Mohammad Ali Baghapour; Zohre Moeini; Yousef Kamali; Mohammad reza Shooshtarian; Mohammad Reza Zare
Volume 5, Issue 3 , July 2017, , Pages 107-115
Abstract
Background: Monitoring the water quality and analyzing its changes over time is an important aspect of sustainable management and development of water resources. The purpose of the present study was to analyze the trend of temporal variations in the quality of drinking water supplied from groundwater ...
Read More
Background: Monitoring the water quality and analyzing its changes over time is an important aspect of sustainable management and development of water resources. The purpose of the present study was to analyze the trend of temporal variations in the quality of drinking water supplied from groundwater sources in Shiraz, using IRWQI (Iran Water Quality Index) as well as statistical analysis.Methodology: This study was conducted on groundwater resources in Shiraz, Iran from 2011 to 2015. 10 water quality parameters were used in this index including NO3, Fecal Coliform, EC, TH, SAR, BOD5, PO4, COD, pH, and DO, with their own weights. Repeated measure test was used in order to analyze the differences between IRWQI values between the study years.Results: The results showed that IRWQI varied between 89/96 (very good quality) and 49/51 (average quality) in the study years. The main causes of water quality decline were average to relatively high levels of hardness and nitrate. The general pattern of the changes in water quality has been accompanied by an increase and decrease, so that the water quality has improved from 2011 to 2013 but then declined until the end of the study.Conclusion: Regarding the necessity of clarifying the water quality condition and its changes and the importance of using IRWQI as an emerging national indicator, water quality analysis in different parts of the country, taking advantage of this indicator and statistical analyses will help the country promote and accelerate the integrated management of water resources quality.
Leila Keshtgar; Ali Akbar Azimi
Volume 4, Issue 3 , July 2016, , Pages 149-157
Abstract
Abstract Background: The compounds which contain nitrogen entering the environment can cause some problems, such as eutrophication for water resources and potential risk for human health because of methemoglobinemia and cancer. Biological techniques are effective in removing nitrate. The aim of this ...
Read More
Abstract Background: The compounds which contain nitrogen entering the environment can cause some problems, such as eutrophication for water resources and potential risk for human health because of methemoglobinemia and cancer. Biological techniques are effective in removing nitrate. The aim of this study was to remove nitrate from groundwater using denitrification. The main objectives of this research were determining the reduction of water nitrate based on different retention time and also the effect of using grape extract as organic matter and electron acceptor in biological nitrate removal from water. Methods: In this experimental study, the effect of heterotrophic Pseudomonas separated from Shiraz wastewater treatment plant on removing nitrate from groundwater was investigated at pilot scale using grape extract as carbon source and filamentous media at constant pH (7±0.1) and temperature (20±1 °C). During this study, 2 pilots were made. Pilot number 1 was used for separation and growth of the above mentioned bacteria (Pseudomonas) that are able to remove nitrate. Pilot number 2 was also used for surveying the removal of nitrate by these bacteria. At least, 13 samples were examined in every retention time and each test was repeated for 2 or 3 times. Statistical analysis was performed in SPSS (ver.19) software using one-way repeated measures ANOVA, and Bonferroni tests. Results: According to the results, nitrate removal rates were 49%, 55%, 67% and, 67% at retention times of 1, 1.5, 2, and 2.5 hours, respectively. The best retention time was 2 hours with 67% removal rate (P<0.05). Conclusion: The results showed that using grape extract as the carbon source and proper growth of bacteria in filamentous media led to a significant increase in the removal rate.