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Результаты 2351-2360 из 7,250
Microalgae removal technology for the cold source of nuclear power plant: A review
2022
Lv, Ziwei | Zhang, Hong | Liang, Jinsheng | Zhao, Tianyu | Xu, Yuena | Lei, Yinyuan
In the past three decades, nuclear energy has gained much attention as carbon-free electricity. Due to the supply of cooling water in nuclear power plant, large amount of waste heat will increase the water temperature, promote the microalgae and cyanobacteria propagation and increase the chance of red tide. Excess phytoplankton of cool source will result in abnormal operation of cooling system, even core overheating and nuclear leakage. Consequently, it is very important to remove microalgae and cyanobacteria from cold source of nuclear power plants. This review summarizes the formation mechanism and monitoring methods of red tide, compares the advantages and disadvantages of traditional microalgae removal technology including physical, chemical and biological methods. Furthermore, the improved electrochemical method and micro-nano bubble method are introduced in detail. Their combination is considered to be a low-cost, efficient and environmentally-friendly technology to prevent and control red tides for cold source of nuclear power plant.
Показать больше [+] Меньше [-]Metal and PAH loads from ships and boats, relative other sources, in the Baltic Sea
2022
Ytreberg, Erik | Hansson, Katarina | Hermansson, Anna Lunde | Parsmo, Rasmus | Lagerström, Maria | Jalkanen, Jukka-Pekka | Hassellöv, Ida-Maja
The Baltic Sea is a sensitive environment that is affected by chemical pollution derived from multiple natural and anthropogenic sources. The overall aim of this study was to estimate the load of metals and polycyclic aromatic hydrocarbons (PAHs) from shipping and leisure boating, relative other sources, to the Baltic Sea and to identify possible measures that could lead to major reductions in the loads of hazardous substances from maritime shipping and leisure boating. The use of copper-based antifouling paints, and operation of scrubbers in open loop mode, were the two most dominant identified sources of hazardous substances to the Baltic Sea. Open loop scrubbers accounted for 8.5 % of the total input of anthracene to the sea. More than a third of the total load of copper can be reduced if copper-free antifouling paints or other biocide-free antifouling strategies are used on ships and leisure boats.
Показать больше [+] Меньше [-]Tire rubber chemicals reduce juvenile oyster (Crassostrea gigas) filtration and respiration under experimental conditions
2022
Tallec, Kevin | Gabriele, Marta | Paul Pont, Ika | Alunno-Bruscia, Marianne | Huvet, Arnaud
Tires can release a large number of chemical compounds that are potentially hazardous for aquatic organisms. An ecophysiological system was used to do high-frequency monitoring of individual clearance, respiration rates, and absorption efficiency of juvenile oysters (8 months old) gradually exposed to four concentrations of tire leachates (equivalent masses: 0, 1, 10, and 100 μg tire mL⁻¹). Leachates significantly reduced clearance (52 %) and respiration (16 %) rates from 1 μg mL⁻¹, while no effect was observed on the absorption efficiency. These results suggest that tire leachates affect oyster gills, which are the organ of respiration and food retention as well as the first barrier against contaminants. Calculations of scope for growth suggested a disruption of the energy balance with a significant reduction of 57 %. Because energy balance directs whole-organism functions (e.g., growth, reproductive outputs), the present study calls for an investigation of the long-term consequences of chemicals released by tires.
Показать больше [+] Меньше [-]Shipping spills and plastic pollution: A review of maritime governance in the North Sea
2022
Saliba, Mayya | Frantzi, Sofia | Beukering, Pieter van
Plastic pollution of our oceans from land-based sources and shipping spills raises concerns for marine ecosystems, maritime industries and human health. This paper examines the systems and processes in place in the case of plastic pollution due to a shipping spill in the North Sea and the instruments and mechanisms to hold polluters accountable. A desk-based analysis was conducted, and 11 expert interviews contextualised the desk findings. From the 263 reported incidents from 1917 to 2021, 39 % of the reported container loss cases occurred in, or near, the North Sea. Fragmented jurisdiction, frail and uncoordinated policies, aid the shipping sector to deflect responsibility. Around 62 % of the obstacles mentioned by the interviewees addressed governance, including, notably, the lack of international measures, and regulations on shipping routes to protect sensitive areas. The study also identifies the difficulty to enforce compensation for the damage made to ecosystems and biodiversity.
