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Preliminary toxicological assessment of phthalate esters from drinking water consumed in Portugal Full text
2014
Santana, Jose | Giraudi, Clara | Marengo, Emilio | Robotti, Elisa | Pires, Sara | Nunes, Inês | Gaspar, Elvira M.
This paper reports, for the first time, the concentrations of selected phthalates in drinking water consumed in Portugal. The use of bottled water in Portugal has increased in recent years. The main material for bottles is polyethylene terephthalate (PET). Its plasticizer components can contaminate water by leaching, and several scientific studies have evidenced potential health risks of phthalates to humans of all ages. With water being one of the most essential elements to human health and because it is consumed by ingestion, the evaluation of drinking water quality, with respect to phthalate contents, is important. This study tested seven commercial brands of bottled water consumed in Portugal, six PET and one glass (the most consumed) bottled water. Furthermore, tap water from Lisbon and three small neighbor cities was analyzed. Phthalates (di-n-butyl phthalate ester (DnBP), bis(2-ethylhexyl) phthalate ester (DEHP), and di-i-butyl phthalate ester (DIBP)) in water samples were quantified (PET and glass) by means of direct immersion solid-phase microextraction and ionic liquid gas chromatography associated with flame ionization detection or mass spectrometry due to their high boiling points and water solubility. The method utilized in this study showed a linear range for target phthalates between 0.02 and 6.5 μg L⁻¹, good precision and low limits of detection that were between 0.01 and 0.06 μg L⁻¹, and quantitation between 0.04 and 0.19 μg L⁻¹. Only three phthalates were detected in Portuguese drinking waters: dibutyl (DnBP), diisobutyl (DIBP), and di(ethylhexyl) phthalate (DEHP). Concentrations ranged between 0.06 and 6.5 μg L⁻¹for DnBP, between 0.02 and 0.16 μg L⁻¹for DEHP, and between 0.1 and 1.89 μg L⁻¹for DIBP. The concentration of DEHP was found to be up to five times higher in PET than in glass bottled water. Surprisingly, all the three phthalates were detected in glass bottled water with the amount of DnBP being higher (6.5 μg L⁻¹) than in PET bottled water. These concentrations do not represent direct risk to human health. Regarding potable tap water, only DIBP and DEHP were detected. Two of the cities showed concentration of all three phthalates in their water below the limits of detection of the method. All the samples showed phthalate concentrations below 6 μg L⁻¹, the maximum admissible concentration in water established by the US Environmental Protection Agency. The concentrations measured in Portuguese bottled waters do not represent any risk for adult's health.
Show more [+] Less [-]Isolation and characterization of a Pseudomonas aeruginosa from a virgin Brazilian Amazon region with potential to degrade atrazine Full text
2014
Fernandes, Ana Flavia Tonelli | da Silva, Michelle Barbosa Partata | Martins, Vinicius Vicente | Miranda, Carlos Eduardo Saraiva | Stehling, Eliana Guedes
The use of pesticides to increase agricultural production can result in the contamination of the environment, causing changes in the genetic structure of organisms and in the loss of biodiversity. This practice is also inducing changes in the rainforest ecosystem. In this work, a Pseudomonas aeruginosa isolated from a preservation soil area of the Brazilian Amazon Forest, without usage of any pesticide, was evaluated for its potential to degrade atrazine. This isolate presented all responsible genes (atzA, atzB, atzC, atzD, atzE, and atzF) for atrazine mineralization and demonstrated capacity to use atrazine as a nitrogen source, having achieved a reduction of 44 % of the initial concentration of atrazine after 24 h. These results confirm gene dispersion and/or a possible contamination of the area with the herbicide, which reinforces global concern of the increase and intensive use of pesticides worldwide.
Show more [+] Less [-]Dynamic energy budget model: a monitoring tool for growth and reproduction performance of Mytilus galloprovincialis in Bizerte Lagoon (Southwestern Mediterranean Sea) Full text
2014
Béjaoui-Omri, Amel | Béjaoui, Béchir | Harzallah, Ali | Aloui-Béjaoui, Nejla | El Bour, Monia | Aleya, Lotfi
Mussel farming is the main economic activity in Bizerte Lagoon, with a production that fluctuates depending on environmental factors. In the present study, we apply a bioenergetic growth model to the mussel Mytilus galloprovincialis, based on dynamic energy budget (DEB) theory which describes energy flux variation through the different compartments of the mussel body. Thus, the present model simulates both mussel growth and sexual cycle steps according to food availability and water temperature and also the effect of climate change on mussel behavior and reproduction. The results point to good concordance between simulations and growth parameters (metric length and weight) for mussels in the lagoon. A heat wave scenario was also simulated using the DEB model, which highlighted mussel mortality periods during a period of high temperature.
