Showing 7 results for Mesdaghinia
K Azizi , Ar Mesdaghinia , F Vaezi , S Nasseri ,
Volume 1, Issue 1 (6 2003)
Abstract
Bromide which is present in many water resources has the potential to create adverse health effects after water disinfection by oxidizing agents, and it is considered to be the most important mineral in this respect. Bromide removal is not feasible in conventional water treatment plants. This survey with the aim of removing Br" from water has been accomplished by performing pilot tests in which a GAC fixed - bed contactor and two different resins have been employed. Synthetic water samples of known concentrations of Br" (1-10 mgL -&apos) and TDS (250 - 1000 mg/L-1) have been treated, at the first phase of this study.
Results showed that the best efficiency of GAC treatment was for samples having more than 1 mgL"1 Br" and less than 1000 mgL-1 TDS.
At the second phase of the study, a strong anionic-cathionic resin had been used for Br" removal. Either low or high concentrations of Br", in the influent a considerable reduction in Br" content was always observed at the first 5 minutes of contact.
At the third phase of the study a weak anionic resin (WBA) has been employed. Using this resin in the treatment of synthetic samples proved that WBA is also very effective for Br" removal during 10 min contact while , Br- was reached less than 0.4 mgL"1 . Simultaneous removing of TDS was also showed well efficiency. However, TDS has never decreased to near zero as it was possible for the strong resins.
Finally in the 4th phase of this research, natural samples from four water resources supplying potable water for the city of Qom have been chosen to continue the process of Br" removal by above-mentioned pilots. Despite of high levels of TDS of the samples, there was no important problem in the process of Br" treatment. The acceptable removal efficiencies of bromide were minimum 50% and maximum around 100% .
T Khamechian , Z Tabasi , T Mazuchi , A Mesdaghinia ,
Volume 4, Issue 3 (3 2006)
Abstract
Background and Aim: Pap smear test is considered the best screening method for cervical disease, especially for malignant lesions. The crucial factor here is obtaining high-quality samples, as poorly-prepared ones cause a great deal of confusion for patients and physicians alike. Attempts to define an ideal sampling technique have been going on for many years, and in this study we compare three different sampling methods to determine which one provides the best quality.
Materials and Methods: This interventional study was performed in a private obstetrics-gynecology clinic and involved 600 women who met the criteria for cervical screening. The Pap test was done by three different methods: "Swab spatula", "Cytobrush – spatula" and "Spatula only".
Results: Each method was performed on 200 randomly-selected patients. Cytopathologic examination was done by a single pathologist and in a blind fashion. For each specimen, a quality rating was reported as "satisfactory" or "unsatisfactory".
Among the 200 samples obtained by the "Swabspatula” method, 150 (75%) were of satisfactory quality and the remaining 50 cases (25%) were rated as unsatisfactory. As for the cytobrush–spatula group, 88 samples (94%) were satisfactory and 12 (6%) were unsatisfactory. Finally, 179 samples (88%) in “Spatula-only” group were satisfactory and 24 (12%) were unsatisfactory. The difference in the proportion of good-quality samples was significant in pairwise comparisons between the three methods: swab-spatula versus spatula-only (P = 0.0013), swab-spatula versus cytobrush-spatula (P = 0.0001) and cytobrush-spatula versus spatula-only (P = 0.036).
Conclusion: The study revealed that the cytobrush-spatula sampling method yielded the highest proportion of high-quality samples. Hence, it would be desirable to familiarize physicians, midwives and other health care workers in this country with the technique of cytobrush cervical sampling and its potential advantages. However, financial and cultural aspects must be taken into account before adopting the procedure for routine cervical screening in Iran.
A Gholampour , A.r Mesdaghinia , F Vaezi , R Nabizadeh , M Farrokhi , A Ghasri ,
Volume 5, Issue 2 (3 2007)
Abstract
Background and Aim: 2,4-Dichlorophenol (DCP) is a compound generated in a variety of industrial processes and also by chlorine disinfection of water polluted with phenolic compounds . Dumping of DCP into the environment and water resources is of great concern because of the compound's intense odor and toxicity. DCP is very soluble and resistant to biodegradability so it cannot be removed through conventional water and wastewater treatment processes. On the other hand, pollution prevention (P2) strategies have not been able to resolve the problem.
