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11.
Mohammed Nadim Sardoiwala Babita Kaundal Subhasree Roy Choudhury 《Environmental Chemistry Letters》2018,16(1):147-160
Nanotechnology has many potential applications in medical, agriculture, electronic and sports industries. Nonetheless, there is actually little knowledge on toxic effects of nanomaterial. Here we review nanotoxicity, action mechanisms and fate of nanomaterials. We discuss the impact of nanotoxicity on microbes, plant, animal and human health, and factors like size, shape, surface charge, composition, ionic concentration and physiological. We explain the detection of nanotoxicity at cell and genome levels. Toxicities of commercial nanomaterials, risk management, rules and regulations regarding marketed nanoproducts are also summarized. 相似文献
12.
Farag Malhat Amani El-Mesallamy Mohamed Assy Walid Madian Naglaa M. Loutfy 《毒物与环境化学》2013,95(8):1309-1317
A validated high-performance liquid chromatography–diode array detector method for simultaneous determination of the acaricide fenpyroximate on grape was developed. Estimated limit of detection and limit of quantification for fenpyroximate were 0.01 and 0.05 mg kg?1, respectively. The intra- and inter-day precisions performed with relative standard deviation were better than 9.3% and 8%, respectively, while recoveries were in the range of 88.5%–100.4%. Residue levels of fenpyroximate in grape samples collected 10 days after field application were below the established maximum residue level values. The dissipation rates of fenpyroximate were described using first-order kinetics and its half-life, were approximately 3.5 days in grape. This study provides basic information for developing regulations to safeguard the use of fenpyroximate in grapes and prevent any potential health concerns for consumers. 相似文献
13.
A facility for the treatment and disposal of industrial hazardous waste has been established in Alexandria, Egypt. Phase I of the facility encompassing a secure landfill and solar evaporation ponds is ready to receive waste, and Phase II encompassing physico-chemical treatment, solidification, and interim storage is underway. The facility, the Nasreya Centre, is the first of its kind in Egypt, and represents the nucleus for the integration, improvement and further expansion of different hazardous waste management practices and services in Alexandria. It has been developed within the overall legal framework of the Egyptian Law for the Environment, and is expected to improve prospects for enforcement of the regulatory requirements specified in this law. It has been developed with the overall aim of promoting the establishment of an integrated industrial hazardous waste management system in Alexandria, serving as a demonstration to be replicated elsewhere in Egypt. For Phase I, the Centre only accepts inorganic industrial wastes. In this respect, a waste acceptance policy has been developed, which is expected to be reviewed during Phase II, with an expansion of the waste types accepted. 相似文献
14.
Farhad Nadim Amvrossios C Bagtzoglou Sandrine A Baun Glenn S Warner Fred Ogden Richard A Jacobson Piotr Parasiewicz 《Water environment research》2007,79(1):43-56
A study was conducted to determine the effect of water withdrawals from the University of Connecticut's (Storrs) water supply wells on the fisheries habitat of the Fenton River adjacent to the well field. The study was designed to investigate the relationships between in-stream flow and selected fish habitat in the section of the Fenton River situated in the main zone of influence of the pumping field. With the aid of historical data, new data collection, and mathematical simulation modeling, the relation between the magnitude and timing of groundwater withdrawals on the stage and flow of water in the stream was derived. Fish sampling and habitat modeling were used to assess the effects of human influence on certain reaches of the Fenton River. Among the various water management scenarios studied, several are presented that would optimize water withdrawals, while minimizing adverse effects on the stream flow and in-stream habitat. 相似文献
15.
Volatile fatty acids (VFAs) are key intermediates in anaerobic digestion. Enriched acetogenic and methanogenic cultures were used for the syntrophic anaerobic digestion of VFAs in a continuous fixed-bed reactor at mesophilic conditions. The interactive effects of propionic (HPr), butyric (HBu), and acetic (HAc) acids were analyzed. Furthermore, hydraulic retention time (HRT) and methanogen-to-acetogen ratios (M/As) were investigated as the key microbiological and operating variables of VFA anaerobic degradations. Experiments were carried out based on central composite design (CCD) and results were analyzed using response surface methodology (RSM). Effluent concentrations of HPr, HBu, HAc, and biogas production rate (BPR) were directly measured as responses. The optimum conditions were found to be HPr = 1122.9 mg/L, HBu = 1792.4 mg/L, HAc = 1735.4 mg/L, HRT = 21 hours, and M/A = 2.4 (corresponding to the maximum VFA removal and BPR). The results of verification experiments and predicted values from fitted correlations were in close agreement at a 95% confidence interval. 相似文献
16.
