Septage unit treatment by sludge treatment reed beds for easy management and reuse: performance and design considerations
Résumé
Sustainable treatment and management of fecal sludge in rural area requires adapted solutions. Rustic and simple operating processes such as sludge treatment reed beds (STRB) have been increasingly considered for this purpose. The biggest full scale septage treatment unit in France had been built in Nègrepelisse with the final objectives of reusing treated sludge and leachates for agriculture spreading and trees irrigation, respectively. The aim of this investigation was to validate the treatment chain of this installation. The obtained field data showed firstly that the overall removal efficiencies of STRB were satisfactory and stable. Removal rates higher than 98% for COD and SS and a bit lower for KN represented so far a beneficial septage treatment by STRB. The highlighted necessity of a suitable complementary leachate treatment (before tree irrigation) justified the presence of the second stage of vertical flow constructed wetland. The sludge deposit drying and mineralization efficiencies were on the right track. According to hydrotextural diagram analysis, surface deposit was however found to have high deformability probably due to the youngness of the installation. An in-depth understanding of STRB system needs continuous long-term studies.
Origine : Fichiers produits par l'(les) auteur(s)
Loading...