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1.
Airborne particulate matter (PM) concentrations were measured in Iksan, a suburban area in South Korea during April, 2003.
PM2.5 (particles with an aerodynamic diameter less than 2.5 μm) and PM10 (particles with an aerodynamic diameter less than 10 μm) samples were collected, and the chemical characteristics of particles
were examined for diurnal patterns, yellow dust/rainfall influences, and scavenging effects. Average concentrations of PM2.5 and PM10 mass measured were 37.3 ± 16.2 μg m−3 and 60.8 ± 29.5 μg m−3, respectively. The sum of ionic chemical species concentrations for PM2.5 and PM10 was 16.9 ± 7.3 and 23.1 ± 10.1 μg/m3, respectively. A significant reduction in PM mass concentrations during rainfall days was observed for coarse mode (PM2.5 − 10) particles, but less reduction was found for fine (PM2.5) mass concentration. SO4
2−, NH4
+, and K+ predominated in fine particulate mode, NO3
− and Cl− predominated in fine particle mode and coarse particle mode, but Na+, Mg2+, and Ca2+ mostly existed in coarse mode. The high concentration of ammonium due to local emissions and long-range transport neutralized
sulfate and nitrate to ammonium sulfate and ammonium nitrate, which were major forms of airborne PM in Iksan. Average mass
concentrations of PM10 in daytime and at night were 57.6 and 70.0 μg m−3, and those of PM2.5 were 35.4 and 42.5 μg m−3, respectively. NO3
− and Cl− in both PM2.5 and PM10 were about double at night than in the daytime, while the rest of the chemical species were equal or a little higher at night
than in the daytime. The results suggest the formation of ammonium nitrate and chloride when high ammonia concentration and
low air temperature are allowed. Backward air trajectory analyses showed that air masses arriving at the site during yellow
dust period were transported from arid Chinese regions, which resulted in high concentrations of airborne PM mass concentrations.
In the meantime, air mass trajectories during a rainfall period were mostly from the Pacific Ocean or the East China Sea,
along with a relatively low PM concentration. 相似文献
2.
Pierre Sicard Patrice Coddeville Stéphane Sauvage Jean-Claude Galloo 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):49-58
The long-term monitoring of precipitation and its chemical composition are important for identifying trends in rain quality
and for assessing the effectiveness of pollution control strategies. A statistical test has been used to the atmospheric concentrations
measured in the French rural monitoring network (MERA) in order to bring out spatio-temporal trends in precipitation quality
in France over the period 1990–2003. The non-parametric Mann–Kendall test which has been developed for detecting and estimating
monotonic trends in the time series was used and applied in our study at annual values of wet-only precipitation concentrations.
The emission data suggest that SO2 and NO
x
emissions decreased (−3.3 and −2.0% year−1, respectively) contrary to NH3 emissions that increased slightly (+0.2% year−1) over the period 1990–2002 in France. On the national scale, the pH values have a significant decreasing trend of −0.025 ± 0.02
unit pH year−1. and concentrations in precipitation have a significant decreasing trend, −3.0 ± 1.6 and −3.3 ± 0.6% year−1, respectively, corresponding with the downward trends in SO2 emissions in France (−3.3% year−1). A good correlation (R
2 = 0.84) between SO2 emissions and concentrations was obtained. The decreasing trend of was more significant (−5.4 ± 5.2% year−1) than that of (−1.3 ± 2.4% year−1). Globally, the concentration of the major ions showed a clear downward trend including marine and alkaline ions. In addition,
the relative contribution of HNO3 to acidity precipitation increased by 51% over the studied period. 相似文献
3.
