| Title | A model approach to assess the long-term trends of indirect photochemistry in lake water. The case of Lake Maggiore (NW Italy) |
| Abstract | A model-based approach is here developed and applied to predict the long-term trends of indirect photochemical processes in the surface layer (5 m water depth) of Lake Maggiore, NW Italy. For this lake, time series of the main parameters of photochemical importance that cover almost two decades are available. As a way to assess the relevant photochemical reactions, the modelled steady-state concentrations of important photogenerated transients ((OH)-O-center dot, (CDOM)-C-3* and CO3-center dot) were taken into account. A multivariate analysis approach was adopted to have an overview of the system, to emphasise relationships among chemical, photochemical and seasonal variables, and to highlight annual and long-term trends. Over the considered time period, because of the decrease of the dissolved organic carbon (DOC) content of water and of the increase of alkalinity, a significant increase is predicted for the steady-state concentrations of the radicals (OH)-O-center dot and CO3-center dot. Therefore, the photochemical degradation processes that involve the two radical species would be enhanced. Another issue of potential photochemical importance is related to the winter maxima of nitrate (a photochemical (OH)-O-center dot source) and the summer maxima of DOC ((OH)-O-center dot sink and (CDOM)-C-3* source) in the lake water under consideration. From the combination of sunlight irradiance and chemical composition data, one predicts that the processes involving (OH)-O-center dot and CO3-center dot would be most important in spring, while the reactions involving (CDOM)-C-3* would be most important in summer. |
| Source | Science of the total environment 409 (18), pp. 3463–3471 |
| Keywords | Environmental photochemistrySensitised photolysisLake MaggioreLong-term trends |
| Journal | Science of the total environment |
| Editor | Elsevier, Lausanne ;, Paesi Bassi |
| Year | 2011 |
| Type | Articolo in rivista |
| DOI | 10.1016/j.scitotenv.2011.05.028 |
| Authors | Minella, M (Minella, Marco)[ 1 ] ; Rogora, M (Rogora, Michela)[ 2 ] ; Vione, D (Vione, Davide)[ 1,3 ] ; Maurino, V (Maurino, Valter)[ 1 ] ; Minero, C (Minero, Claudio)[ 1 ] |
| Text | 203475 2011 10.1016/j.scitotenv.2011.05.028 ISI Web of Science WOS 000293260100023 Environmental photochemistry Sensitised photolysis Lake Maggiore Long term trends A model approach to assess the long term trends of indirect photochemistry in lake water. The case of Lake Maggiore NW Italy Minella, M Minella, Marco 1 ; Rogora, M Rogora, Michela 2 ; Vione, D Vione, Davide 1,3 ; Maurino, V Maurino, Valter 1 ; Minero, C Minero, Claudio 1 1 Univ Turin, Dipartimento Chim Analit, I 10125 Turin, Italy 2 Ist Studio Ecosistemi, CNR ISE, I 28922 Verbania, VB, Italy 3 Univ Turin, Ctr Interdipartimentale NatRisk, I 10095 Grugliasco, TO, Italy A model based approach is here developed and applied to predict the long term trends of indirect photochemical processes in the surface layer 5 m water depth of Lake Maggiore, NW Italy. For this lake, time series of the main parameters of photochemical importance that cover almost two decades are available. As a way to assess the relevant photochemical reactions, the modelled steady state concentrations of important photogenerated transients OH O center dot, CDOM C 3 and CO3 center dot were taken into account. A multivariate analysis approach was adopted to have an overview of the system, to emphasise relationships among chemical, photochemical and seasonal variables, and to highlight annual and long term trends. Over the considered time period, because of the decrease of the dissolved organic carbon DOC content of water and of the increase of alkalinity, a significant increase is predicted for the steady state concentrations of the radicals OH O center dot and CO3 center dot. Therefore, the photochemical degradation processes that involve the two radical species would be enhanced. Another issue of potential photochemical importance is related to the winter maxima of nitrate a photochemical OH O center dot source and the summer maxima of DOC OH O center dot sink and CDOM C 3 source in the lake water under consideration. From the combination of sunlight irradiance and chemical composition data, one predicts that the processes involving OH O center dot and CO3 center dot would be most important in spring, while the reactions involving CDOM C 3 would be most important in summer. 409 ID_PUMA cnr.ise/2011 A0 016 A model approach to assess the long term trends of indirect photochemistry in lake A_model_approach_to_assess_the_long_term_trends_of_indirect_photochemistry_in_lake.pdf Articolo in rivista Elsevier 0048 9697 Science of the total environment Science of the total environment Sci. total environ. michela.rogora ROGORA MICHELA TA.P02.014.002 Impatto dei cambiamenti globali sugli ecosistemi acquatici |
