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Algae community and trophic state of subtropical reservoirs in southeast Fujian, China Full text
2012
Yang, Jun | Yu, Xiaoqing | Liu, Lemian | Zhang, Wenjing | Guo, Peiyong
BACKGROUND,: aim, and scope Fujian reservoirs in southeast China are important water resources for economic and social sustainable development, although few have been studied previously. In recent years, growing population and increasing demands for water shifted the focus of many reservoirs from flood control and irrigation water to drinking water. However, most of them showed a rapid increase in the level of eutrophication, which is one of the most serious and challenging environmental problems. In this study, we investigated the algae community characteristics, trophic state, and eutrophication control strategies for typical subtropical reservoirs in southeast Fujian. MATERIALS AND METHODS: Surface water samples were collected using polyvinyl chloride (PVC) plastic bottles from 11 Fujian reservoirs in summer 2010. Planktonic algae were investigated by optical microscopy. Water properties were determined according to the national standard methods. RESULTS AND DISCUSSION: Shallow reservoirs generally have higher values of trophic state index (TSI) and appear to be more susceptible to anthropogenic disturbance than deeper reservoirs. A total of 129 taxa belonging to eight phyla (i.e., Bacillariophyta, Chlorophyta, Chrysophyta, Cryptophyta, Cyanophyta, Euglenophyta, Pyrrophyta, Xanthophyta) were observed and the most diverse groups were Chlorophyta (52 taxa), Cyanophyta (20 taxa), Euglenophyta (17 taxa), Chrysophyta (14 taxa). The dominant groups were Chlorophyta (40.58%), Cyanophyta (22.91%), Bacillariophyta (21.61%), Chrysophyta (6.91%). The species richness, abundance, diversity, and evenness of algae varied significantly between reservoirs. TSI results indicated that all 11 reservoirs were eutrophic, three of them were hypereutrophic, six were middle eutrophic, and two were light eutrophic. There was a strong positive correlation between algal diversity and TSI at P < 0.05. Our canonical correspondence analysis (CCA) results illustrated that temperature, transparency, conductivity, DO, TC, NH4-N, NO x -N, TP, and chlorophyll a were significant environmental variables affecting the distribution of algae communities. The transparency and chlorophyll a were the strongest environmental factors in explaining the community data. Furthermore, the degradation of water quality associated with excess levels of nitrogen and phosphorus in Fujian reservoirs may be impacted by interactions among agriculture and urban factors. A watershed-based management strategy, especially phosphorus control, should be developed for drinking water source protection and sustainable reservoirs in the future. CONCLUSION AND RECOMMENDATIONS: All investigated reservoirs were eutrophicated based on the comprehensive TSI values; thus, our results provided an early warning of water degradation in Fujian reservoirs. Furthermore, the trophic state plays an important role in shaping community structure and in determining species diversity of algae. Therefore, long-term and regular monitoring of Euglenophyta, Cyanophyta, TN, TP and chlorophyll a in reservoirs is urgently needed to further understand the future trend of eutrophication and to develop a watershed-based strategy to manage the Cyanophyta bloom hazards.
Show more [+] Less [-]Perfluorooctane sulfonate increases β-oxidation of palmitic acid in chicken liver Full text
2012
Nordén, Marcus | Westman, Ola | Venizelos, Nikolaos | Engwall, Magnus
PURPOSE: Perfluorooctane sulfonate (PFOS) belongs to a group of chemicals called perfluoroalkyl acids that have been extensively used in various applications such as stain and oil resistant treatments for fabrics, fire-fighting foams, and insecticides. These chemicals present an environmental and health risk being present in many samples both in wildlife and humans. In this study, we investigate the effect of PFOS on fatty acid β-oxidation in developing chicken embryos. METHODS: Fertilized chicken eggs were exposed in ovo to PFOS at day 4 of incubation. On day 10, the eggs were dissected and livers were incubated in vitro with 3H-palmitic acid for 2 h. The media were collected, and after clean up, the amount of tritiated water was measured with liquid scintillation counting to determine the rate of palmitic acid β-oxidation. RESULTS: PFOS was found to induce fatty acid β-oxidation at doses starting from a lowest observed effect level (LOEL) of 0.1 μg/g egg weight. Maximum induction of 77 % compared to control was seen at 0.3 μg/g. CONCLUSIONS: The administered doses in which effects are seen are around and even lower than the levels that can be found in wild populations of birds. General population human levels are a factor of two to three times lower than the LOEL value of this study. The environmental contamination of PFOS therefore presents a possibility of effects in wild populations of birds.
