Maritime transportation, widely used both in international transport of goods and touristic purposes, has been identified as a significant source of ultrafine particles (UFP). In-land passenger ferry is a source of UF...Maritime transportation, widely used both in international transport of goods and touristic purposes, has been identified as a significant source of ultrafine particles (UFP). In-land passenger ferry is a source of UFP far less addressed;however, in locations with relatively high frequency of this transportation mode, it is expected that they contribute to an increase of their concentration. Moreover, the negative effects of UFP on human health and environment are known and therefore, monitoring UFP produced by ferries is vital to assess the degree of exposure of who work or live close to ferries’ terminals or downwind to their cruising path. This work aims to study the influence of in-land ferries activities on UFP in the urban/suburban areas near ferries’ terminals and downwind across the cruising path. The UFP monitoring campaign was carried out from September to December 2018 for 19 non-consecutive periods. The sampling sites were chosen in order to maximize measurements under downwind conditions and allow the association between ferry operation and UFP concentration response. Based on data collected, correlation analysis was performed between ferry’s traffic and particle number counting (PNC) of UFP, and also with meteorological variables. Results show an increase in PNC ranging from 25 to 197% during the third minute around a ferry movement and are moderate to positive significant correlations between PNC values and the number of ferry operations (r = 0.79 to r = 0.94), showing that UFP emitted by in-land ferries contributes to PNC increase. Moreover, negative correlations (r = -0.85 to r = -0.93) between PNC and wind intensity were also found.展开更多
Two media bed （gravel and Filtralite NR） were tested in a mesocosm to evaluate the removal of organic matter （as chemical oxygen demand （COD））, ammonia （NH4-N）, nitrite, nitrate and solid matter （as total sus...Two media bed （gravel and Filtralite NR） were tested in a mesocosm to evaluate the removal of organic matter （as chemical oxygen demand （COD））, ammonia （NH4-N）, nitrite, nitrate and solid matter （as total suspended solids （TSS）） for a synthetic wastewater （acetate-based） and a domestic wastewater. The use of Filtralite allowed average removal rates （6--16.8 g COD/（m^2·day）, 0.8-1.1 g NH4-N/（m^2·day） and 3.1 g TSS/（m^2·day）） and removal efficiencies （65%-93%, 57%-85% and 78% for COD, NH4-N and TSS, respectively）, higher than that observed in the experiments with gravel. The applied loads of COD, ammonia, nitrate and TSS seem to influence the respective removal rates but only for the treatment of domestic wastewater with nigher correlation coefficients for Filtralite. Regardless the type of media bed and the type of wastewater, nitrate was completely removed for nitrogen loading rates up to 1.3 g NO3-N/（m^2·day）. There was no evidence of the influence of nitrate loads on the removal of organic matter.展开更多
The new properties of engineered nanoparti- cles drive the need for new knowledge on the safety, fate, behavior and biologic effects of these particles on organisms and ecosystems. Titanium dioxide nanoparticles have ...The new properties of engineered nanoparti- cles drive the need for new knowledge on the safety, fate, behavior and biologic effects of these particles on organisms and ecosystems. Titanium dioxide nanoparticles have been used extensively for a wide range of applica- tions, e.g, self-cleaning surface coatings, solar cells, water treatment agents, topical sunscreens. Within this scenario increased environmental exposure can be expected but data on the ecotoxicological evaluation ofnanoparticles are still scarce. The main purpose of this work was the evaluation of effects of TiO2 nanoparticles in several organisms, covering different trophic levels, using a battery of aquatic assays. Using fish as a vertebrate model organism tissue histological and ultrastructural observations and the stress enzyme activity were also studied. TiO2 nanoparticles （Aeroxide~ P25）, two phase composition ofanatase （65%） and rutile （35%） with an average particle size value of 27.64-11 nm were used. Results on the ECs0 for the tested aquatic organisms showed toxicity for the bacteria, the algae and the crustacean, being the algae the most sensitive tested organism. The aquatic plant Lemna minor showed no effect on growth. The fish Carassius auratus showed no effect on a 21 day survival test, though at a biochemical level the cytosolic Glutathione-S-Transferase total activity, in intestines, showed a general significant decrease （p〈0.05） after 14 days of exposure for all tested concentrations. The presence of TiO2 nanoparticles aggregates were observed in the intestine lumen but their internalization by intestine cells could not be confirmed.展开更多