Показать больше [+] Меньше [-]Eutrophication status assessment in the Laizhou Bay, Bohai Sea: Further evidence for the ecosystem degradation
2022
Wei, Yuqiu | Cui, Hongwu | Hu, Qingjing | Bai, Ying | Qu, Keming | Sun, Jun | Cui, Zhengguo
Laizhou Bay is plagued by many environmental problems (e.g., acidification and eutrophication) that are likely to increase in the coming decades along with social and demographic trends. We thus conducted 12 cruises from July 2019 to December 2021 in the Laizhou Bay to evaluate the potential influences of human activities on its eutrophication status. The results showed that the parameters of dissolved inorganic nitrogen (DIN) and oxygen (DO) exceeded the water quality standard in some cases during the past 3 years, suggesting DIN and DO were the crucial factors controlling water quality in the bay. Meanwhile, DIN was identified as a major pollutant in the region, and played an important role in driving the phytoplankton dynamics. Furthermore, with the increases in human-related nutrient inputs (especially DIN), the bay environment reached the mild eutrophication level and was probably at risk from excessive nutrient loads at present, further evidencing the ecosystem degradation.
Показать больше [+] Меньше [-]Measuring concentrations of a dye in the hemolymph of a marine amphipod: Development of a protocol for exposure assessment
2022
dos Santos, Amanda | Vannuci-Silva, Monizze | Vendemiatti, Josiane A de Souza | Artal, Mariana Coletty | Silva, Bianca Ferreira da | Zanoni, Maria Valnice Boldrin | Umbuzeiro, Gisela de Aragão
The increasing pollution of aquatic environments due to old and emerging contaminants requires the development of integrative methods for exposure assessment. Internal concentrations are a reliable way to estimate total exposure of contaminants originated from different routes (water, sediment, and food). We developed a protocol to evaluate the concentration of a dye, C.I. Disperse Red 1, in the hemolymph of Parhyale hawaiensis, a marine amphipod. LOD and LOQ were satisfactory to detect the dye in all hemolymph samples. The concentration detected in the hemolymph varied related to exposure time and dye concentration (0.003 to 0.086 μg mL⁻¹). Polynomial regression model was the best fit. The protocol was reliable to detect and quantify dye exposure in marine amphipods and can be considered for future assessments of estuarine and marine regions under the influence of dye processing plants. The method possibly can be easily adapted to other amphipods and other azo dyes.
Показать больше [+] Меньше [-]Metals and metalloids concentrations in three genotypes of pelagic Sargassum from the Atlantic Ocean Basin-scale
2022
Cipolloni, Océanne-Amaya | Gigault, Julien | Dassié, Émilie Pauline | Baudrimont, Magalie | Gourves, Pierre-Yves | Amaral-Zettler, Linda | Pascal, Pierre-Yves
Since 2011, the Caribbean Islands have witnessed unprecedented massive stranding of a pelagic brown algal Sargassum spp. inducing damages for coastal ecosystems and economy. By accumulating heavy metals, Sargassum can play a role in contaminant transportation from offshore to the coast. In 2019, three genotypes of Sargassum (S. fluitans III, S. natans I, and VIII) were sampled in seven stations along a 3400 km transect in the Atlantic Ocean. Concentrations of 15 heavy metal(loid)s elements were analyzed by Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). Mean metal concentrations were ranked following descending order: As >Fe > Al > Mn > Cd > Zn > Ni > V > Cu > Cr > Hg. The metalloid As was the most abundant contaminant with a maximum value of 115 ppm, previously observed in the Caribbean area (80–150 ppm). At Atlantic Ocean Basin-scale, metallic element concentrations do not present spatial longitudinal gradients. Genotypes S. fluitans III and S. natans (I and VIII), present differents metal(loid)s contamination distinct patterns.
