Showing 22 results for Gholami
P Bahmani, R Rezaei Kalantary, M Gholami, A Jonidi Jafari, Z Javadi,
Volume 3, Issue 4 (8 2011)
Abstract
Backgrounds and Objectives: Reactive dyestuff has potential of toxicity, carcinogenesis and mutagenesis for mammals and aquatic organisms. The current physical and chemical methods such as adsorption, coagulation, precipitation, filtration and ... can been used for removing of dyestuff. Biological treatment which is effective and economic for decontamination of dyestuff wastewaters was preferred because of limitation and difficulty of physicochemical methods. In order to investigate the trend of pollution reduction of color compounds, ability of Remazol Black-B dyestuff removal from aqueous medium by bacterial consortium under anoxic conditions was studied.
Materials and Methods: The mix culture of bacteria from textile industries activated sludge was enriched in luria broth medium containing RB-B dyestuff as a carbon source. Then biodegradation was assessed in 4 batch reactors. Microbial population of bacterial and decolorization quantities of samples were detected by MPN and UV-Vis spectrophotometer.
Results: Decolorization efficiency by the bacterial consortium was obtained more than 99% for 50 and 250 mg/L concentrations in 72 and 144 h (3 and 6 days) respectively, while for the initial concentration of 500 mg/L was 98.1in 240 h (10 days) of biodegradation period. Dyestuff reduction rate after completed removal was about 0.69, 1.74,2 mg/L/h for initial concentration of 50, 250, 500 mg/L respectively.
Conclusion: Results showed that Alcaligenes denitrificans and Alcaligenes xylosoxidans bacteria
which were isolated from activated sludge have good potential of RB-B dyestuff removal and this removal is depending on primary concentration of dye. Removal efficiency increased as primary concentration went up.
A Dalvand, A Jonidi Jafari, M Gholami, A Ameri, N.m Mahmoodi,
Volume 4, Issue 1 (24 2011)
Abstract
Background and Objectives: Discharge of textile colored wastewater industries without providing enough treatment in water bodies, is harmful for human and aquatic organisms and poses serious damages to the environment. Most of conventional wastewater treatment methods don't have enough efficiency to remove textile dyes from colored wastewater thus in this research the efficiency of electrocoagulation treatment process with aluminum electrodes for treatment of a synthetic wastewater containing C.I. Reactive Red 198 in batch reactor was studied.
Material and Methods: The experiment conducted in a Plexiglas reactor with a working volume of 2L that equipped with 4 aluminum electrodes. The effects of operating parameters such as voltage, time of reaction, initial dye concentration and interelectrode distance on the color removal efficiency, electrical energy consumption and electrode consumption were investigated.
Results: in the optimum operational condition electrocoagulation, is able to remove color and COD as high as 99.1 and 84.3% in aluminum electrode in 75 minutes at 20 volt and 2 cm interelectrode distance, respectively. Under this condition, operating cost was 2986 rails per cubic meter of treated wastewater. Increase in the interelectrode distance and initial dye concentration,lead to the decrease in efficiency of dye and COD removal.While as the voltage and time of reaction increased, energy consumption, electrode consumption, final pH and color removal, increased too.
Conclusion: electrocoagulation process by aluminum electrode is an efficient and suitable method for reactive dye removal from colored wastewater.
M Gholami, A Sabzali, E Dehghani Fard, R Mirzaei, D Motalebi,
Volume 4, Issue 3 (1 2011)
Abstract
Background and Objectives: One of the complete treatment processes for industrial and municipal wastewater treatment is membrane bioreactor process which has dominant potential in process and operation sections. This study was conducted to compare the performance of extended aeration activated sludge (EAAS) with submerged membrane bioreactor (SMBR) systems in the treatment of strength wastewater, in the same condition.
Materials and Methods: The initial activated sludge was brought from the Plascokar Saipa wastewater plant. The Plexiglas reactor with effective volume of 758 L was separated by a baffle into the aeration and secondary sedimentation parts with effective volumes of 433 L and 325 L, respectively. The chemical oxygen demand (COD) concentration of the influent wastewater of the EAAS and SMBR systems were between 500-2700 and 500-5000 mg/L, respectively.
