French vertical flow treatment wetlands in a subtropical climate: Characterization of the organic deposit layer and comparison with systems in France

• DOI: 10.1016/j.scitotenv.2020.140608
• Publication Date: 2020-06-30T23:29:03Z
• Authors: Camila Maria Trein; Camille Banc; Kevin Maciejewski; Amanda de Moraes ...; Rémy Gourdon; Pascal Molle; Mathieu Gautier; Marcos von Sperling
• Keywords: [CHIM.INOR] Chemical Sciences/Inorganic chemistry; Mineralization; [CHIM.ANAL] Chemical Sciences/Analytical chemistry; 550; 0207 environmental engineering; 02 engineering and technology; [CHIM.INOR]Chemical Sciences/Inorganic chemistry; Sludge deposit; Vertical flow constructed wetland; [CHIM.ANAL]Chemical Sciences/Analytical chemistry; [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; [SDU.STU.GC] Sciences of the Universe [physics]/Earth Sciences/Geochemistry; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment; [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology; [SDE.IE]Environmental Sciences/Environmental Engineering; [SDU.ENVI] Sciences of the Universe [physics]/Continental interfaces, environment; 6. Clean water; Mature sludge; [SDU.STU.AG] Sciences of the Universe [physics]/Earth Sciences/Applied geology; [SDE.IE] Environmental Sciences/Environmental Engineering; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; Raw sewage; environment; [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy; [SDU.STU.MI] Sciences of the Universe [physics]/Earth Sciences/Mineralogy

This paper presents an advanced characterization of the organic fraction of the top deposit layer collected in a French vertical flow treatment wetland (first stage) in operation in Brazil (two units with different organic deposit layer accumulation times), and compares the results with those obtained from studies in France. The organic and inorganic constituents of the samples collected were analysed by biological, chemical and thermochemical methods. The unit with the organic deposit with longer accumulation time (almost 10 years) was characterized as a mature one (organic matter - OM: 51.3 and 52.7%, thermal index - RTGA: 0.79 and 0.85, humification index - HI: 0.61 and 1.16, respectively for the depths of 0-5 cm and 5-10 cm). The unit with the deposit organic with less than three years of accumulation also presented characteristics of a mature deposit (OM: 61.2%, RTGA: 0.79, HI: 1.01 for the depth of 0-5 cm), indicating a rapid mineralization of the deposit under the existing subtropical environment. Despite several differences in term of conception, hydraulic and mass loading rates and accumulation rates, the characteristics of the OM of Brazilian deposits were found to be quite similar to the French ones.