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81.
Environmental Science and Pollution Research - Arsenic (As) indelibly exists in the environment and may reach to a food chain. Flavors and herbs are recognized sources of natural antioxidants that...  相似文献   
82.
The Linggi river drainage basin in Negeri Sembilan, Malaysia supplies water to the whole of Port Dickson district and meets 50% of the Seremban district needs. The Linggi River, the main tributary, passes through the highly urbanised and densely populated Seremban district while the water treatment plant is located 16 km downstream. In 1979 the USEPA declared the river unsuitable as a source of raw water whereas the WHO classified it as being heavily polluted requiring more extensive and effective treatment. In order to meet the WHO drinking water standards, an ozonation system was installed in the conventional water treatment plant. The objective of ozonation is for the control and removal of organic micropollutants and other deleterious matters. This study investigated the concentrations and distribution of organic micropollutants, heavy metals, and bacteriological counts in water samples collected from within the catchment and the treated water. The effectiveness of the ozonation system was also studied. The total level of phenolic water pollutants in the catchment was generally found to be very much higher than the maximum recommended level of 2.0 µgl-1. The extensive treatment process carried out at the plant was very effective in reducing the levels of total phenols in the treated water to less than 1.0 µgl-1. However the process was not efficient enough to reduce the levels of some heavy metals as required by the standards, for examples Cd and Pb were still three times higher than the standards of 5µgl-1 and 0.05 mgl-1 respectively. For bacteriological study, coliform group of bacteria, Salmonella, faecal streptococci and injured coliform were monitored in the raw and treated water. The raw water contained coliforms about 1000 times higher than the required standard for raw ater, but after the secondary treatment by ozonation coliform bacteria were absent, however a small number of Salmonella was still present occasionally. The study also showed that restructuring of the district and relocating of some commercial activities along the river banks to other areas carried out over the last five years has improved the general quality of the river water.  相似文献   
83.
Journal of Polymers and the Environment - A Green nanomaterial synthesis could be considered as an alternative bio-controller source of insect pest management as well as saving the environment....  相似文献   
84.
This study proposed to detect the enterovirus (EV) infection in children with type 1 diabetes mellitus (T1D) and to assess the role of insufficiently treated water and sewage as sources of viral spreading. Three hundred and eighty-two serum specimens of children with T1D, one hundred serum specimens of children who did not suffer from T1D as control, and forty-eight water and sewage samples were screened for EV RNA using nested RT-PCR. The number of genome copies and infectious units of EVs in raw and treated sewage and water samples were investigated using real-time (RT)-PCR and plaque assay, respectively. T1D markers [Fasting blood glucose (FBG), HbA1c, and C-peptide], in addition to anti-Coxsackie A & B viruses (CVs A & B) IgG, were measured in control, T1D-negative EV (T1D–EV?), and T1D-positive EV (T1D–EV+) children specimens. The prevalence of EV genome was significantly higher in diabetic children (26.2%, 100 out of 382) than the control children (0%, 0 out of 100). FBG and HbA1c in T1D–EV? and T1D–EV+ children specimens were significantly higher than those in the control group, while c-peptide in T1D–EV? and T1D–EV+ children specimens was significantly lower than that in the control (n = 100; p < 0.001). Positivity of anti-CVs A & B IgG was 70.7, 6.7, and 22.9% in T1D–EV+, T1D–EV?, and control children specimens, respectively. The prevalence of EV genome in drinking water and treated sewage samples was 25 and 33.3%, respectively. The prevalence of EV infectious units in drinking water and treated sewage samples was 8.5 and 25%, respectively. Quantification assays were performed to assess the capabilities of both wastewater treatment plants (WWTPs) and water treatment plants (WTPs) to remove EV. The reduction of EV genome in Zenin WWTP ranged from 2 to 4 log10, while the reduction of EV infectious units ranged from 1 to 4 log10. The reduction of EV genome in El-Giza WTP ranged from 1 to 3 log10, while the reduction of EV infectious units ranged from 1 to 2 log10. This capability of reduction did not prevent the appearance of infectious EV in treated sewage and drinking water. Plaque purification was performed for isolation of separate EV isolates from treated and untreated water and sewage samples. Characterization of the EV amplicons by RT-PCR followed by sequencing of these isolates revealed high homology (97%) with human coxsackievirus B4 (CV B4) in 60% of the isolates, while the rest of the isolates belonged to poliovirus type 1 and type 2 vaccine strains. On the other hand, characterization of the EV amplicons by RT-PCR followed by sequencing for T1D–EV+ children specimens indicated that all samples contained CV B4 with the same sequence characterized in the environmental samples. CV B4-contaminated drinking water or treated sewage may play a role as a causative agent of T1D in children.  相似文献   
85.
New comprehensive numerically solved 1D and 2D absorption rate/kinetics models have been developed, for the first time, to interpret the experimental kinetic data obtained with a laminar jet apparatus for the absorption of carbon dioxide (CO2) in CO2 loaded mixed solutions of mixed amine system of methyldiethanolamine (MDEA) and monoethanolamine (MEA). Three MDEA/MEA weight ratios ranging from 27/03 to 23/07, over a concentration range of 2.316–1.996 kmol/m3 for MDEA and of 0.490–1.147 kmol/m3 for MEA were studied. The models take into account the coupling between chemical equilibrium, mass transfer, and the chemical kinetics of all possible chemical reactions involved in the CO2 reaction with MDEA/MEA solvent. The partial differential equations of the 1D model were solved by two numerical techniques; the finite difference method (FDM) based on in-house coded Barakat–Clark scheme and the finite element method (FEM) based on COMSOL software. The FEM comprehensive model was then used to solve the set of partial differential equations in the 2D cylindrical coordinate system setting. Both FDM and FEM produced very accurate results for both the 1D and 2D models, which were much better than our previously published simplified model. The reaction rate constant obtained for MEA blended into MDEA at 298–333 K was kMEA = 5.127 × 108 exp(−3373.8/T). In addition, the 2D model, for the first time, has provided the concentration profiles of all the species in both the radial and axial directions of the laminar jet, thereby enabling an understanding of the correct sequence in which the reaction steps involved in the reactive absorption of CO2 in aqueous mixed amines occur.  相似文献   
86.