Results: Results showed that the SMBR system produced a much better quality effluent than EAAS system in terms of COD, biochemical oxygen demand (BOD5), total suspended solids (TSS) and ammonium. By increasing the COD concentration, the concentration of mixed liquor suspended solids (MLSS) and the removal efficiency of organic matter in the SMBR system, were increased regularly, however the removal efficiency of COD in the EAAS system was irregular.
Conclusion: The average BOD5/COD ratio of effluent in the EAAS and SMBR systems were 0.708±0.18 and 0.537±0.106, respectively. These show that the organic matters in the effluent of the SMBR system was less degradable and thereupon more biological treatment was achieved. Nitrification process was completely done in the SMBR system while the EAAS system could not achieve to complete nitrification.
Majid Kermani, Mitra Gholami, Abdolmajid Gholizade, Mahdi Farzadkia, Ali Esrafili,
Volume 5, Issue 1 (6 2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Phenols in trace quantities are usually present in the treated
effluent of many wastewater-treatment plants. Phenol compounds even at low
concentration can cause toxicity, health and significant taste and odor problem
in drinking waters. This research focuses on understanding the sorption process
and developing a cost-effective technology for the treatment of water
contaminated with phenolic compounds, which are discharged into the aquatic
environment from a variety of sources. In order to remove phenolic compounds
from water, a new natural sorbent, rice husk ash, was developed.
Materials and Methods: Removal of phenol, 2-chlorophenol and 4-chlorophenol were characterized by
spectrophotometric technique at wavelengths of 269.5, 274 and 280 nm,
respectively, under batch equilibrium conditions and via changing the
parameters of contact time, initial pH, and initial concentration of adsorbates
and dosages of sorbent. Finally, the results were analyzed by the kinetic and
isotherm models.
Results: in this
study, the equilibrium time was found to be 240 min for full equilibration of
adsorbates. Removal percent of 2-chlorophenol was lower than two others. The
maximum removal of phenol, 2-CP and 4-CP was observed at an initial pH of 5.
The percentage removal of these phenolic compounds increased with increasing
adsorbent dose and decreasing initial concentration. In kinetics studies,
correlation coefficient and ARE factor showed that the sorption of phenol
(R2=0.9999), 2-chlorophenol (R
2=0.9992) and 4-chlorophenol (R
2=1)
fitted by pseudo second order model. Isotherm studies also revealed that,
Langmuirmodel for phenol (R
2=0.9499), Freundlich model for
2-chlorophenol (R
2=0.9659) and 4-chlorophenol (R
2=0.9542)
were the best choices to describe the sorption behaviors.
Conclusion: Sorption
process is highly dependent on the pH and it affects adsorbent surface
characteristics, the degree of ionization and removal efficiency. At high pH
hydroxide ions (OH-)
compete for adsorption sites with phenol molecules. The sorption was done
rapidly and a plateau was reached
indicating the sorption sites occuupied till
they were saturated. Since the increasing sorbent dose would improve
sorption site, its increasing enhances phenolic compounds removal.
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Ruhollah Rostami, Ahmad Jonidi Jafari, Roshanak Rezaee Kalantari, Mitra Gholami,
Volume 5, Issue 1 (6 2012)
Abstract
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MicrosoftInternetExplorer4 Background and Objectives:Benzene,
toluene and Xylenes (BTX) are organic pollutants, which are mainly associated
with oil and its derivatives. BTX is environmental contaminants and considered
harmful to human health. Application of surface absorbents such as zeolite is
one of several methods for the removal of these compounds. In this study,
BTX compounds'
removal efficiencies were
investigated and compared by using
clinoptilolite
type zeolite
and zeolite
with copper
oxide nanoparticles.
Materials
and Methods: In this study, the modified zeolite by
hydrochloric acid in the grain size 1-2 mm and modified zeolite with nano
particle of copper oxide were used. Artificially- Contaminated Air
flow was used
continuously .To determine
BTX concentrations,
samplings were done by charcoal tube in
current input and output. The
concentrations of contaminants were determined by gas chromatography with FID
detector.
