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suspended particulate mercury associated with tidal fluxes in a lagoon environment impacted by cinnabar mining activity(northern Adriatic sea)

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Journal of Environmental sciences 2018年第6期30卷 100-113页

作者： Alisè Turritto Alessandro Acquavita Annelore Bezzi stefano covelli Giorgio Fontolan Elisa Petranich Raffaella Piani simone Pillon Department of mathematics and Geoscience University of Trieste Via Weiss 2 34128 Trieste Italy co.n.i.s.ma. consorzio nazionale interuniversitario per le scienze del mare Piazzale Flaminio 9 00196 Rome Italy ARPA FVG Environmental Protection Agency of Friuli Venezia Giulia Via Cairoli 14 33057 Palmanova (Udine) Italy

The isonzo River has been demonstrated to be a continuing point source of mercury（Hg）in the Gulf of Trieste although the idrija mine was last active in 1996. The present study aims to investigate the role of the suspended particulate matter（sPM） associated with tidal fluxes to disperse particulate Hg（PHg） into the Grado coastal lagoon system. PHg concentrations（avg. 3.11 ± 2.62 μg/g, d.w.）, notwithstanding the ebb or flood tides, were significantly higher than the local sediment background（0.13 μg/g）. The relative affinity of Hg for the particulate phase in surface waters was confirmed by higher average distribution coefficient（Kd） values（5.6–6.7）. PHg contents showed the highest values in ebb tide conditions, thus suggesting their origin from the erosion of tidal flats and saltmarshes of the lagoon. When compared to river discharge, high PHg surface concentrations in flood tide are related to rainfall events occurring within the river basin. Results can be used to make an indicative assessment of the amount of Hg bound to sPM which is transported in and out of the lagoon basin following the action of tidal fluxes. A simple estimation provides a negative budget for the Grado lagoon sub-basin which loses between 0.14 and 1.16 kg of PHg during a tidal semi-cycle. This conclusion is in agreement with the evidence of morphological deterioration which has emerged from recent studies on the lagoon environment, and which testifies to a current sedimentary loss from the lagoon into the northern Adriatic sea.

关键词： Mercury Tidal fluxes suspended particulate matter Lagoon

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Evaluation of mercury biogeochemical cycling at the sediment–water interface in anthropogenically modified lagoon environments

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Journal of Environmental sciences 2018年第6期30卷 5-23页

作者： Elisa Petranich stefano covelli Alessandro Acquavita Jadran Faganeli Milena Horvat marco contin Dipartimento di matematica e Geoscienze Universita degli Studi di Trieste Via Weiss 2 34128 Trieste Italy Dipartimento di scienze della Vita Universita degli Studi di Trieste Via Licio Giorgieri 5 34128 Trieste Italy con.i.s.ma. consorzio nazionale interuniversitario per le scienze del mare Piazzale Flaminio 9 00196 Rome Italy Agenzia Regionale per la Protezione Ambientale del Friuli Venezia Giulia ARPA FVC Via Cairoli 14 33057 Palmanoua (Udine) Italy marine Biological station Fornace 41 6330 Piran Slovenia Department of Environmental sciences Joker Stefan Institute Jamova 39 1000 Ljubljana Slovenia Dipartimento di scienze Agro-Alimentari Ambientali e Animali Universita di Udine Via delle Scienze 206 33100 Udine Italy

The marano and Grado Lagoon is well known for being contaminated by mercury（Hg） from the idrija mine（slovenia） and the decommissioned chlor-alkali plant of Torviscosa（italy）.Experimental activities were conducted in a local fish farm to understand Hg cycling at the sediment–water interface. Both diffusive and benthic fluxes were estimated in terms of chemical and physical features. Mercury concentration in sediments（up to 6.81 μg/g）showed a slight variability with depth, whereas the highest methylmercury（MeHg） values（up to 10 ng/g） were detected in the first centimetres. MeHg seems to be produced and stored in the 2–3 cm below the sediment–water interface, where sulphate reducing bacteria activity occurs and hypoxic–anoxic conditions become persistent for days. DMeHg in porewaters varied seasonally（from 0.1 and 17% of dissolved Hg（DHg）） with the highest concentrations in summer. DHg diffusive effluxes higher（up to 444 ng/m^2/day） than those reported in the open lagoon（~ 95 ng/m^2/day）, whereas DMeHg showed influxes in the fish farm（up to-156 ng/m^2/day）. The diurnal DHg and DMeHg benthic fluxes were found to be higher than the highest summer values previously reported for the natural lagoon environment. Bottom sediments, especially in anoxic conditions, seem to be a significant source of MeHg in the water column where it eventually accumulates. However, net fluxes considering the daily trend of DHg and DMeHg, indicated possible DMeHg degradation processes. Enhancing water dynamics in the fish farm could mitigate environmental conditions suitable for Hg methylation.

关键词： Mercury Benthic fluxes Biogeochemistry lagoons sediment–water interface

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short-Term Response of soil Microbial Biomass to Different Chabazite Zeolite Amendments

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Pedosphere 2018年第2期28卷 277-287页

作者： Giacomo FERRETTi Katharina maria KEiBLinGER Dario Di GiUsEPPE Barbara FACCini nicolò coLOMBAni sophie ZECHMEisTER-BOLTEnsTERn massimo coLTORTi Micòl masTROCiCco Deptartment of Physics and Earth sciences University of Ferrara Via Saragat 1 Ferrara 44122 (Italy) institute of soil Research Department of Forest and Soil Sciences University of Natural Resources and Life Sciences Vienna (BOKU) Peter Jordan Strasse 82 Vienna 1190 (Austria) consorzio nazionale interuniversitario per le scienze del mare (conisma) Piazzale Flaminio Roma 900196 (Italy) Department of Environmental Biological and Pharmaceutical Sciences and Technologies Second University of Naples Caserta 81100(Italy)

Zeolitites (ZTs) are rocks containing more than 50% of zeolite minerals and are known to be a suitable material for agricultural purposes by improving soil physicochemical properties and nitrogen (n) use efficiency. However, little is known about their effects on soil microbial biomass. This study aimed to evaluate short-term effects of different chabazite-rich ZT (CHAZT) amendments on soil microbial biomass and activity. A silty-clay agricultural soil was amended in three different ways, including the addition of natural (5% and 15%) and nH_4^+-enriched (10%) CHAZT. soil dissolved organic carbon (C), total dissolved n, nH_4^+, nO_3^-, nO_2^-, microbial biomass C and n, and ergosterol were measured periodically over 16 d in a laboratory incubation. To verify the microbial immobilization of the n derived from nH_4^+-enriched CHAZT, a high15n source was used for enriching the mineral to measure the microbial biomass δ15n signature. An increase in the ergosterol content was observed in the soil amended with 5% natural CHAZT. However, no similar result was observed in the soil amended with 15% natural CHAZT, suggesting that the fungal biomass was favored at a lower CHAZT application rate. in the soil amended with nH+ 4-enriched CHAZT, microbial biomass n was related to nO_3^-production over time and inversely related to nH_4^+, suggesting high nitrification process. isotopic measurements on microbial biomass confirmed immediate assimilation of n derived from nH_4^+-enriched CHAZT. These results suggested that the nH_4^+-enriched CHAZT used in this study supplied an immediately available n pool to the microbial biomass.

关键词： ergosterol microbial biomass δ15n natural zeolite nH4+-enriched zeolite nitrification slow-release fertilizer

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