Showing 40 results for Kia
Mr Mehrasbi, Z Farahmand Kia,
Volume 1, Issue 1 (26 2008)
Abstract
Background and Objectives: Heavy Metals in Water resources is one of the most important environmental problems of countries. Up to now various methods of removing of these metals is considered, which is including using of low prices materials. In this study the potential of banana shells was assessed for adsorption of heavy metal ions such as Pb and Cd from aqueous solution.
Materials and Methods: Banana shells were pretreated separately with 0.4 mol/L NaOH, 0.4 mol/L HNO and distilled water and their adsorption ability were compared. Batch adsorption experiments were carried out as a function of the initial ion concentration, pH and adsorbent dosage. Adsorption isotherms of metal ions on adsorbents were determined and correlated with common isotherm equations such as Lungmuir, Freundlich and BET models.
Results: The maximum adsorption capacities were achieved by alkali modified banana shells (36 mg/g) for Pb and by acidic modified banana shells (16 mg/g) for Cd. Experimental results showed that the best pH for adsorption was 6 and the adsorption values decreased with lowering pH. Isotherm models indicated best fit for Freundlich model for modified banana shells.
Conclusion: In comparing the parameters of models, it was observed that the capacity of banana shells for adsorption of lead is higher than for adsorption of cadmium, but the adsorption of cadmium is stronger than the adsorption of lead.
M Farzadkia, R Rezaee Kalantari, S Jorfi, A.r Talaee, G.r Moussavi,
Volume 2, Issue 1 (16 2009)
Abstract
Background and Objectives : Propylene glycol is the main compound of anti-freezing chemicals. A significant amount of propylene glycol is released to the environment after application and contaminates the soil. The main objective of this study was to determine the biological removal of propylene glycol from wastewater and its degradation in soil by the isolated bacteria from activated sludge process.
Materials and Methods: In the present study, the sludge taken from the return flow in a local activated sludge treatment system was used as the initial seed. The performance of the bioreactor in treating the wastewater was evaluated at four different retention times of 18, 12, 6 and 4 h all with the inlet COD concentration of 1000 mg/L. This phase lasted around 4 months. Then, a part of the adapted microorganisms were transported from the bioreactor to the soil which was synthetically contaminated to the propylene glycol.
Results: The average of propylene glycol removal efficiency from the wastewater in detention times of 18, 12, 8 and 4 h in steady state conditions was 98.6%, 97.1%, 86.4% and 62.2% respectively. Also, the maximum degradation in soil was found to be 97.8%.
Conclusion: According to the results obtained from this study, it appears that propylene glycol is inherently well biodegradable and can be biodegraded in liquid phase and soil after a short period of adaptation.
F Rashid Ashmagh, R Rezaei Kalantary, M Farzadkia, A Joneidy Jafari, R Nabizadeh,
Volume 2, Issue 3 (25 2009)
Abstract
Backgrounds and Objectives: Polycyclic aromatic hydrocarbons (PAHs) are a group of hazardous pollutants which have carcinogenic and mutagenic properties and accumulated in environment by different actions, therefore treatment of them is important. Biological treatments are simple and cheep technologies. This technology was recommended as a cost- effective method for treatment of these pollutants. In order to investigate the trend of pollution reduction of petroleum hydrocarbons in bioremediation, the phenanthrene biodegradation&aposs model in contaminated soils was studied.
Materials and Methods: Firstly, PAHs capable degrading bacteria was isolated from petroleum contaminated soils and then their ability for biodegradation of phenanthrene was assessed in slurry phase. After that by using Acinetobacter which have the most potential of removing phenanthrene from soil, the biodegradation model was investigated in bench scale.
Results: Phenantherene removal efficiency was obtained 99.4% for 100 mg/kg and 96 % for 500 mg/kg concentrations in 33 and 60 days biodegradation period respectively. Phenantherene reduction rate varied from 2.99 to 8.86 and 1.4 to 11.09 mg/kg/day for 100 and 500 mg/kg concentrations, respectively.