Results: Removal efficiency of benzene,
toluene, p-xylene, m-xylene and o-xylene by clinoptilolite were 78.3%, 62.1%,
32.2% 32.15% and 18.8%, respectively. For the clinoptilolite
containing copper oxide nano particles efficiency were 25.42%, 35.65%, 36.33%,
33.24% and 29.39%, respectively. Average removal efficiency of BTX compounds
observed when the zeolite without nanoparticles used (43.31%) was more than
zeolite with nanoparticles (32%). The results showed that the concentration of
CO2 in the outlet air of the zeolite-containing nanoparticle (550
ppm) was more than the zeolite without nanoparticle (525 ppm).
Conclusion: Results showed that adding nanoparticles to the
zeolite, although the removal efficiency of benzene and toluene
can be reduced.
The results showed that adding
nanoparticles to the zeolite, although can be reduced removal efficiency of
benzene and toluene, which may be due to occupying or blocking of the pollution
absorption sites by the nanoparticles on the zeolite, but It cause promote more
catalytic effect of zeolite in the decomposition process of contaminants by
breaking the molecules of pollutants and their further degradation progress is
done for conversion to carbon dioxide
Emad Dehghani Fard, Ahmad Jonidi Jafari, Roshanak Rezae Kalantari, Mitra Gholami, Ali Esrafili,
Volume 5, Issue 2 (13 2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Aniline has been used in different processes of chemical
industries, however due to its side effects on the environment, several methods
have been considered for its removal. In this study, we evaluated the
performance of photocatalytic process using ZnO nanoparticles (nZnO) and
ultraviolet (UV) irradiation for removal of Aniline from a synthetic effluent.
Materials and Methods: A 5L photocatalytic reactor made from Plexiglas, which the UV lamp (20w)
installed in the center of that (inside a quartz jacket), was designed and nZnO
(0.2-0.5 g/l) was being added into synthetic effluent with Aniline concentration
of 250 ppm. After retention times of 30, 60, and 90 min, samples were
centrifuged and supernatant was filtered using a 0.2 µ PTFE filter. The
liquid-liquid method and Gas Chromatography instrument was used for extraction
and analysis respectively.
Results: Results
showed that the photocatalytic process of nZnO+UV could effectively remove
Aniline from effluent. Increasing trend in the removal efficiency of Aniline
using nZnO = 0.5 g/l was slower in comparison with other nZnO concentrations
and the ANOVA analysis shows no significant difference between removal
efficiency of Aniline in different concentrations of nZnO. The most removal
efficiency of Aniline (76.3%) was observed in alkaline pH, retention time of 90
min and nZnO of 0.5 g/l.
Conclusion: It could be concluded that the
photocatalytic process of nZnO+UV could be suitable technique for Aniline
removal from effluents.
Saeed Parastar, Simin Nasseri, Amir Hossein Mahvi, Mitra Gholami, Amir Hossein Javadi, Saeedeh Hemmati,
Volume 5, Issue 3 (21 2012)
Abstract
Background and Objectives: Pollution of water resources to nitrate is an
environmental problem in many parts of the world. This problem possibly causes
diseases such as methemoglobinemia, lymphatic system cancer and Leukemia.
Hence, nitrate control and removal from water resources is necessary.
Considering that application of nanomaterials in treatment of environmental pollutants
has become an interesting method, in this research use of Ag-doped TiO2 nanoparticles synthesized through photodeposition produced under UV irradiation
was studied for removal of nitrate from aqueous solutions.
Materials and Methods: Three nitrate concentrations of 20, 50, and 100 mg/L were considered. In order
to determine the effect of Ag-doped TiO2 nanoparticles on nitrate removal, dosages of 0.1, 0.4, 0.8 and 1.2 g/L nanoparticles were
used pH range of 5-9 was also considered. The effect of Ag-doped TiO2 nanoparticles both in darkness and under UV irradiation was studied. Moreover,
the presence of chloride and sulfate anions on the system removal efficiency
was investigated.