Material and methods: In this study, one of the AOPS named Fenton was used for DCP degradation. The method is based on simultaneous use of hydrogen peroxide and ferrous sulfate.
Results: Results of treatment with hydrogen peroxide and ferrous ion (as Fenton reagent ingredients) indicate that by oxidation of 50 mg/L DCP at 60 minutes contact time with iron concentration kept at 15 mg/L and various concentrations of H2O2 (50 and 100 mg/L), the efficiency of COD(Chemical Oxygen Demand) reduction would go up from 65% to 80% with higher concentrations of H2O2. We also determined the effect of various concentrations of ferrous ion on DCP oxidation rate. The results showed the prominent role of this ion in DCP treatment: increasing Fe concentration from 5 to 15mg/L produced a 60% reduction in COD occurred in 10 and 60 minutes contact times. Another conclusion was that the oxidation of DCP solutions by Fenton had a major effect on biodegradability so that BOD: COD ratios of these solutions increased significantly after this oxidation.
Conclusion: Pretreatment of waste containing dichlorophenol by the Fenton reagent can enhance the biodegradability of this chemical and perhaps of similar compounds in a short time interval.
A.r Mousavi, A.h Mahvi, A.r Mesdaghinia, S Nasseri,
Volume 6, Issue 1 (4 2008)
Abstract
Background and Aim: Discharge of Wastewater of Cleaning Industries to environment with special physicochemical characteristics has negative effects and in the other hand is not easily biodegradable because in these wastewaters ratio BOD5/COD is low and therefore biological treatment of them is difficult. Nowadays best method for degradation of Wastewater is advance oxidation processes .In this study investigated efficiency of Fenton process in remove anionic detergent and COD and improved from ratio of BOD5/COD.
Materials and Methods: This investigating is descriptive- empirical study that paksan factory was local sampling of wastewater. 30 wastewater composite sample24hr were taken during study period and then chemical characterization was performed by determining the following parameters: (COD, BOD, MBAS, PH, T) Then Sample of row wastewater were prepared and used in the experiments for determining the efficiency of Fenton process in treatment. Treatment experiments performed by use of various concentrations of H2O2 and ferrous iron at constant pH of 3and temperature of 25 in a jar test apparatus adjusted at 200 rpm and for contact time 60 min. Fe+2 on removal (COD, MBAS & BOD ) applied ANOVA. and after that for analysis of effect H2O2
Results: The results of analyze showed that the concentrations of COD, ranging from 6254-13040 mg/l and concentration of BOD was 2590-3200mg/l and concentrations of MBAS were 245-1120 mg/l and results showed that the BOD5/COD ratio was 0.34±0.09. At constant pH of 3 and temperature of 25 for contact time 60 min, about 40% of MBAS with first concentration 470 mg/l removed by H2o2 with concentration1800and fe+2 with concentration 340 mg/l .concentration of COD reduced from 8750 to 5998 mg/l, and the ratio of BOD5/COD improved from 0.334 to 0.340.
Conclusion: Wastewater from this industry has quality characteristics with deferent ranging and high organic load and because of high concentration of foaming that prohibit of oxygen infiltration in wastewater and nonbiodgredable material. These wastewaters are not easily subjected to conversation system of biological treatment therefore suitable method for treatment of this wastewater should reduce organic load foaming and improve ratio of BOD5/COD advance oxidation process is one method with good efficiency for treatment of this wastewater.
A Mesdaghinia, H Nourmoradi, F Vaezi, S Naseri, R Nabizadeh, M Ali Mohammadi, Sh Nazmara,
Volume 6, Issue 2 (27 2008)
Abstract
Background and Aim: Methyl tertiary butyl ether (MTBE) is an oxygenated additive chemical added to gasoline, which is as a substitute for tetra ethyl lead, to reduce discharge of pollutants from automobile exhausts. This organic chemical is present in water samples collected from areas where gasoline wastes are abundant. The objective of this study was to investigate the possibility of MTBE removal from drinking water at the point of use (POU) by using an Iranian granulated active carbon (GAC) bed.
