Open AccessDewatering, Stabilization, and Final Disposal of Waste Activated Sludge in Constructed Wetlands
Author(s) -
Alejandro Jorge Mariñelarena,
Hugo Di Giorgi,
Jorge Luis Donadelli
Publication year - 2021
Publication title -
ingenieria y universidad/ingenieria y universidad
Language(s) - English
Resource type - Journals
eISSN - 0123-2126
pISSN - 2011-2769
DOI - 10.11144/javeriana.iued25.dsfd
Subject(s) - biosolids , environmental science , sewage treatment , waste management , wastewater , sewage sludge , amendment , wetland , activated sludge , reuse , sewage , environmental engineering , pulp and paper industry , ecology , engineering , biology , political science , law
Objective: This research aimed to assay the dehydration and stabilization of surplus biosolids from a wastewater activated sludge treatment plant, with sludge-treatment wetlands, at the Iguazú National Park (Misiones, Argentina). Materials and Methods: A 12-cell sludge-treatment reed beds (STRB) system was built and operated for four years. Afterwards, the accumulated sediments were analyzed for total solids (TS) concentration, volatile solids (VS) reduction, specific oxygen-uptake rate (SOUR), and heavy metals and pathogens concentrations. Results and Discussion: TS concentration increased from 0.55 % to 14.3 %, VS were reduced by 33.3 %, and SOUR lowered to 1.09 mg O2gTS-1 h-1. These figures and the final concentrations of heavy metals and pathogenic microorganisms (102 MPN E.coli.gTS-1) indicated a degree of stabilization and sanitation that allowed classifying these biosolids as Class A, according to the Argentine guidelines, National Resolution 410/18, and enabled their reuse for soil amendment in landscapes and other agronomic purposes. Conclusion: The technology tested showed good results applied under a tropical climate, with annual temperatures between 17 and 27 °C, rainfall of 1870 mm y-1, and planted with autochthonous vegetation. Furthermore, it allowed the reuse of 221 t (144 m3) of a harmless product in an environmentally sustainable way.