Conclusion: Rate of phenantherene removal is depended on primary concentration of contamination and by increasing of primary concentration, phenantherene removal rate was increased. Also removal efficiency followed zero and first order kinetic model with good correlation.
M Farzadkia, S Salehi, A Aameri, A Joneidy Jafari, R Nabizadeh,
Volume 2, Issue 3 (25 2009)
Abstract
Backgrounds and Objectives: Over than 70% of solid wastes is consisted of food wastes with high putrecibility in Iran. Due to this regard, construction of composting factories for sanitary disposal or fertilizer production from solid wastes was very appreciated in our country. The objective of this research was to study on the quality and comparing of the compost produced by Khomain and Tehran compost factories.
Materials and Methods: This study was accomplished on the compost produce from Khomain and Tehran compost factories about 9 months. For investigation of chemical qualities of these materials, some indexes such as percentage of organic materials, carbon, nitrogen, phosphorus, potash and heavy metals consists of lead, cadmium, mercury and chromium were measured. Microbial quality of these compost materials were defined by assessing of the amounts of coliforms bacteria, salmonella bacteria and parasites ova.
Results: The average amounts of some indexes in compost of Khomain and Tehran were been: organic materials % (37.77, 29.80), carbon %( 22.14, 18.12), nitrogen% (2.08, 1.6), lead (229.6, 59.44 ppm), and chromium (70.2, 19.75), respectively. The microbial quality of these compost samples were agreement with class B of USEPA guidelines.
Conclusion: This study showed that quality of organic materials percent in Tehran's samples was better than Khomain's samples, but these indexes on these samples were lower than the grade No.2 of compost. The percentage of carbon, nitrogen and potash in these samples were desirable but, phosphorus amount were not in sufficient. The heavy metals especially lead and chromium in Tehran's samples were higher than Khomain's samples, but these samples were usually in agreement with guidelines of compost. Due to the defined microbial qualities, these samples could be used as well as amendment agents for poor soil.
Z Farahmand Kia, M.r Mehrasbi, M.s Sekhawatju, A.sh Hasanalizadeh, Z Ramezanzadeh,
Volume 2, Issue 4 (9 2010)
Abstract
Backgrounds and Objectives : Heavy metals in dust can enter to the human body through ingestion andinhalation. They can pollute the water and soil resources via atmospheric precipitation and accumulate in the plants tissue and enter human body by water and food. The aim of this study was measurement of the heavy metals in wet and dry atmospheric precipitation and effects of pollution sources at the ground surface on the concentration of heavy metals in the atmospheric precipitations.
Materials and Methods: In this study the zanjan city was divided into 5 zones and wet and dry precipitations were collected in autumn, winter and spring (2008- 2009) from zones. The concentrations of Pb, Cd, Cr and Zn the collected precipitations were determined by Atomic Absorption spectroscopy method.
Results: The averages of concentrations of Pb, Cd, Cr and Zn were 0.082, 0.286, 0.018, and 0.009 (mg/m 2.d)respectively. The correlation coefficients between Pb-Zn was 0.8 (P<0.01) and for Cr-Cd, Cd-Pb, and Cr-Pb were 0.89, 0.58 and 0.61 respectively.
Conclusion: The results showed that the industrial sources of heavy metals play the main role in concentration of heavy metals in wet and dry atmospheric precipitation in Zanjan.The correlation coefficients showed that the lead and zinc result from a common source. This source can be the lead and zinc factories locating around the city. The measurement of heavy metals in atmospheric precipitation shows the effects of anthropogenic sources in air quality. The heavy metals concentration in atmospheric precipitation can be use as air pollution index.
M. A Karami, M Farzadkia, A Jonidi Jaafari, R Nabizade, M. R Gohari, M Karimaee,
Volume 4, Issue 4 (2 2012)
Abstract
Background and Objectives: In recent years, poor industrial waste managements have created many crises in human societies. The aim of this study was to investigate industrial waste management located between Tehran and Karaj zone in 2009-2010.
