AbstractThis work reports the development of a very-simple-to-construct stir-bar extraction device so called “a dumbbell-shaped stainless steel stir-bar.” The extraction device was assembled from a rolled up stainless steel net filled with an XAD-2 sorbent and a metal rod to allow the use of a magnetic stirrer during extraction. The dumbbell-shaped stainless steel stir-bar was used to extract diethyl phthalate (DEP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP) before analysis by a gas chromatograph equipped with an electron capture detector (GD-ECD). Under the optimal conditions, the developed method provided a good linearity from 10.0 to 1,000.0?ng mL?1 for all three compounds. Limits of detection and limits of quantification were 9.37?±?0.29?ng mL?1 and 31.22?±?0.95?ng mL?1 for DEP, 5.73?±?0.31?ng mL?1 and 19.1?±?1.0?ng mL?1 for DBP and 3.30?±?0.06?ng mL?1 and 11.0?±?0.19?ng mL?1 for DEHP, respectively. Good recoveries in the range of 81.89?±?0.17 to 109.5?±?2.0% were achieved when the method was used to extract phthalate esters in five instant noodle and two rice soup samples. 相似文献
Ibuprofen is amongst the most worldwide consumed pharmaceuticals. The present work presents the first data in the occurrence of ibuprofen in Portuguese surface waters, focusing in the north area of the country, which is one of the most densely populated areas of Portugal. Analysis of ibuprofen is based on pre-concentration of the analyte with solid phase extraction and subsequent determination with liquid chromatography coupled to fluorescence detection. A total of 42 water samples, including surface waters, landfill leachates, Wastewater Treatment Plant (WWTP), and hospital effluents, were analyzed in order to evaluate the occurrence of ibuprofen in the north of Portugal. In general, the highest concentrations were found in the river mouths and in the estuarine zone. The maximum concentrations found were 48,720 ng?L?1 in the landfill leachate, 3,868 ng?L?1 in hospital effluent, 616 ng?L?1 in WWTP effluent, and 723 ng?L?1 in surface waters (Lima river). Environmental risk assessment was evaluated and at the measured concentrations only landfill leachates reveal potential ecotoxicological risk for aquatic organisms. Owing to a high consumption rate of ibuprofen among Portuguese population, as prescribed and non-prescribed medicine, the importance of hospitals, WWTPs, and landfills as sources of entrance of pharmaceuticals in the environment was pointed out. Landfill leachates showed the highest contribution for ibuprofen mass loading into surface waters. On the basis of our findings, more studies are needed as an attempt to assess more vulnerable areas. 相似文献
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?1 for DnBP, between 0.02 and 0.16 μg L?1 for DEHP, and between 0.1 and 1.89 μg L?1 for 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. 相似文献
In this study, photocatalytic (photo-Fenton and H2O2/UV) and dark Fenton processes were used to remove ethylenethiourea (ETU) from water. The experiments were conducted in a photo-reactor with an 80 W mercury vapor lamp. The mineralization of ETU was determined by total organic carbon analysis, and ETU degradation was qualitatively monitored by the reduction of UV absorbance at 232 nm. A higher mineralization efficiency was obtained by using the photo-peroxidation process (UV/H2O2). Approximately 77% of ETU was mineralized within 120 min of the reaction using [H2O2]0 = 400 mg L?1. The photo-Fenton process mineralized 70% of the ETU with [H2O2]0 = 800 mg L?1 and [Fe2+] = 400 mg L?1, and there is evidence that hydrogen peroxide was the limiting reagent in the reaction because it was rapidly consumed. Moreover, increasing the concentration of H2O2 from 800 mg L?1 to 1200 mg L?1 did not enhance the degradation of ETU. Kinetics studies revealed that the pseudo-second-order model best fit the experimental conditions. The k values for the UV/H2O2 and photo-Fenton processes were determined to be 6.2 × 10?4 mg L?1 min?1 and 7.7 × 10?4 mg L?1 min?1, respectively. The mineralization of ETU in the absence of hydrogen peroxide has led to the conclusion that ETU transformation products are susceptible to photolysis by UV light. These are promising results for further research. The processes that were investigated can be used to remove pesticide metabolites from drinking water sources and wastewater in developing countries. 相似文献