Effects of Nitrogen Supply on the Sensitivity to O3 of Growth and Photosynthesis of Japanese Beech (Fagus crenata) Seedlings 总被引:1,自引:0,他引:1
Masahiro Yamaguchi Makoto Watanabe Naoki Matsuo Junichi Naba Ryo Funada Motohiro Fukami Hideyuki Matsumura Yoshihisa Kohno Takeshi Izuta 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):131-136
To obtain basic information for evaluating critical levels of O3 under different nitrogen loads for protecting Japanese beech forests, two-year-old seedlings of Fagus crenata Blume were grown in potted andisol supplied with N as NH4NO3 solution at 0, 20 or 50 kg ha−1 year−1 and exposed to charcoal-filtered air or O3 at 1.0, 1.5 and 2.0 times the ambient concentration from 16 April to 22 September 2004. The O3 induced significant reductions in the whole-plant dry mass, net photosynthetic rate at 380 μmol mol−1 CO2 (A
380), carboxylation efficiency (CE) and concentrations of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and total soluble protein (TSP) in the leaves.
The concentrations of Rubisco and TSP were negatively correlated with the concentration of leaf acidic amino acid, suggesting
that O3 enhanced the degradation of protein such as Rubisco. The N supply to the soil did not significantly change the whole-plant
dry mass and A
380, whereas it significantly increased the CE and concentrations of Rubisco and total amino acid. No significant interactive effects of O3 and N supply to the soil were detected on the growth, photosynthetic parameters and concentrations of protein and amino acid
in the leaves. In conclusion, N supply to the soil at ≤50 kg ha−1 year−1 does not significantly change the sensitivity to O3 of growth and net photosynthesis of Fagus crenata seedlings. 相似文献
4.
Regular additions of NH4NO3 (35–140 kg N ha−1 yr−1) and (NH4)2SO4 (140 kg N ha−1 yr−1) to a calcareous grassland in northern England over a period of 12 years have resulted in a decline in the frequency of the
indigenous bryophyte species and the establishment of non-indigenous calcifuge species, with implications for the structure
and composition of this calcareous bryophyte community. The lowest NH4NO3 additions of 35 kg N ha−1 yr−1 produced significant declines in frequency of Hypnum cupressiforme, Campylium chrysophyllum, and Calliergon cuspidatum. Significant reductions in frequency at higher NH4NO3 application rates were recorded for Pseudoscleropodium purum, Ctenidum molluscum, and Dicranum scoparium. The highest NH4NO3 and (NH4)2SO4 additions provided conditions conducive for the establishment of two typical calcifuges – Polytrichum spp. and Campylopus introflexus, respectively. Substrate-surface pH measurements showed a dose-related reduction in pH with increasing NH4NO3 deposition rates of 1.6 pH units between the control and highest deposition rate, and a further significant fall in pH, of
>1 pH unit, between the NH4NO3 and (NH4)2SO4 treatments. These results suggest that indigenous bryophyte composition may be at risk from nitrogen deposition rates of
35 kg N ha−1 yr−1 or less. These effects are of particular concern for rare or endangered species of low frequency. 相似文献
5.
Shaodong Xie Yuanhang Zhang Li Qi Xiaoyan Tang 《Water, Air, & Soil Pollution: Focus》2005,5(3-6):217-229
In the Beijing area, March and April have the highest frequency of sand-dust weather. Floating dust, blowing sand, and dust
storms, primarily from Mongolia, account for 71%, 20%, and 9% of sand-dust weather, respectively. Ambient air monitoring and
analysis of recent meteorological data from Beijing sand-dust storm periods revealed that PM10 mass concentrations during dust storm events remained at 1500 μg m−3, which is five to ten times higher than during non-dust storm periods, for fourteen hours on both April 6 and 25, 2000. During
the same period, the concentrations in urban areas were comparable to those in suburban areas, while the concentrations of
gaseous pollutants, such as SO2, NO
x
, NO2, and O3, remained at low levels, owing to strong winds. Furthermore, during sand-dust storm periods, aerosols were created that consisted
not only of many coarse particles, but also of a large quantity of fine particles. The PM2.5 concentration was approximately 230 μg m−3, accounting for 28% of the total PM10 mass concentration. Crustal elements accounted for 60–70% of the chemical composition of PM2.5, and sulfate and nitrate for much less, unlike the chemical composition of PM2.5 on pollution days, which was primarily composed of sulfates, nitrates, and organic material. Although the very large particle
specific surface area provided by dust storms would normally be conducive to heterogeneous reactions, the conversion rate
from SO2 to SO4
2− was very low, because the relative humidity, less than 30%, was not high enough. 相似文献
6.
