Showing 235 results for Co
M Shirzad Siboni, M.r Samarghandi, M Farrokhi, H Piri Dogahe, M Zarrabi,
Volume 4, Issue 3 (10-2011)
Abstract
Background and Objectives: Industrial wastewater included the cyanide is one of the important sources of environmental pollution which founded in Industrial wastewater which are harmful for human health and environment. Therefore, the purpose of this research that was fundamental designed is investigation of Removal of cyanide from aquatic solution by using of iron and copper powder in experimental scale.
Material and Methods: At first, pilot was designed. Then, acquired pH optimum equal to 2,7 for copper and iron by variation pH= (2,4,6,8,12) and constant other parameters. The effect of initial cyanide concentration (40,60,80 mg/l), initial iron and copper dosage (0.08-1 g/100CC) and contact time (15-12 min) studied at the constant of optimum pH.
Results: The result showed removal efficiency Increased from 46.6% to 90.56% and 31% to 93.78% for copper and iron by increasing of contact time from 15to 120 minute in constant conditions, respectively. Also result showed Removal efficiency decreased and increased by increasing initial cyanide concentration and initial iron and copper dosage. The results showed equilibrium data were explained acceptably by Langmuir isotherms and kinetic parameters were obtained by application of Langmuir&Hinshelwood equation.
Conclusion: The results showed that removal of cyanide can be quick and effective done by iron and copper in experimental scale.
A Mirzaei, A Takdastan, N Alavi Bakhtiarvand,
Volume 4, Issue 3 (10-2011)
Abstract
Backgrounds and Objectives: Selection of proper coagulants for turbidity removal and determination of effective methods to reduce coagulants dose and related costs in water treatment plants is of critical importance. The present study investigates the effect of returned sludge on improving the performance of poly-aluminum chloride (PAC) in turbidity, coliform bacteria, heterotrophic bacteria removal from drinking water during rapid mixing phase.
Materials and Methods: In order to determine the optimal returned sludge volume injected during rapid mixing with PAC for turbidity, total coliform and hetrophic bacteria, experiments were conducted based on variables such as injected silt volume (from 0 - 125 ml), and varying turbidities from 58 - 112 NTU. At the end of each JAR experiments, remaining turbidity , microbial parameters of samples were measured . Coagulant efficiency in turbidity removal and microbial parameters were determined by Covariance, Duncan analyses and graphs were drawn by MS Excel . The results statistically showed significant among variables (P<0.05).
Results: The results showed that the maximum turbidity removal efficiency of 98.92 at 30 ppm was 10 ml while the maximum turbidity removal efficiency of 98.31 at 10 ppm was 4 ml. The maximum total coliform removal efficiency of 95.68 obtained for 10 ppm in 10 cc injected sludge volume.
Conclusion: This study shows that addition of returned sludge to flash mixing can reduce the turbidity of samples.
M Khodadadi, M.t Samadi, A.r Rahmani,
Volume 4, Issue 3 (10-2011)
Abstract
Background and Objectives: Water pollution by pesticides has adverse effects on the environment and human health, as well .In recent years, advanced oxidation processes, have been gone through to a very high degree for pesticides removal. Poly-Aluminum chloride (PAC) used for water treatment, can be effective on pesticides removal. The aim of this research was to study the use of UV/O3 and PAC in the removal of pesticides from drinking water.
Materials and Methods: In this descriptive- analytical survey, specific concentrations of pesticides (1,5,10,15,20 ppm)namely Diazinon, Chlorpyrifos, Carbaril were prepared through addition to deionized water. Dichloromethane was used for samples&apos extraction, samples extracted with Liquid- Liquid & Solid-phase extraction , finally entered bath reactor at pH (6,7,9) .The samples then exposed to UV/O3at contact time of (0.5,1,1.5 and 2 hours) . In the PAC pilot , the effects of various concentrations of pesticides, and PAC - ranging (12/24 and 36 ppm) were investigated for the efficacy of pesticides removal. All samples analyzed by GC/MS/MS and HPLC.
Results: It was found that in UV/O3 reactor, with the rise of pH, decrease in pesticides concentration, and rise of contact time, the efficiency of removal increased too. In the PAC pilot, increase in PAC concentration and decrease in pesticides concentration , both increased the efficiency. Besides, both of the methods showed high efficiencies in the removal of both pesticides,i-e. halogenated Organophosphorus (Chlorpyrifos) , non- halogenated Organophosphorus (Diazinon) at the degree of over (%80 ) In case of carbamate pesticides (e.g. Carbaril) efficiency was over (>%90). One-Way Anova & Two -Way Anova were used to analyze the obtained data.