AbstractThe presence of diethyl-phthalate (DEP), dibutyl-phthalate (DBP), butylbenzyl-phthalate (BBP), diethylhexyl-phthalate (DEHP) and diisononyl-phthalate (DINP) was determined in 295 tequila samples. They were grouped by age of maturation (white, aged, extra aged or ultra aged) and year of production (between 2013 and 2018). Gas Chromatography coupled with Mass Spectrometry was used for identification and quantification. The results showed that 65 samples (22% of the total) were phthalate free. DEP (0.13-0.27?mg/kg), BBP (0.05–2.91?mg/kg) and DINP (1.64–3.43?mg/kg) were detected in 11 (3.73%), 37 (12.54%) and 5 (1.69%) samples, respectively. But, these concentrations did not exceed the maximum permitted limits (MPL) of phthalates for alcoholic beverages. DBP (0.01–2.20?mg/kg) and DEHP (0.03–4.64?mg/kg) were detected in 96 (32.54%) and 224 (75.93%) samples, from them only 10 (3.39%) and 15 (5.08%) samples, respectively, exceeded the MPL for alcoholic beverages and they were few tequilas produced in the year 2014 or before. DEHP was the most frequent phthalate found in tequila and observed DEHP concentrations were 2-times higher in ultra aged tequilas compared to those in white tequilas. We concluded that all tequilas produced in 2015 and after, satisfied the international standards for these compounds. 相似文献
Concentrations and microbial degradation rates were measured for eight phthalate esters (PAEs) found in 14 surface water and six sediment samples taken from rivers in Taiwan. The tested PAEs were diethyl phthalate (DEP), dipropyl phthalate (DPP), di-n-butyl phthalate (DBP), diphenyl phthalate (DPhP), benzylbutyl phthalate (BBP), dihexyl phthalate (DHP), dicyclohexyl phthalate (DCP), and di-(2-ethylhexyl) phthalate (DEHP). In all samples, concentrations of DEHP and DBP were found to be higher than the other six PAEs. DEHP concentrations in the water and sediment samples ranged from ND to 18.5 μg/l and 0.5 to 23.9 μg/g, respectively; for DBP the concentration ranges were 1.0–13.5 μg/l and 0.3–30.3 μg/g, respectively. Concentrations of DHP, BBP, DCP and DPhP were below detection limits. Under aerobic conditions, average degradation half-lives for DEP, DPP, DBP, DPhP, BBP, DHP, DCP and DEHP were measured as 2.5, 2.8, 2.9, 2.6, 3.1, 9.7, 11.1 and 14.8 days, respectively; under anaerobic conditions, respective average half-lives were measured as 33.6, 25.7, 14.4, 14.6, 19.3, 24.1, 26.4 and 34.7 days. In other words, under aerobic conditions we found that DEP, DPP, DBP, DPhP and BBP were easily degraded, but DEHP was difficult to degrade; under anaerobic conditions, DBP, DPhP and BBP were easily degraded, but DEP and DEHP were difficult to degrade. Aerobic degradation rates were up to 10 times faster than anaerobic degradation rates. 相似文献
Ammonia nitrogen pollution control is an urgent issue of landfill. This research aims to select an optimal refuse for ammonia nitrogen removal in landfill from the point of view of adsorption and desorption behavior. MSW (municipal solid waste) samples which deposit ages were in the range of 5 to 15 years (named as R15, R11, R7, and R5) were collected from real landfill site. The ammonia nitrogen adsorption behaviors of MSW including equilibrium time, adsorption isotherms, and desorption behaviors including equilibrium time were determined. Furthermore, the effects of pH, OM, Cu(II), Zn(II), and Pb(II) on adsorption and desorption behavior of ammonia nitrogen were conducted by orthogonal experiment. The equilibrium time of ammonia nitrogen adsorption