as pH, temperature, conductivity and pollution parameters show that the effluent from the Al-Hoceima wastewater treatment plant is within the standard acceptable limit for irrigation.