Show more [+] Less [-]Analyses on influencing factors of airborne VOCS pollution in taxi cabins Full text
2014
Chen, Xiaokai | Feng, Lili | Luo, Huilong | Cheng, Heming
Due to the long time in vehicular cabins, people have high exposure to the airborne volatile organic compounds (VOCS), which will lead to negative effects on human health. In order to analyze the influencing factors of in-car VOCSpollution concentrations, 38 taxis were investigated on the static and closed conditions. The interior air of taxis was collected through activated Tenax adsorption tubes, and the air samples were analyzed with thermally desorbed gas chromatograph. The average concentrations of in-car benzene, toluene, ethylbenzene, xylenes, styrene, butyl acetate, undecane, and total VOCS(TVOC) were 82.7, 212.3, 74.7, 182.3, 24.7, 33.5, 61.3, and 1,441.7 μg/m³, respectively. Furthermore, the VOCSand TVOC concentrations increase with the rise of in-car temperature and relative humidity, and decrease with the increase of car age and total mileage. In addition, the VOCSand TVOC concentrations are higher in vehicles with small cabins than in ones with big cabins, and change with different sampling sites and various vehicular grades. Finally, according to the multiple linear regression analysis and hierarchical cluster analysis, car age is the most important factor influencing airborne VOCSand TVOC pollution concentrations in vehicular cabins, followed by interior temperature and total mileage.
Show more [+] Less [-]Effects of hydraulic retention time and nitrobenzene concentration on the performance of sequential upflow anaerobic filter and air lift reactors in treating nitrobenzene-containing wastewater Full text
2014
Wu, Jinhua | Chen, Guocai | Gu, Jingjing | Yin, Weizhao | Lu, Mengxiong | Li, Ping | Yang, Bo
Sequential upflow anaerobic filter (UAF)/air lift (ALR) reactors were employed to investigate the effects of hydraulic retention time (HRT) and nitrobenzene (NB) concentration on treatment of NB-containing wastewater. The results showed that NB was effectively reduced to aniline (AN) with glucose as co-substrate in the UAF reactor. The AN and the remaining intermediates after the UAF reactor were then efficiently degraded in the ALR reactor. A removal efficiency of 100% and 96% was obtained for NB and chemical oxygen demand (COD), respectively, using sequential UAF/ALR reactors with an HRT of 8–72 h in the UAF reactor and 2–18 h in the ALR reactor. The corresponding optimal influent NB concentration varied between 100 and 400 mg l⁻¹to achieve the optimal NB and COD removal. The NB removal efficiency decreased to 90% and to 97% if the HRT in the UAF reactor decreased from 8 to 2 h and the influent NB concentration increased from 400 to 800 mg l⁻¹, respectively. The results showed that sequential UAF/ALR system can be operated at low HRTs and high NB concentrations without significantly affecting the removal efficiency of NB in the reactor system. The UAF/ALR system can provide an effective yet low cost method for treatment of NB-containing industrial wastewater.
Show more [+] Less [-]Standard inocula preparations reduce the bacterial diversity and reliability of regulatory biodegradation tests Full text
2014
Goodhead, Andrew K. | Head, I. M. (Ian M.) | Snape, Jason R. | Davenport, Russell J.
OECD ready biodegradability tests have been central to understanding the biodegradation of chemicals from a regulatory perspective for many decades. They are not fit for contemporary prioritisation of chemicals based on persistence, however, due to the low concentration of inocula used, short duration and high variability between tests. Two OECD standard inoculum pretreatment methods (settlement and filtration) were investigated to observe their effect on the probability of biodegradation and associated changes in bacterial community structure and diversity of inocula sourced from the activated sludge process of wastewater treatment plants. Both settlement and filtration were shown to dramatically and significantly reduce the probability and increase the variability of biodegradation of 4-nitrophenol compared to the use of unprocessed inocula. These differences were associated with a significant hundred-fold reduction in cell numbers and solids content and a significant shift in bacterial community structure that was sometimes accompanied by significant reductions in detectable operational taxonomic unit richness and evenness. The natural variation (between different environments) and variation due to differential selection of bacterial communities (by different pretreatment methods) is offered as an explanation for the historical high variability in standard OECD ready biodegradability tests.