Показать больше [+] Меньше [-]Additives, plasticizers, small microplastics (<100 μm), and other microlitter components in the gastrointestinal tract of commercial teleost fish: Method of extraction, purification, quantification, and characterization using Micro-FTIR
2022
Corami, Fabiana | Rosso, Beatrice | Sfriso, Andrea Augusto | Gambaro, Andrea | Mistri, Michele | Munari, Cristina | Barbante, Carlo
One of the aims of this study is the development of a pretreatment method for additives, plasticizers and other components of micro-litter (APFs), and small microplastics (SMPs <100 μm) in the gastrointestinal tract (GIT) of five of the most widely distributed and consumed commercial fish species, Engraulis encrasiculos, Sardina pilchardus, Mullus surmuletus, Solea solea, and Sparus aurata. The second aim was to develop a simultaneous quantification and identification method via Micro-FTIR of APFs and SMPs ingested by these commercial fish species. The distribution of SMPs and APFs is characteristically different for each species investigated. E. encrasiculos and S. pilchardus had a higher weight of SMPs than the other species investigated. Regarding APFs, the highest abundance was observed in E. encrasiculos. This study highlights the importance of studying additives and plasticizers that can be used as efficient proxies of microplastics, as shown by the presence of vulcanizing agents such as Vanax®.
Показать больше [+] Меньше [-]Severe, rapid and widespread impacts of an Atlantic blue crab invasion
2022
Clavero, Miguel | Franch, Nati | Bernardo-Madrid, Rubén | López, Verónica | Abelló, Pere | Queral, Josep Maria | Mancinelli, Giorgio
The Atlantic blue crab (Callinectes sapidus) has rapidly invaded coastal environments in the western Mediterranean, but there is no consistent assessment of its impacts yet. We use interviews and long-term data series in the Ebro Delta (NE Spain) to: i) characterise the evolution of the blue crab invasion; and ii) identify its impacts. The blue crab was first recorded in 2012, but its expansion started around 2016, with an exponential increase in abundance between 2017 and 2018. Aquatic communities have tended to be dominated by the blue crab, coinciding with the steep and consistent declines of several species, including threatened and commercially exploited ones. Blue crab impacts seem to be exerted even at low abundances, arguably hindering the recovery of declining species. The blue crab is becoming a keystone species in invaded systems and efforts should be made to understand its many-folds impacts in order to prevent or mitigate them.
Показать больше [+] Меньше [-]Research Progress on Volatile Organic Compounds Emissions from Coal-fired Power Plants
2022
Xu, Jingxin | Zhu, Fahua | Ge, Xinlei | Li, Haiwei | Zhao, Xiuyong | Tian, Wenxin | Zhang, Xi | Bai, Yuan | An, Fengxia | Wang, Sheng
Known as the high-priority air pollutants in the atmosphere, volatile organic compounds (VOCs) are a dominated precursor of secondary organic aerosols (SOAs), leading to complex PM₂.₅ and O₃ pollution and severe risks to human health. Considering upward concentrations of VOCs emitted from a great number of coal-fired power plants in China, considerable contributions of this primary source to current air pollution remain to be addressed. Previous studies have underestimated the concentration level of VOCs emissions from actual coal-fired power plants, largely because of incomplete monitored species, inconsistent results of emission characteristics and unclear effectiveness of VOCs removal by current flue gas purification units. Herein, recent progress on the field measurement techniques, pollution characteristics of VOCs (i.e., concentrations, chemical speciation and transformation) and impacts of flue gas purifying technologies on the VOCs control in coal-fired power plants were reviewed. In addition, key research perspectives in the future are proposed to formulate the technical standards for precise monitoring of VOCs from coal-fired power plants. The optimal combustion conditions under low-load operation conditions are to be determined. The ideal synergistic control strategies of VOCs emissions are anticipated to work out. As such, this review will provide some new insights into the development and formulation of VOCs control technologies in coal-fired power plants for the air quality improvement in China.
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