Show more [+] Less [-]Biomonitoring the genotoxic effects of pollutants on Tradescantia pallida (Rose) D.R. Hunt in Dourados, Brazil Full text
2012
Crispim, Bruno do Amaral | Vaini, Jussara Oliveira | Grisolia, Alexeia Barufatti | Teixeira, Tatiane Zaratini | Mussury, Rosilda Mara | Seno, Leonardo Oliveira
PURPOSE: This study aimed to associate the intensity of vehicular traffic in the city of Dourados (Mato Grosso do Sul State, Brazil) with mutagenic effects and alterations in leaf physiology as measured by the quantity of micronuclei and the leaf surface parameters of Tradescantia pallida. METHODS: Five collections of inflorescences were undertaken for 24 weeks to determine the quantities of micronuclei using the Tradescantia Micronuclei (Trad-MCN) bioassay. Leaf surface parameters, including stomatal index (SI), stomatal density, and the size of the stomatal ostiole opening size (SO), were evaluated in addition to Trad-MCN. Collections were made at four sampling points with different vehicular traffic intensities. Statistical analyses were performed with SAS software using the Tukey’s and Kruskal–Wallis test. Additionally, associations of the characteristics were verified using Pearson’s simple correlation analysis. RESULTS: Significant effects were observed with the Trad-MCN bioassay (p < 0.01) that were related to the collection period and location, as well as significant differences (p < 0.05) for the effects of the collection points using the Kruskal–Wallis test. In general, the locations with greatest vehicular traffic had plants with the greatest stomatal density values. The characteristics SI and SO did not demonstrate significant differences (p > 0.05) in relation to the collection sites. The simple correlation analysis demonstrated a negative association (−0.65) between SI and Trad-MCN (p < 0.05). CONCLUSION: Plants growing in localities with more intense vehicular traffic had greater quantities of micronuclei as well as higher frequencies and average numbers of stomata than localities with less traffic, indicating the presence of atmospheric contaminants that damaged their DNA.
Show more [+] Less [-]Structural elucidation of main ozonation products of the artificial sweeteners cyclamate and acesulfame Full text
2012
Scheurer, Marco | Godejohann, Markus | Wick, Arne | Happel, Oliver | Ternes, Thomas A. | Brauch, Heinz-Jurgen | Ruck, Wolfgang K. L. | Lange, Frank Thomas
PURPOSE: The two artificial sweeteners cyclamate (CYC) and acesulfame (ACE) have been detected in wastewater and drinking water treatment plants. As in both facilities ozonation might be applied, it is important to find out if undesired oxidation products (OPs) are formed. METHODS: For the separation and detection of the OPs, several analytical techniques, including nuclear magnetic resonance experiments, were applied. In order to distinguish between direct ozone reaction and a radical mechanism, experiments were carried out at different pH values with and without scavenging OH radicals. Kinetic experiments were used for confirmation that the OPs are formed during short ozone contact time applied in waterworks. Samples from a waterworks using bank filtrate as raw water were analyzed in order to prove that the identified OPs are formed in real and full-scale ozone applications. RESULTS: In the case of CYC, oxidation mainly occurs at the carbon atom, where the sulfonamide moiety is bound to the cyclohexyl ring. Consequently, amidosulfonic acid and cyclohexanone are formed as main OPs of CYC. When ozone reacts at another carbon atom of the ring a keto moiety is introduced into the CYC molecule. Acetic acid and the product ACE OP170, an anionic compound with m/z=170 and an aldehyde hydrate moiety, were identified as the main OPs for ACE. The observed reaction products suggest an ozone reaction according to the Criegee mechanism due to the presence of a C=C double bond. ACE OP170 was also detected after the ozonation unit of a full-scale drinking water treatment plant which uses surface water-influenced bank filtrate as raw water. CONCLUSIONS: Acesulfame can be expected to be found in anthropogenic-influenced raw water used for drinking water production. However, when ACE OP170 is formed during ozonation, it is not expected to cause any problem for drinking water suppliers, because the primary findings suggest its removal in subsequent treatment steps, such as activated carbon filters.
