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601.
Adomako D Nyarko BJ Dampare SB Serfor-Armah Y Osae S Fianko JR Akaho EH 《Environmental monitoring and assessment》2008,141(1-3):165-175
Waters and sediments of Subin River, which flows through the industrial and commercial areas of Kumasi in the Ashanti region
of Ghana, were geochemically investigated to ascertain heavy metal pollution levels due to anthropogenic activities. The study
shows preoccupying pollution levels that constitute a threat to public and ecological systems. The waters of Subin River are
neutral to slightly basic, inferred from pH values of 6.89–7.65). Electric conductivity (EC) of the waters ranges from 822
to 1,821 μs/cm and the range of total dissolved solids (TDS) is from 409 to 913 mg/l. Toxic elements contents of sediments
and waters from 10 sites along the river were analysed by instrumental neutron activation analysis (INAA), and Al, As, Cd,
Cr, Cu and Zn were determined. The concentrations of Al, As, Cd, Cr, Cu and Zn in the waters range between 4.02–15.18, 0.007–0.16,
0.002–0.05, 0.001–0.019, 1.32–7.04 and 4.28–10.2 mg/l, respectively. The contamination factors (CF) computed for the elements
indicate that with the exception of sampling site S10, the sediments are polluted with Cd. Chromium contamination in the sediments
is observed at S6 and S7, where the CF values were 1.39 and 1.52, respectively. The pollution load indices (PLI) were low
(<1) and ranged from 0.14 to 0.75, suggesting that the overall sediment column of the river is not polluted. 相似文献
602.
Wet weather impact on trihalomethane formation potential in tributaries to drinking water reservoirs
During rain storm events, land surface runoff and resuspension of bottom sediments cause an increase in Trihalomethane (THM)
precursors in rivers. These precursors, when chlorinated at water treatment facilities will lead to the formation of THMs
and hence impact drinking water resources. In order to evaluate the wet weather impact on the potential formation of THMs,
river samples were collected before, during and after three rain storms ranging from 15.2 to 24.9 mm precipitation. The samples
were tested for THM formation potential and other indicators including UV254 absorbance, turbidity and volatile suspended
solid (VSS). Average levels of THMs increased from 61 μg/l during dry weather to 131 μg/l during wet weather, and then went
back to 81 μg/l after rain ended. Wet weather values of THM are well above the maximum contaminant level (MCL) 80 μg/l, set
by EPA for drinking water. THM indicators also exhibited similar trends. Average levels increased from 0.6 to 1.8 abs; 2.6
to 6 ntu; and 7.5 to 15 mg/l respectively for UV254, turbidity and VSS. A positive correlation was observed between THM formation
and THM indicators. The t-test of significance (p-value) was less than 0.05 for all indicators, and R values ranged from 0.85 to 0.92 between THMs and the indicators, and 0.72 to 0.9 among indicators themselves. 相似文献
603.
The long-term water quality monitoring program implemented by the Massachusetts Water Resources Authority in 1992 is extensive
and has provide substantial understanding of the seasonality of the waters in both Boston Harbor and Massachusetts Bay and
the response to improvements in effluent quality and offshore transfer of the effluent in September 2000. The monitoring program
was designed with limited knowledge of spatial and temporal variability and long-term trends within the system. This led to
an extensive spatial and temporal sampling program. The data through 2003 showed high correlation within physical parameters
measured (e.g., salinity, dissolved oxygen) and in biological measures such as chlorophyll fluorescence. To address the potential
sampling redundancies in the measurement program, an assessment of the impact of reduced levels of monitoring on the ability
to make water quality decisions was completed. The optimization was conducted by applying statistical models that took into
account whether there was evidence of a seasonal pattern in the data. The optimization used model survey average readings
to identify temporal fixed effects, model survey-average-corrected individual station readings to identify spatial fixed effects,
corrected the individual station readings for temporal and spatial fixed effects and derived a correlation model for the corrected
data, and applied the correlation model to characterize the correlation of annual average readings from reduced monitoring
programs with true parameter levels. Reductions in the number of sampling stations were found less detrimental to the quality
of the data for annual decision-making than reductions in the number of surveys per year, although there is less of a difference
in this regard for dissolved oxygen than there is for chlorophyll. The analysis led to recommendations for a substantially
lower monitoring effort with minimal loss of information. The recommendation supported an annual budget savings of approximately
$183,000. Most of the savings was from fewer surveys as approximately $21,000 came from the reduction in the number of stations
monitored from 21 to 7 and associated laboratory analytical costs. 相似文献
604.
