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Cơ quản chủ quản: Springer Science + Business Media , Springer Heidelberg
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PollutionMedicine (miscellaneous)Health, Toxicology and MutagenesisEnvironmental Chemistry
Các bài báo tiêu biểu
Mechanistic modeling of the bioconcentration of (super)hydrophobic compounds in Hyalella azteca Abstract Bioconcentration tests using the freshwater amphipod Hyalella azteca as an alternative to conventional fish tests have recently received much attention. An appropriate computational model of H. azteca could help in understanding the mechanisms behind bioconcentration, in comparison to the fish as test organism. We here present the first mechanistic model for H. azteca that considers the single diffusive processes in the gills and gut. The model matches with the experimental data from the literature quite well when appropriate physiological information is used. The implementation of facilitated transport was essential for modeling. Application of the model for superhydrophobic compounds revealed binding to organic matter and the resulting decrease in bioavailable fraction as the main reason for the observed counterintuitive decrease in uptake rate constants with increasing octanol/water partition coefficient. Furthermore, estimations of the time needed to reach steady state indicated that durations of more than a month could be needed for compounds with a log K ow > 8, limiting the experimental applicability of the test. In those cases, model-based bioconcentration predictions could be a preferable approach, which could be combined with in vitro biotransformation measurements. However, our sensitivity analysis showed that the uncertainty in determining the octanol/water partition coefficients is a strong source of error for superhydrophobic compounds.
Study of microbes having potentiality for biodegradation of plastics
Tập 20 Số 7 - Trang 4339-4355 - 2013
Plastic is a broad name given to the different types of organic polymers having high molecular weight and is commonly derived from different petrochemicals. Plastics are generally not biodegradable or few are degradable but in a very slow rate. Day by day, the global demand of these polymers is sharply increasing; however, considering their abundance and potentiality in causing different environmental hazards, there is a great concern in the possible methods of degradation of plastics. Recently, there have been some debates at the world stage about the potential degradation procedures of these synthetic polymers and microbial degradation has emerged as one of the potential alternative ways of degradation of plastics. Alternatively, some scientists have also reported many adverse effects of these polymers in human health, and thus, there is an immediate need of a potential screening of some potential microbes to degrade these synthetic polymers. In this review, we have taken an attempt to accumulate all information regarding the chemical nature along with some potential microbes and their enzymatic nature of biodegradation of plastics along with some key factors that affect their biodegradability.
Hydrochemical characteristics and groundwater quality in the thick loess deposits of China
Tập 29 - Trang 8831-8850 - 2021
Water quality and quantity should be paid more attention in regions with arid climate and thick vadose zones since the limited groundwater cannot be replenished rapidly once polluted. This study focused on the Loess Plateau of China to investigate the geochemical mechanism affecting groundwater chemistry and to calculate contribution rates of multiple sources to groundwater solutes. We employed multiple methods (diagrams, bivariate analyses, hierarchical cluster analysis (HCA), sodium adsorption ratio (SAR), water quality index (WQI), correlation analysis, and forward model) for the above purposes. We collected 64 groundwater samples in the thick loess deposits in June 2018 (flood season) and April 2019 (dry season). The average concentrations of cation were in the order of Ca2+ > Na+ > Mg2+ > K+ in the flood season, and Na+ > Ca2+ > Mg2+ > K+ in the dry season. The order of anions contents in the flood season and the dry season were HCO3- > SO42- > Cl- > NO3-. The major hydrochemical facies were Ca-HCO3 and Ca·Mg-HCO3 in the flood season and Na·Ca-HCO3·SO4 and Na-HCO3 in the dry season, respectively. Most of the groundwater (95% in the flood season and 96% in the dry season) was suitable for drinking, and the overall water quality was acceptable for irrigation. Mineral dissolution and cation exchange were important natural processes affecting groundwater chemistry. The forward model showed that the contribution of atmospheric input, anthropogenic input, evaporite dissolution, silicate weathering, and carbonate weathering to solutes in groundwater was 2.3±1.5%, 5.0±7.1%, 19.3±21.4%, 42.8±27.3%, and 30.6±27.1% in the flood season, and 9.1±6.4%, 3.4±5.2%, 20.3±15.9, 56.6±23.2%, and 10.7±15.4% in the dry season, respectively. Obviously, silicate and carbonate weathering contribute the most to groundwater chemistry in the flood season, while silicate weathering and evaporite dissolution contribute the most in the dry season. Although the overall contribution of anthropogenic inputs was insignificant, it was the dominant source of solutes for local groundwater. This study provides fundamental information for water management in arid areas.
Source apportionment of metallic elements in urban atmospheric particulate matter and assessment of its water-soluble fraction toxicity
Tập 27 Số 11 - Trang 12202-12214 - 2020
Dust and microbial filtration performance of regular and antimicrobial HVAC filters in realistic conditions
Tập 28 - Trang 39907-39919 - 2021
Two polypropylene HVAC electret filters: a regular filter and an antimicrobial filter containing zinc pyrithione (ZPT), were compared for filtration performance. The study was conducted over 7 months in realistic conditions with semi-urban outdoor air. Several parameters were monitored over the study period: the average temperature was about 20 °C and relative humidity about 60%, the average inlet concentration of cultivable microorganisms was 50 CFU m−3, the average inlet concentration of particles was 10 μg m−3, the filter pressure drop increased moderately by about 30 Pa, and the particle collection efficiency of soda fluorescein (median diameter 0.35 μm) decreased in the first half of the study period by about 30% and then stabilized. The microbial concentration on the filters was quantified every 2 months using an innovative methodology based on media coupons in conjunction with microorganism quantification by CFU counting, with 5 culture media favorable to bacteria and/or fungi growth. The microbial concentrations on the filters were between 100 and 2000 CFU cm−2. The antimicrobial effect of zinc pyrithione was confirmed by the fungi cultivated with DRBC agar: no effects in the level of filter clogging were revealed in the range studied. The high statistical deviation in the results regarding the inhibiting effect of zinc pyrithione on bacteria prevents any conclusion.