Nor‐Amani‐Filzah Mohd‐Kamil Noor‐Hana Hussain Meizareena Binti Mizad Suhaimi Abdul‐Talib 《补救:环境净化治理成本、技术与工艺杂志》2014,24(3):119-128
Many biodegradation studies have focused on survival of isolated bacteria to increase the bacteria population and subsequently enhance the efficiency of polycyclic aromatic hydrocarbon (PAH) biodegradation. However, there is limited research on enhancing the performance of isolated bacteria through reinoculation. Thus, this study was designed to evaluate the effects of reinoculation on the performance of Sphingobacterium spiritivorum in degradation of phenanthrene contaminated sand. Experiments were performed in three different reactors. Inoculation was performed once (day 0) in reactor 1. In reactor 2, inoculation was performed twice (day 0 and day 5). The bacteria was isolated from reactor 2 and inoculated into reactor 3. The study results show reactor 3 having the highest degradation rate (13.61 mg/kg/day) and percentage removal (95.36 percent). In contrast, without reinoculation in reactor 1, 68.93 percent of phenanthrene was removed. Thus, the performance of S. spiritivorum in phenanthrene degradation can be enhanced through reinoculation. © 2014 Wiley Periodicals, Inc. 相似文献
17.
Atmospheric mercury monitoring survey in Beijing,China 总被引:20,自引:0,他引:20
With the aid of one industrial, two urban, two suburban, and two rural sampling locations, diurnal patterns of total gaseous mercury (TGM) were monitored in January, February and September of 1998 in Beijing, China. Monitoring was conducted in six (two urban, two suburban, one rural and the industrial sites) of the seven sampling sites during January and February (winter) and in four (two urban, one rural, and the industrial sites) of the sampling locations during September (summer) of 1998. In the three suburban sampling stations, mean TGM concentrations during the winter sampling period were 8.6, 10.7, and 6.2 ng/m3, respectively. In the two urban sampling locations mean TGM concentrations during winter and summer sampling periods were 24.7, 8.3, 10, and 12.7 ng/m3, respectively. In the suburban-industrial and the two rural sampling locations, mean mercury concentrations ranged from 3.1-5.3 ng/m3 in winter to 4.1-7.7 ng/m3 in summer sampling periods. In the Tiananmen Square (urban), and Shijingshan (suburban) sampling locations the mean TGM concentrations during the summer sampling period were higher than winter concentrations, which may have been caused by evaporation of soil-bound mercury in warm periods. Continuous meteorological data were available at one of the suburban sites, which allowed the observation of mercury concentration variations associated with some weather parameters. It was found that there was a moderate negative correlation between the wind speed and the TGM concentration at this suburban sampling location. It was also found that during the sampling period at the same site, the quantity of TGM transported to or from the sampling site was mainly influenced by the duration and frequency of wind occurrence from certain directions. 相似文献
18.
Alireza Ashori Yahya Hamzeh Fatemeh Amani 《Journal of Polymers and the Environment》2011,19(1):297-300
This work investigates the potentials of lemon balm (Melissa officinalis L.) stalk (LBS), a massive waste part of medicinal plant, for pulp and papermaking by assessing its fiber characteristics
and chemical composition. In addition, LBS properties were compared with some important agro-residues such as bagasse stalk
(BS), cotton stalk (CS) and tobacco stalk (TS). There is no information about suitability of the LBS in the open literature.
Chemically, LBS fibers contain a relatively high percentage of alpha-cellulose (32.7%), but a low percentage of lignin (25%),
which benefits pulping and bleaching. The hemicelluloses in LBS are mainly glucose and xylose. Ash content was about 6%, superior
to the average value corresponding to woods, which makes pulping difficult. It was verified that the chemical compositions
of the studied agro-residues vary significantly. Morphologically, the LBS fibers are comparable to those of hardwoods. Rather
a significant amount of parenchyma cells was found in LBS. The TS has the highest average fiber length, while the LBS has
the least, and the lengths of BS and CS fibers fall in between. In general, based on the results of this study, some propositions
can be made about the possible applications of LBS as a non-wood renewable source of natural products for use in the production
of pulp and paper. 相似文献
19.