Satoru Fujita Kenzi Suzuki Yasuo Shibasaki Toshiaki Mori 《Journal of Material Cycles and Waste Management》2002,4(1):70-76
Hydrogarnet was synthesized hydrothermally below 200°C using molten slag obtained from municipal solid waste. For comparison,
it was also synthesized using pure-phase CaO–Al2O3–SiO2–H2O, as reported previously. The structural and textural properties of this material were investigated using various analytical
and spectroscopic techniques such as X-ray diffraction, X-ray fluorescence spectrometry, atomic absorption spectrometry (AAS),
thermogravimetry/differential thermal analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy.
The Cl− fixation ability of hydrogarnet was investigated in the temperature range 500–800°C in a fixed-bed flow reactor using a HCl
concentration (1000 p.p.m.v.) similar to that of incinerator exhaust gas. Under these experimental conditions, the hydrogarnet
was capable of reducing the HCl gas level to less than 1 p.p.m.v. Analysis of the spent catalyst revealed that the hydrogarnet
was being transformed into wadalite and CaCl2 at high temperatures. The elution test for chromium ions in hydrogarnet obtained from slag was also used, and it was found
that chromium ions were not eluted from hydrogarnet.
Received: January 27, 2001 / Accepted: October 11, 2001 相似文献
7.
Mohammad Taghi Taghizadeh Reza Abdollahi Naser Sadeghpour Orang 《Journal of Polymers and the Environment》2012,20(1):208-216
The degradation of chitosan by means of ultrasound irradiation and its combination with homogeneous photocatalysis (photo-Fenton)
was investigated. Emphasis was given on the effect of additive on degradation rate constants. 24 kHz of ultrasound irradiation
was provided by a sonicator, while an ultraviolet source of 16 W was used for UV irradiation. To increase the efficiency of
degradation process, degradation system was combined with Fe(III) (2.5 × 10−4mol/L) and H2O2 (0.020–0.118 mol/L) in the presence of UV irradiation and the rate of degradation process change from 1.873 × 10−9−6.083 × 10−9 mol1.7 L s−1. Photo-Fenton process led to complete chitosan degradation in 60 min with the rate increasing with increasing catalyst loading.
Sonophotocatalysis in the presence of Fe(III)/H2O2 was always faster than the respective individual processes. A synergistic effect between ultrasound and ultraviolet irradiation
in the presence of Fenton reagent was calculated. The degraded chitosans were characterized by X-ray diffraction (XRD), gel
permeation chromatography (GPC) and Fourier transform infrared (FT-IR) spectroscopy and average molecular weight of ultrasonicated
chitosan was determined by measurements of intrinsic viscosity of samples. The results show that the total degree of deacetylation
(DD) of chitosan change, partially after degradation and the decrease of molecular weight led to transformation of crystal
structure. A negative order for the dependence of the reaction rate on total molar concentration of chitosan solution within
the degradation process was suggested. Results of this study indicate that the presence of catalyst in the reaction medium
can be utilized to reduce molecular weight of chitosan while maintaining the power of irradiated ultrasound and degree of
deacetylation. 相似文献
8.