Results: The optimum
performance of nitrate removal (95.5%) was obtained using nitrate concentration
of 100 mg/L, in acidic pH and 0.8 g/L Ag-TiO2. Increase of
nanoparticle dosage up to 0.8 g/L, increased the removal efficiency, but for
1.2 g/L dosage of nanoparticles, the removal efficiency decreased. Maximum
reduction performance without nanoparticles, under UV irradiation and under
darkness conditions were 32% and 23.3% , respectively. In addition, we found
that presence of sulfate and chloride anions in aqueous solution reduced
efficiency of nitrate removal.
Conclusion: Results of
this study showed that Ag-doped TiO2 nanoparticles may be
efficiently used for nitrate removal from aqueous solutions.
Mohamad Hadi Dehghani , Mamood Alimohammadi , Amir Hossein Mahvi, Noushin Rastkari, Masoome Mostofi, Maryam Gholami ,
Volume 6, Issue 4 (3-2014)
Abstract
Background and Objective: Various industries such as petrochemical, oil refinery, pharmaceutical, plastics, paper, steel and, resin produce a substantial of phenol and its derivatives. Wastewaters containing phenol need careful treatment before discharging into the environment due to their poor biodegradability and high toxicity. The objective of this study was to remove phenol by multiwall carbon nanotubes from aqueous solution. Materials and Methods: Adsorption process was implemented in a laboratory-scale batch with emphasis on the effect of various parameters such as contact time (5 to 120 minutes), pH (3- 11), initial concentration of phenol (5 - 50 mg/l) and the sulfate and chloride ions (20 - 200 mg/l) on adsorption process. To achieve a better realization of adsorption process, sorption kinetics and equilibrium isotherms were also determined. Results: The results indicated that maximum adsorption capacity occurred at concentration 50 mg/L and t =30 minutes. The uptake fluctuated very little in the pH range of 3–9, and at greater than 9 the absorption decreased suddenly. Moreover, the presence of sulfate and chloride ions had no effect on the process. It was found that adsorption kinetics and equilibrium data follow a pseudo-second-order kinetics model and a Freundlich isotherm model respectively. Conclusion: It is concluded that carbon nanotubes being effective in a wide range of pH, short time to reach equilibrium and the absence of competing ions on the absorption process can be used effectively in removing phenol from aqueous solution.
Majid Kermani, Mitra Gholami, Zahra Rahmani, Ahmad Jonidi Jafari, Niaz Mohammad-Mahmoodi,
Volume 6, Issue 4 (3-2014)
Abstract
Background & Objectives: Cationic dyes such as basic violet have many applications in different industries. The degradation of basic violet by means of UV, UV/H2O2, US, and US/H2O2 processes was investigated. Materials and Methods: Photolysis process was accomplished in a laboratory-scale batch photoreactor equipped with a 55 W immersed-type low-pressure mercury vapor lamp (UVC) and sonolysis process was investigated in a sonoreactor with high frequency (130 KHZ) Plate Type transducer at 100 W of acoustic power with emphasis on the effect of various parameters and addition of Na2SO4 on discoloration and degradation efficiency. Results: Complete decolonization of cationic BV 16 was achieved in 8 minutes using UV/H2O2 process. In addition, it was found that sonochemical decolorization is a less efficient process, comparing with photochemical process, as the decolorization proceeds to only 65% within 120 min. Low concentration of dye and natural pH resulting from dissolution of salt favors the degradation rate of dye. The results showed that sodium sulfate enhances the rate of sonochemical degradation of dye. In addition, kinetic parameters were obtained by application of first order equations. Conclusion: The results showed that UV/H2O2 and US/H2O2 processes can be effective in the removal of BV16 from aqueous solutions. Considering dye removal efficiency and availability, photochemical process combined with hydrogen peroxide can be recommended as a fast effective method for removal of dyes from aqueous solutions.
