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1.
Throughfall and open field bulk precipitation were measured at three coniferous sites during 1995–2002 in the framework of
ICP Integrated Monitoring and at five coniferous sites during 1996–2002 in the framework of ICP Forests (Level II). The coniferous
canopies acted as a sink for nitrate and ammonium and as a source for base cations: Ca2+, Mg2+ and K+. The estimated share of SO4–S dry deposition from total deposition was 1.5–4 times higher for dormant period compared to growing period. During the study
period average annual throughfall and bulk deposition of SO4–S decreased significantly, 2.8 and 2.3 times, respectively.
Throughfall enrichment with base cations increased in the order Mg < Na < Ca < K. Using Na as a tracer ion, average dry deposition
and canopy leaching were calculated. Leaching was the dominant process for TF enrichment by potassium. Leaching of base cations
occurred during growing as well as dormant period.
The calculated internal flux of Ca2+ and Mg2+ varied in the range of 0.6–2.0 and 0.6–1.2 kg ha−1 per year in spruce and pine stands, respectively. The internal circulation of K+ was significantly higher (8.9–10.9 kg ha−1 per year) in spruce stands than in pine stands (2.7–4.4 kg ha−1 per year). 相似文献
2.
Lakhani A Parmar RS Satsangi GS Prakash S 《Environmental monitoring and assessment》2007,133(1-3):435-445
Fog water samples were collected in the months of December and January during 1998–2000 at Agra, India. The samples were analyzed
for pH, major anions (F−, Cl−, SO4
2−, NO3
−, HCOO− and CH3COO−), major cations (Ca2+, Mg2+, Na+ and K+) and NH4
+ using ion chromatography, ICP-AES and spectrophotometer methods, respectively. pH of fog water samples ranged between 7.0
and 7.6 with a volume weighted mean of 7.2, indicating its alkaline characteristic. NH4
+ contributed 40%, SO4
2− and NO3
− accounted for 28%, while Ca2+, Mg2+, Na+ and K+ accounted for 16% of the total ionic concentration. The ratios of Mg2+/Ca2+ and Na+/Ca2+ in fog water indicates that 50–75% of fog water samples correspond to the respective ratios in local soil. Significant correlation
between Ca2+, Mg2+, Na+ and K+ suggests their soil origin. The order of neutralization, NH4
+ (1.4) > Ca2+ (0.28) > Mg2+ (0.12), indicates that NH4
+ is the major neutralizing species. Fog water and atmospheric alkalinity were also computed and were found to be 873 and 903 neqm−3, respectively. Both of these values are higher than values reported from temperate sites and thus indicate that at the present
level of pollutants, there is no risk of acid fog problem. The study also shows that the alkaline nature of fog water is due
to dissolution of ammonia gas and partly due to interaction of fog water with soil derived aerosols. 相似文献
3.
Hydrogeochemical characterization of contaminated groundwater in Patancheru industrial area,southern India 总被引:1,自引:0,他引:1
The groundwater is one of the most contaminated natural resources in Patancheru industrial area due to unplanned and haphazard
industrial growth and urbanization without following basic pollution control norms. The rapid industrialization initiated
in early 1970 has started showing up its after effects few years later in the form of physiochemical contamination of the
both surface and groundwater bodies of the area. It has resulted in local people being deprived of safe drinking water, plant
and aquatic life has severely affected, and situation is deteriorating over the years in the area in spite of some preventive
and remedial measures being initiated. The focus of the present study is to understand the chemical characteristics of groundwater
and geochemical processes the contaminant water is undergoing which are normally imprinted in its ionic assemblages. The water
samples collected in pre- and post-monsoon seasons from forty two groundwater and four surface water sources were analyzed
for major constituents such as Ca2+, Mg2+, Na+, K+, CO3−, HCO3−, Cl−, SO42−, NO3−, and F−, and selected samples were tested for ten important trace metals like Fe, Pb, Bi, Mn, Cr, Co, Ni, Cu, Zn, and Cd. Na+ among cations and Cl− among anions dominate the water in both the seasons where as Ca2+, HCO3−, and Cl− show significant reduction in their ionic strength in post-monsoon. The groundwater in general is of mixed type, but most
of it belong to Na+–Cl−, Na+–HCO3−, Ca2+–Mg2+–HCO3−, and Ca2+–Mg2+–Cl− facies. The Na+ and Ca2+ are in the transitional state with Na+ replacing Ca2+ and HCO3−–Cl− due to physiochemical changes in the aquifer system. The evaluation of hydrochemistry through various ionic indices, ratios,
and plots suggest that silicate–carbonate weathering, ion exchange, dissolution, and evaporation processes are responsible
for origin of the present chemical status of the groundwater which is also controlled by the contamination from extraneous
sources that could have accelerated the dissolution processes. Gibbs plots authenticate that the evolution of water chemistry
is influenced by interaction of percolating water with aquifer matrix apart from anthropogenic enrichment of elements which
get over concentrated due to evaporation. 相似文献
4.
