scaricabile in rete - Enea

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Fig. 5 – δ 34 SSO4 and δ 18 OSO4 vertical profiles in Incrociata sandpit. Fig. 6 – Fractionation factors of the reduction process of sulphate. Fig. 7 – δ 34 S(SO4 –2 )/δ 18 O(SO4 –2 ) diagram for Incrociata sandpit waters. 40
The slope of the linear correlation between δ 18 O(SO4 –2 ) vs. δ 34 S(SO4 –2 ) of Figure 7 is close to 0.5, which falls almost exactly in the middle of the range reported [16] – 0.25 to 0.71 – for the microbial reduction of sulphate. 4. Conclusion This work gives underline that the distribution in the system of trace elements depends on the presence and intensity of biotic activity. Photosynthesis and degradation of organic matter are key processes. In particular, low δ 13 CDIC values, approaching the typical isotopic signal of C4 vegetation, are measured within channels with high pCO2. In fact the corn is the main cultivation in the southern basin. In the lake δ 13 C values correspond to the value expected for equilibrium with the atmosphere. In the excavation area, which represents a meromictic system, a significant increase in alkalinity is detected in the deepest anoxic part, together with a decrease in pH and SO4 and NH3 and H2S production. At the same time, δ 13 CDIC and δ 34 SSO4 signals decrease, suggesting occurrence of oxidation of organic matter and reduction of SO4 mediated by sulphate-reducing bacteria. The high B concentrations in the agricultural network than the mean value of lake water. Indeed, the B/Cl correlation plot underlines three compartments within the studied area: 1) waters draining the agricultural network, 2) lake waters and 3) waters from the Burlamacca channel and the excavation area. Samples with highest B/Cl values are characterized by lowest δ 11 B values. These anomalies have been ascribed to contamination by animal manure. We can conclude that isotopical research allowed us to underline the influence of agricultural activity on the chemical composition of lake water, the hydrodynamic equilibrium and superficial sediment composition. 41
Page 2 and 3: Giornate Itineranti SoGeI 2012 La v
Page 4 and 5: Si ringraziano L’ACCADEMIA NAZION
Page 7: La valutazione del rischio geochimi
Page 11 and 12: Geochimica e gestione del territori
Page 13 and 14: Metodi di captazione sostenibili in
Page 15 and 16: Ruolo della speciazione nella valut
Page 17 and 18: Mercurio nell’area costiera del F
Page 19 and 20: Fig. 1 - a) Distribuzione delle con
Page 21 and 22: Se, infatti, il decorticamento dei
Page 23 and 24: Le vie dell’Arsenico: dal compart
Page 25: I sintomi di tossicità da arsenico
Page 28 and 29: I depositi vulcanici, costituiti si
Page 30 and 31: Le acque che circolano nel sistema
Page 32 and 33: Non si tratta di alluminio disciolt
Page 34 and 35: mineraria. L’impatto potenziale d
Page 36 and 37: The lake is kept vertically well mi
Page 38 and 39: Fig. 3 - Correlation between 13 CDI
Page 42 and 43: 5. References [1] ROMANEK, C.S., et
Page 44 and 45: I dati termodinamici calcolati ab i
Page 47 and 48: La contaminazione degli acquiferi a
Page 49 and 50: L’attività di campionamento, ese
Page 51: Le contaminazioni da VOC rilevate i
Page 54 and 55: Csg Kh = Csl in cui Csg e Csl sono
Page 56 and 57: Di seguito (Figura 3) è riportata
Page 59 and 60: Monitoraggio geochimico di processi
Page 61 and 62: 3-Il degassamento a scala regionale
Page 63 and 64: Fig. 5 - Contenuto in ione cloruro
Page 65 and 66: Geochimica dei fluidi vulcanici e i
Page 67: Capaccioni, B. & Mangani, F., 2001:
Page 70 and 71: Capaccioni, B., Taran, Y., Tassi, F
Page 72 and 73: Dalla figura è evidente la presenz
Page 74: Edito dall’ENEA Servizio Comunica

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