Wastewater treatment technologies and challenges in Algeria and their future prospects

Algeria, facing increasing water stress in a hyper-arid climate, must urgently optimize the management of its water resources. With only about 500 m 3 of freshwater per person, the country struggles to meet its growing drinking water needs. The use of treated wastewater is considered a strategic and sustainable solution in various sectors, including agriculture and industry. However, its effectiveness remains limited in Algeria due to several factors, including the lack of favorable legal frameworks, the deterioration of old infrastructure, technical failures, and the shortage of skilled workers. Through this study, we aim to assess the performance of the wastewater treatment system and its plants in Algeria, comparing the different technologies used (primary, secondary, and tertiary treatment) and their suitability and capacity to meet growing local needs. The results reveal numerous gaps and shortcomings, including inefficient sludge management, a low recycling rate not exceeding 40%, and a technological and material lag compared to neighboring countries such as Tunisia and Morocco. Despite all this, the use of innovative solutions and modern technologies, such as membrane bioreactors and artificial intelligence, offers promising prospects and sustainable solutions to improve treatment quality and reduce operating costs. These results also highlight the need to address gaps and shortcomings by modernizing infrastructure, strengthening legal frameworks, and improving public–private partnerships. Better operator training and increased use of sludge and recycled water, particularly in agriculture, are also essential to ensure sustainable water resource management. By incorporating these measures, Algeria could catch up and strengthen its resilience to future climate and demographic challenges.