Search published articles


Showing 5 results for Jahangiri
Removal of Reactive Blue 29 Dye from Water by Single-Wall Carbon Nanotubes
K Naddafi, R Nabizadeh Nodehi, M Jahangiri Rad,
Volume 3, Issue 4 (8 2011)
Abstract

Backgrounds and Objectives: Anthraquinone dyes such as reactive blue29 in water resources and industrial wastewater effluents are one of the most environmental setbacks in many countries. Various methods have been considered to remove these dyes One of which is adsorption.
Materials and Methods: All adsorption experiments were conducted in different pHs and various concentrations of adsorbents. The initial concentration of reactive blue 29 chosen in this study was 30mg/L.Adsorption isotherms were determined and correlated with Longmuir, Freundlich and BET models.
Results: The maximum adsorption capacity of reactive blue 29 onto single wall carbon nanotubes was 496mg/g.Results showed that the best pH for adsorption was 5 followed by pH3 and 8. Kinetic study showed that the equilibrium time for adsorption of RB 29 to SWCNT is 4 hr.
Conclusion:According to the results obtained BET isotherm fitted well the experiment. It shows the adsorption of reactive blue 29 onto single wall carbon nanotubes is multilayers and the mechanism of SWCNTs adsorption toward RB29 is based on weak van der waals forces.


Investigating Density and Type of Bioaerosols in a Petrochemical Wastewater Treatment Plant: Mahshar - Iran, 2013
Mahdi Jahangiri, Masoud Neghab, Vahid Kahdemain, Reza Rostami, Ali Karimi, Mandana Aghabeigi, Abasali Kasayee Nasab,
Volume 6, Issue 1 (5-2013)
Abstract

Background and Objectives: Wastewater contains various pathogens including viruses, bacteria, fungi, etc. These microorganisms can easily become airborne during normal operations of wastewater treatment plant and contaminate the neighborhood environment. The aim of this study was to investigate the type and density of bioaerosols in a petrochemical wastewater treatment plant in Iran.
Materials and Methods: In this cross sectional study, bioaerosols density was measured in different units of a petrochemical wastewater treatment plant according to the NIOSH 0800 method and the values measured were compared with background level (control area). For this purpose, air samples were collected on blood agar and dextro agar in Andersen single-stage sampler with air flow of 28.3 l/min for 10 minutes. Samples collected were shipped to the laboratory immediately and were incubated for 48 hours. Then, incubated samples were counted for colonies concentration.
 Results: Average concentration of bacteria and fungi bioaerosols measured were 731.70±185.49 and 28.43±10.58 (M±SD) CFU/m3 respectively throughout the wastewater treatment plant units. These values were 35 and 1.45 times higher than background level (Control area). The differences between average concentrations of bacteria in all units of wastewater treatment plant with control area were statistically significant.
Conclusions: Generally, it was found that the density of bioaerosols, especially bacteria was much higher than the background level. The maximum density was measured at aeration chamber, where the emission of bioaerosols could be reduced through replacing nozzle diffused aeration system.


Efficiency Assessment of Fixed Bed Adsorption Column for the Removal of nitrate using PAN-oxime-nano Fe2O3
M Jahangiri-Rad, R Nabizadeh, J Nouri, M Yunesian, F Moattar,
Volume 8, Issue 1 (8-2015)
Abstract

Background and Objective: Nitrate is one of the dissolved anions having great health importance in water. Human activities and natural sources are considered as the main roots of nitrate intrusion in to water bodies. The main objective of this paper was to study nitrate removal by packed bed column filled with (PAN)-oxime-nano Fe2O3. Materials and Methods: PAN-oxime-nano Fe2O3 were synthesized and used as an adsorbent in glass column for the removal of nitrate from aqueous solution. Nitrate solution tank was set above the prepared column. The effect of factors, such as flow rate (2, 5, and 7 mL/min) and bed depth (5, 10, and 15 cm) were studied. Results: It was found that the data fit well with Thomas model and breakthrough curve was designed accordingly. The column performed well at lowest flow rate. As the flow rates and time increased, earlier breakthrough was observed. The column breakthrough time (Ce/C0 = 0.05) was reduced from 9 to 4 h, as the flow rates increased from2 to 7 mL/min. Conclusion: fixed-bed using PAN-oxime-nano Fe2O3 exhibited good removal of nitrate. The adsorption studies showed that at longer bed depth, better removal of nitrate would be achieved. Thomas model was suitable for the normal description of breakthrough curve at the experimental condition. The data also were in good agreement with logistic regression.


