Showing 5 results for Mahvi
M Mokhtari , K Naddafi , A.h Mahvi , S Naseri ,
Volume 3, Issue 3 (3 2005)
Abstract
There is a need for simple and inexpensive water supply systems in small communities, mainly because of high costs and water resource shortages. Ceramic filters used as a Point-of-Use (POU) system could serve as a safe and inexpensive means for supplying water. In this research we looked at the possibility of using Iranian traditional ceramics as filters for drinking water, bearing in mind the importance of ceramic filters as a POU system. A number of parameters relating to water quality were measured before and after filtration through a ceramic pipe wall. We used ceramic pipes made of clay (with 90% purity). It turned out that ceramic filters are capable of eliminating indicator microorganisms and turbidity to a considerable degree. They can also remove 70% of the water's color. But this system could not eliminate Dissolved Solids, Electrical Conductivity, Hardness and the Nitrate ion content of water. Using Mann-Withney U Test and T- Test, it is confirmed that increasing the thickness and number of ceramic pipes is not effective for improving some water parameters. This research showed ceramic filters can be useful for household water treatment in places where there is microbial pollution or high turbidity.
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.
M Yunesian , M.j Dastoorani , J Nouri , A.h Mahvi , A.a Neshat , S.s Mahmoodian ,
Volume 7, Issue 1 (23 2009)
Abstract
Background and Aim: Environmental health impact assessment of industrial estates will help greatly in better planning for sustainable development and reducing disease risk in a community. The objective of this study was to assess the positive and negative effects of establishing an industrial estate in Jovein, Sabzevar, Iran in 2006-7 and suggest managerial strategies to reduce undesirable environmental health impacts.
Methods and Materials: A modified Leopold Matrix and Scaling checklist method was used. The existing environmental situation was investigated and then environmental impact assessment alternatives were determined, bearing in mind the amounts and kinds of predicted pollutants in the construction and operational phases . The assessment was made considering the immediate, direct, and indirect impacts in the short and long terms. It was attempted to use a wide range of values of different factors (-5, +5) in order to estimate the impact of all activities on the environmental status.
Results: The results of the study are presented with two alternatives, i.e., "No" (conducting the project with no concern for environmental issues), and "Yes" (performance of the project with application of methods to reduce the environmental harmful impacts), when establishing the industrial estate, in the construction and operation phases. The impact assessment with the "No" alternative scored -791, meaning that execution of the project had to be rejected. However, after reducing the harmful impacts the score rose to +252, indicating that the project would be accepted.
Conclusion: The method of reducing harmful environmental impacts along with environmental management programs introduced are accepted in this study. It is recommended that the Ministry of Health and Medical Education and The Iranian Environmental Protection Agency collaborate closely in the area of environmental health impact assessment of industries and industrial estates.
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.