The atmospheric deposition of reactive nitrogen on turf grassland in Tsukuba, central Japan, was investigated from July 2003
to December 2004. The target components were ammonium, nitrate, and nitrite ions for wet deposition and gaseous ammonia, nitric
and nitrous acids, and particulate ammonium, nitrate, and nitrite for dry deposition. Organic nitrogen was also evaluated
by subtracting the amount of inorganic nitrogen from total nitrogen. A wet-only sampler and filter holders were used to collect
precipitation and the atmospheric components, respectively. An inferential method was applied to calculate the dry deposition
velocity of gases and particles, which involved the effects of surface wetness and ammonia volatilization through stomata
on the dry deposition velocity. The mean fraction of the monthly wet to total deposition was different among chemical species;
37, 77, and 1% for ammoniacal, nitrate-, and nitrite-nitrogen, respectively. The annual deposition of inorganic nitrogen in
2004 was 47 and 48 mmol m−2 yr−1 for wet and dry deposition, respectively; 51% of atmospheric deposition was contributed by dry deposition. The annual wet
deposition in 2004 was 20, 27, and 0.07 mmol m−2 yr−1, and the annual dry deposition in 2004 was 35, 7.4, and 5.4 mmol m−2 yr−1 for ammoniacal, nitrate-, and nitrite-nitrogen, respectively. Ammoniacal nitrogen was the most important reactive nitrogen
because of its remarkable contribution to both wet and dry deposition. The median ratio of the organic nitrogen concentration
to total nitrogen was 9.8, 17, and 15% for precipitation, gases, and particles, respectively. 相似文献
9.
Marcos A. dos Santos Cynthia F. Illanes Adalgiza Fornaro Jairo J. Pedrotti 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):85-92
During the period from July 2002 to June 2004, the chemical characteristics of the rainwater samples collected in downtown São Paulo were investigated. The analysis of 224 wet-only precipitation samples included pH and electrical conductivity, as well as major ions (Na+, $ \rm NH^{ + }_{4} During the period from July 2002 to June 2004, the chemical characteristics of the rainwater samples collected in downtown
S?o Paulo were investigated. The analysis of 224 wet-only precipitation samples included pH and electrical conductivity, as
well as major ions (Na+, , K+, Ca2+, Mg2+, Cl−, , ) and carboxylic acids (acetic, formic and oxalic) using ion chromatography. The volume weighted mean, VWM, of the anions
, and Cl− was, respectively, 20.3, 12.1 and 10.7 μmol l−1. Rainwater in S?o Paulo was acidic, with 55% of the samples exhibiting a pH below 5.6. The VWM of the free H+ was 6.27 μmol l−1), corresponding to a pH of 5.20. Ammonia (NH3), determined as (VWM = 32.8 μmol l−1), was the main acidity neutralizing agent. Considering that the H+ ion is the only counter ion produced from the non-sea-salt fraction of the dissociated anions, the contribution of each anion
to the free acidity potential has the following profile: (31.1%), (26.0%), CH3COO− (22.0%), Cl− (13.7%), HCOO− (5.4%) and (1.8%). The precipitation chemistry showed seasonal differences, with higher concentrations of ammonium and calcium during
autumn and winter (dry period). The marine contribution was not significant, while the direct vehicular emission showed to
be relevant in the ionic composition of precipitation. 相似文献
10.
Hirotoshi Kawabata Bokka Yabunaka Masayuki Tanabe Tateo Usui Katsukiyo Marukawa Shigeta Hara Toshihiro Tanaka 《Journal of Material Cycles and Waste Management》2007,9(1):80-89
A simple, low-cost method for suppression of dioxins/furans (hereinafter referred to as dioxins) is required because many
middle- and, especially, small-scale incinerators have fallen into disuse or have been dismantled because of the high running
and system costs of measures for the suppression of dioxins. Therefore, the purpose of the present study was to develop a
simple removal method for dioxins from combustion gas and to evaluate the basic removal rate of dioxins. The removal method
for suspended matter in a gas mixture (cold model) and dioxins in exhaust gases (hot model) has been investigated by means
of gas injection into water, the mechanism of which is that the suspended matter in the gas gathers at the gas–liquid interface.