Aerosol samples for dry deposition and total suspend particulates (TSP) were collected from August to November of 2003 in central Taiwan. Ion chromatography was used to analyze the related water-soluble ionic species (Cl−, NO3
−, SO4
2−, Na+, NH4
+, K+, Mg2+ and Ca2+). The results obtained in this study indicated that the ambient air particulate mass concentrations in the daytime period (averaged 975.4 μg m−3) were higher than the nighttime period (averaged 542.1 μg m−3). And the daytime dry deposition fluxes (averaged 58.12 μg m−2 sec−1) were about 2.2 times as that of nighttime dry deposition fluxes (averaged 26.54 μg m−2 sec−1) of the downward dry deposition. The average values downward and upward of dry deposition fluxes for the weekend period were almost higher than the weekday period for either daytime or nighttime period. Furthermore, the average daytime dry deposition fluxes (averaged 26.37 μg m−2 sec−1) were also about 2.3 times as that of nighttime dry deposition fluxes (averaged 11.52 μg m−2 sec−1). Moreover, the results also indicate that SO4
2− and Ca2+ have higher average composition for total suspended particulates in the daytime period while Ca2+, SO4
2−, and Na+ have the higher average composition for total suspends particulates in the nighttime period. 相似文献
5.
Reduction of dissolved organic matter in terms of DOC, UV-254, SUVA and THMFP in industrial estate wastewater treated by stabilization ponds 总被引:1,自引:0,他引:1
The aim of this research was to monitor the influent and effluent water quality of the aeration, facultative and oxidation
water treatment ponds of an industrial estate. This industrial estate, the largest in northern Thailand, has proposed to utilization
of reclaimed treated wastewater in their raw water supply so as to cope with the yearly water shortage during the dry season.
Water samples were collected four times from four sampling points and evaluated for their dissolved organic matter (DOM) content
in terms of dissolved organic carbon (DOC), ultraviolet light absorbance at 254 nm (UV-254), specific ultraviolet absorption
(SUVA), trihalomethane formation potential (THMFP) and trihalomethane (THM) species. Average values of DOC, UV-254, SUVA and
THMFP in the influent wastewater of 12.9 mg L−1, 0.165 cm−1, 1.29 L mg−1m−1 and 1.24 mg L−1, respectively, were observed. The aeration ponds produced the best results: a 54% reduction of DOC, a 33% reduction of UV-254,
and a 57% reduction of THMFP. However, SUVA in the aeration pond effluent showed a moderate increase. The facultative ponds
and oxidation ponds did not take part in the reduction of DOC, UV-254, SUVA and THMFP. Average DOC, UV-254, SUVA and THMFP
value of the treated wastewater were 5.8 mg L−1, 0.107 cm−1, 1.85 L mg−1m−1 and 468 μg L−1, respectively. Chloroform, at 72.6% of total THMFP, was found to be the predominant THM species. 相似文献
6.
Al-Momani IF Momani KA Jaradat QM Massadeh AM Yousef YA Alomary AA 《Environmental monitoring and assessment》2008,136(1-3):209-218
Wet and dry deposition samples were collected in the capital of Jordan, Amman. Concentrations of Al, Ba, Bi, Cd, Co, Cr, Cu,
Mn, Mo, Ni, Pb, Sb, V, Zn, Fe, Sr, Mg2+, Ca2+, Na+, K+, Cl−, NO3
− and SO4
2−, along with pH were determined in collected samples. Mean trace metal concentrations were similar or less than those reported
for other urban regions worldwide, while concentrations of Ca2+ and SO4
2− were among the highest. High Ca2+ concentrations were attributed to the calcareous nature of the local soil and to the influence of the Saharan dust. However,
high SO4
2− concentrations were attributed to the influence of both anthropogenic and natural sources. Except for Cl−, NO3
−, SO4
2− and Cu, monthly dry deposition fluxes of all measured species were higher than wet deposition fluxes. The annual wet deposition
fluxes of trace metals were much lower than those reported for other urban areas worldwide. 相似文献
7.