K. Naddafi, M. Gholami,
Volume 7, Issue 3 (5-2014)
Abstract
Background & objective: Synthetic dyes are extensively used in various industries such as textile, leather tanning, plastic, pulp and paper. Since dyes are toxic and even carcinogenic, discharging dye-containing wastewater into the environment poses serious environmental and health problems. Therefore, the purpose of this paper was to evaluate the removal of Reactive Red 120 from aqueous solutions using surface modified natural zeolite. Materials &Methods: The Semnan zeolite was sieved using standard sieves in size of 0.2 - 0.3 mm and then was modified by cationic surfactant. Batch adsorption studies carried out to study various parameters included contact time, initial concentration of Reactive Red 120, pH, and adsorbent dosage. The concentration of dye was measured using a UV-vis Spectrophotometer at the wavelength of 537 nm. Freundlich and Langmuir isotherms and Pseudo-first order and pseudo-second order kinetics were used to analyze the isotherm and kinetic data respectively. Results: The adsorption studies indicated that increasing of the contact time, initial concentration of Reactive Red 120, decreasing pH and adsorbent dosage leads to increasing dye adsorption. Equilibration of Reactive Red 120 adsorption was reached at lapse of 90 min. Moreover, it was found that Langmuir isotherm (R2=0.9814) and pseudo second-order kinetic (R2=0.9814) are well fitted with our data. Conclusion: The results of the study show that Iranian modified zeolite can be used effectively for removal of Reactive Red 120 in comparison with other parts of the world. Considering the cost, availability and ease of modification, it can be used to remove dye in industrial wastewater.
A Heidari, R Nabizadeh, M Alimohammadi, M Gholami, A.h Mahvi,
Volume 8, Issue 1 (8-2015)
Abstract
Background and Objectives: Reduction of released extracellular polymeric substances (EPS) during sludge dewatering is one of the main challenges in sludge treatment process. The aim of this study was to investigate the EPS quantity changes within sludge dewatering by continues ultrasonic – electrocoagulation (US – EC) reactor under different conditions and to determine the most efficient case for reducing these substances. Materials and Methods: In this study, the EPS quantity changes in supernatant were compared after undergoing different conditions of ultrasonic (frequency of 35 and 130 KHz, detention time of 3,5,10, and 30 min) and electrocoagulation (voltage of 20, 30, and 40 V, detention time of 10, 20, and 30 min) processes were compared. Results: The research found that the maximum efficiency of the US-EC reactor was achieved at a frequency of 35 KHz and detention time of 5 min for ultrasonic with voltage of 40 V and at detention time of 30 min for electrocoagulation process as under these conditions total EPS concentration reduced by 69%. Conclusion: According to the results achieved, US – EC reactor significantly reduced the released EPS in supernatant in addition to dewatering sludge.
Y Dadban Shahamat, M Farzadkia, S Nasseri, A.h Mahvi, M Gholami, A Esrafily,
Volume 8, Issue 3 (12-2015)
Abstract
Background and Objectives: Phenol is one of the industrial pollutants in wastewaters, which due to its toxicity for biological systems various pretreatment processes have been used for its detoxification. In this study, the combination of catalytic ozonation process (COP) and sequencing batch reactor (SBR) were used for detoxification of these types of wastewaters.
Materials and Methodology: In this study, the effect of COP on phenol degradation, COD removal, and detoxification of wastewater was investigated. To determine the acute toxicity of effluents and identification of intermediate compounds produced in COP, bioassay using Daphnia Magna and GC / MS were used, respectively. Then, phenol and COD removal of pretreated wastewater was investigated in SBR.
Results: It was found that under optimal conditions in COP (time = 60 min), the concentrations of phenol and COD reduced from 500 and 1162 to 7.5 and 351 mg/L respectively and pretreated effluent toxicity (TU = 36), after rising in the initial stage of reaction, effectively reduced at the end of process (TU=2.3). the integration of this process with SBR could decreased the COD and phenol concentration less than the detectable range by HPLC.
Conclusion: Results showed that COP has a high effect on biodegradability, detoxification, and mineralization of phenol and combination of COP with SBR process can effectively treat wastewaters containing phenol.
