Assessing extracted organic matter quality from river sediments by elemental and molecular characterization: Application to the Tiete circumflex accent and Piracicaba Rivers (Sa tilde o Paulo, Brazil)

Autor(es)

de Morais, Carla Pereira ^{[1, 2, 3]} ; Tadini, Amanda Maria ^[1] ; Bento, Lucas Raimundo ^{[1, 2]} ; Oursel, Benjamin ^[3] ; Gontijo Guimaraes, Francisco Eduardo ^[4] ; Martin-Neto, Ladislau ^[1] ; Mounier, Stephane ^[3] ; Bastos Pereira Milori, Debora Marcondes ^[1]

Afiliação do(s) autor(es)

^[1] Embrapa Instrumentat, BR-13560970 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Sao Carlos Inst Chem, BR-13566590 Sao Carlos, SP - Brazil

^[3] Univ Toulon & Var, Aix Marseille Univ, Mediterranean Inst Oceanog, CNRS INSU, IRD, MIO UM 110, CS 60584 83041, Toulon 9 - France

^[4] Univ Sao Paulo, Sao Carlos Inst Phys, BR-13566590 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: APPLIED GEOCHEMISTRY; v. 131, AUG 2021.
• Citações Web of Science: 0

Resumo

Urban river pollution causes serious problems to the environment, human health, and water scarcity. Developing tools to identify and assess the health of aquatic river systems is essential for monitoring the quality of rivers and implementing actions. This study assesses the elemental and molecular characteristics of organic matter (OM) extracted from river sediments and associates them with river quality. To assess the quality of sediment cores, the most reactive and available OM from two urban rivers (Tiete<SIC> and Piracicaba Rivers, Sa similar to o Paulo, Brazil) was isolated with alkaline and water solutions. It was then characterized by elemental composition, ultraviolet-visible spectroscopy, and fluorescence excitation-emission matrix with parallel factor analysis. The average yield of alkaline extraction was 40.71% +/- 5.52% of OM present in the bulk sediments. Extracted organic matter from sediments (EOMSed) from the Tiete<SIC> River presented the highest average concentrations of nonpurgeable organic carbon (NPOC) and total organic nitrogen (TON), and the lowest average NPOC/TON molar ratios and specific UV absorbance at 254 nm (SUVA254). Considering the high degree of eutrophication in the Tiete<SIC> River, these results suggest a greater input of simple OM with nitrogenous structures. The humic-like component in EOMSed was the most abundant in both rivers. The aromaticity of EOMSed from the Piracicaba River was evidenced by the greater contribution of complex structures in the form of aromatic and polyaromatic moieties and higher SUVA254. EOMSed from the Tiete<SIC> River also featured enhanced biological activity due to the greater contribution of microbial-derived products and the presence of small molecules and nitrogenous structures. As this combination of elemental and spectroscopic techniques successfully identified the characteristics of extracted OM, it can be used as a tool to assess the global river quality. (AU)

• Processo FAPESP: 13/07276-1 - CEPOF - Centro de Pesquisa em Óptica e Fotônica
• Beneficiário: Vanderlei Salvador Bagnato
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs