Production d’agents de conditionnement a partir de micro algues cultivés sur eaux usées (une approche de valorisation )

Abstract

In a global context where environmental preservation has become a priority, wastewater treatment represents a major challenge in limiting the impact of industrial discharges on aquatic ecosystems. While chemical coagulants are widely used for their effectiveness, they present several drawbacks: generation of toxic sludge, health risks, high costs, and negative environmental effects. In response to these limitations, the present study adopts a circular economy approach by valorizing natural bio-coagulants (conditioning agents) extracted from microalgae, cultivated on an innovative substrate based on blood, abundant organic waste rich in nutrients. The study is based on a series of experiments aimed at producing, extracting, and evaluating the effectiveness of these conditioning agents in the sludge dewatering process. The microalgae were subjected to different types of stress (thermal, light, mechanical) to stimulate the production of extracellular polymers. The resulting extracts were then applied to sludge samples from local wastewater treatment plants. The results are very promising. A direct comparison with a chemical polymer used in a treatment plant revealed that the microalgae-based bio-coagulant delivers comparable, if not better, performance while being biodegradable and derived from a renewable resource. This approach not only allows the valorization of slaughterhouse by-products and the production of useful biomass, but also offers an ecological, economical, and sustainable alternative to conventional coagulants. This work confirms the feasibility of a more environmentally friendly wastewater treatment process and opens the way for local solutions tailored to the specific needs and resources available in Algeria.