Conclusion: According these results these two methods are suggested for the removal of pesticides from aqueous solutions.
J Azami, A Esmaili-Sari, N Bahramifar,
Volume 4, Issue 4 (3-2012)
Abstract
Background and Objectives: The heavy metals pollution in aquatic ecosystems especially mercury, always makes concern about health of aquatic organisms. So, the purposes of this study were determination of total mercury in different tissues of the three species of the most important water birds at north of Iran and comparison with world health standards.
Materials and Methods: Generally, 51 birds were captured randomly. Then, samples of feather, liver, kidney and muscle were taken and the mercury concentrations were determined by Advanced Mercury Analyzer (Model Leco, AMA 254).
Results: The most amount of accumulated mercury was in great cormorant's liver (piscivorous species). Means of mercury concentration in liver of great cormorant, mallard, and coot were 14.80, 2.05, 0.18 in kidney 12.00, 1.90, 0.17 in feather 6.57, 1.09, 0.23 and in muscle 8.67, 0.26, 0.09 mg/kg dry weight respectively. Means Comparison showed significant difference among all tissues (P < 0.05), But there were not significant difference between sexes (P > 0.05)
Conclusion: The levels of accumulated mercury in all tissues of great cormorant were more than the established limits by WHO, FAO and EPA. The other species had less use limitation, but mercury concentration in mallards was considerable. These results can be a serious warning for consumers these birds, especially vulnerable people.
Hamid Reza Salari-Joo, Mohammad Reza Kalbassi, Seyed Ali Johari,
Volume 5, Issue 1 (4-2012)
Abstract
MicrosoftInternetExplorer4
Background
and Objectives: Nanotechnology defined as understanding
and controlling of materials at dimension between 1-100 nm, which show unusual
physical and chemical properties. With Increasing development of
nanotechnology, concerns associated with release of materials containing
nanoparticles into the environment is rising. The purpose of this study is
investigation of salinity effect on the acute toxicity of silver nanoparticles
in rainbow trout fry (Oncorhynchusmykiss).
Materials
and Methods: In order to conduct the toxicity tests,
the Caspian Seawater(12±0.2 ppt) and (0.4 ppt) as sources of brackish water and
freshwater were used, respectively. Toxicity of silvernano particles were
evaluated in brackish water and freshwater at concentrations of1, 2, 4, 8, 16,
32and64ppm and 0.12, 0.25, 0.5, 1, 2, 4
and8 ppm, respectively. In addition, in order to investigate the quality of the
used silver nanoparticles the Zetasizer, ICP, and TEM method were applied.
Results: Results of 96-hour median lethal concentration(LC50 96h), showed that toxicity
of silver nanoparticles for rain bow trout fry in brackish water is 12 times
less than its toxicity in freshwater.
Conclusion: According to the toxicity categories, analysis of the results showed that, for
rainbow trout fry (1g), silver nanoparticles are classified as highly toxic
agent substances in fresh water, and little toxic in brackish water,
respectively.
Majid Kermani, Mitra Gholami, Abdolmajid Gholizade, Mahdi Farzadkia, Ali Esrafili,
Volume 5, Issue 1 (4-2012)
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.
!mso]>
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Fahim Amini, Masoud Yunesian, Mohammad Hadi Dehghani, Nima Hosseni Jazani, Ramin Nabizadeh Nodehi, Maasoumeh Moghaddam Arjomandi,
Volume 5, Issue 1 (4-2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Nosocomial infection is the cause of deaths, morbidity, higher costs
and increased length of stay in hospitals. Correct and appropriate use of
antiseptic and disinfectants play an important role in reducing infections. In
this study the efficacy of antiseptics on bacteria causing hospital infections
has been studied.
Materials and Methods: This study was conducted in the laboratory of Imam Khomeini Hospital of Uremia.