Show more [+] Less [-]Levoglucosan and carbonaceous species in the background aerosol of coastal southeast China: case study on transport of biomass burning smoke from the Philippines Full text
2012
Zhang, Yi Nan | Cheung, Chi Sing | Chan, Chuen-Yu | Engling, Guenter | Sang, Xue-Fang | Shi, Si | Wang, Xue-Mei
INTRODUCTION: Levoglucosan and carbonaceous species in the background aerosol of coastal southeast China were measured at Jianfengling (JFL), a background mountain site in a National Reserve Park on Hainan Island, and at Hok Tsui (HT), a rural site on the southern coast of Hong Kong from April to May of 2004 during an intensive field study. METHODS: We integrated the information from field study, satellite and backward trajectory model to examine the long-range transport of biomass burning smoke from the Philippines and assess its impact on background aerosol in coastal southeast China. RESULTS AND DISCUSSION: The average levoglucosan concentrations were 42 and 30 ng m−3 at JFL and HT, respectively, while the organic and elemental carbon concentrations were 3.1 and 0.4 μg C m−3 respectively at JFL, and 4.1 and 1.3 μg C m−3 respectively at HT. Elevated levoglucosan concentrations of 85–106 ng m−3 (250–340% extra loadings) at JFL and 57 ng m−3 (170% extra loading) at HT were observed during transport events in which air masses originated from the Philippines. Fire hot spot counts and aerosol index derived from satellite data showed that the spread of biomass burning smoke from the Philippines resulted in large-scale dense aerosol clouds in the adjacent South China Sea and the western Pacific Ocean. The observed high ratio of two biomass-burning tracers (levoglucosan to mannosan) at JFL (7–36) and HT (27) indicated that the biomass smoke originating from the Philippines had significant contributions from open-field burning of agricultural residues, such as rice straw. The pollution plumes were transported to southeast China resulting in elevated concentrations of carbonaceous aerosol and levoglucosan in particular. Using a simplified receptor-based approach, biomass smoke aerosol was estimated to account for 16–28% of OC in the background atmosphere of Hainan and 4.9% of OC at the rural site of Hong Kong during these episode cases, indicating that biomass burning smoke generated in the Philippines could have a significant contribution to background ambient aerosol of southeast coastal China.
Show more [+] Less [-]Photocatalytic degradation of Orange G dye under solar light using nanocrystalline semiconductor metal oxide Full text
2012
Thennarasu, G. | Kavithaa, S. | Sivasamy, A.
INTRODUCTION: The photocatalytic degradation of Orange G (OG) dye has been investigated using synthesised nanocrystalline ZnO as a photocatalyst and sunlight as the irradiation source. The formation of ZnO prepared from its precursor was confirmed through FT-IR and powder X-ray diffraction analyses. MATERIALS AND METHODS: Surface morphology was characterised by scanning electron microscope and transmission electron microscope analysis. Band gap energy of synthesised nanocrystalline ZnO was calculated using diffuse reflectance spectroscopy (DRS). Different experimental parameters such as effects of pH, dye concentrations and mass of catalyst were standardised in order to achieve complete degradation of the dye molecules under solar light irradiation. RESULTS: The kinetics of oxidation of OG was also studied. The complete degradation of OG was evident after 90 min of irradiation at an initial pH of 6.86. The degradation of OG was confirmed by UV–Visible spectrophotometer, high-pressure liquid chromatography, ESI-Mass and chemical oxygen demand analyses. CONCLUSION: The adsorption of dye onto catalytic surface was analysed employing model equations such as Langmuir and Freundlich isotherms, and it was found that the Langmuir isotherm model best fitted the adsorption data. The solar photodegradation of OG followed pseudo-first-order kinetics. HPLC and ESI-Mass analyses of the degraded samples suggested that the dye molecules were readily degraded under solar irradiation with nanocrystalline ZnO.