A Jonidi Jafari, M Farzadkia, M Gholami, M Mohagheghi,
Volume 11, Issue 2 (9-2018)
Abstract
Background and Objective: Nowadays, the increasing use of antibiotics to control diseases and mismanagement and inappropriate disposal of medicinal wastes cause environmental problems and threatens human health. The present study was conducted to determine removal of antibiotic Metronidazole as one of the most used drugs during the process of composting.
Materials and Methods: In this experimental study, a mixture of livestock manure, fruit, straw and sludge were used for the preparation of compost. Duration of the process was 40 days. Metronidazole was added to the compost reactors at three concentrations of 20, 50 and 100 mg/kg. Totally, 42 Samples were taken weekly. HPLC was used to analyze the samples. The experiment was repeated twice. SPSS22 software was used to analyze the results.
Results: The rate of Metronidazole removal after day 21 and end of the thermophilic phase was 99.9, 96.73 and 93.48 % in the reactors contained 20, 50 and 100 mg/kg, respectively. Increasing concentrations in the reactors caused the removal rate to decrease, while increasing removal time caused to increase the removal rate. At the end of the process, the removal rate for all three reactors was 99.99 %. The physico-chemical properties of the final compost were within the national standard.
Conclusion: The use of an aerobic composting process to degrade antibiotic Metronidazole is an economical, effective and, environmentally friendly method. At the end of the process, 99.99 % of Metronidazole was degraded.
R Mirzaei, M Yunesian, Ar Mesdaghinia, S Nasseri, M Gholami, E Jalilzadeh, Sh Shoeibi,
Volume 11, Issue 3 (12-2018)
Abstract
Background and Objective: Antibiotics are a group of emerging contaminants in the aquatic environment. Antibiotic residues threaten the human health and ecosystem in the low concentrations found in the environment. Hence, the present work has been conducted to investigate the occurrence and removal efficiency of most prescribed antibiotics including amoxicillin, penicillin, cefixime, cephalexin, ciprofloxacin, erythromycin and azithromycin detected in two urban wastewater treatment plants (WWTPs) in Tehran.
Materials and Methods: The present work is an applied research based on USEPA method no. 1694, to investigate pharmaceuticals residues in water by HPLC/MS/MS in year 2016. The differences between target antibiotics residues were investigated statistically. After the calculation of the removal efficiencies, the normality of the data was assessed. Then, parametric and non-parametric tests were used to compare the removal efficiencies in both WWTPs.
Results: There was not a significant difference between the influent and effluent concentrations of cefixime and azithromycin (in Ekbatan WWTP) and cefixime (in southern Tehran WWTP). There is a significant difference between the removal efficiencies of cephalexin (p=0.005) and erythromycin (p=0.002) in two WWTPs. The Highest median removal efficiencies were observed for cephalexin 94.41 and 99.47 in Ekbatan WWTP and southern Tehran WWTP, respectively.
Conclusion: In addition to the type of treatment processes, it is physicochemical properties of the selected compound has a significant influence on removal efficiencies.
J Gorgani, R Nabizadeh, M Gholami, H Pasalari, M Yegane Badi, M Farzadkia, Ha Asgharnia, Ma Zazouli,
Volume 12, Issue 3 (12-2019)
Abstract
Background and Objective: Hospital wastes with the content of infectious, pathologic, sharp, pharmaceupitical and genotoxic materials are classified as hazardous wastes. Of which, genotoxic residues wirh mutagenic and teratogenic effects are of most great concern on human health. Genetic wastes are referred to as cytotoxic, chemical, and radioactive drugs used to treat cancer or treat transplantation. The purpose of this study was to evaluate the management of hospital wastes in Mazandaran province with emphasis on genotoxic waste.
Materials and Methods: This descriptive cross-sectional study was carried out in 35 governmental and social hospitals in Mazandaran province to determine the satus of hospital waste with focus on geotoxic waste. The quanity, quality and management approaches of hospital and genotoxic wastes in the studied hospitals were surveyed with a validated questionnaire. Results obtained from the present study were analyzed with Excel software.