In this study the Antimicrobial activity of Descocid, Korsolex basic, Mikrobac
forte and persidin 1% was studied against bacteria causing hospital infections
such as Enterobacter aeruginosa 1221 (NCTC 10006), Staphylococcus epidermidis
(PTCC: 1435 (Cip81.55) and Pseudomonas aeruginosa Strain PAO1. Sensitivities of
bacteria were determined by Minimum inhibitory Concentration (MIC) and Minimum
bactericidal Concentration (MBC) antiseptics. In the second stage, the
concentration of antiseptics was prepared according to the manufacturer's
suggested protocol and the effect of antimicrobial agents were studied at the
certain concentration and contact time.
Result: All
disinfectants (Descocid, Korsolex basic, Mikrobac forte) concentration and
contact time, Accordance with the manufacturer's brochure, had inhibitory
effect on all bacteria. That this is consistent with the manufacturer's
brochure. Persidin one percent in concentration of from 2 and 4 V/V % and
exposure time 5 minutes could not inhibit the growth of bacterial. But at
concentrations of 10 and 20% respectively 15 and 30 minutes exposure time, all
three types of bacteria can be inhibited, which is consistent with the
manufacturer's claims.
Conclusion: In this
study, the efficacy of antiseptics was determined with the Micro-dilution
method recommended by the NCCLS. Korsolex basic, weakest antiseptics (the
highest MIC) for the inhibition of three bacteria was determined. But Between
all four antiseptics (according to manufacturer concentration), Only one percent
Percidine 2 and 4 V/V % in consumer
dilution and 5 minutes exposure time failed to inhibit the growth of
Pseudomonas aeruginosa, Staphylococcus epidermidis and Enterobacter aeruginosa.
Ramin Nabizadeh, Masoud Binesh Brahmand, Kazem Naddefi, Ali Reza Mesdaghiniya,
Volume 5, Issue 1 (4-2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Guilan province, with unique
environmental values of the Caspian Sea is located in
the southwest of Caspian Sea. Disposal of
untreated domestic sewage, industrial and agricultural surface water cause
pollution of the Caspian Sea region and
endanger the health of swimmers. This study performed to determine the
microbial contamination of coastal water in Guilan.
Materials and Methods: In this work, 21 sampling point
in the Caspian Sea littoral provinces of
Guilan were selected and microbial contaminations were assessed using microbial indicators of fecal and total
coliform. Parameters such as pH, temperature, and turbidity also monitored
during the year. In this study, 122 samples were taken and then analyzed by
statistical software.
Results: The results showed that the average values of total
coliform and fecal coliform were 234.8 and
60 MPN per 100 ml, respectively. The fecal pollution appeared to be high
in some stations. Also significant relationship between temperature, turbidity
and microbial contamination was observed (P< 0.05).
Conclusion: The results revealed high total coliform in the two
stations. The average fecal coliform of six stations were higher than the local
standards.
!mso]>
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Ruhollah Rostami, Ahmad Jonidi Jafari, Roshanak Rezaee Kalantari, Mitra Gholami,
Volume 5, Issue 1 (4-2012)
Abstract
Normal
0
false
false
false
EN-US
X-NONE
AR-SA
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
Mahmood Alimohamadi, Ebrahim Molaee Aghaee, Ramin Nabizadeh Nodehi, Gholam Reza Jahed, Sasan Rezaee, Akbar Goldasteh, Shahrokh Nazmara, Hassan Aslani,
Volume 5, Issue 2 (10-2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Heavy metals including antimony and cobalt as two
contaminant factors leach from polyethylene terephthalate packages into water
under some conditions. Therefore, their detection was concerned at different
storage conditions.
Materials and Methods: Five time-temperature treatments were carried out for 5 water samples. Storage
conditions were defined as following: at outdoor and sunlight ambient
temperature, room temperature, and at 40˚C at different intervals for 8 weeks,
at 65˚C for 6 weeks and 80˚C for 7 days. Detection was performed by ICP-AES
method and the data analysis was processed by SPSS software.
Results: Antimony
concentration increased by storage time at all temperatures and for all
samples, however enhancing proportion was different in samples. At outdoor,
40˚C and room temperature, concentration increase was below the MCL by the end
of storage period. But at 65˚C and 85˚C, antimony concentration exceeded MCL by
study time and the difference between samples 4 and 5, for example, was
significant (p≤0.05). Cobalt concentration at the beginning and during the
study was also too less and lower than the detection limit.
Conclusion: By
increasing temperature and time, leaching of antimony into water increases.
Moreover, sunlight has effect but not noticeable at the temperature of present
study. In this study, blue or clear packaging had no significant effect on
antimony leakage (P>0.05).