Materials and Methods: Adsorption of MTBE from drinking water at POU was studied by using an Iranian GAC bed. The water samples treated by this filter adsorber were prepared synthetically at two concentrations (50 ppb and 100 ppb). In addition, the effects of residual chlorine at concentrations of 0.2 and 0.5 mg/L and of chloroform at a concentration of 100 ppb on removal of MTBE were determined.
Results: It was found that this filter adsorber could treat 375 liters of water containing 50 ppb MTBE, 100 ppb chloroform and 0.2 ppm residual chorine. If the residual chlorine content was increased to 0.5 ppb, the volume of water treated would be 335 liters. The filter could t eat 195 liters of water containing 100 ppb MTBE, 100 ppb chloroform and 0.2 ppm residual chlorine to acceptable levels for drinking, provided the amount of MTBE is below the respective standard.
Conclusion: Both residual chlorine and chloroform reduced the MTBE adsorption capacity on GAC due to occupation of adsorption sites. In addition, to the tendency of GAC to adsorb chloroform and chlorine was greater than that of MTBE.
Mohammad Ali Zazouli, Simin Nasseri, Amir Hossein Mahvi, Ali Reza Mesdaghinia,
Volume 7, Issue 3 (7 2009)
Abstract
Background and Aim: Natural organic matter (NOMs), measured on the basis of organic carbon, produces disinfection by-products precursors (DBPs) during the chlorination process. Some DBPs are carcinogenic. NOMs are not completely removed by conventional water treatment. As a result, in addition to forming DBPs, they support bacterial regrowth in the water distribution systems and cause unpleasant odor and taste and other problems. The objective of this study was to determine organic carbon concentration and DBPs formation potential in drinking water of the water distribution system in Tehran, Iran.
Methods and Materials: Water sampling was done by standard methods, monthly between August 2006 and Feb 2007, at four points of the drinking water distribution system in Tehran. Quantitative parameters, including pH, EC, UV254 (UV absorbance at a wavelength of 254nm), dissolved organic carbon (DOC), and specific UV absorbance (SUVA) were determined. DOC and UV-254 of the samples were determined using a Total Organic Carbon (TOC) analyzer and a Lambda 25 UV/Vis spectrophotometer, respectively. SUVA (L/mg.m) was calculated as thea ratio of the UV absorbance at 254 nm (1/m) to DOC (mg/ L).
Results: The water content of DOC at the four points of the distribution system was less than 0.7 mg /L. The mean DOC concentration was 0.3±0.14mg/L, ranging between 0.12 and 0.687mg/L, with no monthly variation. The mean SUVA was 1.3±0.7.
Conclusion: It can be concluded that the Tehran water treatment systems cannot eliminate completely natural organic matter. SUVA values show, however, that the system can eliminate the majority of hydrophobic compounds. Therefore, formation of haloacetic acids is more probable than that of trihalomathanes.
A.r Mesdaghinia , J Nouri , A.h Mahvi , F Vaezi , K Naddafi , M Ansarizadeh ,
Volume 7, Issue 4 (27 2010)
Abstract
Background and Aim: The aims of this study was to explore the feasibility of improving efficiency of the wastewater treatment system of the Fars Pegah Dairy Industries (FPDI) and propose ways to upgrade it in 2006-2007. The FPDI wastewater treatment system was of a successive anaerobic-aerobic type using anaerobic stabilization ponds and conventional and extended aeration activated sludge. Due to improper design and operation, it did not meet the required standards with regard to disposal to the surrounding cultivated land.
Materials and Methods: To overcome the problem and eliminate the bad smell, modifications were made, such as changing the entries and exits of the ponds, adjustment of the activated sludge process, and converting the conventional activated sludge F/M to a step-feed activated sludge shift. The efficiency of the system was assessed before and after these modifications
Results: The efficiency of the system to eliminate biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total dissolved solids (TDS), total suspended solids (TSS), total coliform, and fecal coliform increased from 82.42%, 86.87%, 64.18%, 20.23%, 54.56% and 50.87% to 97.34%, 98.61%, 90.4%, 28.44%, 90.09% and 89.95%, respectively.
Conclusion: The findings show improvements in the efficiency of the wastewater treatment system due to the changes made in it. It was also observed that efficiencies of the feed-step aeration and the extended aeration are similar. This means that application of the extended aeration in the treatment system of the plant would result in waste of money and energy.
