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101.
102.
The goal of this study was to investigate the activity of the coagulant extracted from the cactus Opuntia ficus-indica (OFI) in the process of coagulation/flocculation of textile effluents. Preliminary tests of a kaolinite suspension achieved maximum turbidity removal of 95 % using an NaCl extraction solution. Optimization assays were conducted with actual effluents using the response surface methodology (RSM) based on the Box–Behnken experimental design. The responses of the variables FeCl3, dosage, cactus dosage, and pH in the removal of COD and turbidity from both effluents were investigated. The optimum conditions determined for jeans washing laundry effluent were the following: FeCl3 160 mg L?1, cactus dosage 2.60 mg L?1, and pH 5.0. For the fabric dyeing effluent, the optimum conditions were the following: FeCl3 640 mg L?1, cactus dosage 160 mg L?1, and pH 6.0. Investigation of the effects of the storage time and temperature of the cactus O. ficus-indica showed that coagulation efficiency was not significantly affected for storage at room temperature for up to 4 days.  相似文献   
103.
流域的可持续管理:国际多个流域的案例研究   总被引:3,自引:0,他引:3  
全球淡水资源正在不断受到污染和亏耗,威胁着可持续发展及人类和生态系统的健康.本文通过美国、日本、瑞士和巴西四个不同流域的案例研究,阐述了与淡水资源密切相关的可持续发展中的缺陷,指明了水资源可持续管理的总体方向.由于近几十年来人口的增长和经济的发展,每个流域的水质、流量和生物资源量都在下降.但是对于不同的流域来说,与水有关的这些问题的严重程度和文化观念大不相同,因而形成各自独特的水资源管理政策.在工业化国家,例如美国、瑞士和日本,这类政策允许采用资金密集型和能源密集型技术,使得这些国家在满足其水资源需求的同时还能尽量降低人类健康风险.然而,从可持续发展的观点看,以有限的自然资源为基础制定的这类政策,并非长久之计.对于新兴工业化国家(如巴西)来说,昂贵的水资源管理技术在经济上常常行不通,因而限制了新兴工业化国家和发展中国家对发达国家提供的技术的利用程度.要实现水资源的可持续管理,发达国家、新兴工业化国家和发展中国家都需要经历一个学习的过程,同时还需要遵循本文介绍的可持续发展的通用原则.  相似文献   
104.
In the 1950s, a production plant of hexachlorocyclohexane (HCH) was established in Brazil with the main purpose of producing chemicals for vectors control. This factory was closed down in 1955 and around 300 tons of production residues were left behind in the open air. In 1995, the area was treated with lime to eliminate the HCH contamination. Soil sample gave a PCDD/F concentration of 13 900 ng I-TEQ/kg whereas samples from the neighborhood ranged from 0.19 to 2.08 ng I-TEQ/kg. PCDD/F levels in cow's milk samples varied from 4.1 to 6.5 pg I-TEQ/g of milk fat. High concentration in soil collected from the site suggests that treatment and recovery shall be made. Further dioxin monitoring is needed to better estimate the risk posed to local population through food consumption and soil usage.  相似文献   
105.
Pesticides in the surface waters of the Camanducaia River watershed,Brazil   总被引:1,自引:0,他引:1  
Abstract

Camanducaia River is part of the Piracicaba watershed responsible for pumping water into the Cantareira System, which is one of the main water sources for the metropolis of São Paulo and Campinas, Brazil. Intensive use of pesticides and hilly topography represents a situation of high risk for river water contamination. Therefore, water samples from 12 locations were collected along the Camanducaia River and its tributaries, over a period of 4?mo during the rainy season, and analyzed by GC-MS/MS or UPLC- MS/MS for the presence of 46 pesticides. Seven pesticides (fipronil, methyl parathion, metolachlor, atrazine, carbofuran, diuron, and simazine) were positively detected. Only atrazine (the most frequently detected) and diuron were present at concentrations above the limit of quantification of the analytical method (0.32 and 0.57?μg L?1 for atrazine and diuron, respectively). Pesticides detection frequency was higher than expected for a river system where only 11.8% of the land area is under agriculture. The vulnerability of the Camanducaia basin to pesticide contamination is attributed to the high annual precipitation (> 1.5?m y?1 in the headwaters), associated with topographical features (steep terrain) and soil types that favor surface runoff, which has been exacerbated by poor soil management practices.  相似文献   
106.

The management of urban trees generates wood wastes that are commonly destined for use as firewood or compost. However, they can be used for more noble purposes such as making furniture or small wooden objects. This study aimed to investigate the drying and the shrinkage of the wood of seven typical urban afforestation species to determine the possibility of high-valued alternative use(s). Samples of these species (Cenostigma pluviosum (DC.) E. Gagnon & G.P. Lewis.; Delonix regia (Bojer ex Hook.) Raf.; Ficus benjamina L.; Licania tomentosa (Benth.) Fritsch; Nectandra megapotamica (Spreng.) Mez; Terminalia catappa L.; and Tipuana tipu (Benth.) Kuntze) underwent a drastic drying test in a laboratory oven at 103?±?2 °C, followed by weighing on an analytical balance to monitor the weight over a 24-h period, separated into four intervals of 4 h and one of 8 h. The drying rate, shrinkage and anisotropy coefficient of the species were evaluated. Wood wastes of the species C. pluviosum and L. tomentosa showed greater shrinkage during drying, with the lowest drying rates being found among the other species. F. benjamina, D. regia, N. megapotamica, T. catappa and T. tipu showed lower values of shrinkage and regular anisotropy coefficients close to ideal for application to make small wooden objects according to the characteristics of the species already present in the industrial market. The seven species thus have potential for application in the production of small wooden objects and furniture. This use is a potential alternative for environmental and social betterment.