Edris Bazrafshan, Ahmad Joneidi Jaafari, Ferdos Kord Mostafapour, Hamed Biglari,
Volume 5, Issue 2 (10-2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Presence of humic acids in
water resources is important because it is a precursor to disinfection
by-products (DBPs) and affects many treatment processes. In this study, we
investigated the performance of electrocoagulation process duad with hydrogen
peroxide (creating Fenton process) in removal of humic acids (HA) from aqueous
environment.
Materials and Methods: The experiments were performed using a 1 L bipolar batch reactor (covered with
the aluminum foil) equipped with iron electrodes and connected to electric
source having electrical potential 10 V in bipolar mode. First, reactor was
filled up using aqueous solution containing 20 mg/L HA. Later, several working
parameters, such as initial pH (3, 5, 7, and 8), electrical conductivity
produced from adding 1, 1.5, 2 and 3 g/l KCl and reaction time were studied to
achieve the highest humic acid removal capacity. To follow the progress of the
treatment, hydrogen peroxide (50 mg/l) was added to reactor and then samples of
10 ml were taken at 5, 15, 30, 45, and 60 min and then filtered (0.45 μ) to
eliminate sludge formed during electrolysis. Finally, humic acid and iron
concentration was measured using TOC analyzer and atomic absorption method
respectively.
Results: Results of
this study showed that the most effective removal capacities of humic acid
(97.19%) could be achieved when the pH was kept 5(KCl 3g/l and reaction time 60
min). The share of Fenton and electrocoagulation process was %7.9 and %92.1
respectively. In addition, our results indicated that the removal efficiency of
humic acid with increase of pH and electrical conductivity parameters decreases
and increases respectively.
Conclusion: It can be
concluded that the Fenton process duad with electrocoagulation process has the
potential to be utilized for cost-effective removal of humic acid from aqueous
environments.
Mohammad Malakootian, Hassan Izanloo, Maryam Messerghany, Mohammad Mahdi Emamjomeh,
Volume 5, Issue 2 (10-2012)
Abstract
MicrosoftInternetExplorer4
Background and
Objectives: leachate from municipal solid waste
landfill is a strong sewage having hazardous toxic substances. It should
be
treated
by
choosing a
simple,
economical,
and eco-friendly method. The aim of this study is reduction of COD
from the
Qom City landfill leachate using electrocoagulation process.
Materials
and Methods: The experimental study
was carried out at bench scale using a batch reactor during 2010. We used a Plexiglas reactor having 0.7 liter
capacity, containing nine plate aluminum electrodes connected to a DC power supply (10-60V, 1-5A). Samples were
collected in the middle of cell at regular (every 10 minutes) time intervals.
The concentration of COD was determined using
a COD analyzer. The effects of different parameters
including current density (52.08, 69.44 mA/cm
2), electrolyte time (10, 20,30,40,50 and 60 min), and voltage range
(10, 20, 30, 40, 50 and 60 volt) were investigated.
Results: For a voltage of 60 V and electrolysis time 60 min, the COD removal
efficiency was increased from 48.7% for 52.08
mA/cm
2 to 77.4% for 69.44
mA/cm
2. The highest TSS removal
efficiency was obtained at the largest current input when the voltage and
electrolysis time were kept at 60V and 60 min respectively.
Conclusion: The results showed that the highest COD removal
efficiency (77.4%) was obtained when the current density was 69.44 Ma/cm
2 and the voltage and electrolysis time were kept at 60V and 60 min respectively. Power consumption for this removal level was measured to
be 431.26 kWh per kg COD removal. The results obtained revealed that the electrocoagulation
technology is an effective treatment process for landfill leachate.
!mso]>
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Ramin Nabizadeh Nodehi, Hassan Aslani, Mahmood Alomohammadi, Reza Nemati, Kazem Naddafi, Maryam Ghany,
Volume 5, Issue 2 (10-2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Irrigation of agricultural crops using wastewater will
increase, in some cases, their growth by 40 to 60 percent. However, this has a
high risks for human health because of the presence of higher number of
pathogenic organisms. The main purpose of this study was to investigate the
feasibility use of Fenton and modified Fenton with copper for the disinfection
of raw wastewater.
Materials and Methods: After primarily laboratory physicochemical and biological analysis, the
disinfection process was performed in three different phases in each process.