Materials and Methods: This study is descriptive and sectional which was done by site visits, (Iranian environmental protection organization) use of questionnaires, database production and results analysis. The questionnaire consisted of 45 questions mainly about industrial waste quantity, quality and management. Total number of industries with over 50 personnel's, calculated as 283. Class-weighted sampling was used in which the sample size contained 50 industries.
Results: Total generated industrial waste was 123451, kg per day. Major hazardous waste generated in industrial sections included: chemical and plastic making. About 45.28% of waste generated disposed by private sectors. Landfill with 62% and reuse with 17% were the first and second alternative of common methods for final disposal of solid waste in this zone.
Conclusion: In order to reduce hazardous waste generation in this zone, reuse and recovery maximization of the waste must be noted in short-term. In long-term, some industries such as chemical-plastic and electronics which have high rate of hazardous waste production must be replaced with other industries with low rate production, such as wood-cellulose and paper industries.
M.h Dehghani, A Zarei, A.h Mahvi, Gh.r Jahed Khaniki, E.b Kia,
Volume 4, Issue 4 (2 2012)
Abstract
Background and Objectives: Free living nematodes due to their active movement and resistance to chlorination don't remove in conventional water treatment processes thus can be entered to distribution systems and cause adverse health effects. UV irradiation can be used as a method of inactivating these organisms.
Materials and Methods: This study is done to investigate the effect of ultraviolet lamp on inactivation of free living nematode (Rhabitidae) in water. The effects of duration of irradiation, turbidity, temperature, UV dose and pH are investigated in this study. Ultraviolet lamp used in this study was a 11 watt lamp with intensity of 24 µw / cm2.
Results: Contact time required to achieve 100% efficiency for larvae nematodes and adults were 9 and 10 minutes, respectively. Increase of turbidity up to 25 NTU decreased inactivation efficiency of larvae and adult nematodes from 100% to 66% and 100% to 64%, respectively. Change in pH ranged from 6 to 9 did not affect the efficiency of inactivation. With increasing temperature inactivation rate increased.
Conclusion: The results showed that there was a significant correlation between the increase in contact time, temperature rise and turbidity reduction with inactivation efficiency of lamp)p<0.001(. Also the effect of the lamp on inactivation of larvae nematode was more than the adults.
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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Mohammad Sadegh Hassanvand, Ayoub Torkian, Mohammad Reza Sahebnasagh, Kazem Naddafi, Mohammad Kazem Moayyedi,
Volume 5, Issue 3 (21 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.
Edris Bazrafshan, Ferdos Kord Mostafapour, Mahdi Farzadkia, Kamaledin Ownagh, Hossein Jaafari Mansurian,
Volume 5, Issue 3 (21 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 BOD5, 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.
Maasoumeh Ravanipour, Roshanak Rezaei Kalantary, Mahdi Farzadkia, Samireh Hashemi-Najafabadi, Ali Esrafily,
Volume 5, Issue 4 (15 2013)
Abstract
MicrosoftInternetExplorer4
Background and Objectives:The poor accessibility of microorganisms to PAHs in soil has limited success in the process of
bioremediation as an effective method for removing pollutants from soils.
Different physicochemical factors are effective on the rate of biodegradation.
The main objective of this study is to assess effects of nutrient and salinity
on phenanthrene removal from polluted soils.
Materials and Methods:The
soil having no organic and microbial pollution was first artificially polluted
with phenanthrene then nutrients and salinity solution in two concentrations
were added to it in order to have the proportion of 10% w:v (soil: water).
After that a microbial mixture enable to degrade phenanthrene was added to the
slurry and was aerated. Finally, the residual concentration of Phenanthrene in
the soil was extracted by ultrasonic and was analyzed using GC. We measured the
microbial populationusing MPN test. This study was conducted based on the two
level full factorial design of experiment.
Results: MPN test
showed that the trend of microbial growth has experienced a lag growth. The
full factorial design indicated that nutrient had the maximum effect on
bioremediation the rate of phenanthrene removal in the maximum nutrients -
minimum salinity solution was 75.14%.
