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Результаты 2411-2420 из 4,308
Variation in accumulation and translocation of di-n-butyl phthalate (DBP) among rice (Oryza sativa L.) genotypes and selection of cultivars for low DBP exposure Полный текст
2017
Cai, Quan-Ying | Xiao, Pei-Yun | Zhao, Hai-Ming | Lü, Huixiong | Zeng, Qiao-Yun | Li, Yan-Wen | Li, Hui | Xiang, Lei | Mo, Ce-Hui
Di-n-butyl phthalate (DBP) is a typical endocrine-disrupting chemical with higher detection frequency and concentration in agricultural soil (particularly in paddy-field soil of Guangdong Province) of China. In this study, a greenhouse experiment was conducted to investigate variation in uptake and accumulation of DBP by 20 rice cultivars and to screen low DBP-accumulating cultivars. DBP concentrations in plants varied greatly with rice cultivars, growth stages, and tissues. The highest DBP concentrations in both roots and shoots were observed at the ripening stage, with concentrations 2–100-fold higher than those at tillering, jointing, and flowering stages. At the ripening stage, DBP concentrations decreased in the order of leaf > root > stem > grain, and significant differences of DBP concentrations were observed among various rice cultivars. Moreover, the magnitude of variation in DBP concentrations among various cultivars was greater in stems and grains than in roots and leaves. The translocation factors of DBP from roots to stems and from shoots to grains were <1.0, and those from stems to leaves were almost >1.0. Overall, cultivars Yuxiangyouzhan, Jinnongsimiao, Tianyou 122, and Wuyou 380 accumulated relatively lower DBP in grains, resulting in lower DBP exposure. The DBP uptake and translocation pathways in rice require further investigation. Graphical abstract ᅟ
Показать больше [+] Меньше [-]The study on the evaluation of the pollution control situation of the sewage systems in the counties and cities of Taiwan by applying the VIKOR method Полный текст
2017
Kuo, Jun-Yuan
Currently, the pollution control situation of the sewage systems across Taiwan can be divided into the two major sewage systems, namely, industrial area sewage and public community sewage. When the counties and cities of Taiwan cannot effectively control the sewage pollution situation, ecological pollution of the environment and personal health damage would result. Therefore, evaluating the pollution control situation of the sewage systems can help the environmental protection authorities developing strategies for the pollution control of the sewage systems in the future. In this study, the Vise Kriterijumska Optimizacija I Kompromisno Resenje (VIKOR) method was applied to evaluate the pollution control situation of the sewage systems. The water sample test qualification rate, the emission permit issuance rate, and the staff setting rate of the dedicated wastewater treatment company were used as the pollution control evaluation indexes. According to the results, the use of the VIKOR method to evaluate the pollution control situation of the sewage systems is effective. In cities and counties in Taiwan, public community sewage systems, dedicated to pollution control case, the public community should be actively coached in emission control technology to upgrade sewage capacity, the issuance of discharge permits, and the staff setting rate of the dedicated wastewater treatment, to improve public community sewage pollution control system capabilities. In Taiwan, the industrial area sewage systems, dedicated to pollution control situations, must pay attention to business units in raw materials, spare part inventory, and machine supplier of choice, and we must choose to meet environmental supply chain of green suppliers, which would be effective in reducing effluent produce and improve water sample test qualification rate. The VIKOR value of Yilan County is 1.0000, which is the worst in the pollution control of all the industrial area sewage systems, followed by Taoyuan County (0.2253) and Kaohsiung City (0.1334). Other cities and counties of Taiwan have good performance in the pollution control of the industrial area sewage systems. The VIKOR value of Kinmen County is 1.0000, which is the worst pollution control among the all public community sewage systems, followed by Hsinchu County (0.7458) and New Taipei City (0.5527). Among the cities and counties with good pollution control of the public community sewage systems, the best is Chiayi County (0.0000), followed by Kaohsiung City (0.0159) and Hsinchu City (0.0352). Chiayi County is a good performance compromise between all VIKOR values (0.0000), whether in industrial or public community area pollution control sewage systems. Yilan County industrial pollution control has the poorest performance of all the industrial area sewage systems in Taiwan, but in the public community, it ranked as fourth place of all the public community area sewage systems in Taiwan. The VIKOR method proposed in this study can effectively evaluate the pollution control situation of the sewage systems, and serve as a reference for the environmental protection authorities in developing the strategies for the pollution control of the sewage systems.
