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Showing 2 results for Hamadan
Determination of Organophosphorous and Carbamat  Pesticides Residue in Drinking Water Resources of Hamadan in 2007
M Khodadadi, M.t Samadi, A.r Rahmani, R Maleki, A Allahresani, R Shahidi,
Volume 2, Issue 4 (3-2010)
Abstract

Backgrounds and Objectives: Water contamination by pesticides is considered as an environmentalproblem today. In terms of agricultural development and diversity of plant pests, the use of pesticides has been increasing. Hamedan province has a suitable agricultural condition, it has enjoyed significant development in this respect. Among all the cities of Hamedan province, Hamedan city has the highest rank in tiller crops. Therefore, yearly use of pesticides is increasing in this area which could be a serious threat to water resources of the city. The aim of this survey was determinaton of Organophosphorous and Carbamat pesticides residue in drinking water resources of Hamadan in 2007.
Materials and Methods: In this survey, 126 water samples were collected from 7 drinking water resources of Hamedan during 12 consecutive months in 2007. for determination of these pesticides,two methods (solid- phase extraction and Liquid-Liquid extraction) were adopted .and samples were analyzed by means of HPLC and GC/MS applying standard methods.
Results: Final results showed that the most concentration of Chlorpyrifos and Carbaryl pesticides were found to be about 3.85 ppb (part per billion) and 1.8 ppb in spring and June respectively the maximum concentration of Diazinon was about 36.5ppb in October (autumn).The minimum concentration of the three pesticides was detected in winter. According to the statistical test Two - Way ANOWA there were significant differences among pesticides concentrations in the water samples in different seasons (p<0.05) . However, there wasn't a significant difference in pesticides concentrations in surface and ground water samples(p>0.05).
Conclusion: Different studies have shown that pesticides residue concentration in water samples have a relationship with the amount of pesticides used in an area, physical and chemical refractory properties of pesticides and environmental conditions. Thus, using resistant pollutants such as pesticides will be a serious threat to health of water consumers if they are not properly controlled.


Investigating the relationship between the alkalinity of the influent wastewater and the performance of the anaerobic unit of the wastewater treatment plant and providing a solution to increase the alkalinity of the influent wastewater
Abdolmotaleb Seid Mohammadi, Ghorban Asgari, Reza Shokoohi, Parastoo Shahbazi,
Volume 13, Issue 3 (11-2020)
Abstract
Background and Objective: Considering the importance of alkalinity in pH regulation and its buffering role, in this study, the effect of inlet wastewater alkalinity on the efficiency of the anaerobic unit of the wastewater treatment plant. Moreover, a superior chemical compound in providing alkalinity to wastewater was investigated.
Materials and Methods: This study was performed in the treatment plant to determine the relationship between input alkalinity and removal efficiencies of COD, BOD5 and TSS. In order to determine the optimal alkali material for superb anaerobic wastewater performance, four common chemical substances including, NaOH, Na2CO3, Ca(OH)2 and MgO were selected and examined using One Factor At Time (OFAT) test method.
Results: According to the results maximum removal efficiencies were obtained 62, 66.6 and 71.2% for COD, BOD5 and TSS, respectively under alkaline condition of 1260 mg/L CaCO3. Furthemore, the optimal dose to supply one unit of alkalinity by Na2CO3, Ca(OH)2 and MgO were 0.53, 0.54 and 0.3 mg/L, respectively. These values were obtained 5 min contact time and mixing rate of 150 rpm. However, for NaOH the optimal dose supply was obtained 0.35 mg/L for 3 min contact time and mixing rate of 100 rpm.
Conclusion: In conclusion, the performance of anaerobic baffled reactor is highly related to the supply of influent alkalinity to the reactor. In addition, the use of MgO can be considered as a suitable alkaline substance to neutralize acidic wastewater and provide alkalinity for ABR system.

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