First, the disinfectants were injected separately, then we performed
disinfection using Fe++ and cu++ ions combined with hydrogen peroxide in order
to determine synergistic effect of each catalyst. Direct method was used for
fecal coliforms counting.
Results: Hydrogen
peroxide maximum efficiency for inactivation of fecal coliforms was only
0.66log inactivation. Fenton and modified Fenton with copper ions showed a
remarkable effect on the bacterial inactivation so that Fenton and modified
Fenton with 1 and 2 mg/l of Cu++ inactivated coliforms by 4.73, 3.28, and 4.88
log respectively.
Conclusion: Application of HP alone for the disinfection of raw wastewater is not
practicable due to low observed efficiency. However, its combination with ions
such as Fe++ and Cu++ increases HP performance in disinfection and has a
notable synergistic effect on HP
disinfection power, where, in the presence of each catalyst, hydrogen
peroxide can reduce the fecal coliforms of raw wastewater to meet the Iranian
Environmental Protection Agency Standards.
Kazem Naddafi, Mehran Mohammadian Fazli, Ali Reza Mesdaghinia, Simin Nasseri, Mahnaz Mazaheri Assadi, Masoud Yunesian,
Volume 5, Issue 2 (10-2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Environmental pollution and health risks of dyestuffs
extensively are caused by many industries. Nonbiodegradability of dyes is
important so that different methods are studied for removing them. The use of
white rot fungi is promising technique in this regard. Therefore, objective of
this work is to investigate Rimazol Brilliant Blue Royal decolorization by
immobilized Ganoderma sp. in sodium alginate from aqueous solution.
Material and Methods: This is an experimental study. First, the nutritional, environmental, and
operational conditions of decolorization process were optimized. Then,
efficiency of immobilized fungal cells was investigated. Experimental designs
were provided using fractional factorial methods and quadratic model was fitted
on decolorization data by MiniTab software.
Results: Our findings
showed that type and concentration of carbon source, temperature, and pH were
the most important factors affecting decolorization and statistically
significant. Optimal conditions to 95.3 percent color removal were: glycerol as
carbon source at 19.14 g/L temperature, 27 oC and initial pH, 6.26. Moreover,
decolorization efficiency increased from 75 percent up to 95 percent by improving
process and fungal immobilization.
Conclusion: Ganoderma
fungus has suitable potential to decolorization. Besides, optimization and cell
immobilization can improve its capability. Application of experimental design
to research methodology is important because of decreasing in experiments and
saving resources. It is suggested to use these potentials in environmental
pollution control.
Mohammad Sadegh Hassanvand, Ayoub Torkian, Mohammad Reza Sahebnasagh, Kazem Naddafi, Mohammad Kazem Moayyedi,
Volume 5, Issue 3 (10-2012)
Abstract
MicrosoftInternetExplorer4
Background and
Objectives: Wind-induced particulate air pollution from iron ore piles can
causes environmental and economic problems for steel industries. In this
experimental study, the effectiveness of various additives in reducing
particulate air pollution from iron ore piles was investigated in a laboratory
wind tunnel.
Materials and Methods: The experimental set up consisted of a
prismatic pile and a wind tunnel. Four different wind speeds of 4.3, 5, 7 and
11 m/s was used in the study Municipal
water, quick lime (2%), seawater, treated industrial wastewater and Polylatice
(0.25%) were used as additives to stabilize the upper layer of the pile.
Results: Emission factors for
non-stabilized (without additive) piles at 4.3, 5, 7 and 11 m /s wind speeds
were 46.7, 73.2, 1025.4 and 13768.7 g/m
2, respectively. Stabilized
piles with 2.6, 2.7, 2.8, 2.7 and 2.8 percent additive (moisture content of the
upper layer of the pile) for municipal water, Polylattice (0.25%), treated
industrial wastewater, seawater and quick lime (2%) indicated a decrease of
99.4%, 100%, 99.3%, 99.5% and 99.5% particulate emission reduction,
respectively.
Conclusions: Proper selection and use
of additives on iron piles has the potential for decreasing more than 99% of the wind-induced particulate
emissions. Operational factors such as covered area, spray frequency, pile
geometry, seasonal adjustments related to ambient temperature and humidity,
wind speed and operator training need to be an integral part of the pollutant
reduction program.