Показать больше [+] Меньше [-]Influential impacts of combined government policies for safe disposal of dead pigs on farmer behavior Полный текст
2017
Chen, Xiujuan | Qiu, Guangqian | Wu, Linhai | Xu, Guoyan | Wang, Jianhua | Hu, Wuyang
Improper disposal of dead pigs by pig farmers may have an adverse impact on the ecological environment and food safety. In this paper, disposal of dead pigs by pig farmers in four main pig production provinces in China (Jiangsu, Anhui, Hubei, and Hunan) was empirically investigated. Then, pig farmers’ awareness and evaluation of current combined government policies for the safe disposal of dead pigs were analyzed. Furthermore, the influential effects of combined government policies on the disposal of dead pigs by pig farmers were examined using Decision-Making Trial and Evaluation Laboratory (DEMATEL). Results indicated that the issue of disposal of dead pigs by farmers was very complex and was influenced by the combination of subsidy and compensation, facility and technology, and supervision and punishment policies. The findings also indicated that the different types of policies had different effects and interacted with each other. Among these three combinations, supervision and punishment policies were the most influential policies and facility and technology policies were in most urgent need to improve for regulating the current state of the disposal of dead pigs by farmers. These findings have implications for sustainable pig production.
Показать больше [+] Меньше [-]Assessment of the sediment quality of freshwater ecosystems in eastern China based on spatial and temporal variation of nutrients Полный текст
2017
Zhang, Wenqiang | Jin, Xin | Liu, Dong | Tang, Wenzhong | Shan, Baoqing
Comprehensively characterizing and assessing the sediment quality in freshwater ecosystems based on the condition of the nutrients in eastern China was urgent. The distribution and concentration of nutrients were investigated; meanwhile, sediment quality guidelines (SQGs), organic pollution index (OPI), and organic nitrogen index (ONI) were used to assess the sediment quality. Total phosphorus (TP), total nitrogen (TN), and total sulfur (TS) concentrations in sediment samples were 48.4, 72.5, and 89.5% higher than the soil background value, respectively. In terms of the Ontario SQGs, 41.8 and 74.7% of sediment samples were severely polluted by TP and TN, respectively. The Haihe, Yangtze, and Pearl River Basins were much more severely contaminated than other basins. TN pollution was much more severe than TP pollution in all basins. The Haihe, Huaihe, and Pearl River Basins were seriously contaminated according to the OPI and ONI. On temporal scale, the TP and TN significantly increased since 1980s because of the social and economic development in eastern China. For most severely contaminated basins, TN contamination was higher than TP contamination, and concentrations of TN and TP continuously increased from 2007 to 2016, which ranged from 2.06 to 2.51 g/kg, and 1.02 to 1.22 g/kg, respectively, in the Haihe River Basin. This trend will continue without effective control. The freshwater sediment quality in eastern China revealed urgent attention.
Показать больше [+] Меньше [-]Assessment of arsenic content in soil, rice grains and groundwater and associated health risks in human population from Ropar wetland, India, and its vicinity Полный текст
2017
Sharma, Sakshi | Indaraprīta Kaura, | Nagpal, Avinash Kaur
In the present study, potential health risks posed to human population from Ropar wetland and its vicinity, by consumption of inorganic arsenic (i-As) via arsenic contaminated rice grains and groundwater, were assessed. Total arsenic (t-As) in soil and rice grains were found in the range of 0.06–0.11 mg/kg and 0.03–0.33 mg/kg, respectively, on dry weight basis. Total arsenic in groundwater was in the range of 2.31–15.91 μg/L. i-As was calculated from t-As using relevant conversion factors. Rice plants were found to be arsenic accumulators as bioconcentration factor (BCF) was observed to be >1 in 75% of rice grain samples. Further, correlation analysis revealed that arsenic accumulation in rice grains decreased with increase in the electrical conductivity of soil. One-way ANOVA, cluster analysis and principal component analysis indicated that both geogenic and anthropogenic sources affected t-As in soil and groundwater. Hazard index and total cancer risk estimated for individuals from the study area were above the USEPA limits of 1.00 and 1.00 × 10⁻⁶, respectively. Kruskal-Wallis H test indicated that groundwater intake posed significantly higher health risk than rice grain consumption (χ ²(1) = 17.280, p = 0.00003).