This study monitored atmospheric pollutants during high wind speed (> 7 m s−1) at two sampling sites: Taichung Harbor (TH) and Wuci traffic (WT) during March 2004 to January 2005 in central Taiwan. The
correlation coefficient (R
2) between TSP, PM2.5, PM2.5−10 particle concentration vs. wind speed at the TH and WT sampling site during high wind speed (< 7 m s−1) were also displayed in this study. In addition, the correlation coefficients between TSP, PM2.5 and PM2.5−10 of ionic species vs. high wind speed were also observed. The results indicated that the correlation coefficient order was
TSP > PM2.5−10 > PM2.5 for particle at both sampling sites near Taiwan strait. In addition, the concentration of Cl−, NO3
−, SO4
2−, NH4
+, Mg2+, Ca2+ and Na+ were also analyzed in this study. 相似文献
8.
Thöni L Seitler E Meier M Zürcher F Hertz J 《Environmental monitoring and assessment》2008,138(1-3):207-218
This study presents the results of the analyses of Cd, Pb, cations and anions present in precipitation and dust at a pre-alpine
and a suburban site in Switzerland in the period from 1988 to 2003. The aim of these measurements was to monitor the success
of measures taken to diminish pollutant emissions. No change was found for Ca2+, K+, Na+ and Mg2+ loads – in line with expectations, as no reducing measures had been taken. Statistically significant and largely decreasing
values (50–90%) were found for Cl− and Cd (linked to the fitting of filters in incineration plants), Pb (unleaded petrol), (diminishing the use of mineral oil with high S content), and the proton (lower HCl and SO2 emissions). A smaller decrease (up to 30%) or none was registered for oxidised nitrogen components (fitting cars with catalytic
converters, but an increase in numbers of cars and trucks). No significant change was found for NH3 as farming techniques had undergone no major changes. The long-term measurements show that the measures taken to reduce emissions
were successful. A shorter monitoring period would have been misleading owing to data variability and temporary incidents
e.g. amount of precipitation. 相似文献
9.
Vasanthavigar M Srinivasamoorthy K Prasanna MV 《Environmental monitoring and assessment》2012,184(1):405-420
The Thirumanimuttar sub-basin forms an important groundwater province in south India, facing serious deficiency in both quality
and quantity of groundwater due to increased demand associated with rapid population explosion, agricultural growth and industrial
activities. A total of 194 groundwater samples were collected and 15 water quality parameters were analyzed using standard
procedures. Na + , Cl − , Ca2 + , HCO3-_{3}^{-}, Mg2 + and SO42-_{4}^{2-} concentration ions are more dominant in both seasons. The total dissolved solids and electrical conductivity was observed
good correlation with Na + , Cl − , HCO3-_{3}^{-}, Ca2 + , Mg2 + , Cl − , PO43-_{4}^{3-} and NO3- _{3}^{- } ions indicating dominance of plagioclase feldspar weathering, anthropogenic input and over drafting of groundwater irrespective
of seasons. The Hill–Piper diagram indicates alkaline earths exceed the alkalis, an increase of weak acids was noted during
both the seasons. For assessing the groundwater for irrigation suitability parameters like total hardness, sodium adsorption
ratio, residual sodium carbonate (RSC), permeability index, and sodium percentage are also calculated. Permanent hardness
was noted in higher during both the seasons due to discharge of untreated effluents and ion exchange process. The RSC indicates
56% of the samples are not suitable for irrigation purposes in both seasons, if continuously used will affect the crop yield.
From the results, nearly 72% of the samples are not suitable for irrigation. 相似文献
10.