by each tested MSW was very short, i.e., 20 min, whereas desorption process needed 24 h and the ammonia nitrogen released from refuses was much lesser than that adsorbed, i.e., accounted for 3.20 % (R15), 14.32 % (R11), 20.59 % (R7), and 20.50 % (R5) of each adsorption quantity, respectively. The maximum adsorption capacity estimated from Langmuir isotherm appeared in R15-KCl, i.e., 25,000 mg kg?1. The best condition for ammonia nitrogen removal from leachate was pH >7.5, OM 23.58 %, Cu(II) <5 mg L?1, Zn(II) <10 mg L?1, and Pb(II) <1 mg L?1. Ammonia nitrogen in landfill leachate could be quickly and largely absorbed by MSW but slowly and infrequently released. The refuse deposited for 15 years could be a suitable material for ammonia nitrogen removal. 相似文献
AbstractThe aim of the research was to evaluate the effect of consumption of selenium-enriched pork on selected health indicators of probands. The intake of feed mixture with increased organic selenium at the dose of 0.3?mg.kg?1 probably increases selenium concentration in MSM (musculus semimembranosus). In the pork enriched with organic selenium, the concentration was higher by 1.045?±?0.10?mg.kg?1 compared with the control group 0.701?±?0.05?mg.kg?1 at significance P?<?0.001. Sixteen participants in the experiment were represented by 8 men at the average age of 41.5?±?11.9?years and 8 women at the average age of 41.4?±?7.9?years. All the probands consumed meat enriched with selenium three times a week during one month. By consumption of the enriched pork, there was an increase of the selenium concentration in blood serum of probands traced with selenium increase from 73.19?±?15.68?μg.L?1 to 73.73?±?15.13?μg.L?1 (P?>?0.05). From the results we can see that consumption of enriched pork with selenium was significantly manifested in lowering of total cholesterol levels, which was associated with LDL cholesterol lowering (P?<?0.05). Differences among the HDL cholesterol and triglycerides samples were not significant. 相似文献
A simple and rapid online microchannel preconcentrator coupled with an amperometric detection for the analysis of carbofuran using polyethylene glycol coated onto magnetic particle (PEG-magnetic particles) sorbents was developed. This simple-to-prepare microchannel preconcentrator used an external magnet to retain the PEG-magnetic particle sorbents inside the microchannel. Under optimum conditions, the system provided two linear ranges, from 0.01 to 10.0 mg L?1 and from 10.0 to 130.0 mg L?1 with a limit of detection of 8.7 ± 0.1 μg L?1. The microchannel preconcentrator provided very good stability; it can be used for up to 326 consecutive injections of 5.0 mg L?1 carbofuran with a relative standard deviation of less than 3%. The developed system provided a good microchannel-to-microchannel and a good electrode-to-electrode reproducibility (n = 6, %RSD < 1). It also provided an excellent selectivity when it was tested with two other carbamate pesticides, carbaryl and methomyl, with a 43 and 256 times higher detection sensitivity for carbofuran, respectively. The developed system was successfully applied to detect carbofuran in surface water samples obtained near vegetable plantation areas. The concentrations of carbofuran in these samples were found to be in the range of non-detectable to 0.047 ± 0.001 mg L?1. The developed system is easy to operate and easy to couple with other analytical instruments and it could be easily adapted for the analysis of other polar organic contaminants. 相似文献