  相似文献   
107.
Objective: The objective of this study was to determine the prevalence of alcohol and illicit drug use among victims of fatal traffic accidents in the Metropolitan Region of Vitória, Brazil, during the period 2011–2012.

Methods: Blood samples were collected and analyzed for the presence of drugs from 391 deceased victims of traffic crashes that occurred in the Metropolitan Region of Vitória, Brazil. The victims included drivers, passengers, and pedestrians. Sociodemographic variables such as age, gender, day of the week, and period of the year in which the accidents occurred were recorded. The analyses were performed by a gas chromatography–flame ionization method for alcohol and by a gas chromatography–mass spectrometry for amphetamines, cocaine, and cannabis.

Results: The results showed that 44.8% (n = 175) of all cases were positive for alcohol and/or illicit drugs. The detection of alcohol and/or drugs was more frequent in young males, aged 17 to 34, whose samples were positive in 46.8% of cases. Small differences among drivers, passengers, and pedestrians were observed (drivers = 45.9%, passengers = 46.4%, and pedestrians = 45.6%). In general, the most prevalent drug was alcohol, with 141 positive cases (36.1%), followed by cocaine, with 47 positive cases (12%). Amphetamines and cannabis had positivity rates of 4.1 and 4.3%, with 16 and 17 positive cases, respectively. The combined use of alcohol and other drugs was found in 36 cases (9.2%). Crack cocaine use was observed in 27.7% of the positive cases for cocaine.

Conclusions: For the effective reduction of traffic accidents related to driving under influence of drugs (DUID), we suggest the intensification of enforcement actions against the use of alcohol by drivers, the definition of which illicit drugs should be surveyed, as well the cutoff values, the promotion of changing legislation to oblige drivers to provide samples for toxicological testing, and the establishment of public information programs and specific actions aimed at young drivers to promote behavioral changes.  相似文献   

108.
Aqueous Hibiscus sabdariffa extracts possess antimicrobial properties with limited information available on their antiviral effects. Aichi virus (AiV) is an emerging foodborne pathogen that causes gastroenteritis. Vaccines are currently unavailable to prevent their disease transmission. The objective of this study was to determine the antiviral effects of aqueous H. sabdariffa extracts against AiV. AiV at ~5 log PFU/ml was incubated with undiluted (200 mg/ml), 1:1 (100 mg/ml) or 1:5 (40 mg/ml) diluted aqueous hibiscus extract (pH 3.6), phosphate-buffered saline (pH 7.2 as control), or malic acid (pH 3.0, acid control) at 37 °C over 24 h. Treatments were stopped by serially diluting in cell-culture media containing fetal bovine serum and titers were determined using plaque assays on confluent Vero cells. Each treatment was replicated thrice and assayed in duplicate. AiV did not show any significant reduction with 1:1 (100 mg/ml) or 1:5 (40 mg/ml) diluted aqueous hibiscus extracts or malic acid after 0.5, 1, or 2 h at 37 °C. However, AiV titers were reduced to non-detectable levels after 24 h with all the three tested concentrations, while malic acid showed only 0.93 log PFU/ml reduction after 24 h. AiV was reduced by 0.5 and 0.9 log PFU/ml with undiluted extracts (200 mg/ml) after 2 and 6 h, respectively. AiV treated with 1:1 (100 mg/ml) and 1:5 (40 mg/ml) diluted extracts showed a minimal ~0.3 log PFU/ml reduction after 6 h. These extracts show promise to reduce AiV titers mainly through alteration of virus structure, though higher concentrations may have improved effects.  相似文献   
109.
Blueberry and blueberry extracts are known for their health benefits and antimicrobial properties. Natural therapeutic or preventive options to decrease the incidences of foodborne viral illnesses are becoming popular and being researched. This study aimed to determine the antiviral effects of blueberry juice (BJ) and blueberry proanthocyanidins (BB-PAC, B-type PAC structurally different from A-type PAC found in cranberries) against the infectivity of hepatitis A virus (HAV) and human norovirus surrogates (feline calicivirus (FCV-F9) and murine norovirus (MNV-1)) at 37 °C over 24 h using standard plaque assays. Viruses at ~5 log PFU/ml were mixed with equal volumes of BJ (pH 2.8), neutralized BJ (pH 7.0), BB-PAC (1, 2, 4, and 10 mg/ml), malic acid (pH 3.0), or phosphate-buffered saline (pH 7.2) and incubated over 24 h at 37 °C. Each experiment was carried out in duplicate and replicated thrice. FCV-F9 titers were found to be reduced to undetectable levels with 1 and 2 mg/ml BB-PAC after 5 min, with 0.5 mg/ml BB-PAC after 1-h, and with BJ after 3-h. MNV-1 titers were reduced to undetectable levels after 3 h with 1, 2, and 5 mg/ml BB-PAC and after 6 h with BJ. HAV titers were reduced to undetectable levels after 30 min with 2 and 5 mg/ml BB-PAC, after 3 h with 1 mg/ml BB-PAC, and by ~2 log PFU/ml with BJ after 24-h. BB-PAC shows preventive potential against infection by the tested enteric viruses in a dose- and time-dependent manner, although further in vitro studies in model food systems and in vivo studies using animal models are warranted.  相似文献   
110.
Environmental Science and Pollution Research - A simple, efficient, environmentally friendly, and inexpensive synthesis route was developed to obtain a magnetic nano-hybrid (GH) based on graphene...  相似文献   
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