In the cold model, the removal ratio of fine particles (RP) by gas injection into water was reproduced well by the following equation: RP (%) = 100 × {1−exp(−0.8 · SS · tC)}, where SS (cm2/cm3) is the specific surface area of bubbles and tC (s) is the residence time of bubbles in water. The removal ratio of fine particles increased as the product Ss · tC increased. In a hot model using the exhaust gas from combustion experiments of polyvinyl chloride, the removal ratio of dioxins
(RD) by injecting the exhaust gas into water was estimated by the following equation: RD (%) = 100 × {1−exp(−0.8 · SS · tC · CD0
0.07)}, where CD0 [ng/cm3 (at standard temperature and pressure)] is the dioxins concentration in the exhaust gas before injection into water. RD depends greatly on the specific surface area of bubbles and the residence time of the bubbles in water, and only weakly on
the dioxins concentration in the exhaust gas. Injection of the exhaust gas into water has been shown to be effective and was
evaluated as a simple method for the removal of dioxins from exhaust gas. 相似文献
11.
Ryan Thomas Kristen Jenkins Beth Landale Grant Trigger Thomas M. Holsen Sophia Dore Donald Pope Jennifer Wasielewski 《补救:环境净化治理成本、技术与工艺杂志》2020,30(3):27-37
A bench‐scale treatability study was performed to evaluate the effectiveness of alkaline ozonation on removing per‐ and polyfluoroalkyl substances (PFAS) present in groundwater at a former industrial site in Michigan. The study involved testing the PFAS‐impacted groundwater under alkaline ozonating conditions under a range of experimental conditions, including modifying pH, hydrogen peroxide‐to‐ozone molar ratio doses, length of ozonation pretreatment times, and sampling techniques. PFAS‐spiked samples were used to determine if inorganic ions such as fluoride (F?), sulfate (SO42?), formate (HCOO?), acetate (CH3COO?), and trifluoroacetate (CF3COO?) were generated or if there were decreases in total organic fluorine resulting from PFAS treatment. The results from all tests indicate that decreases in PFAS concentrations were due to a combination of removal and destructive mechanisms with enhanced removal under acidic pH ozonation pretreatment conditions. Short‐chain PFAS concentrations increased during the experiments followed by an overall decrease in concentration under continuous alkaline ozonation conditions. Reductions in concentrations in perfluorooctane sulfonic acid of 75–97% were observed. Reductions in concentrations were also observed in other PFAS such as 6:2 FTS, PFHxS, PFOA, and PFNA. To our best knowledge, this is the first time that alkaline ozonation has been performed on PFAS‐impacted water while monitoring a larger suite of PFAS analytes in addition to destruction byproducts. Treatment of PFAS under the conditions discussed in this paper suggests that alkaline ozonation may be a viable remediation option for PFAS‐impacted waters. 相似文献
12.
Rajendram Thivyatharsan H. A. Y. R. Gunarathna Benedict Francis Antony Basnayake Periyathamby Kuruparan 《Journal of Material Cycles and Waste Management》2012,14(1):27-37
The objective of the study was to develop a low cost and environmentally friendly liner system for a landfill bioreactor to
harness energy from waste. The landfill bioreactor test cell was constructed and evaluated for performance under dry tropical
conditions of Sri Lanka. The research was carried out from March 2009 to September 2010. The clay-waste polyethylene-clay
composite liner system was developed and permeability was tested. The permeability values of the liner under both saturated
and unsaturated conditions at the high estimated hydraulic head of 86.2 cm were in between 6.3 × 10−8 and 2.6 × 10−8 cm/s. The permeability of the liner under waste filled condition varied between 2.17 × 10−9 and 8.15 × 10−9 cm/s, which satisfies the standard permeability value. Thus, the results were below the minimum requirement at very high
estimated leachate head. After loading the test cell, leachate and permeate characteristics were analyzed for 273 days, from
January 2010 to September 2010. The study showed the relationships among various parameters including pH, electrical permeability,
chemical oxygen demand, biological oxygen demand, ammonia, nitrate, phosphate, total solids, volatile solids, total suspended
solids and volatile suspended solids. The results of the analysis indicated that there are significant differences in the
values of leachate and permeate parameters. The permeate parameters had values very much lower than those of leachate. It
reveals that the clay-waste polyethylene-clay composite liner system reduced the concentration of these parameters when the
leachate passed through the liner. The biofilm formed in waste polyethylene within the liner may have degraded most of organic
materials found in the leachate when it passed through the liner. Therefore, the clay-waste polyethylene-clay composite liner
system can be applied for full scale landfill bioreactors, particularly for Asian developing countries, due to better performance
and more environmentally friendly characteristics. 相似文献
13.