The biological treatment of ammonia-rich landfill leachates due to an inadequate C to N ratio requires expensive supplementation of carbon from an external carbon source. In an effort to reduce treatment costs, the objective of the study was to determine the feasibility of nitrogen removal via the nitrite pathway during landfill leachate co-treatment with municipal wastewater. Initially, the laboratory-scale sequencing batch reactor (SBR) was inoculated with nitrifying activated sludge and fed only raw municipal wastewater (RWW) during a start-up period of 9 weeks. Then, in the co-treatment period, consisting of the next 17 weeks, the system was fed a mixture of RWW and an increasing quantity of landfill leachates (from 1 to 10 % by volume). The results indicate that landfill leachate addition of up to 10 % (by volume) influenced the effluent quality, except for BOD5. During the experiment, a positive correlation (r2?=?0.908) between ammonia load in the influent and nitrite in the effluent was observed, suggesting that the second step of nitrification was partially inhibited. The partial nitrification (PN) was also confirmed by fluorescence in situ hybridisation (FISH) analysis of nitrifying bacteria. Nitrogen removal via the nitrite pathway was observed when the oxygen concentration ranged from 0.5 to 1.5 mg O2/dm3 and free ammonia (FA) ranged from 2.01 to 35.86 mg N-NH3/dm3 in the aerobic phase. Increasing ammonia load in wastewater influent was also correlated with an increasing amount of total nitrogen (TN) in the effluent, which suggested insufficient amounts of assimilable organic carbon to complete denitrification. Because nitrogen removal via the nitrite pathway is beneficial for carbon-limited and highly ammonia-loaded mixtures, obtaining PN can lead to a reduction in the external carbon source needed to support denitrification. 相似文献
Diet is an important exposure route for phthalates, such as di-iso-butyl phthalate (DiBP), dibutyl phthalate (DBP), bis(2-ethylhexyl) phthalate (DEHP), and benzyl butyl phthalate (BBP). In this study, we aimed to estimate phthalate exposure in the diet of pregnant women and assess the health risk. A total of 517 pregnant women in the first trimester were recruited, and food frequency questionnaires were collected. A simple distribution assessment method was used to estimate daily exposure, and the hazard index (HI) method was used to assess cumulative risk. The maximum daily dietary exposure to DEHP, DBP, DiBP, and BBP was 5.25, 3.17, 2.59, and 0.58 μg/kg bw/day, respectively, and did not exceed the safety limit values. Cereals and vegetables were the main sources of the estimated daily intake (EDI) of phthalates in the diet. The cumulative risk assessment, based on the European Food Safety Authority tolerable daily intake (TDI) and the US Environmental Protection Agency reference dose (RfD), did not exceed the threshold of 1. DiBP, DBP, and DEHP had higher hazard quotient (HQ) values for cumulative health risk than BBP. In conclusion, a low health risk was posed by the cumulative dietary exposure to phthalates for pregnant women in Beijing.
Phthalic acid esters (PAEs) are one kind of persistent organic pollutants. This study was conducted to investigate the effects of diethylphthalate (DEP) and di(2-ethyl)hexylphthalate (DEHP) with different concentrations (0, 30, 50, 100, and 200 mg L?1) on early seedling growth of Cucumis sativus L. Physiological, biochemical, and ultrastructure of seedling leaves were examined for 7-day exposure. The three antioxidant enzymes’ activities was stimulated at low-DEP treatments and decreased under higher levels (>200 mg L?1) compared to the controls. Furthermore, MDA and H2O2 gradually enhanced with the elevation of DEP and DEHP concentration. Significant impact on the chloroplast and mitochondrion was visible, possibly as a consequence of free radical generation. DEP induced bigger and more starch grains in chloroplasts than DEHP. This study concluded that the effects of DEP and DEHP on cucumber seedlings represented the adverse impacts of DEP and DEHP on the ecosystem and agricultural production. The environmental harm caused by DEP was severer than DEHP. 相似文献
