Fertilizer potential and social perception of the agricultural reuse of sewage sludge and treated wastewater

Sludge and treated wastewater contain nutrients such as nitrogen, phosphorus, and potassium, which can enrich agricultural soils and promote crop growth. Utilizing these by-products as fertilizers allows for reduced reliance on chemical fertilizers, valorization of waste, and preservation of natural resources. However, this practice faces challenges associated with negative social perceptions, potential risks to human and environmental health, religious beliefs, and cultural factors. Our research aims, firstly, to quantify the water and fertilizer gains from the by-products of the Medea Wastewater Treatment Plant (Algeria), and secondly, to assess the social acceptability of this practice through a field survey. The results revealed a water gain sufficient to provide drinking water for a population of 91,130 inhabitants and irrigate 665 ha of arboriculture. The quantities of fertilizers contained in these by-products can fulfill the needs of the arboriculture. Regarding the social survey, inconsistencies observed in the responses of our study sample are attributed to a lack of understanding of wastewater treatment technology. Nonetheless, the majority of respondents support preserving water for future generations and are willing to participate in awareness campaigns aimed at clarifying the ambiguity surrounding this technology. These campaigns aim to maximize the benefits of agricultural reuse while mitigating risks. • Treated water irrigates 665 ha of arboriculture, saving drinking water for 91,130 inhabitants. • Treatment by-products can reduce reliance on chemical fertilizers. • The survey on the social acceptability of treatment by-product reuse is novel in the region. • The well-structured and sequenced social survey questionnaire covers various aspects of agricultural reuse.