Show more [+] Less [-]Spatial and temporal distribution of polycyclic aromatic hydrocarbons (PAHs) in surface water from Liaohe River Basin, northeast China Full text
2014
Lv, Jiapei | Xu, Jian | Guo, Changsheng | Zhang, Yuan | Bai, Yangwei | Meng, Wei
Liaohe River Basin is an important region in northeast China, which consists of several main rivers including Liao River, Taizi river, Daliao River, and Hun River. As a highly industrialized region, the basin receives dense waste discharges, causing severe environmental problems. In this study, the spatial and temporal distribution of aqueous polycyclic aromatic hydrocarbons (PAHs) in Liaohe River Basin from 50 sampling sites in both dry (May) and level (October) periods in 2012 was investigated. Sixteen USEPA priority PAHs were quantified by gas chromatography/mass selective detector. The total PAH concentration ranged from 111.8 to 2,931.6 ng/L in the dry period and from 94.8 to 2766.0 ng/L in the level period, respectively. As for the spatial distribution, the mean concentration of PAHs followed the order of Taizi River > Daliao River > Hun River > Liao River, showing higher concentrations close to large cities with dense industries. The composition and possible sources of PAHs in the water samples were also determined. The fractions of low molecular weight PAHs ranged from 58.2 to 93.3 %, indicating the influence of low or moderate temperature combustion process. Diagnostic ratios, principal component analysis, and hierarchical cluster analysis were used to study the possible source categories in the study area, and consistent results were obtained from different techniques, that PAHs in water samples mainly originated from complex sources, i.e., both pyrogenic and petrogenic sources. The benzo[a]pyrene equivalents (EBaP) characterizing the ecological risk of PAHs to the aquatic environment suggested that PAHs in Liaohe River Basin had already caused environmental health risks.
Show more [+] Less [-]Green synthesis of silver nanoparticles by microorganism using organic pollutant: its antimicrobial and catalytic application Full text
2014
Otari, S. V. | Patil, R. M. | Nadaf, N. H. | Ghosh, S. J. | Pawar, S. H.
A novel approach for the green synthesis of silver nanoparticles (AgNPs) from aqueous solution of AgNO₃using culture supernatant of phenol degraded broth is reported in this work. The synthesis was observed within 10 h, and AgNPs showed characteristic surface plasmon resonance around 410 nm. Spherical nanoparticles of size less than 30 nm were observed in transmission electron microscopy. X-ray diffraction pattern corresponding to 111, 200, 220, and 311 revealed the crystalline nature of the as-formed nanoparticles. It was found that the colloidal solution of AgNP suspensions exhibited excellent stability over a wide range of ionic strength, pH, and temperature. The effect of pH and ionic strength indicated that stabilization is due to electrostatic repulsion arising from the negative charge of the conjugate proteins. The AgNPs showed highly potent antimicrobial activity against Gram-positive, Gram-negative, and fungal microorganisms. The as-prepared AgNPs showed excellent catalytic activity in reduction of 4-nitrophenol to 4-aminophenol by NaBH₄. By manufacturing magnetic alginate beads, the reusability of the AgNPs for the catalytic reaction has been demonstrated.