A comparative study of tea waste derived humic-like substances with lignite-derived humic substances on chemical composition, spectroscopic properties and biological activity
Tập 29 - Trang 60631-60640 - 2022
Emerging demand for humic substances escalated the short supply of coal-related resources from which humic substances are extracted in large quantities for various applications. Production of humic-like substances from lignocellulosic waste materials similar in structural and functional properties to humic substances has gained interest recently. Tea waste is a by-product from tea manufacturing factories enriched in lignocellulose is used to extract two types of humic fractions. One fraction has purified humic-like acid (HLA), and the other has unpurified humic and fulvic acids called as humic-like substances (HLS). Elemental composition, spectroscopic (13C CPMAS NMR and FTIR) properties, and biological activity of tea waste derived humic-like substances (TWDHLS) were compared with commercially available humic acid (CHA) extracted from lignite. Elemental analysis and FTIR characterization showed slight differences between HLA and HLS, while NMR results revealed that both have similar carbon distribution and are abundant in cellulosic polysaccharides and lignin derivatives. The presence of more stable compounds in TWDHLS contribute to its recalcitrant nature. NMR spectra of CHA significantly varied with TWDHLS and were rich in aliphatic compounds. The biological activity of TWDHLS and CHA was studied at five different concentrations (0, 20, 40, 80, and 160 mg L−1). The results show that soil application TWDHLS at 80 mg L−1 concentration showed better results on the growth of tea nursery plants similar to CHA, contrasting to the variation in their structural properties. Our findings revealed that TWDHLS could be used not only as a potential plant biostimulant but also as a better substitute for humic substances.
Development of multimode gas-fired combined-cycle chemical-looping combustion-based power plant layouts
Tập 29 - Trang 54967-54987 - 2022
Operation of power plants with carbon dioxide capture and sequestration (CCS) and without carbon dioxide capture and storage modes and energy penalty or energy utilization in such operations is of great significance. This work reports on two gas-fired pressurized chemical-looping combustion (CLC) power plant layouts with two inbuilt modes of flue gas exit, namely, one with carbon dioxide capture mode and the second mode is letting flue gas (consists of carbon dioxide and water) without capturing carbon dioxide. Without CCS mode, the higher thermal efficiencies of 54.06 and 52.63% are obtained for natural gas and syngas, respectively. In carbon capture mode, a net thermal efficiency of 52.13% is obtained with natural gas and 48.78% with syngas. The operating pressure of the air reactor is taken to be 13 bar for realistic operational considerations, and that of the fuel reactor is 11.5 bar. Two power plant layouts were developed based on combined-cycle chemical-looping combustion (CC CLC) for natural gas and syngas fuels. A single layout is developed for two fuels with a possible retrofit for dual fuel operation. The CLC power plants can be operated with two modes of flue gas exit options, and these operational options make them higher thermal efficient power plants.
Organic carbon sequestration in Chinese croplands under compost application and its contribution to carbon neutrality
Tập 30 - Trang 9022-9035 - 2022
Achieving the carbon neutrality in China has great impact on alleviating global warming. Compost application, an important measure to promote soil organic carbon (SOC) sequestration, has been practiced in China since 2015. However, it is still unclear how much carbon can be fixed by cropland soil under compost application in the whole China. China has pledged to strive for the goal of carbon neutrality by 2060, which brought two issues: whether compost application can consistently promote SOC sequestration until 2060, and how much contribution it can make to the carbon neutrality. In the present study, we analyzed the results from 93 literatures to determine the SOC sequestration under compost application in the different agricultural divisions of China. Results showed that there were regional differences in the effect of compost application on SOC sequestration. The annual SOC sequestration in Northern China (NC) and Gansu + Xinjiang (GX) was significantly high than other regions. In addition, the annual SOC sequestration was negatively related to the duration of the experiment, while the accumulative SOC sequestration during the experimental period increased with the increase of the duration. According to our results, the total SOC sequestration in topsoil of Chinese cropland was 85 Tg C year−1 under compost application, which will make a 4.4% contribution to carbon neutrality during 2021–2060. In conclusion, cropland soil in China can still sequester carbon for more than 35 years under compost application. Thus, abidingly promoting compost application in China is crucial to accomplishing the carbon neutrality goal.
Systemic insecticides (neonicotinoids and fipronil): trends, uses, mode of action and metabolites
Tập 22 Số 1 - Trang 5-34 - 2015
Effects of neonicotinoids and fipronil on non-target invertebrates Abstract We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (Apis mellifera ) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section “other invertebrates” review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. There is a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large-scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.
Tập 22 Số 1 - Trang 68-102 - 2015