Show more [+] Less [-]Environmental risk assessment and concentration trend of atmospheric volatile organic compounds in Hyogo Prefecture, Japan Full text
2012
Okada, Yasushi | Nakagoshi, Akihiro | Tsurukawa, Masahiro | Matsumura, Chisato | Eiho, Jiro | Nakano, Takeshi
PURPOSE: The purpose of this study was to evaluate the influences of volatile organic compounds (VOCs) emissions on hazardousness and photochemical reactivity and to propose efficient VOCs abatement strategies. METHODS: The atmospheric concentrations of 101 components of VOCs were measured at six sites which comprehend four urban areas, a roadside area, and an industrial area in Hyogo Prefecture. VOCs influence on hazardousness and photochemical reactivity were evaluated using VOCs measured data and the index on the health effect evaluation and ozone formation potential. The substances that require emissions reduction were selected from the evaluation results. The state and characteristics of environmental pollution were considered from the concentration trends of the selected substances. RESULTS: In industrial area, n-hexadecane, styrene, vinyl chloride monomer, and 1,2-dichloroethane showed a high concentration. In roadside area, n-hexane, n-undecane, n-dodecane, tetrachloroethylene, formaldehyde, acetaldehyde, and 1-butanol showed a high concentration. The excess cancer incidences for formaldehyde exceeded 10−5 of the level of concern for carcinogenic effect at all sites. Toluene had a high percentage of ozone production. The interannual and seasonal trends of toluene concentrations were different at a regional level and the formaldehyde concentrations in summer were significantly higher than those in winter at the urban sites. CONCLUSIONS: The results show the need to prepare the emission reduction plan for the major sources such as vehicle exhaust, solvent use, and industrial processes to diminish the concentration of toluene that contributes significantly to the formation of photochemical oxidant.
Show more [+] Less [-]Adsorption and photodegradation of microcystin-LR onto sediments collected from reservoirs and rivers in Taiwan: a laboratory study to investigate the fate, transfer, and degradation of microcystin-LR Full text
2012
Munusamy, Thirumavalavan | Hu, Ya-Lan | Lee, Jiunn-Fwu
BACKGROUND, AIM, AND SCOPE: This study demonstrated the adsorption capacity of microcystin-LR (MC-LR) onto sediment samples collected from different reservoirs (Emerald and Jade reservoirs) and rivers (Dongshan, Erhjen, and Wukai rivers) in Taiwan to investigate the fate, transport behavior, and photodegradation of MC-LR. MAIN FEATURES: Langmuir adsorption and photodegradation studies were carried out in the laboratory and tested the capability of sediments for MC-LR adsorption. These data suggested that sediments play a crucial role in microcystins degradation in aquatic systems. RESULTS AND DISCUSSION: The results of batch experiments revealed that the adsorption of MC-LR varied significantly with texture, pH, and organic matter content of sediments. Silty and clay textures of the samples were associated with larger content of organic matter, and they displayed the enhanced MC-LR adsorption. Low pH sediment showed increased adsorption of MC-LR. The effective photodegradation of MC-LR (1.6 μg/mL) was achieved within 60 min under 254 nm light irradiation. CONCLUSION: A comparative study of adsorption capacity of all sediment samples was carried out and discussed with respect to different aspects. Among all, sediments collected from Jade reservoir showed enhanced MC-LR adsorption (11.86 μg/g) due to favored textural properties (BET surface area = 20.24 m2/g and pore volume = 80.70 nm). PERSPECTIVES: These data provide important information that may be applied to management strategies for improvement of water quality in reservoirs and rivers and other water bodies in Taiwan.