Conclusion: This study
revealed that the more nutrient concentration increases, the more degradation
will be happened by microorganisms in the soils. However, salinity in the
concentration used had no effect on inhabitation or promoting on the
Phenanthrene removal.
َahmad Joneidi Jafari, Ayooob Rastegar, Mahdi Farzadkia, Roshanak Rezaee Kalantary, Zahra Rezaee Gozalabad,
Volume 6, Issue 4 (3-2014)
Abstract
Background and Objective:Application of compost containing heavy metals can increase the concentration of metals in soil and groundwater. Therefore,the aim of this study was to investigate leaching lead, chromium,and cadmium from three soils (a sandy loam, a sandy clay loam and silt clay loam) amended with compost from the municipal solid waste. Material andMethod:First, the selected soils were repacked into columns (with an inner diameter of 100mm and a height of 600mm). Treatments included(a) low metal content compost (LMCC), (b) enriched metal content compost (EMCC) and (c) control. Then soil columns were incubated at room temperature for 9 days and were irrigated daily with deionized water to make a total of a 250 mm. Leachates were collected and analyzed for pH, EC, Pb, Cr, and Cd concentration. Results: It was found that the application ofEMCCwas significant (p≤0/05) on reducing pH, increasing electrical conductivity and leakage of metalscompared withcontrolin all three soils. But application of LMCC was not significant (p≥0/05) on the metals leaching compared withcontrolin all three soils. The overall quantities of metals leached followed the sandy loam> sandy clay loam> silt clay loam. Conclusion: The concentration of metals in the leachates depended on the soil characteristics and on the type of compost added to the soil. Therefore,application of enriched metal content compost on the soils containinga high percentage ofsandmay pose a risk in terms of groundwater contamination with heavy metals.
Leila Karimi Takanlu, Mahdi Farzadkia, Amir Hossein Mahvi, Ali Esrafily, Masoumeh Golshan,
Volume 7, Issue 2 (10-2014)
Abstract
Background and Objectives: Cadmium can enter water resources through the industrial wastewater. It could cause intensivly damages to the liver and kidney of humans. Magnetic iron nanoparticles are used to control and eliminate heavy metals from industrial effluents through the mechanisms of adsorption, ion exchange and electrostatic forces. The aim of this study was to evaluate the efficiency of magnetic nanoparticles for adsorption of cadmium. Methods: The magnetite nanoparticles were prepared by co-precipitation method through the addition of bivalent and trivalent iron chloride under alkaline conditions. Characteristics of nanoparticles including particles structure, composition and size were determined using analytical devices such as XRD, SEM, and FT-IR. For optimization of adsorption process of cadmium, some parameters such as pH, contact time, initial concentration of cadmium, nanoparticles concentration, and temperature were studied under different conditions. Results: It was found that 95% of cadmium could be removedAt pH &ge 5.6, 10 mg/L initial cadmium concentration, a dose of 1 mg synthesized magnetite nanoparticles, 10 minutes contact time, and 200 rpm mixing rate at 25 °C. The isotherm of adsorption follows the Langmuir model (R2 < 0.995). Maximum capacity of cadmium adsorption was found to be 20.41 mg/g. Conclusion: Magnetite nanoparticles exhibit high capability for removal of cadmium. The nanoparticles synthesized could be used at industrial scale because of having the magnetic property, which make them easily recovered from aqueous solution through applying a magnetic field.