Farhad Nadim Kun-Chang Huang Amine M. Dahmani 《Water, Air, & Soil Pollution: Focus》2006,6(1-2):227-232
The feasibility of degrading 16 USEPA priority polycyclic aromatic (PAH) hydrocarbons (PAHs) with heat and Fe(II)-EDTA catalyzed
persulfate oxidation was investigated in the laboratory. The experiments were conducted to determine the effects of temperature
(i.e. 20 ∘C, 30 ∘C and 40 ∘ C) and iron-chelate levels (i.e., 250 mg/L-, 375 mg/L- and 500 mg/L-Fe(II)) on the degradation of dissolved PAHs in aqueous
systems, using a series of amber glass jars as the reactors that were placed on a shaker inside an incubator for temperature
control. Each experiment was run in duplicate and had two controls (i.e., no persulfate in systems). Samples were collected
after a reaction period of 144 hrs and measured for PAHs, pH and sodium persulfate levels. The extent of degradation of PAHs
was determined by comparing the data for samples with the controls.
The experimental results showed that persulfate oxidation under each of the tested conditions effectively degraded the 16
target PAHs. All of the targeted PAHs were degraded to below the instrument detection limits (∼4 μ/L) from a range of initial
concentration (i.e., 5 μ/L for benzo(a)pyrene to 57 μ/L for Phenanthrene) within 144 hrs with 5 g/L of sodium persulfate at
20 ∘ C, 30 ∘C and 40 ∘C. The data indicated that the persulfate oxidation was effective in degrading the PAHs and that external heat and iron catalysts
might not be needed for the degradation of PAHs.
The Fe(II)-EDTA catalyzed persulfate also effectively degraded PAHs in the study. In addition, the data on the variation of
persulfate concentrations during the experiments indicated that Fe(II)-EDTA accelerated the consumption of persulfate ions.
The obtained degradation data cannot be used to evaluate the influence of temperature and Fe(II) levels on the PAH degradation
because the PAHs under each of the tested conditions were degraded to below the instrument detection limit within the first
sampling point. However, these experiments have demonstrated the feasibility of degrading PAHs in aqueous systems with persulfate
oxidation. Additional tests are being conducted to evaluate the effectiveness of treating PAHs in soils and obtaining the
rate of degradation of PAHs with persulfate oxidation.
Two sets of laboratory experiments were conducted to evaluate the ability of sodium persulfate in oxidizing real world PAH-contaminated
soils collected from a Superfund site in Connecticut. The first set of soil sample were treated only with persulfate and to
the second batch, mixture of persulfate and Fe(II)-EDTA solutions were added. The results of the second test showed that within
24 hours, 75% to 100% of the initial concentrations of seven PAH compounds detected in the soil samples were degraded by sodium
persulfate mixed with FE(II)-EDTA. 相似文献
20.
Carlos E. Ruiz Nadim M. Aziz Paul R. Schroeder 《Environmental Modeling and Assessment》2001,6(3):151-158
This paper describes the U.S. Army Corps of Engineers screening-level water quality model (RECOVERY version 3.0) for assessing long-term impacts of contaminated bottom sediments on surface waters. The model couples contaminant interaction between the water column and the bottom sediment, as well as between contaminated and clean bottom sediments. The analysis is intended primarily for organic contaminants with the assumption that the overlying water column is well mixed vertically. The contaminant is assumed to follow linear, reversible, equilibrium sorption and first-order decay kinetics. The system is physically represented as a well-mixed water column (i.e., zero-dimensional) underlain by a vertically-stratified sediment column (i.e., one-dimensional). The sediment is well-mixed horizontally but segmented vertically into a well-mixed surface (active) layer and deep sediment. The deep sediment is segmented into variably contaminated and clean sediment regions. Processes incorporated in the model are sorption, decay, volatilization, burial, resuspension, settling, bioturbation, and pore-water diffusion. The solution couples contaminant mass balance in the water column and in the mixed sediment layer along with diffusion in the deep sediment layers. The model was verified against laboratory and field data, as well as against an analytical solution for the water and mixed sediment layers. These comparisons indicate that the model can be used as an assessment tool for evaluating remediation alternatives for contaminated bottom sediments. 相似文献