Shaun A. Watmough Julian Aherne M. Catherine Eimers Peter J. Dillon 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):301-306
In response to reduced sulphur emissions, there has been a large decrease in sulphate (; −0.97 μeq l−1 year−1) and hydrogen (−1.18 μeq l−1 year−1) ion concentration in bulk precipitation between 1980 and 2000 at Plastic Lake in central Ontario. The benefit of this large
reduction in deposition on stream water chemistry was assessed using the gauged outflow from a conifer-forested catchment (PC1; 23.3 ha),
which is influenced by a small wetland located immediately upstream of the outflow. Sulphate concentrations declined, but
not significantly due to large inter-annual variation in concentration. Between 1980 and 2000, there were significant increases in dissolved organic carbon, ammonium and potassium
concentration likely reflecting increased mineralisation in the wetland. Calcium concentrations in PC1 decreased during the
two decade period (−2.24 μeq l−1 year−1), as a consequence there was no improvement in stream pH and the Ca:Al ratio in PC1 continued to decline. A similar response
was noted in an upland-draining sub-catchment of PC1-08 that has been monitored since 1987. Despite large reductions in deposition and almost complete retention of nitrogen in soil, there has been no improvement (in terms of pH) in stream water
at PC1 due to a combination of soil acidification and climatic (droughts, increased mineralisation) perturbations. 相似文献
14.
Bohan Liao Zhaohui Guo Qingru Zeng Anne Probst Jean-Luc Probst 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):151-161
Leaching experiments of rebuilt soil columns with two simulated acid rain solutions (pH 4.6–3.8) were conducted for two natural
soils and two artificial contaminated soils from Hunan, south-central China, to study effects of acid rain on competitive
releases of soil Cd, Cu, and Zn. Distilled water was used in comparison. The results showed that the total releases were Zn>Cu>Cd
for the natural soils and Cd>Zn≫Cu for the contaminated soils, which reflected sensitivity of these metals to acid rain. Leached
with different acid rain, about 26–76% of external Cd and 11–68% external Zn were released, but more than 99% of external
Cu was adsorbed by the soils, and therefore Cu had a different sorption and desorption pattern from Cd and Zn. Metal releases
were obviously correlated with releases of TOC in the leachates, which could be described as an exponential equation. Compared
with the natural soils, acid rain not only led to changes in total metal contents, but also in metal fraction distributions
in the contaminated soils. More acidified soils had a lower sorption capacity to metals, mostly related to soil properties
such as pH, organic matter, soil particles, adsorbed SO4
2−, exchangeable Al3+ and H+, and contents of Fe2O3 and Al2O3. 相似文献
15.
Hatam Godini Abbas Rezaee Ali Khavanin Afshin Nili Ahmadabadi Sayedomid Rastegar Hooshyar Hossini 《Journal of Polymers and the Environment》2011,19(1):283-287
The objective of this study was to investigate the feasibility of using a microbial biopolymer produced by Acetobacter xylinum as a carbon source for heterotrophic biological denitrification. The denitrification rate, COD availability and nitrite concentration
were response parameters. Under the experimental conditions, a denitrification rate of about 0.74 kg NO3
−N/m3d at 6 h retention time was achieved with microbial cellulose (MC). The reactor effluent contained significantly COD concentrations
(20–86 mg/L) so it was not carbon limited, and was receiving enough carbon to facilitate the denitrification process. The
maximum nitrite concentration in the effluent was found to be 0.4 mg/L. However, decreasing the retention time to 3 h significantly
reduced the efficiency. It can be concluded that the MC is a suitable carbon source for nitrate removal in a heterotrophic
biological denitrification process. 相似文献
16.