Results: The average waste per each hospital bed was estimated to be 3.51 kilograms. Of which, 2.2, 1.24, 1.9 kg were categorized as municipal, chemical, and genotoxic wastes, respectively. The average of the hospital waste management index in Mazandaran province was found to be about 84 out of 100, indicating good management of these wastes. The management of genotoxic waste in 7 specialized chemotherapy hospitals was estimated to be 64 out of 100, indicating the average state of genotoxic waste management for these hospitals. In 28 non-chemotherapy hospitals, the genotoxic waste management index was approximated 42 out of 100, indicating poor management of these wastes.
Conclusion: The main weaknesses in hospital waste management are associated with the management of chemical-pharmaceutical and genotoxic wastes. Accordingly, improvement the quality of genotoxic and chemical-pharmaceutical wastes should be concerned in the future planning.
Narjes Khodaygani, Roya Mafigholami,
Volume 14, Issue 4 (3-2022)
Abstract
Background and Objective: Pharmaceutical wastewater has a high level of pollution load that should be treated before discharging to the environment. Integrated processes using different mechanisms are one of the most fruitful methods in wastewater treatment. In this study, combined Integrated Fixed Film Activated Sludge (IFAS) and photocatalytic processes are utilized using of Fe3O4/TiO2 nanocatalysts to decrease the COD value of pharmaceutical wastewater.
Materials and Methods: In this study, the variables of each process are optimized using Response Surface Methodology (RSM). In the IFAS process, the variables were dissolved oxygen (DO), media filling percentage and hydraulic retention time (HRT); while in the photocatalytic process, the effects of pH of wastewater, catalyst dose and reaction time were investigated.
Results: In optimal conditions (DO 3 mg/L, HRT 24 h and media filling percentage 65%), COD removal rate was obtained 59.15%. With the initial concentration of 1725 mg/L COD and the mentioned efficiency, the concentration of COD in the effluent diminished to 704 mg/L. However, in the photocatalytic process, during optimal conditions (pH 6.8, reaction time 105 min and catalyst dose 60 mg/L), The efficiency of the process was determined 81%, which by considering the input COD (704 mg/L), the output concentration was reduced to 134 mg/L.
Conclusion: According to the standards provided by the Environmental Protection Agency (EPA), the effluent from the combined process can be discharged into the environment.
Mohammad Ali Zazouli, Fathollah Gholami Boroujeni, Ali Asghar Nadi, Azam Ebrahimi,
Volume 15, Issue 1 (4-2022)
Abstract
Background and Objective: With increasing population growth and water pollution, fresh water supply sources are declining and can not meet today's human needs. Thus, energy conversion systems with high efficiency and low pollution such as desalination microbial cell have been considered. Therefore the aim of this research was to investigation the efficiency of microbial desalination cell (MDC) for desalination and treatment of salt wastewater.
Materials and Methods: To address this issue, the decision was taken to use saline synthetic wastewater with different initial salt concentrations (2, 5, 7 and 10 g/L NaCl) and, different hydraulic retention times (1, 2, 3 and 72 h) in open circuit voltage (OCV) and closed circuit voltage (CCV) continuous mode.
Results: The results showed that highest EC removal was 11.2% and 14.3% with 10 g/L NaCl in open and closed circuit mode, respectively. Maximum COD removal of 68.7% was achieved in CCV mode that was obtained at 10 g/L NaCl. Additionally, Escherichia coli, Bacillus, Enterobacter, Staphylococcus aureus, Pseudomonas and Citrobacter were diagnose as effective bacteria in decomposing wastewater.
Conclusion: The obtained results proved that MDC desalination microbial cell technology is Emerging technology that has many unknown aspects; however, it is expected to be an appropriate technique for wastewater treatment and desalination.
