Environmental geochemistry is a major branch of regional geochemistry. In this thesis are presented the environmental geochemical investigation of Campania Plain and Napoli and Salerno bays in South Italy, concerning potential toxic elements and compounds distribution. Multivariate and univariate analysis are used to illustrate distribution and sources of elements and compounds. Different pollution impact factors and risk assessment factors are estimated towards soils and sediments that easy to contact with human beings. The results suggest Napoli city and Gulf of Pozzuoli are with the presence of a highly incremental lifetime cancer risk. An attempt of applying in situ Raman spectroscopic detection of pollutants is start with a series of laboratory experiments. With the help capillary high pressure optical cell, following results are achieved: 1) methane diffusion coefficients in water under high pressure and wide temperature range, and the relationship of diffusion coefficients with temperature was established; 2) Raman intensity ratio of asymmetric stretching vibration (ν3) and asymmetric bending overtone (2ν2) of methane were numerical described towards temperature, pressure and gas phase density; 3) reactions of goethite and magnetite with sulfide solutions under CH4 and/or CO2 atmospheres were monitored at room temperature. Pyrrhotite and mackinawite were observed in final products. A demanding of innovative approach to detect organic contaminants encourages various researches on in-situ techniques. A new substrate embedding silver nanoparticles into siloxane polymer is used as the platform to generate Surface-Enhanced Raman scattering (SERS). Polymer serves as supporting material of silver nanoparticles as well as a stationary phase. After a short period of extraction, certain partition of organic compounds from aqueous solution accumulates into polymer. When silver nanoparticles is in touch with organic compounds, enhanced Raman scattering is obtained with 104~106 orders of magnitude. Crystal violet (CV) is chosen to evaluate extraction properties of polymer. Color “transferring” indicates effective extraction of crystal violet into polymer. Intensive Raman bands include SERS effects and resonance scattering of CV. Low concentration of 4-nitrophenol (PNP) and 4-nitroaniline (PNA) in solution (as low as 10-7 M) are deposited onto substrate and generate SERS fingerprint. After subtracting the Raman bands of polymer and silver salts, clear evidence indicates availability of macro SERS spectra. Micro SERS testifies compounds penetrating as depth as 200 um from the surface.
Investigation on pollution level in surface sediments of coastal area, the case of Gulf of Naples / DE VIVO, Benedetto. - (2014).
Investigation on pollution level in surface sediments of coastal area, the case of Gulf of Naples
DE VIVO, BENEDETTO
2014
Abstract
Environmental geochemistry is a major branch of regional geochemistry. In this thesis are presented the environmental geochemical investigation of Campania Plain and Napoli and Salerno bays in South Italy, concerning potential toxic elements and compounds distribution. Multivariate and univariate analysis are used to illustrate distribution and sources of elements and compounds. Different pollution impact factors and risk assessment factors are estimated towards soils and sediments that easy to contact with human beings. The results suggest Napoli city and Gulf of Pozzuoli are with the presence of a highly incremental lifetime cancer risk. An attempt of applying in situ Raman spectroscopic detection of pollutants is start with a series of laboratory experiments. With the help capillary high pressure optical cell, following results are achieved: 1) methane diffusion coefficients in water under high pressure and wide temperature range, and the relationship of diffusion coefficients with temperature was established; 2) Raman intensity ratio of asymmetric stretching vibration (ν3) and asymmetric bending overtone (2ν2) of methane were numerical described towards temperature, pressure and gas phase density; 3) reactions of goethite and magnetite with sulfide solutions under CH4 and/or CO2 atmospheres were monitored at room temperature. Pyrrhotite and mackinawite were observed in final products. A demanding of innovative approach to detect organic contaminants encourages various researches on in-situ techniques. A new substrate embedding silver nanoparticles into siloxane polymer is used as the platform to generate Surface-Enhanced Raman scattering (SERS). Polymer serves as supporting material of silver nanoparticles as well as a stationary phase. After a short period of extraction, certain partition of organic compounds from aqueous solution accumulates into polymer. When silver nanoparticles is in touch with organic compounds, enhanced Raman scattering is obtained with 104~106 orders of magnitude. Crystal violet (CV) is chosen to evaluate extraction properties of polymer. Color “transferring” indicates effective extraction of crystal violet into polymer. Intensive Raman bands include SERS effects and resonance scattering of CV. Low concentration of 4-nitrophenol (PNP) and 4-nitroaniline (PNA) in solution (as low as 10-7 M) are deposited onto substrate and generate SERS fingerprint. After subtracting the Raman bands of polymer and silver salts, clear evidence indicates availability of macro SERS spectra. Micro SERS testifies compounds penetrating as depth as 200 um from the surface.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
