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961.
962.
Z. Bendjoudi F. Taleb F. Abdelmalek A. Addou 《Waste management (New York, N.Y.)》2009,29(4):1383-1387
Algeria as other developing countries faces an array of challenges for healthcare waste management. The management of healthcare waste is of major importance due to its public health risks and potential environmental hazards. Many efforts have been made by the government authorities in order to better manage the waste from healthcare facilities. However most healthcare facilities do not comply with the principles stated in Algerian legislation. A data study was made on 95 hospitals across the country, and the three health sectors of Mostaganem department (Mostaganem, Ain Tédles, and Sidi Ali) were surveyed. The yearly production of infectious healthcare waste in this Algerian department is estimated at 92 tons, which is 1.38% of the national waste production. This represents an average of 0.15 kg/bed/day, which is lower than the national value of 0.72 kg/bed/day. The total healthcare waste by sector ranges from 0.7 to 1.22 kg/bed/day, and healthcare waste comprises 16% of total waste, which is equal to the national percentage. 相似文献
963.
F.Y. Wu H.M. Leung S.C. Wu Z.H. Ye M.H. Wong 《Environmental pollution (Barking, Essex : 1987)》2009,157(8-9):2394-2404
Arsenic, Pb and Zn tolerance and accumulation were investigated in six populations of Pteris vittata collected from As-contaminated and uncontaminated sites in southeast China compared with Pteris semipinnata (a non-As hyperaccumulator) in hydroponics and on As-contaminated soils. The results showed that both metallicolous and nonmetallicolous population of P. vittata possessed high-level As tolerance, and that the former exhibited higher As tolerance (but not Pb and Zn tolerance) than the latter. In hydroponic culture, nonmetallicolous population clearly showed significantly higher As concentrations in fronds than those in metallicolous populations. In pot trials, As concentrations in fronds of nonmetallicolous population ranged from 1060 to 1639 mg kg?1, about 2.6- to 5.4-folds as those in metallicolous populations. It was concluded that As tolerance in P. vittata resulted from both constitutive and adaptive traits, Pb and Zn tolerances were constitutive properties, and that nonmetallicolous population possesses more effective As hyperaccumulation than metallicolous populations. 相似文献
964.
This work analyzes a process known as flash pyrolysis, which produces bio fuels using biomass for power generation. A life-cycle assessment of flash pyrolysis of wood waste was conducted to study whether a flash pyrolysis plant set up locally would be environmentally friendly. The results obtained show that the process of flash pyrolysis of wood waste is in fact environmentally friendly, and the process has little contribution to the environment. However, efforts still have to be made to address the global warming potential issue. Continuous research and developments must be carried out to further reduce the global warming potential of the flash pyrolysis. 相似文献
965.
966.
In this study the biosorption of Yellow RL, a metal-complex anionic dye, by dried Rhizopus arrhizus, a filamentous fungus, was investigated as a function of initial solution pH, initial dye concentration and initial salt (sodium chloride) concentration. The fungus exhibited the maximal dye uptake at pH 2 in the absence and in the presence of salt. Dye uptake increased with the dye concentration up to 1000 mg l?1 and diminished considerably in the presence of increasing concentrations of salt up to 50 g l?1. The fungus biosorbed 85.4 mg dye g?1of dried biomass at 100 mg l?1 initial dye concentration in the absence of salt. When 50 g l?1 salt was added to the biosorption medium, this value dropped to 60.8 mg g?1 resulting in 28.8% reduction in biosorption capacity. The Redlich–Peterson and Langmuir–Freundlich were the most suitable adsorption models for describing the biosorption equilibrium data of the dye both individually and in salt containing medium. The pseudo-second-order and saturation type kinetic models depicted the biosorption kinetics accurately for all cases studied. Equilibrium and kinetic constants varied with the level of salt were expressed as a function of salt concentration. 相似文献
967.
Viscosity, peel and shear strength of epoxidized natural rubber (ENR)-based pressure-sensitive adhesive was studied by using
hybrid tackifiers consisting of a mixture of coumarone-indene resin and petro resin. The coumarone-indene resin concentration
was fixed at 40 parts per hundred parts of rubber (phr). The concentration of petro resin, however, was varied from 20 to
80 phr. Toluene and polyethylene terephthalate (PET) film were used as the solvent and coating substrate respectively throughout
the experiment. Viscosity of adhesive was determined by a HAAKE Rotary Viscometer whereas peel and shear strength was measured
by a Lloyd Adhesion Tester. Results show that viscosity and shear strength decreases with increasing petro resin concentration.