Show more [+] Less [-]Plasma esterases in the tegu lizard Tupinambis merianae (Reptilia, Teiidae): impact of developmental stage, sex, and organophosphorus in vitro exposure Full text
2012
Basso, Agustín | Attademo, Andrés M. | Lajmanovich, Rafael C. | Peltzer, Paola M. | Junges, Celina | Cabagna, Mariana C. | Fiorenza, Gabriela S. | Sanchez-Hernandez, Juan Carlos
PURPOSE: In this study, we determined normal serum butyrylcholinesterase (BChE) and carboxylesterase (CbE) activities in Tupinambis merianae in order to obtain reference values for organophosphorus pesticide monitoring. METHODS: Forty-two T. merianae individuals were grouped by sex and size to identify potential differences in their enzyme levels to allow for proper representation of normal values for females, males, juveniles, and hatchlings. Mean CbE was determined using two model substrates: alpha-naphtylacetate (α-NA) and p-nitrophenyl valerate (4-NPV). BChE and CbE sensitivity to malaoxon (Mx) was also evaluated as well as the possibility of BChE reactivation with pyridine-2-aldoxime methochloride (2-PAM). RESULTS: Mean adult females’ BChE was significantly higher than adult males, juveniles, and hatchlings. No significant differences were found between groups regarding CbE. CbE (4-NPV) activity showed slightly negative correlation with lizard snout–vent length, while BChE and CbE (α-NA) showed no correlation with body size. Apparent IC50 values for BChE and CbE (α-NA) suggested different sensitivities among groups. CbE (4-NPV) could not be inhibited. All Mx-inhibited groups treated with 2-PAM in a final concentration of 2.8 mM showed clear signs of reactivation. CONCLUSIONS: In conclusion, the results demonstrate that (1) plasma esterase activity did not vary with age and sex, except for BChE activity, and (2) because biological and environmental variables could be confounding factors in the response of plasma cholinesterases, complementary biomarkers like CbE inhibition and oxime-induced reactivation of esterases are strongly recommended.
Show more [+] Less [-]Cd accumulation and phytostabilization potential of dominant plants surrounding mining tailings Full text
2012
Zhang, Shujin | Li, Tingxuan | Huang, Huagang | Zou, Tongjing | Zhang, Xizhou | Yu, Haiying | Zheng, Zicheng | Wang, Yongdong
The objectives of the present study were to compare nine dominant plant species growing in mine tailings and nonmining areas in terms of biomass and Cd concentrations and to search for Cd accumulation and tolerance. Also, more detailed experiments were conducted on Athyrium wardii using a pot experiment to assure its Cd-accumulation ability and tolerance as a potential phytostabilizer of Cd-polluted soils. Nine dominant plant species growing on Pb/Zn mine tailings and their corresponding nonmining ecotypes were investigated for their potential to phytostabilize Cd. The performance of A. wardii exposed to high levels of Cd was investigated under controlled conditions. A field study revealed that the Cd concentrations in the roots of these plants ranged from 0.21 to 251.07 mg kg−1, and the highest concentrations were found in A. wardii, which reached a concentration of 69.78, 251.07, and 126.35 mg kg−1 during the early growth stage (May), vigorous growth stage (August), and late growth stage (October), respectively. The Cd concentrations of roots among the nine mining ecotypes were positively correlated with available content of Cd in the rhizosphere soils, whereas a negative correlation was observed in the nonmining ecotypes. A pot experiment showed that the mining ecotype of A. wardii had a higher biomass production and Cd retention capacity in roots than that of the nonmining ecotype. Due to the relatively high tolerance to Cd and the capacity of roots to retain this metal, A. wardii may be useful for the phytostabilization of soils contaminated by Cd.
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