文摘Maritime transportation, widely used both in international transport of goods and touristic purposes, has been identified as a significant source of ultrafine particles (UFP). In-land passenger ferry is a source of UFP far less addressed;however, in locations with relatively high frequency of this transportation mode, it is expected that they contribute to an increase of their concentration. Moreover, the negative effects of UFP on human health and environment are known and therefore, monitoring UFP produced by ferries is vital to assess the degree of exposure of who work or live close to ferries’ terminals or downwind to their cruising path. This work aims to study the influence of in-land ferries activities on UFP in the urban/suburban areas near ferries’ terminals and downwind across the cruising path. The UFP monitoring campaign was carried out from September to December 2018 for 19 non-consecutive periods. The sampling sites were chosen in order to maximize measurements under downwind conditions and allow the association between ferry operation and UFP concentration response. Based on data collected, correlation analysis was performed between ferry’s traffic and particle number counting (PNC) of UFP, and also with meteorological variables. Results show an increase in PNC ranging from 25 to 197% during the third minute around a ferry movement and are moderate to positive significant correlations between PNC values and the number of ferry operations (r = 0.79 to r = 0.94), showing that UFP emitted by in-land ferries contributes to PNC increase. Moreover, negative correlations (r = -0.85 to r = -0.93) between PNC and wind intensity were also found.
文摘Two media bed （gravel and Filtralite NR） were tested in a mesocosm to evaluate the removal of organic matter （as chemical oxygen demand （COD））, ammonia （NH4-N）, nitrite, nitrate and solid matter （as total suspended solids （TSS）） for a synthetic wastewater （acetate-based） and a domestic wastewater. The use of Filtralite allowed average removal rates （6--16.8 g COD/（m^2·day）, 0.8-1.1 g NH4-N/（m^2·day） and 3.1 g TSS/（m^2·day）） and removal efficiencies （65%-93%, 57%-85% and 78% for COD, NH4-N and TSS, respectively）, higher than that observed in the experiments with gravel. The applied loads of COD, ammonia, nitrate and TSS seem to influence the respective removal rates but only for the treatment of domestic wastewater with nigher correlation coefficients for Filtralite. Regardless the type of media bed and the type of wastewater, nitrate was completely removed for nitrogen loading rates up to 1.3 g NO3-N/（m^2·day）. There was no evidence of the influence of nitrate loads on the removal of organic matter.
文摘The new properties of engineered nanoparti- cles drive the need for new knowledge on the safety, fate, behavior and biologic effects of these particles on organisms and ecosystems. Titanium dioxide nanoparticles have been used extensively for a wide range of applica- tions, e.g, self-cleaning surface coatings, solar cells, water treatment agents, topical sunscreens. Within this scenario increased environmental exposure can be expected but data on the ecotoxicological evaluation ofnanoparticles are still scarce. The main purpose of this work was the evaluation of effects of TiO2 nanoparticles in several organisms, covering different trophic levels, using a battery of aquatic assays. Using fish as a vertebrate model organism tissue histological and ultrastructural observations and the stress enzyme activity were also studied. TiO2 nanoparticles （Aeroxide~ P25）, two phase composition ofanatase （65%） and rutile （35%） with an average particle size value of 27.64-11 nm were used. Results on the ECs0 for the tested aquatic organisms showed toxicity for the bacteria, the algae and the crustacean, being the algae the most sensitive tested organism. The aquatic plant Lemna minor showed no effect on growth. The fish Carassius auratus showed no effect on a 21 day survival test, though at a biochemical level the cytosolic Glutathione-S-Transferase total activity, in intestines, showed a general significant decrease （p〈0.05） after 14 days of exposure for all tested concentrations. The presence of TiO2 nanoparticles aggregates were observed in the intestine lumen but their internalization by intestine cells could not be confirmed.