Demirak A Balci A Karaoğlu H Tosmur B 《Environmental monitoring and assessment》2006,123(1-3):271-283
In this study, chemical composition of the rain water in Mugla was investigated from February to April 2002. Rain water samples were obtained from Mugla, a small city in south western Turkey. The Yatagan Power Plant is located 30 km northwest of Mugla city. The values of pH and the concentrations of major ions (Ca2+, Na+, K+, SO4
2−, NO3
−, NH4
+) in the rainwater samples were analyzed. The pH varied from 4.5 to 7.7 with an average of 6.9 which was in alkaline range considering 5.6 as the neutral pH of cloud water with atmospheric CO2 equilibrium. In the total 30 rain events, only two events were observed in acidic range (< 5.6) which occurred after continuous rains. The equivalent concentration of components followed the order: Ca2+ > SO4
2− > NH4
+ > NO3
− > Na+ > K+ > H+. The volume-weighted mean (VWM) of the measured ionic sum is 371.62 μeq/l. The ratio of between sum cations and sum anions (∑cations /∑ anions) is 1.52 μeq/l. The alkaline components (Ca2+, Na+, K+) contribute 52%, NH4
+ 8%, whereas, the contribution from the acidic components is relatively small (40%). The low concentrations of H+ found in rainwater samples from Mugla suggest that an important portion of H2SO4 and HNO3 have been neutralized by alkaline particles in the atmosphere. The dust-rich local and surrounding limestone environment might have caused the high concentration of Ca2+ in Mugla area. The relatively high concentration of NH4
+ observed at Mugla is suspected to be due to surrounding agricultural. The results obtained in this study are compared with those other studies conducted at various places in the world. 相似文献
11.
Factors controlling the salinity in groundwater in parts of Guntur district, Andhra Pradesh, India 总被引:1,自引:0,他引:1
Subba Rao N 《Environmental monitoring and assessment》2008,138(1-3):327-341
Groundwater chemistry has been studied to examine the associated hydrogeochemical processes operating for the development
of salinity in the groundwater in parts of Guntur district, Andhra Pradesh, India. The study area is underlain by charnockites
and granitic gneisses associated with schists of the Precambrian Eastern Ghats. Groundwater is the main resource for irrigation
besides drinking. Chemical parameters, pH, EC, TDS, Ca2+, Mg2+, Na+, K+, , , Cl−, , , F− and SiO2, are taken into account. Groundwater is of brackish type. Na+−Cl− facies dominates the groundwater. Examination of compositional relations and mineral saturation states shows that the ion
exchange of Ca2+ for adsorbed Na+, evapotranspiration, dissolution of soil salts, dissolution of NaCl and CaSO4, and precipitation of CaCO3 are the dominant hydrogeochemical processes associated with the groundwater composition in the area. Evapotranspiration causes
accumulation of salts in the soil/weathered zone. These salts reach the water table by leaching through infiltrating recharge
water. A positive relation between depth to water table and TDS with season supports this inference. The effects of human
activities, such as intensive and long-term irrigation, irrigation-return-flow, application of unlimited agricultural fertilizers
and recycling of saline groundwater, act to further increase the salinity in the groundwater. Therefore, the groundwater quality
increases towards the flow path, while the post-monsoon groundwater shows higher concentrations of TDS, Na+, Mg2+, Cl−, , , F− and SiO2 ions. The study could help to understand the hydrogeochemical characteristics of the aquifer system for taking effective
management measures to mitigate the inferior groundwater quality for sustainable development. 相似文献
12.
Evrendilek F Berberoglu S Taskinsu-Meydan S Yilmaz E 《Environmental monitoring and assessment》2006,119(1-3):527-543
Abstact Aboveground biomass, aboveground litterfall, and leaf litter decomposition of five indigenous tree stands (pure stands ofPinus brutia,Pinus nigra,Cedrus libani,Juniperus excelsa, and a mixed stand ofAbies cilicica,P. nigra, andC. libani) were measured in an eastern Mediterranean evergreen needleleaf forest of Turkey. Measurements were converted to regional scale estimates of carbon (C) stocks and fluxes of forest ecosystems, based on general non-site-specific allometric relationships. Mean C stock of the conifer forests was estimated as 97.8± 79 Mg C ha−1consisting of 83.0 ± 67 Mg C ha−1in the aboveground and 14.8 ± 12 Mg C ha−1in the belowground biomass. The forest stands had mean soil organic carbon (SOC) and nitrogen (SON) stocks of 172.0 ± 25.7 Mg C ha−1and 9.2 ± 1.2 Mg N ha−1, respectively. Mean total monthly litterfall was 376.2± 191.3 kg C ha−1, ranging from 641 ± 385 kg C ha−1forPinus brutiato 286 ± 82 kg C ha−1forCedrus libani. Decomposition rate constants (k) for pine needles were 0.0016 forCedrus libani, 0.0009 forPinus nigra, 0.0006 for the mixed stand, and 0.0005 day−1forPinus brutiaand
Juniperus excelsa. Estimation of components of the C budgets revealed that the forest ecosystems were net C sinks, with a mean sequestration rate of 2.0 ± 1.1 Mg C ha−1 yr−1ranging from 3.2 ± 2 Mg C ha−1forPinus brutiato 1.6 ± 0.6 Mg C ha−1forCedrus libani. Mean net ecosystem productivity (NEP) resulted in sequestration of 98.4 ± 54.1 Gg CO2 yr−1from the atmosphere when extrapolated for the entire study area of 134.2 km2(Gg = 109 g). The quantitative C data from the study revealed the significance of the conifer Mediterranean forests as C sinks 相似文献
13.