Majagi SH Vijaykumar K Vasanthkaumar B 《Environmental monitoring and assessment》2008,138(1-3):273-279
In this study, some heavy metals concentrations (Zn, Pb, Fe, Mn, Cu, Ni) and other physico-chemical parameters were studied
during October 2001 to September 2003 in Karanja reservoir, Bidar district. Water quality parameters were collected monthly
basis whereas heavy metals were analyzed by Atomic Adsorption Spectrometer (AAS). Heavy metals have shown within the permissible
limits, except Fe and Ni were recorded higher values in southwest monsoon, where as Mn has showed higher concentration in
northeast monsoon in and summer. All other physico-chemical parameters are with in the permissible limit. Water is moderately
hard and reservoir is productive. 相似文献
605.
May TW Fairchild JF Petty JD Walther MJ Lucero J Delvaux M Manring J Armbruster M 《Environmental monitoring and assessment》2008,137(1-3):213-232
The Solomon River Basin is located in north-central Kansas in an area underlain by marine geologic shales. Selenium is an
indigenous constituent of these shales and is readily leached into the surrounding groundwater. Portions of the Basin are
irrigated primarily through the pumping of selenium-contaminated groundwater from wells onto fields in agricultural production.
Water, sediment, macroinvertebrates, and fish were collected from various sites in the Basin in 1998 and analyzed for selenium.
Selenium concentrations were analyzed spatially and temporally and compared to reported selenium toxic effect thresholds for
specific ecosystem components: water, sediments, food-chain organisms, and wholebody fish. A selenium aquatic hazard assessment
for the Basin was determined based on protocol established by Lemly. Throughout the Basin, water, macroinvertebrate, and whole
fish samples exceeded levels suspected of causing reproductive impairment in fish. Population structures of several fish species
implied that successful reproduction was occurring; however, the influence of immigration of fish from low-selenium habitats
could not be discounted. Site-specific fish reproduction studies are needed to determine the true impact of selenium on fishery
resources in the Basin.
The U.S. Government’s right to retain a non-exclusive, royalty free license in and to any copyright is acknowledged. 相似文献
606.
Transportation system has contributed significantly to the development of human civilization; on the other hand it has an
enormous impact on the ambient air quality in several ways. In this paper the air and noise pollution at selected sites along
three sections of National Highway was monitored. Pakistan National Highway Authority has started a Highway Improvement
program for rehabilitations and maintenance of National highways to improve the traffic flows, and would ultimately improve
the air quality along highways. The ambient air quality and noise level was monitored at nine different locations along these
sections of highways to quantify the air pollution. The duration of monitoring at individual location was 72 h. The most of
the sampling points were near the urban or village population, schools or hospitals, in order to quantify the air pollution
at most affected locations along these roads. A database consisting of information regarding the source of emission, local
metrology and air quality may be created to assess the profile of air quality in the area. 相似文献
607.
环境质量评价的生物方法研究 总被引:1,自引:0,他引:1
环境质量的生物评价是以生物对环境污染的表现为基础的.环境质量评价的生物方法包括环境指示生物的选择,环境质量生物评价指标的确定和环境质量分类等3个步骤.论述了环境污染的生物表现,提出了选择环境指示生物的原则,给出了环境质量生物评价的3类指标,建立了环境质量4级分类体系. 相似文献
608.
大体积进样-气相色谱法测定水中多种痕量有机磷农药 总被引:1,自引:0,他引:1
建立了大体积进样气相色谱-火焰光度法检测水中多种痕量有机磷农药的方法.重点研究了程序升温汽化(PTV)进样条件的选择,通过对分流排空量、吹扫时间、PIV起始温度等PTV参数的选择,优化了测试条件,提高了检测灵敏度.水中9种有机磷农药的线性良好,10ml水样中三乙基偶磷硫酯的检出限为0.01μg/L,硫磷嗪、致螟磷、甲拌磷、乐果、乙拌磷、甲基对硫磷、对硫磷和氨磺磷的检出限可达0.001μg/L.水中添加多种有机磷农药准确度精密度试验,平均回收率为85.8%~108%,相对标准差在3.3%~11.4%之间.与常规方法相比,该方法前处理简单快速、分析成本低.灵敏度、准确度和精密度均符合地表水检测质量的要求,适用于水环境中多种农药残留的快速检测. 相似文献
609.
610.
Effective water resources management programs have always incorporated detailed analyses of hydrological and water quality
processes in the upland watershed and downstream waterbody. We have integrated two powerful hydrological and water quality
models (SWAT and CE-QUAL-W2) to simulate the combined processes of water quantity and quality both in the upland watershed
and downstream waterbody. Whereas the SWAT model outputs water quality variables in its entirety, the CE-QUAL-W2 model requires
inputs in various pools of organic matter contents. An intermediate program was developed to extract outputs from SWAT at
required subbasin and reach outlets and converts them into acceptable CE-QUAL-W2 inputs. The CE-QUAL-W2 model was later calibrated
for various hydrodynamic and water quality simulations in the Cedar Creek Reservoir, TX, USA. The results indicate that the
two models are compatible and can be used to assess and manage water resources in complex watersheds comprised of upland watershed
and downstream waterbodies. 相似文献