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Molecular monitoring effectiveness of human adenovirus removal in Isfahan water treatment plant
P Atabakhsh, M Kargar, A Doosti,
Volume 12, Issue 2 (9-2019)
Abstract
Background and Objective: Human adenoviruses transmitted from contaminated water are one of the major pathogens that has been introduced as one of the most important new qualitative water indicators due to their resistance against the purification processes. The main objective of this study was to evaluate efficiency of human adenovirus removal in different units of Isfahan Water Treatment Plant.
Materials and Methods: Sampling was conducted from 5 points of a water treatment plant including raw water, clarifier, ozonation, filtration, and treated water for one year. Virosorb 1MDS electropositive cartridge filter was used for the concentration of water samples. To test the adenovirus antigens, enzyme-linked immunosorbent assay (ELISA) was employed. Real-time PCR and PCR were also employed for quantitative identification and genotyping, respectively. Moreover, total and fecal coliform and physicochemical parameters of the samples were measured.
Results: Out of the 60 samples examined, 12 (20%) samples were diagnosed with ELISA and 16 (26.67%) with molecular method. The highest number of adenoviruses detected in autumn was 7 (12%) in raw water influent, 6 (10%) in clarifier, and 3 (5%) samples in ozonation. The high frequency of adenovirus detection was in autumn (50%) and the lowest was in spring (12.5%). Furthermore, it was found that the total coliform in raw water influent was between 102-103 CFU/mL.
Conclusion: The results showed that the removal efficiency of adenovirus in filtration and disinfection units of the treatment plant was high and the filtration unit in the plant was an effective unit for the virus removal.
 

Evaluation of the performance of conventional and baffled horizontal subsurface constructed wetland in the removal of Reactive Red 198
Hadi Entezari Zarch, Mohamad Javad Zoqi, Mohamad Reza Doosti, Somayeh Rahmani,
Volume 13, Issue 1 (4-2020)
Abstract

Background and Objective: Reactive Red 198 is a mono azo dye widely used in the textile industry of Iran. The toxicity of reactive dyes is higher than other dyes and causes disorders such as irritation, cancer and mutation in humans. The overall objective of this study was to determine the efficiency of a Constructed Wetland pilot system with conventional and baffled horizontal subsurface flow to remove Reactive Red 198.
Materials and Methods: In order to remove Reactive Red 198, two cells were constructed in parallel with 2 × 0.6 × 0.5 m. In the conventional and baffled cell, native straw of Phragmites australis was used. In the research process, COD concentration and reactive dye concentration were investigated. The effect of retention time and type of plant on the efficiency were also investigated.
Results: The results showed that the maximum removal efficiency of the Reactive Red dye 198 was obtained at 100 mg/L inlet pollutant concentration and 3.5 days retention time, which was related to the baffled cells. Also, the presence of the baffles in the constructed wetland system increased the removal efficiency. The presence of straw in both cells was directly affected the removal efficiency. The effect of the retention time in the conventional cell was more effective in removal efficiency than the baffled cell. The pollutant inlet concentration was also inversely correlated with the removal efficiency.
Conclusion: According to the results, it can be concluded that the baffled and conventional horizontal subsurface constructed wetland can be used for low concentrations and at low retention time as a well-functioning system in the removal of Reactive Red 198.


Efficiency of the electrokinetic process in copper recovery from the waste of the mine
Mohammad Javad Zoqi, Mohammad Amin Rasooli, Behnoosh Khataei, Mohammad Reza Doosti,
Volume 16, Issue 2 (9-2023)
Abstract
Background and Objective: Mining is one of the important economic activities all over the world. It causes the release of various emissions, especially heavy metals in the soil, due to the weak exploitation and improper disposal of mineral wastes. Different techniques are used for soil remediation and heavy metal extraction; including the electrokinetic method (so effective in fine-grained soils). In this research, the electrokinetic process was used to extract copper from the waste of the mine in Birjand.
Materials and Methods: In this research, a 24 cm long PVC reactor was used. The retention time was 2, 4, and 6 days and the voltage gradient was 1 V/cm. Graphite electrodes and electrolyte solutions of nitric acid and citric acid were investigated for copper extraction. The electrode polarity was alternately changed in order to pH control and improve the extraction process.
Results: According to the results, the highest removal efficiency (54%) was obtained after 6 days using 0.1 M citric acid and distilled water in the anode and cathode reservoir, respectively. Further, by 24-hour polarity reversing, the copper removal efficiency increased to about 60%.
Conclusion: The use of citric acid in anode was more effective than nitric acid, leading to more copper removal. In addition, by periodically polarity change and keeping the soil pH in the neutral range, further dissolution of the metal and reducing its sedimentation in the soil occurred. As a result, the rate of its transfer outside the treatment area and removal efficiency increased.
 

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