جستجوی مقالات مرتبط با کلیدواژه "water quality index" در نشریات گروه "شیلات"

This study was conducted to understand the health status of Karaj River ecosystem as one of the most important rivers in Iran, the physicochemical parameters, toxicity and saprobic indices were analyzed due to sampling from 12 stations in 2021. Identification of benthic organisms and calculation of biological value was performed. Qualitative status, toxicity analysis, measurement of PAHs along with statistical analysis were performed as well. According to the results, the general water quality index decreased in downstream except for the branches. Toxicity had fluctuating and generally decreased from upstream to downstream. The biological value index had the highest rate in Chamran Park and the lowest recorded in Haft Cheshmeh branch. In terms of saprobic index, the river categorized in Oligosaprob, β-mesosaprob and α-amesosaprob classes. Upstream stations had favorable status compared to downstream in both cold and warm seasons. Karaj basin subdivision maps were prepared based on the Munich method, IRWQIsc index and the combination of saprobi map, BOD and land use in the region. The results of the analysis confirmed the important role of human activities in river water quality, especially in rural and garden uses, and in the next stage, roads. From upstream to downstream, the number of pollutant sources has increased and their roles were evident. Development of rural areas negatively increased BOD and benthic index. Therefore, it is necessary to monitor and treat wastewater, to issue the environmental standards for agriculture activities and groundwater uses, as well as deal with violators with the aim of conserving the river.

Water quality index is a tool that integrates data of effective factors on water quality. The final result of the index provides simple understanding of water quality for general people. Regarding the importance and application of water quality index in decision making of active and executive units in conservation and exploitation, the present study was conducted for the first time in the southern of Caspian Sea. The aims of paper are to determine: the environmental parameters which are important in water quality, determining weight (wi) of parameters affecting water quality index and sub-indices (qi) of each important parameters of Caspian Sea water quality index (WQIcs). This research will provide the specific and necessary information and data for calculating the water quality index in this aquatic ecosystem. The provided wi and qi were applied for water quality index calculating of the Caspian Sea data in 2018-2019. Using Principal Component Analysis results on long-term data 2003-2019 years (920 water samples), 9 important parameters (turbidity, chlorophyll-a, BOD5, COD, pH, DO%, NO3, NH4 and PO4) were determined for WQIcs and indicator weighting (wi) of each parameter was determined. The sub-index (qi) of each parameter was calculated based on standards threshold, coastal water quality requirements in marine ecosystems and reference value data of Caspian Sea. Finally, by calculating the geometric mean, the value of water quality index in the Caspian coastal waters was obtained. The application of this formula in 2018-2019 showed that 74 and 26% of WQIcs were in the range of 70-91 (medium class) and 35-69 (bad class), respectively. Among the 9 parameters mentioned above, nitrate and phosphorus (the factors of trophic enrichment) had the greatest effect on decreasing water quality index.

Aquaculture development and construction materials have reduced water health. In this study, we have measured the water quality parameters of Mohammad Abad River, has a mean role in flood control, Fazelabad water supply and ecological balance, compared it with surface water standards. The value of Water Temperature, Turbidity, Dissolved Solids, Salinity (EC), Phosphate, Nitrate, Nitrite, Ammonia, Dissolved Oxygen, pH, BOD and Total Coliform have been measured in 12 stations selected based on sandstone and aquaculture industries. In this river, there are three sandstone and 4 aquaculture industries that only Salinity and Turbidity were upper of standard value due to agricultural waste while other parameters were placed in the standard range. The result of IRWQI index in each station is 79.2, 77, 77.3, 77.7, 62, 70.7, 73.6, 74.2, 79.2, 77.4, 79.9, 83, respectively that are in good level and is presenting a good purification of this ecosystem, therefore, though the studied industries have effected on water health quality, but, its physical condition such as substrate have moderated the industries’ impacts.

Rivers and streams are one of the most important water resources. Rivers water quality depends on various conditions such as hydrological, physicochemical and biological processes.Water resources have significant impact on social, economical and political developments. The Zyarat Watershed which is the main source of surface water to supply water for city of Gorgan and surrounding areas has been confronted with potable water quality deterioration problem in the recent years, therefore its management and water quality control has specific importance .In order to, Samples were taken from 10 hydrometery stations (in Spring and Summer 2012) along the Zyarat Stream. At each sampling DO, pH, BOD5, NH3, NO3, PO4, TS, Water temperature, turbidity and Fecalcoli quality was measured. The data were analyzed by NSFWQI quality index. The result showed that the best situation was related to first station in Khordad month and the worst situation was related to 5 station in Ordibehesht month. As for present results quality condition of Zyarat Straem was unsuitable and the decision making process for reducing the pollutant of the Zyarat watershed can be facilitated by taking into consideration the results of this research given the time/budget constraints.