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981.
Quality parameters from 17 sampling stations from Lake Koronia and 18 from Lake Volvi were determined during sampling period
of one year. Physicochemical parameters (pH, conductivity, DO) did not show remarkable differences neither between sampling
sites nor between sampling periods. Nutrient concentrations (nitrogen and phosphorus compounds) were higher in lake Koronia
than in Volvi showing relatively small temporal and spatial variations. As far as heavy metals in sediments, lake Koronia
is considerably more polluted than Volvi lake especially with the metals Fe, Mn, Zn, Pb and Cd. The mean total concentrations
of metals in lake Koronia decrease in the order Mn > Zn > Cr > Pb > Cu > Fe > Cd. The mean total concentrations of metals
in lake Volvi decrease in the order Mn > Zn > Cr > Cu > Pb > Fe $>$ Cd. 相似文献
982.
Kuroshima KN Barreiros MA Lacava LA Costódio PF 《Environmental monitoring and assessment》2007,129(1-3):179-187
Since February 1999, the Municipal Wastewater Treatment Plant (MWTP) of Balneário Camboriú, Brazil, started a complementary
treatment with ClO2 application on its effluent. It was realized to minimize its impacts caused by increase of the population during summer.
This study was realized in order to verify the influence of this compound in the water quality and the environmental evaluations.
Samples of surface water were collected in this environment between January 1997 and June 2001 for chemical and microbiological
surveys. The results had shown that after application of ClO2, fecal coliforms were decreased about six times in the beach (2.3 × 103 to 3.5 × 102 MPN/100 ml) and three times in the river (3.3 × 104 to 1.0 × 104 MPN/100 ml), during summer time. NH4
+ showed an increase of about four times and 1.5 times, respectively, to beach and river. These results are showing the influence
of ClO2 on chemical and microbiological parameters. 相似文献
983.
Groundwater overdraft is a resource management issue that poses a threat for the security of communities. Impacts of groundwater overdraft are influenced by the biophysical and social contexts of water management. This paper presents a method for assessing vulnerability to water scarcity in spatial terms using biophysical and social indicators. A geographic information system was used to establish areas of vulnerability based upon hydrologic variability in water resource availability within a groundwater basin, three types of water management systems, and 10 sociodemographic characteristics. Our study area is in the rapidly urbanizing Arizona Central Highlands, located 150 km north of the Phoenix metropolitan region, USA. Results indicate that the most biophysically vulnerable places do not necessarily intersect with the most vulnerable populations and that local differences in vulnerability are interrelated, rather than independent, outcomes in a process of socioenvironmental transformation. Vulnerability is influenced by laws that deny access to local surface waters and lead to dependence on fossil groundwater, and by economic reliance on urbanization. Localities attempt to reduce vulnerability through the development of community water systems and the expansion of water frontiers. While such strategies may reduce local vulnerability, they are not sustainable solutions because they transfer risks to other places, and thus contribute to vulnerability elsewhere. 相似文献
984.
Angeler DG Sánchez-Carrillo S Rodrigo MA Alvarez-Cobelas M Rojo C 《Environmental monitoring and assessment》2007,125(1-3):9-17
This study evaluates whether the size structure of seston (the sum of living and nonliving particles in the water column)
reflects the effects of fish on wetland water quality. Using enclosures, we measured water quality and zooplankton community
structure in the presence and absence of two fish species with distinct foraging strategies [benthivorous carp (Cyprinus
carpio) and planktivorous mosquitofish (Gambusia
holbrooki)]. Seston collected from the enclosures was counted and sized automatically with a Coulter counter, and the size structure
in the range of 1–60 μm was modelled using the underlying Pareto distribution of particles. Only Cyprinus contributed to a loss of water quality (increased nutrient levels, algal and non-algal turbidity, hypoxia), while both fish
species changed zooplankton community composition compared to fishless controls. However, these changes were not reflected
in parameters [goodness of fit (r
2) and parameter c (slopes)] of Pareto models. Multivariate statistics suggest that seston size structure responded more to environmental gradients
related to water depth but the relationships were also weak. Our overall result contrasts with the regulation of size spectra
constructed from living organisms. Although seston integrates many structural and functional features of the water column,
the lack of strong relationships between Pareto model parameters and water quality suggests that a size-based approach to
characterise seston structure has a limited potential for assessing biota-mediated effects in wetlands in a straightforward
manner. 相似文献
985.
986.
介绍高纯铜锌合金滤材的特性和先进性,以及讨论了去除水中铅、砷、汞的机理,可应用的范围,应用现状及前景。介绍高纯铜锌合金滤材的特性和先进性,以及讨论了去除水中铅、砷、汞的机理,可应用的范围,应用现状及前景。 相似文献
987.
固相微萃取-气相色谱法测定水中痕量有机氯农药 总被引:4,自引:0,他引:4
建立了固相微萃取-气相色谱联用快速测定水中14种痕量有机氯农药的方法,对比研究了浸入式直接固相微萃取与顶空固相微萃取两种方式对不同有机氯农药的富集效率,优化了试验条件.方法线性关系良好,检出限为0.1 ng/L~10 ng/L,定量下限为0.2 ng/L~40 ng/L,RSD<8%,实际水样的加标回收率为67.0%~133%. 相似文献
988.
乙酰丙酮分光光度法测定水中甲醛时影响空白值的因素 总被引:2,自引:0,他引:2
针对水质中甲醛测定时试剂水、pH值、乙酰丙酮试剂、加热温度和显色时间等影响因素进行了讨论,并提出了减小空白值的对策. 相似文献
989.
选择出11项评价因子,采用单项分指数法和平均分指数法,在涨潮、落潮、涨落潮时分别对伶仃洋东部海域水质进行监测,并与历史资料进行对比,对评价因子超标进行评价和原因分析,提出了补救与预防措施. 相似文献
990.