Fe-pillared montmorillonite has been used as a Fenton-type heterogeneous catalyst for the removal of cinnamic acid in water. The influences of the cinnamic acid, catalyst and H2O2 concentrations and pH on the removal rate of cinnamic acid have been studied. The results show that the efficiency of Fe-pillared montmorillonite is higher than that of the Fe ions in the homogeneous phase, and less sensitive to pH.  相似文献   
87.
Public opinion and siting solid waste landfills in Kuwait   总被引:1,自引:0,他引:1  
Siting municipal solid waste landfills in Kuwait had not considered public concerns about the location of such facilities. Kuwait Municipality has disposed urban waste in abandoned sand quarries for the past 20 years in an unplanned fashion. Due to this improper siting criteria, environmental and health problems have risen from old landfills that are located in residential areas. In an effort to help responsible decision-makers in assessing public support for siting landfills a structured, yet simple, questionnaire was designed and distributed to a random sample of heads of households. Statistical techniques were employed to examine trends and relationships between the sample public responses concerning landfill siting criteria. The findings of the research indicated that a significant percentage of the responding sample did not know about the various landfill impacts and less than 50% were aware of the negative impacts of landfills on the public health and the environment. The visual appearance of the landfill scored the lowest impact in the opinion of the sample public while the most important aspect in siting a landfill appeared to be its economic consideration. The research findings also directed attention to the important role that the media could play in increasing public awareness. Results from the cross-classification analysis demonstrated the existence of differences in awareness levels according to age, nationality, martial status, education, and occupation of the responding sample. Statistically, these differences were significant at the 95% significance level, as supported by the test of the χ-square.  相似文献   
88.
Water quality is a critical challenge in Asia in the context of growing industrialization, urbanization, and climate change. Nature-based solutions (NbS) could play an important role in reducing urban water pollution, while generating multiple co-benefits that could make cities more liveable and resilient. In this regard, a number of pilot and demonstration projects have been set up to explore their potential across cities in Asia. Their effectiveness and impacts, however, have not been adequately documented, thus how they can be sustained, replicated and up-scaled remain poorly understood. This study aims to contribute to addressing this challenge by co-developing an integrated assessment framework and employing it to understand how existing evaluations of NbS in the region can be improved. It focuses specifically on a set of nature-based solutions that have been employed for water treatment across six cities in Southeast Asia (two in each Sri Lanka, the Philippines, and Vietnam), namely, floating wetlands, constructed wetlands and maturation ponds. The study also suggests specific methodologies for capturing a set of core indicators considered relevant for assessing the effectiveness and capturing the multi-faceted impacts of the examined NbS.  相似文献   
89.
The leaves of two legumes, peas and beans, harbored on their surfaces up to 9×10? cells g?1 of oil-utilizing bacteria. Less numbers, up to 5×10? cells g?1 inhabited leaves of two nonlegume crops, namely tomato and sunflower. Older leaves accommodated more of such bacteria than younger ones. Plants raised in oily environments were colonized by much more oil-utilizing bacteria than those raised in pristine (oil-free) environments. Similar numbers were counted on the same media in which nitrogen salt was deleted, indicating that most phyllospheric bacteria were probably diazotrophic. Most dominant were Microbacterium spp. followed by Rhodococcus spp., Citrobacter freundii, in addition to several other minor species. The pure bacterial isolates could utilize leaf tissue hydrocarbons, and consume considerable proportions of crude oil, phenanthrene (an aromatic hydrocarbon) and n-octadecane (an alkane) in batch cultures. Bacterial consortia on fresh (but not on previously autoclaved) leaves of peas and beans could also consume substantial proportions of the surrounding volatile oil hydrocarbons in closed microcosms. It was concluded that phytoremediation through phyllosphere technology could be useful in remediating atmospheric hydrocarbon pollutants.  相似文献   
90.
ABSTRACT

This article aims to study the influence of the addition of graphene oxide nanoparticles (GO) to diesel/higher alcohols blends on the combustion, emission, and exergy parameters of a CI engine under various engine loads. The higher alcohols mainly n-butanol, n-heptanol, and n-octanol are blended with diesel at a volume fraction of 50%. Then, the 25 and 50 mg/L concentrations of GO are dispersed into diesel/higher alcohols blends using an ultrasonicator. The GO structures are examined using TEM, TGA, XRD and FTIR. The findings show that there is a reduction in pmax. and HRR when adding higher alcohols with diesel fuel. Regarding engine emission, there is a significant improvement in emissions formation with adding higher alcohols. The addition of GO into diesel/higher alcohols blends improves the brake thermal efficiency by 15%. Moreover, the pmax. and HRR are both enhanced by 4%. The CO, UHC and smoke formation are reduced considerably by 40%, 50 and 20%, respectively, while NOx level is increased by 30% with adding GO. Finally, adding high percentages of n-butanol, n-heptanol, and n-octanol with diesel fuel with the presence of GO has the potential to achieve ultra-low CO, UHC, and smoke formation meanwhile keeping high thermal efficiency level.  相似文献   
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