66 research outputs found
Removal of reactive dyes from aqueous solutions by a non-conventional and low cost agricultural waste: adsorption on ash of Aloe Vera plant
Dyes are an important class of pollutants and disposal of them in precious water resources must be avoided. Among various methods adsorption occupies a prominent place in dye removal. The aim of this study is to evaluate adsorption of dye Reactive Red 198 and Blue 19 (RR-198 & RB-19 (on to Aloe Vera plant ash from aqueous solutions.
In this research Aloe Vera ash was prepared at laboratory conditions and then after shredding, screened by ASTM standard sieve with 60 -200 mesh sizes and the effects of pH (3-12), adsorbent dose (0.1-1 g/L), contact time (10-60 min), initial dye concentration (10-160 mg/L) and temperature were investigated in the experiment. In different samples Dye concentration was measured by spectrophotometer at 592 nm and 520 nm wavelength for RR198 and RB19 respectively. Also the Langmuir and Freundlich adsorption isotherms were determined in order to describe the relations between the colored solutions and the adsorbent.
The results of this study showed that acidic conditions were more conducive to enhance the hydrolysis rate than basic ones as the decomposition was optimum at pH 3. The adsorption rate of RR-198 and RB-19 dyes was increased by increasing of initial dye concentration, increasing of adsorbent dose in 0.1 to 0.4 mg/L. Dye solution was decolorized in a relatively short time (20 min). The efficiencies for RR-198 and RB- 19 reactive dyes were 82.68% and 90.42% respectively. The maximum adsorption capacity (qmax) has been found to be 80.152 mg/g for RR-198 reactive dye and 88.452 mg/g for Blue 19 reactive dye. Adsorption isotherms were examined by Freundlich and Langmuir isotherm that finally showed the Freundlich multilayer isotherm has better accordance with dates.
The results indicate that Aloe Vera ash plant as a natural and inexpensive adsorbent is a suitable adsorbent for the adsorption of textile dyes
Ferroptosis as a Potential Cell Death Mechanism Against Cisplatin-Resistant Lung Cancer Cell Line
Purpose: Drug resistance is a challenging issue in cancer chemotherapy. Cell death induction is one of the main strategies to overcome chemotherapy resistance. Notably, ferroptosis has been considered a critical cell death mechanism in recent years. Accordingly, in this study, the different cell death strategies focused on ferroptosis have been utilized to overcome cisplatin resistance in an in vitro lung cancer model. Methods: The physiological functions of Akt1 and GPX4, as critical targets for ferroptosis and apoptosis induction, were suppressed by siRNA or antagonistic agents in resistant A549 cells. Afterward, the interventions’ impacts on cell viability and reactive oxygen species (ROS) amount were analyzed by flow cytometry. Moreover, the alteration in the relevant gene and protein expression levels were quantified using Real-time PCR and western blot methods. Results: The result showed that the treatment with Akt1 siRNA reversed the cisplatin resistance in the A549 cell line through the induction of apoptosis. Likewise, the combination treatment of the GPX4 siRNA or FIN56 as ferroptosis inducers alongside cisplatin elevated ROS’s cellular level, reduced the cellular antioxidant genes level and increased the cisplatin cytotoxic effect. Conclusion: In conclusion, our study indicated that ferroptosis induction can be considered a promising cell death strategy in cisplatin-resistant cancer cells
Fluoride Adsorption by Pumice from Aqueous Solutions
Drinking water provides many vital elements for the human body, but the presence of some dissolved elements more than permissible concentration can endanger human health. Among the dissolved elements in drinking water, fluoride is noticeable, because both the very low or very high concentrations have adverse health impacts such as dental caries. Therefore, fluoride concentration should be kept in acceptable levels. In this study Pumice was used for fluoride removal. It was found that Fluoride sorption kinetic was fitted by pseudo-second-order model. The maximum sorption capacity of Pumice was found to be 13.51 mg/g at laboratory temperature (24°C). Maximum sorption study occurred at pH= 3. Results of Isotherm showed the fluoride sorption has been well fitted with Freundlich isotherm model. This study has demonstrated that Pumice can be used as effective adsorbents for fluoride removal from aqueous solutions. The adsorbent prepared in this study was cheap and efficient in removal of fluoride than other adsorbents
Sludge quality in wastewater treatment plant in Shokohieh industrial Park of Qom province in Iran
The general attitude of the wastewater treatment process in our country is focus on the effluent quality and unfortunately waste sludge quality is rarely considered. Since multiple natural hazards and routes the contact with sludge requires a comprehensive approach to protect public health and the environment. The aim of this study is an assessment of sludge management and finding out the potential use of sludge for land application. The study was conducted in January to December 2014. samples were gathered in four seasons, winter, spring, summer and autumn from wastewater treatment plant in industrial park of Shokohieh of Qom province according to the instructions in standard method. Sampling was moments and composite. Numbers of Samples were 24 that 2 samples were captured in every month. Samples measured base on standard method for water wastewater examination references and then data was analyzed by SPSS and t-test. The results show that the Physical Parameters qualities and nutrients qualities in sludge are good. The Phosphate quality is not suitable. Based on t-test, the results show that levels of fecal coliform and total coliform in cold and warm seasons are different (
An evaluation of hospital admission respiratory disease attributed to sulfur dioxide ambient concentration in Ahvaz from 2011 through 2013
There is no doubt that air pollutants have adverse
impacts on human health. The main objective of this study
was to evaluate hospital admission respiratory disease
(HARD) attributed to sulfur dioxide levels in Ahvaz during
three successive years. Data was taken from Iranian
Environmental Protection Agency (EPA). The AirQ2,2,3
model is used to quantify the impact of SO2 on inhabitants
of Ahvaz and in terms of hospital admission respiratory diseases.
This is a kind of statistical model which is based on
some epidemiological indices such as relative risk, baseline
incidence, and attributable proportion. Sampling was already
performed for 24 h in four stations during 2011–2013. Four
stations are good representative for residential, high traffic,
industry, and background sites which cover the whole area
of the Ahvaz city. Regarding to gravimetric scale, raw data
of sulfur dioxide was processed using Excel software.
Encoding, filtering, and processing were conducted to prepare
input file for the Air Q2,2,3 model. After running model,1 Air Pollution and Respiratory Diseases Research Center, Ahvaz
Jundishapur University of Medical Sciences, Ahvaz, Iran
2 Environmental Technologies Research Center, Ahvaz Jundishapur
University of Medical Sciences, Ahvaz, Iran
3 Islamic Azad University, Tehran Medical Sciences Branch,
Tehran, Iran
4 Razi Teaching Hospital, Clinical Research Development Center,
Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
5 Department of Internal Medicine, Division of Pulmonology, Imam
Khomeini Hospital, Ahvaz Jundishapur University of Medical
Sciences, Ahvaz, Iran
6 Nutrition&Metabolic Diseases Research Center, Ahvaz Jundishapur
University of Medical Sciences, Ahvaz, