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Individual PM2.5 exposure is associated with the impairment of cardiac autonomic modulation in general residents Full text
2016
Xie, Yuquan | Bo, Liang | Jiang, Shuo | Tian, Zhenyong | Kan, Haidong | Yigang, | Song, Weimin | Zhao, Jinzhuo
Fine particulate matter (PM₂.₅) is one of the major pollutants in metropolitan areas. The current study was conducted to observe the effects of PM₂.₅ on cardiac autonomic modulation. The participants included 619 men and women aged from 35–75 in a residential area in Shanghai, China. All the participants were divided into four categories according to the distance between their apartments and major road. In addition, individual PM₂.₅ was measured using SIDEPAKTM AM510 (TSI, USA) from 8:00 am to 6:00 pm. At the end of the individual PM₂.₅ measurement, the systolic pressure, diastolic pressure, heart rate (HR), low-frequency (LF), high-frequency (HF), and LF/HF were determined. The association between individual PM₂.₅ level and the above health effects was analyzed using generalized linear regression. The results showed that the average concentration of individual PM₂.₅ was 95.5 and 87.0 μg/m³ for men and women. Residential distance to major road was negatively correlated with the individual PM₂.₅. The results indicated that per 1.0 μg/m³ increase of individual PM₂.₅ was associated with a 2.3 % increase for systolic pressure, 0.3 % increase for diastolic pressure, 0.4 % decrease for LF, and 0.4 % decrease for HF. Nevertheless, there was no statistical association between individual PM₂.₅ and heart rate and LF/HF in the total model. In addition, the similar results were found in men and women excluding a significant association between PM₂.₅ and the heart rate in men. The alterations of cardiac autonomic modulation hinted that PM₂.₅ exposure might be associated with the potential occurrence of cardiovascular disease, such as arrhythmia and ischemic heart diseases.
Show more [+] Less [-]Preparation and Characterization of a Novel Activated Carbon from Vine Shoots by ZnCl2 Activation and Investigation of Its Rifampicine Removal Capability Full text
2016
Erdem, Mehmet | Orhan, Ramazan | Şahin, Mehmet | Aydın, Ekrem
Preparation and characterization of a novel activated carbon obtained from vine shoots by ZnCl₂ activation and its rifampicine removal capacity were investigated in this study. The effects of activation temperature and impregnation ratio (precursor/ZnCl₂) on the activated carbon properties were investigated. The prepared activated carbon was characterized by BET surface area, surface functional group analysis by Boehm’s titration and FT-IR analysis, pHₚzc, iodine number, SEM-EDX, and particle size distribution. The results showed that the surface area, pore size, and pore volume of the activated carbon increased with the increasing temperature and impregnation ratio and reached maxima at the impregnation ratio of 40/30 at 700 °C. Under the optimal conditions, it was determined that the BET surface area, total pore volume, iodine number, and pHₚzc of the activated carbon were 1689 m²/g, 0.842 cm³/g, 1276 mg/g, and 4.8, respectively, and it has mainly acidic functional groups (total 0.2516 meq/g) on its surface. The activated carbon obtained was evaluated for rifampicine removal efficiency depending on contact time, adsorbent dosage, and initial concentration of rifampicine. Maximum adsorption capacity of rifampicine by the activated carbon (Q°) was determined according to Langmuir adsorption isotherm. The adsorption data was best fitted to the Langmuir isotherm with R ² of 0.983 and Q° was found to be 476.2 mg/g.
Show more [+] Less [-]Long-term tobacco plantation induces soil acidification and soil base cation loss Full text
2016
Zhang, Yuting | He, Xinhua | Liang, Hong | Zhao, Jian | Zhang, Yueqiang | Xu, Chen | Shi, Xiaojun
Changes in soil exchangeable cations relative to soil acidification are less studied particularly under long-term cash crop plantation. This study investigated soil acidification in an Ali-Periudic Argosols after 10-year (2002–2012) long-term continuous tobacco plantation. Soils were respectively sampled at 1933 and 2143 sites in 2002 and 2012 (also 647 tobacco plants), from seven tobacco plantation counties in the Chongqing Municipal City, southwest China. After 10-year continuous tobacco plantation, a substantial acidification was evidenced by an average decrease of 0.20 soil pH unit with a substantial increase of soil sites toward the acidic status, especially those pH ranging from 4.5 to 5.5, whereas 1.93 kmol H⁺ production ha⁻¹ year⁻¹ was mostly derived from nitrogen (N) fertilizer input and plant N uptake output. After 1 decade, an average decrease of 27.6 % total exchangeable base cations or of 0.20 pH unit occurred in all seven tobacco plantation counties. Meanwhile, for one unit pH decrease, 40.3 and 28.3 mmol base cations kg⁻¹ soil were consumed in 2002 and 2012, respectively. Furthermore, the aboveground tobacco biomass harvest removed 339.23 kg base cations ha⁻¹ year⁻¹ from soil, which was 7.57 times higher than the anions removal, leading to a 12.52 kmol H⁺ production ha⁻¹ year⁻¹ as the main reason inducing soil acidification. Overall, our results showed that long-term tobacco plantation not only stimulated soil acidification but also decreased soil acid-buffering capacity, resulting in negative effects on sustainable soil uses. On the other hand, our results addressed the importance of a continuous monitoring of soil pH changes in tobacco plantation sites, which would enhance our understanding of soil fertility of health in this region.
Show more [+] Less [-]Influence of Humic Acid on the Photolysis of Triclosan in Different Dissociation Forms Full text
2016
Chen, Lei | Wang, Zheng | Wang, Zhulai | Gu, Xin
Photolysis is a major transformation pathway for triclosan, an antibacterial agent frequently detected in aquatic environment. Though many studies have been conducted on the influence of dissolved organic matter on the photolysis of triclosan, there are still controversies and the mechanism involved is still not clear. In the present study, influence of humic acid on the photolysis of triclosan in molecular form and anionic form was investigated. Reactive substances involved were identified and photolysis pathways were proposed. The addition of humic acid significantly enhanced the photolysis of triclosan in molecular form and inhibited that of triclosan in anionic form. •OH and intra-humic acid ¹O₂ played the dorminant role in the enhanced photolysis of triclosan. Different photolysis pathways of triclosan in different forms in the presence of humic acid were proposed, and dioxin products were not found during the indirect photolysis. Here, we show that humic acid has the opposing effects on the photolysis of triclosan in different forms. These findings will help us better understand the photolysis process of triclosan in natural waters.
Show more [+] Less [-]Oak (Quercus robur) Acorn Peel as a Low-Cost Adsorbent for Hexavalent Chromium Removal from Aquatic Ecosystems and Industrial Effluents Full text
2016
Kuppusamy, Saranya | Thavamani, Palanisami | Megharaj, Mallavarapu | Venkateswarlu, Kadiyala | Lee, Yong Bok | Naidu, R.
The efficiency of low-cost, abundantly available local forestry waste, oak (Quercus robur) acorn peel (OP), to remove toxic Cr(VI) from aqueous solutions was studied in a batch system as a function of contact time, adsorbate concentration, adsorbent dosage, and pH. In an equilibrium time of 420 min, the maximum Cr removal by OP at pH 2 and 10 was 100 and 97 %, respectively. The sorption data fitted well with Langmuir adsorption model. Evaluation using Langmuir expression presented a monolayer sorption capacity of 47.39 mg g⁻¹ with an equilibrium sorbent dose of 5 g L⁻¹ and pH 7. Uptake of Cr by OP was described by pseudo-second-order chemisorption model. ICP-OES, LC-ICPMS analysis of the aqueous and solid phases revealed that the mechanism of Cr(VI) removal is by ‘integrated adsorption and reduction’ mechanism. ESEM-EDX and XRD analysis of OP before and after adsorption also confirmed that both adsorption and reduction of Cr(VI) to less toxic Cr³⁺ forms followed by complexation onto the adsorbent surface contributed to the removal of Cr(VI). Consistent with batch studies, OP effectively removed (>95 %) Cr from the real water samples collected from lake and sea. The results of this study illustrate that OP could be an economical, green, and effective biomaterial for Cr(VI) removal from natural aquatic ecosystems and industrial effluents.
Show more [+] Less [-]Nontargeted evaluation of the fate of steroids during wastewater treatment by comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry Full text
2016
Kopperi, Matias | Parshintsev, Jevgeni | Ruiz-Jiménez, José | Riekkola, Marja–Liisa
Emerging organic contaminants in wastewater are usually analyzed by targeted approaches, and especially estrogens have been the focus of environmental research due to their high hormonal activity. The selection of specific target compounds means, however, that most of the sample components, including transformation products and potential new contaminants, are neglected. In this study, the fate of steroidal compounds in wastewater treatment processes was evaluated by a nontargeted approach based on comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry. The potential of the nontargeted approach to generate comprehensive information about sample constituents was demonstrated with use of statistical tools. Transformation pathways of the tentatively identified compounds with steroidal four-ring structure were proposed. The purification efficiency of the wastewater treatment plants was studied, and the distribution of the compounds of interest in the suspended solids, effluent water, and sludge was measured. The results showed that, owing to strong adsorption of hydrophobic compounds onto the solid matter, the steroids were mostly bound to the suspended solids of the effluent water and the sewage sludge at the end of the treatment process. The most abundant steroid class was androstanes in the aqueous phase and cholestanes in the solid phase. 17β-estradiol was the most abundant estrogen in the aqueous phase, but it was only detected in the influent samples indicating efficient removal during the treatment process. In the sludge samples, however, high concentrations of an oxidation product of 17β-estradiol, estrone, were measured.
Show more [+] Less [-]Kinetic Simulations of Volatile Organic Compounds Decomposition by Non-thermal Plasma Treatment Full text
2016
Xia, Dehong | Li, Zhiyong | Xie, Yulei | Zhang, Xinru
Volatile organic compounds (VOCs) decomposition by non-thermal plasma (NTP) has been receiving increasing attention from the scientific communities due to its advantages of easy operation, high efficiency, energy saving, and non-secondary pollution. But most of the researches are doing experiments and existing experiment methods cannot observe the micro physical and chemical processes. In order to make up for the deficiency of the experiment, herein, a numerical method was developed to analyze the decomposition behavior of HCN, C₃H₃N, C₃H₈, C₃H₆, CO, and NO in the VOCs treatment by NTP. Results indicated that increasing electron density or energy was beneficial to VOCs decomposition, but when the electron density and energy was too high, the promotion would be weakened. The influences of initial concentration of O₂ and H₂O on different VOCs decomposition were totally different. The increase of initial concentration of oxygen was beneficial to the decomposition of HCN, C₃H₈, CO, and NO, but the high concentration of oxygen could promote to generate C₃H₆ at the initial reaction stage. The decomposition of HCN and C₃H₃N are not restricted by dry or wet conditions, but the increase of the concentration of water vapor is advantageous to the decomposition of C₃H₈, CO, and NO. Graphical Abstract ᅟ
Show more [+] Less [-]Radiostrontium monitoring of bivalves from the Pacific coast of eastern Japan [Erratum: December 2021, Vol.28(47), p.67907] Full text
2016
Karube, Zin’ichi | Inuzuka, Yoko | Tanaka, Atsushi | Kurishima, Katsuaki | Kihou, Nobuharu | Shibata, Yasuyuki
In early April 2011, radiostrontium was accidentally released from the Fukushima Daiichi Nuclear Power Plant to the Pacific coast of eastern Japan. We developed a simple procedure to analyze radiostrontium levels in marine mussels (Septifer virgatus) and seawater using crown ether (Sr Resin; Eichrom). Then, we used our method to describe the spatial and temporal distribution of radiostrontium in mussels and seawater on the Pacific coast of eastern Japan from 2011 to 2013 and for 2015. Activity of ⁹⁰Sr in mussels and seawater decreased with distance from the Fukushima Daiichi Nuclear Power Plant and between 2011 and 2013 tended to be higher in areas south of the Fukushima Daiichi Nuclear Power Plant than to the north of it. Activity in mussels and seawater also tended to decrease from 2011 to 2013 and by 2015 had reached levels experienced prior to the Fukushima accident. Our results suggest that radiostrontium discharged from the Fukushima Daiichi Nuclear Power Plant was dispersed by coastal currents in a southerly direction along the Pacific coast of eastern Japan from 2011 to 2013, following which its activity decreased to background levels by 2015.
Show more [+] Less [-]Determination the Usefulness of AhHMA4p1::AhHMA4 Expression in Biofortification Strategies Full text
2016
Weremczuk, Aleksandra | Barabasz, Anna | Ruszczyńska, Anna | Bulska, Ewa | Antosiewicz, Danuta Maria
AhHMA4 from Arabidopsis thaliana encodes Zn/Cd export protein that controls Zn/Cd translocation to shoots. The focus of this manuscript is the evaluation of AhHMA4 expression in tomato for mineral biofortification (more Zn and less Cd in shoots and fruits). Hydroponic and soil-based experiments were performed. Transgenic and wild-type plants were grown on two dilution levels of Knop’s medium (1/10, 1/2) with or without Cd, to determine if mineral composition affects the pattern of root/shoot partitioning of both metals due to AhHMA4 expression. Facilitation of Zn translocation to shoots of 19-day-old transgenic tomato was noted only when plants were grown in the more diluted medium. Moreover, the expression pattern of Zn-Cd-Fe cross-homeostasis genes (LeIRT1, LeChln, LeNRAMP1) was changed in transgenics in a medium composition-dependent fashion. In plants grown in soil (with/without Cd) up to maturity, expression of AhHMA4 resulted in more efficient translocation of Zn to shoots and restriction of Cd. These results indicate the usefulness of AhHMA4 expression to improve the growth of tomato on low-Zn soil, also contaminated with Cd.
Show more [+] Less [-]Investigation of the Soil Sorption of Neutral and Basic Pesticides Full text
2016
Vitoratos, Andreas | Fois, Christos | Danias, Panagiotis | Likudis, Zisimos
Adsorption of six neutral (chlorpyrifos, α-endosulfan, fenthion, parathion, parathion metyl, and cis permethrin) and six basic (pirimicarb, prochloraz, prometryn, pirimiphos ethyl, quinoxyfen, and triadimefon) pesticides was measured in ten natural soils in order to unravel the parameters influencing soil sorption. Linear regression confirmed that organic carbon content of soil is the determinant factor of soil sorption along with a secondary role of clay in the case of basic pesticides. Concerning pesticides themselves, their potential to be absorbed is governed by hydrophobic, electrostatic, and polar interactions. Electrostatic interactions can be expressed by considering the molecular fraction of positively charged species (F⁺). The combination of these parameters led to good prediction models, where the two expressions of lipophilicity, octanol-water partition (logP) and distribution coefficient (logD), showed similar performance. Finally, the role of electrostatic interactions to soil sorption and their successful expression by F⁺ parameter was further confirmed using artificial adjustment of the acidity of one soil at different pH values not covered by the natural acidity of the investigated soils.
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