Compost leachates were collected to investigate the influence of the composition and removal of volatile fatty acids (VFAs), humic-like substances (HSs), and dissolved organic nitrogen (DON) on heavy metal distribution during the leachate treatment process. The results showed that acetic and propionic acids accounted for 81.3 to 93.84 % of VFAs, and that these acids were removed by the anaerobic-aerobic process. Humic- and fulvic-like substances were detected by excitation–emission matrix spectroscopy coupled with parallel factor analysis, and their content significantly decreased after the anaerobic and membrane treatments. DON in compost leachates ranged from 26.53 mg L-1 to 919.46 mg L-1, comprised of dissolved free amino acids and the protein-like matter bound to humic- and fulvic-like substances, and was removed by the aerobic process. Correlation analysis showed that Mn, Ni, and Pb were bound to VFAs and protein-, fulvic-, and humic-like substances in the leachates. Co was primarily bound to fulvic- and humic-like matter and inorganic sulfurs, whereas Cu, Zn, and Cd interacted with inorganic sulfur. 相似文献
Interest in identifying pools of antibacterial-resistance genes has grown over the last decade, with veterinary antibiotics (VAs) receiving particular attention. In this paper, a mesoscale study aimed at evaluating the vertical transport of common VAs—namely, fluoroquinolones, tetracyclines, sulfonamides, and lincosamides in agricultural soil subjected to drip irrigation—was performed under greenhouse conditions. Accordingly, leachates of cropped and uncropped soil, amended with swine-slurry leading to 19–38 μg kg?1 (dry mass) antibiotics in the soil, were analyzed over the course of the productive cycle of a lettuce (42 days) with three sampling campaigns (N?=?24). High lincomycin (LCM) concentrations (30–39 μg L?1) were detected in the leachates collected from the swine-slurry-amended soil. The highest LCM mass recovered in the leachates (30.1?±?1.63 %) was obtained from cropped experimental units. In addition, the LCM leaching constant and its leaching potential as obtained from the first-order model were higher in the leachates from the cropped experimental units. Lower concentrations of sulfadimethoxine were also detected in leachates and in soil. Enrofloxacin and oxytetracycline occurred only in soil, which is consistent with high soil interaction. 相似文献
Four subsurface horizontal-flow constructed wetlands (CWs) at a pilot scale planted with a polyculture of the tropical plants Gynerium sagittatum (Gs), Colocasia esculenta (Ce) and Heliconia psittacorum (He) were evaluated for 7 months. The CW cells with an area of 17.94 m2 and 0.60 m (h) each and 0.5 m of gravel were operated at continuous gravity flow (Q?=?0.5 m3 day?1) and a theoretical HRT of 7 days each and treating landfill leachate for the removal of filtered chemical oxygen demand (CODf), BOD5, TKN, NH4+, NO3?, PO43?–P and Cr(VI). Three CWs were divided into three sections, and each section (5.98 m2) was seeded with 36 cuttings of each species (plant density of six cuttings per square metre). The other unit was planted randomly. The final distributions of plants in the bioreactors were as follows: CW I (He-Ce-Gs), CW II (randomly), CW III (Ce-Gs-He) and CW IV (Gs-He-Ce). The units received effluent from a high-rate anaerobic pond (BLAAT®). The results show a slightly alkaline and anoxic environment in the solid-liquid matrix (pH?=?8.0; 0.5–2 mg L?1 dissolved oxygen (DO)). CODf removal was 67 %, BOD5 80 %, and TKN and NH4+ 50–57 %; NO3? effluents were slightly higher than the influent, PO43?–P (38 %) and Cr(VI) between 50 and 58 %. CW IV gave the best performance, indicating that plant distribution may affect the removal capacity of the bioreactors. He and Gs were the plants exhibiting a translocation factor (TF) of Cr(VI) >1. The evaluated plants demonstrated their suitability for phytoremediation of landfill leachate, and all of them can be categorized as Cr(VI) accumulators. The CWs also showed that they could be a low-cost operation as a secondary system for treatment of intermediated landfill leachate (LL). 相似文献