Mohmmad Reza Massoudinejad, Hajar Sharifi, Ashraf Mazaheri Tehrani,
Volume 5, Issue 3 (10-2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: The presence of chemical dyes in the water resources not
only pollutes them, but also brings about death of organisms and serious
indemnities to the environment through stopping oxygen production and preventing
penetration of the sunlight. In this study, we investigated the efficiency of
the electrolysis process for decolonization of phenolphthalein and phenol red
from aqueous environment.
Materials and Methods: The experiments were conducted in an electrochemical reactor having a working
volume of 1 liter equipped with 2 graphite electrodes. This study was conducted
at laboratory scale. Samples were prepared by dissolving two phenol red and
phenolphthalein dyes in drinking water. Then, the effect of operating
parameters such as voltage, inter-electrode distance, and NaCl concentration on
the complete dye removal was determined considering optimum retention time
using Factorial variance analyses and
the graphs were plotted using MS Excel software.
Results: the results
showed that the optimum conditions for completely removal of phenolphthalein
was achieved applying a voltage of 48 V, the retention time of 9 minutes, 5 cm
inter-electrode distance, and the salt concentration of 1.5 g/l, whereas,
complete removal of phenol red was achieved applying a voltage of 48 V, the
retention time of 8 minutes, 5 cm inter-electrode distance, and the salt
concentration of 2 g/l. Under these conditions, COD removal efficiency for
phenol red and phenolphthalein was 85 and 80 percent respectively.
Conclusion: This study
revealed that electrolysis process is an effective method to remove both
phenolphthalein and phenol red dyes from effluent, because it can completely
remove the dyes in a short time.
Edris Bazrafshan, Ferdos Kord Mostafapour, Mahdi Farzadkia, Kamaledin Ownagh, Hossein Jaafari Mansurian,
Volume 5, Issue 3 (10-2012)
Abstract
Background and Objectives: Slaughterhouse wastewater contains various and high amounts of organic
matter (e.g., proteins, blood, fat, and lard). In order to produce an effluent
suitable for stream discharge, chemical coagulation and electrocoagulation
techniques have been particularly explored at the laboratory pilot scale for
organic compounds removal from slaughterhouse effluent. The purpose of this
work was to investigate the feasibility of treating cattle-slaughterhouse
wastewater by combined chemical coagulation and electrocoagulation process to
achieve the required standards.
Materials and Methods:
At present study, slaughterhouse wastewater after initial analysis was tested
for survey of coagulation process using Poly aluminum chloride (PAC) at various
doses (25-100 mg/L). Then we measured the concentrations of wastewater
pollutants (BOD5, COD, TKN, TSS and fecal Coliforms). Later, we transferred the
effluent to the electrocoagulation unit and we evaluated the removal efficiency
of pollutants in the range 10 to 40 volts of electric potential during 60 min.
Results: It was found
that the efficiency of chemical coagulation process using poly-aluminum
chloride (PAC) as coagulant increases with increasing doses (from 25 to 100
mg/L) we achieved maximum removal efficiency during the chemical coagulation
for parameters of BOD5, COD, TSS, and TKN at 100 mg/L of PAC equivalent to
44.78%, 58.52%, 59.9%, and 39.58% respectively. Moreover, the results showed
that with increasing the electric potential and reaction time, the yield
increases linearly so that maximum removal efficiency at a dose of 100 mg/L
PAC, an electrical potential of 40 volts and a reaction time of 60 minutes for
the parameters BOD
5, COD, TSS, and TKN was 99.18% 99.25%, 82.55%,
and 93.97% respectively.
Conclusion: The
experiments demonstrated the effectiveness of combined chemical coagulation and
electrocoagulation processes for pollutants removal from the slaughterhouse
wastewaters. Consequently, this combined process can produce effluent
compliance with the effluent discharge standards.
Mohamad Taghi Samadi, Roghaye Nourozi, Mohamad Hadi Mehdinejad, Reza Aminzadeh,
Volume 5, Issue 4 (2-2013)
Abstract
Backgrounds and Objectives: Determination of arsenic(As) in drinking water has received increasing interest due to its detrimental effects on health. The aim of this research is to investigate effect of coating coral limestone using aluminum sulfate as an adsorbent on the arsenic(V) removal efficiency from aqueous solution.
Materials and Methods: In this laboratory scale study, we prepared coral lime granules using mesh 30 during several stages. Then, we investigated the arsenate removal efficiency under different conditions and changing main factors including pH, contact time and amount of no coated and aluminum sulfate-coated adsorbent. Moreover, we fitted our results with Langmuir and Freundlich models and kinetic data with pseudo- first order, pseudo- second order and modified pseudo- first order models.