Show more [+] Less [-]Effect of Zn toxicity on root morphology, ultrastructure, and the ability to accumulate Zn in Moso bamboo (Phyllostachys pubescens) Full text
2014
Liu, Dan | Chen, Junren | Mahmood, Qaisar | Li, Song | Wu, Jiasen | Ye, Zhengqian | Peng, Danli | Yan, Wenbo | Lu, Kouping
The effects of zinc (Zn) on seed germination and growth of Moso bamboo (Phyllostachys pubescens) were investigated. Under zinc stress, the seed germination rate did not show significant difference from that of the control. Hydroponics experiments indicated that Moso bamboo had a strong ability to accumulate Zn in the shoot and it reached its maximum value in the shoot at 100 μM Zn. The root Zn concentration ranged from 2,329.29 to 8,642.51 mg kg⁻¹, with the root Zn concentration at 10 μM Zn being 58.23 times that of the control. The root morphology parameters slightly increased at the lower Zn treatments, while growth restriction was evident at higher Zn treatments. Root ultrastructural studies revealed that the cell structure, root tips, and organelles were significantly changed under Zn stress as compared to those of the control. Some abnormalities were evident in the cell walls, vacuoles, mitochondria, plasmalemma, tonoplast, and xylem parenchyma of root cells. While Moso bamboo seems a suitable candidate for phytoremediation, its metal remediation ability should be further explored in future investigations.
Show more [+] Less [-]Isotherm studies for the determination of Cd (II) ions removal capacity in living biomass of a microalga with high tolerance to cadmium toxicity Full text
2014
Torres, Enrique | Mera, Roi | Herrero, Concepción | Abalde Alonso, Julio
Isotherm studies for the determination of Cd (II) ions removal capacity in living biomass of a microalga with high tolerance to cadmium toxicity Full text
2014
Torres, Enrique | Mera, Roi | Herrero, Concepción | Abalde Alonso, Julio
The biosorption characteristics of Cd (II) ions using the living biomass of the marine diatom Phaeodactylum tricornutum were investigated. This microalga is a highly tolerant species to cadmium toxicity; for this reason, it is interesting to know its potential for use in the removal of this metal. The use of living biomass offers better possibilities than that of dead biomass since cadmium can also be bioaccumulated inside the cells. For this purpose, tolerant species are necessary. P. tricornutum is within this category with an EC₅₀,₉₆ₕof 19.1 ± 3.5 mg Cd (II)/L, and in the present manuscript, it is demonstrated that this microalga has a very good potential for bioremediation of Cd (II) ions in saline habitats. Cadmium removed by the cells was divided into three fractions: total, intracellular and bioadsorbed. The experiments were conducted for 96 h in natural seawater with a concentration range of 1–100 mg Cd (II)/L. Each fraction was characterized every 24 h by sorption isotherms. The experimental isotherm data were analyzed using the Langmuir, Freundlich, Dubinin-Radushkevich and Temkin equations. The biosorption was well described by Langmuir isotherm followed by Freundlich. The worst model was Temkin. The biosorption capacity of this microalga for Cd (II) ions was found to be 67.1 ± 3.2 mg/g after 96 h with approximately 40 % of this capacity in the intracellular fraction. The bioconcentration factor determined was 2,204.7 after 96 h and with an initial Cd (II) concentration of 1 mg/L.
Show more [+] Less [-]Isotherm studies for the determination of Cd(II) ions removal capacity in living biomass of a microalga with high tolerance to cadmium toxicity. Full text
2014
Torres, Enrique | Mera, Roi | Herrero, Concepción | Abalde, Julio
The biosorption characteristics of Cd(II) ions using the living biomass of the marine diatom Phaeodactylum tricornutum were investigated. This microalga is a highly tolerant species to cadmium toxicity, for this reason is interesting to know its potential for use in the removal of Cd(II) ions. The use of living biomass offers better possibilities than dead biomass since cadmium can also be bioaccumulated inside the cells. For this purpose, tolerant species are necessary. P. tricornutum is within this category and in the present manuscript is demonstrated that this microalga has a very good potential for bioremediation of Cd(II) ions. Cadmium removed by the cells was divided into three fractions: total, intracellular and bioadsorbed. The experiments were conducted for 96 h in a concentration range of 1-100 mg Cd(II)/L. Each fraction was characterized every 24 h by sorption isotherms. The experimental isotherm data were analysed using the Langmuir, Freundlinch, Dubinin-Radushkevich and Temkin equations. The biosorption was well described by Langmuir isotherm followed by Freundlich. The worst model was Temkin. The biosorption capacity of this microalga for Cd(II) ions was found to be 67.140 ± 3.247 mg/g after 96 h with approximately 40% of this capacity in the intracellular fraction. The bioconcentration factor determined was 2204.7 after 96 h and with an initial Cd(II) concentration of 1 mg/L.
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