The hydrochemical characterization of groundwater is important to bring out its nature and usefulness. The main objective
of this paper was to discuss the major ion chemistry of groundwater in the Mambakkam mini watershed. Besides its semi-arid
nature, rapid socioeconomic development encourages a greater demand for water, which leads to uncontrolled groundwater development.
The groundwater of the study area is characterized by the dominance of alkaline earth (Ca2+, Mg2+) and strong acids (Cl−, SO4−) over alkalies (Na+, K+) and weak acids (HCO3−, CO3−) during both post-monsoon and pre-monsoon seasons of the year 2010, based on the hydrochemical facies. These have been probably
derived from natural chemical weathering of rock minerals, ion exchange and anthropogenic activities of the fertilizer source.
The classification based on the total hardness reveals that a majority of groundwater samples fall in the hard to very hard
category during the pre-monsoon season. Based on the values of EC, SAR and RSC and the diagrams of USSL and Wilcox, most of
the groundwater samples range from excellent to permissible for irrigation purposes, with a low alkalinity and high salinity
hazard, except for a few samples in the study area. 相似文献
14.
H. Plaisance S. Sauvage P. Coddeville R. Guillermo 《Environmental monitoring and assessment》1998,51(3):657-671
The variability in performance of three precipitation sensor types, mounted on three identical wet-only collectors, has been compared for eight months at a single site. The catch efficiencies, determined from the sample volumes, are relatively high for these three apparatuses, since they exceed 89% on average. The recorded data of openings and closings of collector lids reveal that the highest losses of collection efficiency, observed for rainfalls of low intensity and low amount, are largely imputable to design and running characteristics of each sensor. Ionic compositions between the samples of these three collectors are relatively close, although significant differences are especially found for H+, Ca2+, Mg2+ and K+, suggesting that these apparatuses are differently exposed to the dry deposition of soil particles. The RS 85 sensor seems to be the most suitable one of the three, since it ensures a high catch efficiency for all rain types and tends to limit the exposures of funnel to the dry deposition. 相似文献
15.
Atmospheric aerosol particles and metallic concentrations, ionic species were monitored at the Experimental harbor of Taichung
sampling site in this study. This work attempted to characterize metallic elements and ionic species associated with meteorological
conditions variation on atmospheric particulate matter in TSP, PM2.5, PM2.5–10. The concentration distribution trend between TSP, PM2.5, PM2.5–10 particle concentration at the TH (Taichung harbor) sampling site were also displayed in this study. Besides, the meteorological
conditions variation of metallic elements (Fe, Mg, Cr, Cu, Zn, Mn and Pb) and ions species (Cl−, NO3
−, SO4
2−, NH4
+, Mg2+, Ca2+ and Na+) concentrations attached with those particulate were also analyzed in this study. On non-parametric (Spearman) correlation
analysis, the results indicated that the meteorological conditions have high correlation at largest particulate concentrations
for TSP at TH sampling site in this study. In addition, the temperature and relative humidity of meteorological conditions
that played a key role to affect particulate matter (PM) and have higher correlations then other meteorological conditions
such as wind speed and atmospheric pressure. The parameter temperature and relative humidity also have high correlations with
atmospheric pollutants compared with those of the other meteorological variables (wind speed, atmospheric pressure and prevalent
wind direction). In addition, relative statistical equations between pollutants and meteorological variables were also characterized
in this study. 相似文献
16.
Johnson KB Haines TA Kahl JS Norton SA Amirbahman A Sheehan KD 《Environmental monitoring and assessment》2007,126(1-3):55-67
Throughfall and bulk precipitation samples were collected for two watersheds at Acadia National Park, Maine, from 3 May to
16 November 2000, to determine which landscape factors affected mercury (Hg) deposition. One of these watersheds, Cadillac
Brook, burned in 1947, providing a natural experimental design to study the effects of forest type on deposition to forested
watersheds. Sites that face southwest received the highest Hg deposition, which may be due to the interception of cross-continental
movement of contaminated air masses. Sites covered with softwood vegetation also received higher Hg deposition than other
vegetation types because of the higher scavenging efficiency of the canopy structure. Methyl mercury (MeHg) deposition was
not affected by these factors. Hg deposition, as bulk precipitation and throughfall was lower in Cadillac Brook watershed
(burned) than in Hadlock Brook watershed (unburned) because of vegetation type and watershed aspect. Hg and MeHg inputs were
weighted by season and vegetation type because these two factors had the most influence on deposition. Hg volatilization was
not determined. The total Hg deposition via throughfall and bulk precipitation was 9.4 μg/m2/year in Cadillac Brook watershed and 10.2 μg/m2/year in Hadlock Brook watershed. The total MeHg deposition via throughfall and bulk precipitation was 0.05 μg/m2/year in Cadillac Brook watershed and 0.10 μg/m2/year in Hadlock Brook watershed. 相似文献
17.
Response of non-point source pollutant loads to climate change in the Shitoukoumen reservoir catchment 总被引:3,自引:0,他引:3
The impacts of climate change on streamflow and non-point source pollutant loads in the Shitoukoumen reservoir catchment are
predicted by combining a general circulation model (HadCM3) with the Soil and Water Assessment Tool (SWAT) hydrological model.
A statistical downscaling model was used to generate future local scenarios of meteorological variables such as temperature
and precipitation. Then, the downscaled meteorological variables were used as input to the SWAT hydrological model calibrated
and validated with observations, and the corresponding changes of future streamflow and non-point source pollutant loads in
Shitoukoumen reservoir catchment were simulated and analyzed. Results show that daily temperature increases in three future
periods (2010–2039, 2040–2069, and 2070–2099) relative to a baseline of 1961–1990, and the rate of increase is 0.63°C per
decade. Annual precipitation also shows an apparent increase of 11 mm per decade. The calibration and validation results showed
that the SWAT model was able to simulate well the streamflow and non-point source pollutant loads, with a coefficient of determination
of 0.7 and a Nash–Sutcliffe efficiency of about 0.7 for both the calibration and validation periods. The future climate change
has a significant impact on streamflow and non-point source pollutant loads. The annual streamflow shows a fluctuating upward
trend from 2010 to 2099, with an increase rate of 1.1 m3 s−1 per decade, and a significant upward trend in summer, with an increase rate of 1.32 m3 s−1 per decade. The increase in summer contributes the most to the increase of annual load compared with other seasons. The annual
NH4+-N load into Shitoukoumen reservoir shows a significant downward trend with a decrease rate of 40.6 t per decade. The annual
TP load shows an insignificant increasing trend, and its change rate is 3.77 t per decade. The results of this analysis provide
a scientific basis for effective support of decision makers and strategies of adaptation to climate change. 相似文献
18.
An experiment was conducted under laboratory conditions to investigate the effect of two systemic herbicides viz., pendimethalin
and quizalofop, at their recommended field rates (1.0 kg and 50 g active ingredient ha − 1, respectively) on the growth and activities of non-symbiotic N2-fixing bacteria in relation to mineralization and availability of nitrogen in a Typic Haplustept soil. Both the herbicides, either singly or in a combination, stimulated the growth and activities of N2-fixing bacteria resulting in higher mineralization and availability of nitrogen in soil. The single application of quizalofop
increased the proliferation of aerobic non-symbiotic N2-fixing bacteria to the highest extent while that of pendimethalin exerted maximum stimulation to their N2-fixing capacity in soil. Both the herbicides, either alone or in a combination, did not have any significant difference in
the stimulation of total nitrogen content and availability of exchangeable NH4
+ while the solubility of NO3
− was highly manifested when the herbicides were applied separately in soil. 相似文献
19.