Shin-ichi Sakai Yasuhiro Hirai Hirofumi Aizawa Shizuko Ota Yasuhiro Muroishi 《Journal of Material Cycles and Waste Management》2006,8(1):56-62
Atmospheric emissions of deca-brominated diphenyl ether (DBDE) in Japan were estimated based on the material flow of DBDE
products and their emission factors. In 2002, the demand for DBDE in Japan was 2200 ton/year and the stock level was about
60 000 ton. The DBDE flow into the waste stream was estimated to be about 6000 ton/year and the flow out through second-hand
product exports was more than 700 ton/year. Home appliance recycling facilities dismantle and crush domestic wastes containing
about 600 ton of DBDE annually. Material recycling of crushed plastics is not commonly practiced as yet. Emission factors
from plastics processing (2 × 10−9–1 × 10−7), textile processing (9 × 10−7), home appliance recycling (8 × 10−9–5 × 10−6), and waste incineration (1 × 10−7–2 × 10−6) were estimated using field measurement data. The DBDE emission rate through house dust during the service life of final
products (2 × 10−7–9 × 10−7 per year) was estimated using the DBDE concentration in dust and the amount of dust in used televisions. Emission factors
from previous studies were also used. The estimated total DBDE emission was 170–1800 kg/year. These results suggest the necessity
of characterizing emissions during the service life of products, which is essential information for formulating an appropriate
e-waste recycling strategy. 相似文献
17.
Jelena Todorovic Malin Svensson Inga Herrmann Holger Ecke 《Journal of Material Cycles and Waste Management》2006,8(2):145-153
In municipal solid waste incineration (MSWI), bottom ash, generated at a stoker grate type incinerator, the critical elements
were identified in terms of EU regulation. The stabilizing effect of moderate carbonation (pH 8.28 ± 0.03) on critical contaminants
was studied through availability and diffusion leaching protocols. Data from the performed tests were evaluated with the goal
of reusing MSWI bottom ash as secondary construction material. To investigate the mobilizing effect of CO2, suspended MSWI bottom ash was severely carbonated (pH 6.40 ± 0.07). The effect of CO2 and its interaction with other leaching factors, such as liquid/solid (L/S) ratio, leaching time, pH, ultrasound treatment,
and leaching temperature, were examined using a reduced 26-1 experimental design. Contaminants identified as critical were Cr, Cu, Mo, Sb, Cl−, and SO4
2−. Although moderate carbonation decreased the release of Cr, Cu, Mo, and Sb from compacted bottom ash, the main disadvantage
remains its inability to demobilize Cl− and SO4
2−. The hypothesized mobilizing effect of severe carbonation was proven. The treatment enhanced the separation of critical components
(α = 0.05) (except for Cl−), i.e., about fivefold for Sb and about twofold for Cr, Cu, and S. Nevertheless, the prospect is good that severe carbonation
could constitute the deciding key parameter to facilitate the technical feasibility of a future washing process for MSWI bottom
ash. 相似文献
18.
A. Matsuki Y. Iwasaka G.-Y. Shi H.-B. Chen K. Osada D. Zhang M. Kido Y. Inomata Y.-S. Kim D. Trochkine C. Nishita M. Yamada T. Nagatani M. Nagatani H. Nakata 《Water, Air, & Soil Pollution: Focus》2005,5(3-6):101-132
This study focuses on providing a direct insight into the process by which sulfate is formed on mineral dust surface in the
actual atmosphere. Six sets of aerosol measurements were conducted in the outskirts of Beijing, China, in 2002–2003 using
a tethered balloon. The mineralogy of individual dust particles, as well as its influence on the S (sulfur) loadings was investigated
by SEM-EDX analysis of the directly collected particles.
The mixed layer in the urban atmosphere was found to be quite low (500–600m), often appearing as a particle dense stagnant
layer above the surface. It is suggested that mineral dust is a common and important fraction of the coarse particles in Beijing
(35–68%), and that it is relatively enriched with Calcite (>28%).