Factors affecting scale formation in water distribution networks of Semnan city and preventive measures
Mahsa Jahangiri-Rad, Mohammad Rafiee,
Volume 14, Issue 3 (12-2021)
Abstract
Background and Objective: Corrosion and precipitation are important indicators of water quality assessment. The aim of this study was to analyze water stability water in Semnan distribution networks.
Materials and Methods: To achieve the purpose, samples were taken from 5 points (3 points of storage tanks and 2 distribution network points) and analyzed for physical-chemical analysis. The concentration of common anions and cations was determined by ion chromatography (IC). The sediment formed in the water distribution network was also investigated for studying its structure and main elements by using X-ray fluorescence spectroscopy (XRF) and induced coupling plasma spectroscopy (ICP). The corrosion and scaling indices, including the Ryznar stability index (RSI), Langelier index (LI), and calcium carbonate precipitation potential (CCPP) were also studied.
Results: According to the obtained results, the quality (physically-chemically) of most of the taken samples lies within the permissible limits of Iran's national standard (1053). However, in terms of total harness all sampling point showed values beyond WHO guidelines for drinking water. Magnesium and sulfate concentrations were also exceeded in one of the reservoirs. The results also showed the main sediment structures were calcium carbonate (calcite) and silica oxide. Moreover, According to the results, the average values of LSI and CCPP represented the scaling due to carbonate calcium nature of water. Water stability analysis indicated major roles of calcium and magnesium bicarbonate formation as temporary hardness and minor roles of magnesium sulfate and chloride as permanent hardness.
Conclusion: According to the results, to prevent water scaling in pipes it is recommended to use lime softening at pH=10 which not only removes temporary hardness but enhances silicate ions removal by co-precipitation with Mg(OH)2 formed followed by filtration.

Evaluation of the quality of unconventional water (wastewater treatment plant effluent) of Pakdasht city for Cucurbits irrigating in 2022
Abbas Khazaee, Mehrnoosh Abtahi, Mahsa Jahangiri-Rad, Fatemeh Shokri-Daryan, Mohammad Rafiee,
Volume 17, Issue 1 (6-2024)
Abstract
Background and Objective: Identifying the quality of non-conventional waters and exploring their optimal utilization are fundamental measures for maintaining public health. This study aims to investigate the effluent quality of the irrigation canals in Pakdasht farms.
Materials and Methods: In this cross-sectional descriptive study, 120 samples were collected from 6 irrigation canals in Pakdasht fields over a period of 5 months. The physicochemical and microbial characteristics of the canal effluents were determined based on the standard methods of water and wastewater tests. The concentration of heavy metals was measured using an ICP device. To determine the possibility of using the effluent of Pakdasht canals for agricultural purposes, the Environmental Protection Organization of Iran and FAO standards were used.
Results: The average concentrations of COD, BOD5, TSS, TDS, NO3-, SO4-2, PO4-3 parameters were 259, 125, 105, 697, 4.5, 94.4, 13.5 mg/L. Additionally, the average number of total and fecal coliforms in the effluent of the canals exceeded the standard values set by IRNDOE and FAO. The mean pH was 6.97, the electrical conductivity (EC) was 1014 μm/cm, and the turbidity was 76.2 NTU. The detected concentrations of heavy metals were awithin the following ranges: Cr (0.025-0.045 mg/L), Cd (0.0006-0.001 mg/L), Pb (0.0006-0.001 mg/L), Co (0.038-0.059 mg/L), and Ni (0.05-0.06 mg/L), which were roughly lower than the suggested standards. However, both HEI and WWQI indices confirmed that the water was unsuitable for agricultural irrigation.
Conclusion: Based on the comparison of the results of the parameters measured in this study with the environmental and FAO standards, the effluent from the irrigation canals of Pakdasht city is deemed unsuitable for the irrigation of warm-season crops but suitable for fodder and industrial crops.
 

Page 1 from 1     

© 2024 , Tehran University of Medical Sciences, CC BY-NC 4.0

Designed & Developed by: Yektaweb