The present research deals with the development of a new heterogeneous photocatalysis and Fenton hybrid system for the removal of color from textile dyeing wastewater as Rhodamine B (RhB) solutions by using Fe2+/H2O2/Nb2O5 as a photocatalytic system. The application of this photocatalytic system for the decolorization of dye contaminants is not reported in the literature yet. Different parameters like dye concentration, Nb2O5/Fe2+ catalyst amount, pH, and H2O2 concentration have been studied. The optimum conditions for the decolorization of the dye were initial concentration of 10 mg L?1 of dye, pH 4, and Nb2O5/Fe2+ catalyst concentration of 0.5 g L?1/50 mg L?1. The optimum value of H2O2 concentration for the conditions used in this study was 700 mg L?1. Moreover, the efficiency of the Nb2O5/photo-Fenton hybrid process in comparison to photo-Fenton alone and a dark Fenton process as a control experiment to decolorize the RhB solution has been investigated. The combination of photo-Fenton and Nb2O5 catalysts has been proved to be the most effective for the treatment of such type of wastewaters. The results revealed that the RhB dye was decolorized in a higher percent (78 %) by the Nb2O5/photo-Fenton hybrid process (Fe2+/H2O2/Nb2O5/UV) than by the photo-Fenton process alone (37 %) and dark Fenton process (14 %) after 120 min of treatment. Moreover, the Nb2O5 catalyst as a heterogeneous part of the photocatalytic system was demonstrated to have good stability and reusability. 相似文献
Phthalates are common atmospheric contaminants used in the plastic industry. Ants have been shown to constitute good bioindicators of phthalate pollution. Hence, phthalates remain trapped on ant cuticles which are mostly coated with long-chain hydrocarbons. In this study, we artificially contaminated Lasius niger ants with four phthalates: dibutyl phthalate (DBP), diisobutyl phthalate (DiBP), di(2-ethylhexyl) phthalate (DEHP), and benzyl butyl phthalate (BBP). The first three have previously been found on ants in nature in Touraine (France), while the fourth has not. The four phthalates disappeared rapidly (less than 5 days) from the cuticles of live ants. In contrast, on the cuticles of dead ants, DEHP quantities remained unchanged over time. These results indicate that phthalates are actively absorbed by the cuticles of live ants. Cuticular absorption of phthalates is nonspecific because eicosane, a nonnatural hydrocarbon on L. niger cuticle, was similarly absorbed. Ants are important ecological engineers and may serve as bioindicators of ecosystem health. We also suggest that ants and more generally terrestrial arthropods may contribute to the removal of phthalates from the local environment. 相似文献
The study was conducted to assess the effects of in utero di-butyl phthalate (DBP) and butyl benzyl phthalate (BBP) exposure during late gestation on offspring’s development and reproductive system of male rats. Pregnant rats were treated orally with DBP (2, 10, 50 mg/kg), BBP (4, 20, 100 mg/kg), and diethylstilbestrol (DES) 6 μg/kg (positive control) from GD14 to parturition. A significant reduction in dams’ body weight on GD21 in DBP-, BBP-, and DES-treated groups was observed. The gestation length was considerably elevated in the treated groups. Decline in male pups’ body weight was significant at PND75 in DBP- (50 mg/kg), BBP- (20,100 mg/kg), and DES-treated groups. The weight of most of the reproductive organs and sperm quality parameters was impaired significantly in DBP- (50 mg/kg) and BBP- (100 mg/kg) treated groups. Further, a non-significant decline in testicular spermatid count and daily sperm production was also monitored in treated groups. A significant reduction in serum testosterone level in BBP (100 mg/kg), whereas the testicular activity of 17β-HSD was declined non-significantly in the treated groups with respect to control. The data suggests that DBP and BBP exposure during late gestation period might have adverse effects on offspring’s development, spermatogenesis, and steroidogenesis in adult rats. 相似文献