Results: We found that increasing pH from 3 to 10 at arsenate concentration of 500 ppb and 5 g/l adsorbent and 120 min contact time, removal efficiency for no coated and coated adsorbent was reduced from 100 to 86.2% and from 100 to 92.2% respectively. Increasing concentration of both adsorbents from 1 to 5 g/l at contact time 120 min increased the removal efficiency from 76 to 99.2% and from 66.3 to 91.1% respectively. Arsenate removal efficiency was directly proportional with the amount of adsorbent and contact time and reversely proportional with the initial concentration of arsenate and pH. The removal efficiency of the coated adsorbent was more than uncoated adsorbent. Langmuir was the best sorption isotherm model for arsenate in these two processes and absorption kinetic was well described with second order models.
Conclusion: Excellent removal efficiency, cost-effectiveness process, and lack of environmentally harmful substances make application of the Persian Gulf offshore corals a reasonable adsorbent to remove environmental contaminants such as arsenate.
Hamed Biglari, Edris Bazrafshan,
Volume 5, Issue 4 (2-2013)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Phenol is one of the most important organic chemicals
presenting in water and other environments. It not only brings about hygienic
problems but also results in forming 11 toxic priority pollutants in aqueous
environments. Hence, the performance of electrocoagulation process using iron
and aluminum sacrificial anodes was investigated for removal of phenol.
Materials and Methods: We used a glass tank in 1.56 L volume (effective volume 1 L) equipped with four
iron and aluminum plate electrodes to do experiments (bipolar mode). The tank
was filled with synthetic wastewater containing phenol in concentration of 5,
20, 40, and 70 mg/l and to follow the progress of the treatment, each sample
was taken at 20 min intervals for up to 80 min. The percent of phenol removal
was measured at pH 3, 5, 7, and 9 electrical potential range of 20, 40, and 60
volts and electrical conductivity of 1000, 1500, 2000, and 3000 µs/cm.
Results: It was found
that the most effective removal capacities of phenol (95 and 98 %) could be
achieved when the pH was kept 7 and 5 for iron and aluminum electrodes,
reaction time 80 min, electrical
conductivity 3000 µs/cm, initial concentration of phenol 5 mg/l, and electrical
potential in the range of 20-60 V.
Conclusion: The method
was found to be highly efficient and relatively fast compared with existing
conventional techniques and also it can be concluded that the electrochemical
process has the potential to be utilized for the cost-effective removal of
phenol from water and wastewater.
Fatemeh Mousavi, Seyed Adel Jahed, Asadolah Rajab, Amir Kamran Nikuo Sokhantabar, Giti Kashi, Rouzbeh Tabatabaee,
Volume 6, Issue 1 (5-2013)
Abstract
Background and Objectives: Air pollution and its effects on human health had become a major concern of many healthcare centers decision makers. In this study, air pollution effect on variation of Glycosylated Hemoglobin A1C (HbA1C) level in diabetic patients was evaluated, which is a unique study in Iran and Middle East region.
Materials and Methods: During November-January 2010-11, Tehran, capital of Iran, was exposed with high levels of air pollution. A retrospective cohort study was carried out on 330 patients diagnosed with diabetes mellitus for at least 12 months referring to 3 endocrinal care clinics. A questionnaire in two demographic and diabetic related sections was prepared. The patients' HbA1C level recorded on November-January 2009-10 was compared with November-January 2010-11. Descriptive analysis and paired t-test were carried out using SPSS 18 software.
Results: The patients investigated were divided into two groups. The first group was composed of 108 patients (53.7% female and 46.3% male) with diabetes mellitus type I (Insulin Dependent), age mean of 17.22, and SD of 11.57. The second group was composed of 222 patients (58.6% female and 41.4% male) with diabetes mellitus type II (Noninsulin Dependent), age mean of 53.91, and SD of 12.12. The change of HbAIC level in both groups wa not statistically significant in first group, HbA1C level increased from 7.71 to 7.75 mg / 100 ml (P =0.828) and in second group, it increased from 7.06 to 7.08 mg / 100 ml (P = 0.798).
Conclusion: According to the results obtained, it can be concluded that relation of air pollution and HbA1C mean variation in diabetic patients was insignificant.