Masoumeh Golshan, Simin Nasseri, Mahdi Farzadkia, Ali Esrafili, Roshanak Rezaei Kalantary, Leila Karimi Takanlu,
Volume 7, Issue 2 (10-2014)
Abstract
Background and Objectives: The use of surfactants enhance the bioavailability of nonbiodegradable contaminants such as PAHs. Biosurfactants are more environmental friendly. In this study the ability of removing phenenthrene from soil by biosurfactant was assessed and compared with that of chemical surfactant. Materials and Methods: A soil sample free of any organic or microbial contamination was artificially spiked with phenanthrene at two concentrations. Then, mineral salt medium at constant concentration of chemical surfactant TritonX-100 and rhamnolipid MR01biosurfactant was added to it in order to have the proportion of 10% w:v (soil:water). A microbial consortium with a potential of phenanthrene biodegradation was inoculated to the soil slurry in two densities (OD=1 and 2) and then it was aerated on a shaker. After eight weeks, the residual concentration of phenanthrene in the soil was extracted by ultrasonic and was analyzed using HPLC. MPN test was used for measuring microbial population. This study was conducted based on the two level full factorial design of experiment. Results: It was found that chemical surfactant exhibited higher PHE removal efficiency than the biosurfactant. Using 120 mg/L of TritonX-100 and rhamnolipid, the PHE removal for the soil contaminated with 50 mg PHE/kg dry soil was 98.5 and 88.7% respectively, while the removal efficieny was decreased to 87 and 76% respectively for the soil contaminated with 300 mg PHE/kg. In the absence of surfactant, the removal efficiency at concentrations of 50 and 300 mg PHE/kg dry soil was achieved 60.76 and 51% respectively. The phenanthrene removal efficiency in OD=2 was more higher than OD=1. In the presence of rhamnolipid, the maximum microbial populations was observed in the second week, while it decreased in the presence of TritonX-100. Conclusion: Use of biosurfactants can be considered as a suitable option in low level pollutant sites. Chemical surfactants as ex-situ has achieved more satisfactory results in high level contaminant sites.
Z Akbari Jonoush, M Farzadkia, S Naseri, H.r Mohajerani, A Esrafili Dizaji, Y Dadban Shahamat,
Volume 7, Issue 4 (1-2015)
Abstract
Background and Objectives: Increased growing nuclear industry has increased the researchers concerns on uranium presence in the environment and its effects on human health. Uranium is a dangerous radioactive heavy metal with high half-life and chemical toxicity. Therefore, the main objective of this study was to removal uranium (VI) from aqueous solution by uranium benzamide complex using AC_Fe3O4 nanocomposite. Materials and Methods: AC_Fe3O4 nanocomposite was synthesized using co-precipitation method. The experiments were designed as one factor at the time method. The optimum range of pH, contact time, amounts of adsorbent, and concentration of benzamide were determined. Then, kinetic and isotherm of uranium adsorption were studied. In addition, the properties of this adsorbent were characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). Results: The SEM and FTIR analysis confirmed that activated carbon is coated with Fe3O4 nanoparticles and the magnetic property of AC-Fe2O3 was approved. According to the results, the optimum conditions were pH =6, contact time =30 min, and 0.06 g of adsorbent dose. The adsorption of uranium on the AC_Fe3O4 nanocomposite fitted to Langmuir isotherm and pseudo-second order kinetic model. The removal of U(VI) was increased about 6% with increasing in benzamide concentration to 50 mg/L. The best percentage removal of uranium in aqueous solution was 95%. Conclusion: The removal of U(VI) on AC_Fe3O4 nanocomposite with the aid of benzamide is a rapid and highly pH depended process. The maximum sorption capacity (15/87 mg/g) of AC_Fe3O4 nanocomposite shows that this method is a suitable method for Uranium removal.
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.
M Kermani, M Farzadkia, A Esrafili, Y Dadban Shahamat, S Fallah Jokandan,
Volume 10, Issue 2 (9-2017)
Abstract
Background and Objective: Discharge of industrial wastewater containing Catechol has adverse effects on human and environmental health. Purpose of this study was to determine the effects of catechol toxicity before and after advanced oxidation process (ozonation process) by bioassay test with Daphnia Magna.
Materials and Methods: This study is an applied research in which the toxicity of catechol was determined by Daphnia Magna bioassay test during the ozonation process. First, Catechol stock solution was prepared at a concentration of 250 mg/L. Then, 10 samples were prepared that each contained 0 (control), 0.5, 1, 3, 6, 12, 25, 50, 75 and 100% of volume of primary solution. Initial samples were prepared from reactor effluent in the same volume as those of the samples. According to standard method, 10 Daphnia infants were added to each sample. The samples were observed after 24, 48, 72 and 96 hours. Finally, lethal concentration (LC50) and toxicity unit (TU) were calculated using Probit analysis.