Показать больше [+] Меньше [-]Characteristics of Pelargonium radula as a mercury bioindicator for safety assessment of drinking water Полный текст
2017
Majid, N . A. | Phang, I. C. | Darnis, D. S.
Identification of Pelargonium radula as bioindicator for mercury (Hg) detection confers a new hope for monitoring the safety of drinking water consumption. Hg, like other non-essential metals, inflicts the deterioration of biological functions in human and other creatures. In the present study, effects of Hg on the physiology and biochemical content of P. radula were undertaken to understand the occurrence of the morphological changes observed. Young leaves of P. radula were treated with different concentrations of Hg-containing solution (0.5, 1.0 and 2.0 ppb) along with controls for 4 h, prior to further analysis. Elevated Hg concentration in treatment solution significantly prompted an increased accumulation of Hg in the leaf tissues. Meanwhile, total protein, chlorophyll and low molecular mass thiol contents (cysteine, glutathione and oxidized glutathione) decreased as Hg accumulation increased. However, phytochelatin 2 productions were induced in the treated leaves, in comparison to the control. Based on these findings, it is postulated that as low as 0.5 ppb of Hg interferes with the metabolic processes of plant cells, which was reflected from the morphological changes exhibited on P. radula leaves—the colour of the Hg-treated leaves changed from green to yellowish-brown, became chlorosis and wilted. Changes in the tested characteristics of plant are closely related to the Hg-induced morphological changes on P. radula leaves, a potential bioindicator for detecting Hg in drinking water.
Показать больше [+] Меньше [-]Selenium protects against cadmium-induced kidney apoptosis in chickens by activating the PI3K/AKT/Bcl-2 signaling pathway Полный текст
2017
Bao, Rong-kun | Zheng, Shu-fang | Wang, Xin-yue
Cadmium (Cd) is a toxic heavy metal that can induce apoptosis. Selenium (Se) is a necessary trace element and can antagonize the toxicity of many heavy metals, including Cd. PI3K/AKT/Bcl-2 is a key survival signaling pathway that regulates cellular defense system against oxidative injury as well as cell proliferation, survival, and apoptosis. The antagonistic effects of Se on Cd-induced toxicity have been reported. However, little is known about the effect of Se on Cd-induced apoptosis in chicken kidneys via the PI3K/AKT/Bcl-2 signaling pathway. In the present study, we fed chickens with Se, Cd, or both Se and Cd supplements, and after 90 days of treatment, we detected the related index. The results showed that the activity of inducible nitric oxide synthase (iNOS) and concentration of nitric oxide (NO) were increased; activities of the mitochondrial respiratory chain complexes (complexes I, II, and V) and ATPases (the Na⁺-K⁺-ATPase, the Mg²⁺-ATPase, and the Ca²⁺-ATPase) were decreased; expression of PI3K, AKT, and Bcl-2 were decreased; and expression of Bax, Bak, P53, Caspase-3, Caspase-9, and cytochrome c (Cyt c) were increased. Additionally, the results of the TUNEL assay showed that the number of apoptotic cells was increased in the Cd group. By contrast, there was a significant improvement of the correlation indicators and occurrence of apoptosis in the Se + Cd group compared to the Cd group. In conclusion, our results confirmed that Se had a positive effect on ameliorating Cd-induced apoptosis in chicken kidney tissue by activating the PI3K/AKT/Bcl-2 signaling pathway.