Fatemeh Tabatabaei, Roya Mafigholami, Hamid Moghimi, Sanaz Khoramipour,
Volume 15, Issue 1 (4-2022)
Abstract
Background and Objective: Microplastics can have harmful effects on living things, including humans. These particles have been identified in all water, soil, and food sources. Among these, freshwater resources are more important, because they are considered a water source for humans through drinking water treatment plants (DWTPs). Therefore, this study investigates the performance of Tehran DWTPs in removing these particles.
Materials and Methods: In this study, the performance of three DWTPs in Tehran in removing these particles was investigated. In most studies worldwide, particles larger than 1 µm were examined, but in this study, nanoplastic particles smaller than 1 µm, as well as the effect of the warm and cold seasons of the year on the concentration of these particles were also examined.
Results: According to the results of the study, the amount of micro and nanoplastic particles at the inlet of treatment plants in the warm season of the year was 2569 ± 309 to 3918 ± 425 MP/L, and the output was 1492 ± 32 to 2279 ± 146 MP/L, which indicates an increase in these particles in the warm season. As a result, the studied treatment plants were only able to remove 32.1 to 59.9% of these particles. In addition, using electron microscopy, MPs were classified into three categories in terms of appearance: fiber, fragment, and film. This study completes the knowledge of MPs in this area.
Conclusion: Based on the results of this study, Tehran DWTPs have poor performance in removing these particles.
Mobina Nadem Souraki, Fatemeh Nejatzadeh, Fathollah Gholami-Borujeni,
Volume 15, Issue 4 (3-2023)
Abstract
Background and Objective: The current research aimed to evaluate the level of environmental knowledge, attitude, and performance of the citizens of Mazandaran province in 2021.
Materials and Methods: In a descriptive study, the level of environmental knowledge, attitude, and performance of the citizens of Mazandaran province were evaluated. The statistical population of the research (384 people) was selected by simple random method. In order to collect data, a questionnaire whose reliability was determined in previous studies was used. The collected data were analyzed using SPSS 21 software. Using Pearson's correlation test, the relationship between knowledge and environmental performance was analyzed.
Results: Among the 384 participants, only 135 answered all the questions. The results of the study showed that, despite the average knowledge of the citizens, the environmental performance is at a good level. The average score of environmental knowledge, attitude, and performance was 5.93±2.06, 47.67±9.30, and 58.70±12.69 respectively, and the most source of obtaining environmental information is television (46.7 percent) and social conversations (19.3 percent). The results of Pearson's correlation test show that there was a significant relationship between the awareness and environmental performance of citizens (p<0.05).
Conclusion: Despite the average knowledge of the citizens, their environmental performance was at a good level, but according to several reports, the Mazandaran province's environmental indicators are not in good condition, which indicates that probably mechanisms and other factors such as environmental policies and economic factors also affect people's environmental performance, which should be investigated.
Nahid Jalilian, Abdullah Sheykhi, Leila Mirzaei, Zeinab Gholami, Moayed Adiban,
Volume 16, Issue 2 (9-2023)
Abstract
Background and Objective: Butter is a known dairy product in the world and has an important role in human nutrition. Ignoring sanitary tips in this product leads to low quality of the product and outbreak. Therefore, this study aims to investigate bacterial pollution of local butter produced from cow and sheep milk in Ilam city.
Materials and Methods: In this analytical study, 150 samples of traditional cow and sheep butter were collected and studied for microbial contamination for 1 month from different production centers. SPSS version 23 software was used to analyze the collected data.
Results: From 75 samples of cow butter, 25.3% of the samples are polluted to S. aureus, 44% to S. epidermidis, 38.7% to Salmonella, 12% to Total coliform 10.7% to E. coli, and 12% do not have any pollution. From 75 samples of sheep local butter, 12% of the samples are polluted to S. aureus, 72% to S. epidermidis, 48% to Salmonella, 24% to Total coliform, and 17.3% to E. coli. A significant difference (P< 0.05) between pollution to S. aureus and S. epidermis in cow and sheep samples exists.
Conclusion: The results of this study showed that contamination of consumed local butter in Ilam city is considerably high; Therefore, it is important to pay attention to food hygiene in different stages from production to consumption.