However, peel strength exhibits a maximum value at 40 phr petro resin, an observation which is attributed to maximum wettability
and compatibility of adhesive on the substrate. ENR 25-based adhesive exhibits higher viscosity and peel strength but lower
shear strength compared to the ENR 50 adhesive system. 相似文献
968.
Landfill leachate contains high concentrations of organic matter, color, heavy metals and toxic substances. This study presents the feasibility of a commercial nanofiltration membrane (NF-300) in the removal of pollutants from a landfill leachate generated from the Treatment Stabilization and Disposal Facility in Gujarat state of India. Two different leachate samples (Leachates A and B) were collected from the downstream side of closed landfill cells A and B. The average quality of the leachate was 67 719 mg/L COD, 217 mg/L ammonical nitrogen, 22 418 mg/L BOD, 3847 mg/L chlorides and 909 mg/L sulphate. The operating variables studied were applied pressure (4–20 atm), feed flowrate (5–15 L/min) and pH (2, 4, 5.5 and 6.7). It was observed that the solute rejection (RO) increased with increase in feed pressure and decreased with increase in feed concentration at constant feed flowrate. In the present study, the rejection of cations followed the sequence: RO (Cr3+) > RO (Ni2+) > RO (Zn2+) > RO (Cu2+) > RO (Cd2+) for leachates A and B. The order of solute rejection sequence is inversely proportional to the diffusion coefficients. The rejection of sulphate ions by the NF-300 membrane was 83 and 85%, while the rejection of chlorides was 62 and 65% for leachates A and B, respectively. The NF-300 membrane was characterized by using the combined-film theory-Spiegler–Kedem (CFSK) model based on irreversible thermodynamics and the ion transport model based on the extended Nernst–Planck equation. The membrane transport parameters were estimated using the Levenberg–Marquadt method. The estimated parameters were used to predict the membrane performance and the predicted values are in good agreement with the experimental results. 相似文献
969.
L. Erdős Cs. Tölgyesi Z. Bátori Yu. A. Semenishchenkov M. Magnes 《Russian Journal of Ecology》2017,48(4):350-357
Eastern Austrian forest-steppe remnants are extremey important both from conservation and a scientific perspective, yet case studies integrating the examination of the grassland and the forest components are relatively scarce. Consequently, the knowledge on how the pattern of forested vs. non-forested patches influences species composition and diversity remains rather limited. In this study, we compared three sites with different forest/grassland proportions: grassland with a low canopy cover, a mosaic area with alternating forest and grassland habitats, and a forest with some canopy gaps. Our aim was to find out which one of them is the best for conservation purposes. We found that the grassland and the mosaic area had a similar composition, while the forested one was distinct from them. The mosaic vegetation seemed to be the most species rich, also hosting a high number of red-listed species. Beside forest-related and grassland-related species, the mosaic plot also supported some edge-related plants. We conclude that the preservation of mosaic-like forest- grassland habitats is the most favorable for conservation aims. Nevertheless, several species, among them some red-listed ones, were clearly linked either to the forest or to the grassland plot. Therefore, even though mosaics deserve a special attention, open grasslands and xeric forests should also be preserved. 相似文献
970.
M.S. Abbassy H.Z. Ibrahim MM. Abu El‐Amayem 《Journal of environmental science and health. Part. B》2013,48(2):255-267
Abstract A study was conducted from summer 1995 to summer 1997 to assess the seasonal occurrence of pesticide residues and other organic contaminants, polychlorinated biphenyls (PCBs), in water at the estuaries of Rosetta and Damiatta branches of the Nile river. The results indicated that organochlorine compounds (OCs) including HCB, lindane, p,p‘‐DDE, p,p‘DDD, p,p‘‐DDT, aroclor 1254 and aroclor 1260 were present in all the water samples at concentration levels ranging between 0.195–0.240, 0.286–0.352, 0.035–0.067, 0.019–0.033, 0.024–0.031, 0.390–0.70 and 0.166–0.330 μg/l, respectively. The levels of these compounds were higher in water of Damiatta branch than those found in water of Rosetta branch. Aldrin, dieldrin and endrin were not detected in all water samples. Only 4 compounds from 36 organophosphorus insecticides, fungicides and s‐triazine herbicides tested were detected in water samples collected during summer and autumn seasons from Rosetta branch. The concentration levels of these detected compounds, dimethoate, malathion, captan, and ametryne, ranged from 0.011 to 0.340 μg/l, respectively. Similar compounds during the same seasons as found in water of Rosetta branch were also detected in water of Damiatta branch except ametryne. The levels of the detected compounds (dimethoate, malathion and captan) ranged between 0.030 and 0.330 μg/l. The levels of detected organophosphorus insecticides, fungicides and s‐triazine herbicides were in the order: dimethoate > malathion > captan > ametryne. 相似文献