The fertigation effect of distillery effluents concentrations such as 5%, 10%, 25%, 50%, 75% and 100% were studied on Trigonella foenu-graecu (Pusa early bunching) along with control (bore well water). On irrigation of soil with different effluents up to 90 days
of harvesting, it was observed that there was a significant effect on moisture content (P < 0.001), EC, pH, Cl − , total organic carbon (TOC), HCO3-_{3}^{-}, CO3-2_{3}^{-2}, Na + , K + , Ca2 + , Mg2 + , Fe2 + , TKN, NO32-_{3}^{2-}, PO43-_{4}^{3-}, and SO42-_{4}^{2-} (P < 0.0001) and insignificant effect on WHC and bulk density (P > 0.05).There was no significant change in the soil texture
of the soil. Among various concentrations of effluent irrigation, the irrigation with 100% effluent concentration decreased
pH (16.66%) and increased moisture content (30.82%), EC(84.13%), Cl − (292.37%), TOC (4311.61%), HCO3-_{3}^{-} (27.76%), CO3-2_{3}^{-2} (32.63%), Na + (273%), K + (31.59%), Ca2 + (729.76%), Mg2 + (740.47%), TKN (1723.32%), NO32-_{3}^{2-} (98.02%), PO43-_{4}^{3-} (337.79%), and SO42-_{4}^{2-} (77.78%), Fe2 + (359.91%), Zn (980.48%), Cu (451.51%), Cd (3033.33%), Pb (2350.00%), and Cr (2375.00%) in the soil. The agronomical parameters
such as shoot length, root length, number of leaves, flowers, pods, dry weight, chlorophyll content, LAI, crop yield, and
HI of T. foenum-graecum were recorded to be in increasing order at low concentration of the effluent, i.e., from 5% to 50% and in decreasing order
at higher effluent concentration, i.e., from 75% to 100% as compared to control. The enrichment factor of various heavy metals
was ordered for soil Cd>Cr> Pb>Zn>Cu>Fe and for T. foenum-graecum plants Pb>Cr>Cd>Cu>Zn>Fe after irrigation with distillery effluent. 相似文献
20.
Raja S Ravikrishna R Kommalapati RR Valsaraj KT 《Environmental monitoring and assessment》2005,110(1-3):99-120
Seventeen fog events were sampled in Baton Rouge, Louisiana during 2002–2004 as part of characterizing wet deposition by fogwater
in the heavily industrialized corridor along the Louisiana Gulf Coast in the United States. These samples were analyzed for
chemical characteristics such as pH, conductivity, total organic and inorganic carbon, total metals and the principal ion
concentrations. The dominant ionic species in all samples were NH4+, NO3−, Cl− and SO42−. The pH of the fogwater sampled had a mean value of 6.7 with two cases of acidic pH of 4.7. Rainwater and fogwater pH were
similar in this region. The acidity of fogwater was a result of NO3− but partly offset by high NH4+. The measured gaseous SO2 accounted for a small percentage of the observed sulfate concentration, indicating additional gas-to-particle conversion
of SO2 to sulfate in fogwater. The gaseous NOx accounted for most of the dissolved nitrate and nitrite concentration in fogwater. The high chloride concentration was attributable
to the degradation of chlorinated organics in the atmosphere. The metal composition was traced directly to soil-derived aerosol
precursors in the air. The major metals observed in fogwater were Na, K, Ca, Fe, Al, Mg and Zn. Of these Na, K, Ca and Mg
were predominant with mean concentrations > 100 μM. Al, Fe and Zn were present in the samples, at mean concentrations < 100
μM. Small concentrations of Mn (7.8 μM), Cu (2 μM), Pb (0.07 μM) and As (0.32 μM) were also observed in the fogwaters, and
these were shown to result from particulates (PM2.5) in the atmosphere. The contribution to both ions and metals from the marine sources in the Louisiana Gulf Coast was minimal.
The concentrations of all principal ionic species and metals in fogwater were 1–2 orders of magnitude larger than in rainwater.
Several linear alkane organic compounds were observed in the fogwater, representing the contributions from petroleum products
at concentrations far exceeding their aqueous solubility. A pesticide (atrazine) was also observed in fogwater, representing
the contribution from the agricultural activities nearby. 相似文献