Results: According to the results, Daphnia magna was affected by the toxicity of catechol. LC50 (24-hour) for raw effluent was increased from 13.30 mL/100 mL to 30.4 mL/100 mL after 60 minutes Treatment. The toxicity unit was decreased from 7.51 TU to 3.29 TU accordingly, showing reduction of 56% in toxicity. The toxicity of the treated effluent decreased during ozonation process of catechol.
Conclusion: Based on the bioassay test, ozonation process was able to reduce the toxicity of catechol. Therefore, this process can be used as an option to treat wastewater that contains catechol.
R Barati Rashvanlou, M Farzadkia,
Volume 11, Issue 1 (6-2018)
Abstract
Background and Objective: Ultrasonic disintegration is a pretreatment process before stabilization and dewatering that degrades sludge and changes its physical and chemical characteristics. The aim of this study was to investigate the effectiveness of ultrasonic in enhancing hydrolyses, stabilization and dewatering of municipal raw activated sludge.
Materials and Methods: The samples were taken from returned activated sludge and then they were exposed to ultrasonic (Frequency: 20 and 40 kHz) in different times (0.5, 1, 3, 5, 10, 15, 30, and 60 min). The effectiveness of ultrasonic for hydrolysis, stabilization and dewatering processes were determined with measuring TS, TSS, CST, SRF, VS, nVS, VSss, and VSsol.
Results: VSsol was increased by 73% in 15 min and at frequency of 20 kHz, whereas VSsol increas was100% at 10 min and 40 kHz. The reduction of VS was observed at 15 min and 20 kHz. Then after, it was reached 18% after 60 min. For 40 kHz, VS reduction started at 10 min and reached 24% after 60 min. Specific resistance of sludge at two frequencies of 20 and 40 kHz and contact time of 1 min were decreased by 25 and 20% respectively. The capillary suction time at the frequencies of 20 and 40 kHz and contact time of 1 min was decreased 28 and 21%, respectively.
Conclusion: The optimum effectiveness of ultrasonic in hydrolysis of organic matter of raw biological sludge was at the contact time of 10 min and frequency of 40 kHz. The highest stabilization at the frequency of 40 kHz was observed at 60 min contact time. The best condition for sludge dewatering was at frequency of 20 kHz and contact time of 1 min.
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.
M Ansari, T Dehdari, M Farzadkia,
Volume 11, Issue 3 (12-2018)
Abstract
Background and Objective: A scientific questionnaire for assessing the knowledge, attitude and judgment of people on waste management by municipalities has not been developed so far. Therefore, the purpose of this study was to design and validation of an instrument to assess the knowledge, attitude and judgment of people on waste management by municipalities.
Materials and Methods: This analytical study was conducted in District 21 of Tehran in 2017. The initial items of the questionnaire were designed based on previous studies and opinions of the team of specialists and people. Then, the face validity and the content validity of the designed questionnaire was examined. The face validity and the content validity was examined qualitatively and quantitatively, respectively. Finally, the reliability of the attitude and knowledge and evaluation of municipal performance items were measured by Cronbach's alpha and a test-retest method, respectively.
Results: The initial questionnaire had 43 items. In the face validity, 8 items were removed and 8 items were edited. In quantitative content validity, 7 items were excluded, with the content validity index of less than 0.79 and the content validity ratio less than 0.49. Pearson correlation coefficient obtained for knowledge component equal to (r=0.77, p<0.0001) and for component performance (r=0.93, p<0.0001), respectively. Cronbach's alpha coefficient was equal to 0.89 for items attitudes, which were in an acceptable level.
Conclusion: The questionnaire can be used as a valid research instrument to collect information on knowledge, attitude and judgment of people on waste management by municipalities.