An exceptional amount of S was detected in the mineral particles, which can be explained neither by their original composition,
nor by coagulation processes between the submicron sulfates and the dust. Heterogeneous uptake of gaseous SO2, and its subsequent oxidation on dust was suggested as the main pathway that has actually taken place in the ambient environment.
The mineral class found with the largest number of particles containing S was Calcite, followed by Dolomite, Clay, Amphibole
etc., Feldspar, and Quartz. Among them, Calcite and Dolomite showed distinctly higher efficiency in collecting sulfate than
the other types.
A positive correlation was found with the number of S containing particles and the relative humidity. Calcite in particular,
since almost all of its particles was found to contain S above 60% r.h. On the other hand, the active uptake of SO2 by the carbonates was not suggested in the free troposphere downwind, and all the mineral classes exhibited similar S content.
Relative humidity in the free troposphere was suggested as the key factor controlling the SO2 uptake among the mineral types. In terms of sulfate loadings, the relationship was not linear, but rather increased exponentially
as a function of relative humidity. The humidity-dependent uptake capacity of mineral types altogether showed an intermediate
value of 0.07 gSO4
2− g−1 mineral at 30% r.h. and 0.40 gSO4
2− g−1 mineral at 80%, which is fairly consistent with laboratory experiments. 相似文献
19.
Characterizing sorption processes is essential to understand the environmental distribution and toxicity potential of endocrine
disruptors in terrestrial and aquatic systems. The sorption behaviors of three endocrine disruptors (bisphenol A (BPA), 17β-estradiol
(E2), and 17α-ethynylestradiol (EE2)) on sediments were investigated using batch techniques. Samples were taken from some
representative reaches in several major Chinese rivers. More attention has been paid to the effect of sediment organic components
on the sorption of BPA, E2, and EE2. The results show that the sediment organic carbon-normalized partition coefficients (K
oc
(sed)) for three endocrine disruptors are in the order of EE2 > E2 > BPA, which corresponds to the octanol-water partitioning
coefficients (logK
ow) of the compounds. Moreover, the K
oc
values for humic substances (K
oc
(hs)) are comparable with the K
oc
(sed) values and highly dependent on the physico-chemical properties of humic substances in sediments. The UV absorptivity
at 272 nm (A
272), which suggests the abundance of aromatic rings in humic substance structure, correlates well with the K
oc
(hs) values. In addition, the infrared spectra of the humic substances extracted from sediments show four strong bands centered
at 3,400 cm−1, 1,625 cm−1, 1,390 cm−1, and 1,025 cm−1. The K
oc
(hs) values have a positive linear relation with the peak area ratio for peak at 1,025 cm−1 and a negative linear relation with the peak area ratio between peaks at 1,625 cm−1 and 1,025 cm−1. Hence, the hydrogen bonds play a critical role to the sorption of selected endocrine disruptors. 相似文献
20.
Ping-Ping Shen Hong Zhou Ho-Yan Lai Ji-Dong Gu 《Water, Air, & Soil Pollution: Focus》2006,6(5-6):575-581
Benthic infaunal communities at Mai Po Inner Deep Bay mudflat, Hong Kong were investigated between August 2002 and August
2003. A total of 55 species belonging to 8 Phyla from more than 99,074 specimens were recorded. The species richness varied
between 13 at Station B in August 2002 and 28 at Station D in August 2003 with an average of 21 across the mudflat and the
species diversity was low [H′(log2) = 0.7–3.5 with an average H′ = 2.4]. Seasonal variations were also observed through abundance and biomass across the mudflat among the seasons. The abundance
density was between 8,977 individuals m−2 at Station D in February 2003 and 77,256 individuals m−2 at Station B in November 2002 and the overall average density was 25,274 individuals m−2 for the four stations. The benthic infauna were dominated by pollution tolerant species at this wetland mudflat. 相似文献