Показать больше [+] Меньше [-]Modelling the effects of water diversion and combined sewer overflow on urban inland river quality Полный текст
2017
Gu, Xianyong | Liao, Zhenliang | Zhang, Guangqian | Xie, Jiaqiang | Zhang, Jin
In order to assist and optimize the operation of a clean water diversion project for the medium-sized inland rivers in Chaohu, China, an integrated hydrodynamic and water quality model was used in this study. Sixteen diversion scenarios and five sewage interception scenarios were defined to assess the improvement of water quality parameters including ammonia nitrogen (NH₃-N), total phosphorus (TP) and chemical oxygen demand (COD) under different diverted water flows, diverting times, diverting points, diverting routines and sewage interception proportions. An index of pollutant removal rate per unit diverted water flow (PRUWF) was proposed to evaluate the effect of the clean water diversion. Results show that operating conditions played important roles in water quality improvement of medium-sized inland rivers. The optimal clean water diversion was operated under the conditions of a flow rate of 5 m³/s for 48 h with an additional constructed bridge sluice. A global sensitivity analysis using the Latin Hypercube One-Factor-at-a-Time (LH-OAT) method was conducted to distinguish the contributions of various driving forces to inland river water restoration. Results show that sewage interception was more important than diverted water flow and diverting time with respect to water quality improvement, especially for COD.
Показать больше [+] Меньше [-]Chemical composition, structural properties, and source apportionment of organic macromolecules in atmospheric PM10 in a coastal city of Southeast China Полный текст
2017
Chen, Yanting | Du, Wenjiao | Chen, Jinsheng | Hong, Youwei | Zhao, Jinping | Xu, Lingling | Xiao, Hang
Particulate matter (PM₁₀) associated with the fractions of organic macromolecules, including humic acid (HA), kerogen + black carbon (KB), and black carbon (BC), was determined during summer and winter at urban and suburban sites in a coastal city of southeast China. The organic macromolecules were characterized by elemental analysis (EA), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR), and their sources were identified by using stable carbon/nitrogen isotope (δ¹³C/δ¹⁵N) and the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) Model. The results showed that HA, kerogen (K), and BC accounted for the range of 3.89 to 4.55 % in PM₁₀, while they were the dominant fractions of total organic carbon (TOC), ranging from 64.70 to 84.99 %. SEM analysis indicated that BC particles were porous/nonporous and consisted of spherical and non-spherical (i.e., cylindrical and elongate) structures. The FTIR spectra of HA, KB, and BC exhibited similar functional groups, but the difference of various sites and seasons was observed. HA in PM₁₀ contained a higher fraction of aliphatic structures, such as long-chain fatty and carbohydrates with a carboxylic extremity. The C/N ratio, SEM, and δ¹³C/δ¹⁵N values provided reliable indicators of the sources of HA, K, and BC in PM₁₀. The results suggested that HA and K majorly originated from terrestrial plants, and BC came from the mixture of combustion of terrestrial plants, fossil fuel, and charcoal. The air masses in winter originated from Mongolia (4 %), the northern area of China (48 %), and northern adjacent cities (48 %), suggesting the influence of anthropogenic sources through long-range transport, while the air masses for the summer period came from South China Sea (34 %) and Western Pacific Sea (66 %), representing clean marine air masses with low concentrations of organic macromolecules.
Показать больше [+] Меньше [-]Sacrificial photocatalysis: removal of nitrate and hydrogen production by nano-copper-loaded P25 titania. A kinetic and ecotoxicological assessment Полный текст
2017
Lucchetti, Roberta | Siciliano, Antonietta | Clarizia, Laura | Russo, Danilo | Di Somma, Ilaria | Di Natale, Francesco | Guida, Marco | Andreozzi, Roberto | Marotta, Raffaele
The photocatalytic removal of nitrate with simultaneous hydrogen generation was demonstrated using zero-valent nano-copper-modified titania (P25) as photocatalyst in the presence of UV-A-Vis radiation. Glycerol, a by-product in biodiesel production, was chosen as a hole scavenger. Under the adopted experimental conditions, a nitrate removal efficiency up to 100% and a simultaneous hydrogen production up to 14 μmol/L of H₂ were achieved (catalyst load = 150 mg/L, initial concentration of nitrate = 50 mg/L, initial concentration of glycerol = 0.8 mol/L). The reaction rates were independent of the starting glycerol concentration. This process allows accomplishing nitrate removal, with the additional benefit of producing hydrogen under artificial UV-A radiation. A kinetic model was also developed and it may represent a benchmark for a detailed understanding of the process kinetics. A set of acute and chronic bioassays (Vibrio fischeri, Raphidocelis subcapitata, and Daphnia magna) was performed to evaluate the potential ecotoxicity of the nitrate/by-product mixture formed during the photocatalytic process. The ecotoxicological assessment indicated an ecotoxic effect of oxidation intermediates and by-products produced during the process.
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