title: Modelling lake-water photochemistry: three-decade assessment of the steady-state concentration of photoreactive transients (·OH, CO3(-·) and (3)CDOM(∗)) in the surface water of polymictic Lake Peipsi (Estonia/Russia).
abstract: Over the last 3-4 decades, Lake Peipsi water (sampling site A, middle part of the lake, and site B, northern part) has experienced a statistically significant increase of bicarbonate, pH, chemical oxygen demand, nitrate (and nitrite in site B), due to combination of climate change and eutrophication. By photochemical modelling, we predicted a statistically significant decrease of radicals ·OH and CO3(-·) (site A, by 45% and 35%, respectively) and an increase of triplet states of chromophoric dissolved organic matter ((3)CDOM(∗); site B, by ∼25%). These species are involved in pollutant degradation, but formation of harmful by-products is more likely with (3)CDOM(∗) than with ·OH. Therefore, the photochemical self-cleansing ability of Lake Peipsi probably decreased with time, due to combined effects of climate change and eutrophication. In different environments (e.g. Lake Maggiore, NW Italy), ecosystem restoration policies had the additional advantage of enhancing sunlight-driven detoxification, suggesting that photochemical self-cleansing would be positively correlated with lake water quality.
authors.affiliation: Dipartimento di Chimica, Università di Torino, Via P. Giuria 5, 10125 Torino, Italy(1).
authors.forename: Marco
authors.initials: M
authors.lastname: Minella
authors.affiliation: Dipartimento di Chimica, Università di Torino, Via P. Giuria 5, 10125 Torino, Italy(1).
authors.forename: Elisa
authors.initials: E
authors.lastname: De Laurentiis
authors.affiliation: Centre for Limnology, Estonian University of Life Sciences, 61117 Rannu, Tartumaa, Estonia(2).
authors.forename: Olga
authors.initials: O
authors.lastname: Buhvestova
authors.affiliation: Centre for Limnology, Estonian University of Life Sciences, 61117 Rannu, Tartumaa, Estonia(2).
authors.forename: Marina
authors.initials: M
authors.lastname: Haldna
authors.affiliation: Centre for Limnology, Estonian University of Life Sciences, 61117 Rannu, Tartumaa, Estonia(2).
authors.forename: Külli
authors.initials: K
authors.lastname: Kangur
authors.affiliation: Dipartimento di Chimica, Università di Torino, Via P. Giuria 5, 10125 Torino, Italy(1).
authors.forename: Valter
authors.initials: V
authors.lastname: Maurino
authors.affiliation: Dipartimento di Chimica, Università di Torino, Via P. Giuria 5, 10125 Torino, Italy(1).
authors.forename: Claudio
authors.initials: C
authors.lastname: Minero
authors.affiliation: Dipartimento di Chimica, Università di Torino, Via P. Giuria 5, 10125 Torino, Italy(1); Centro Interdipartimentale NatRisk, Università di Torino, Via Leonardo da Vinci 44, 10095 Grugliasco (TO), Italy(3). Electronic address: davide.vione@unito.it.
authors.forename: Davide
authors.initials: D
authors.lastname: Vione
mesh_terms: D057919:Biological Oxygen Demand Analysis; D004957:Estonia; D005609:Free Radicals / Q000032:analysis*; D005618:Fresh Water / Q000032:analysis*; D017665:Hydroxyl Radical / Q000032:analysis; D060106:Lakes / Q000737:chemistry*; D008956:Models, Chemical; D009573:Nitrites / Q000032:analysis; D055668:Photochemical Processes; D025341:Principal Component Analysis; D012426:Russia; D012621:Seasons; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D005609:Free Radicals; D009573:Nitrites; D014874:Water Pollutants, Chemical; D017665:Hydroxyl Radical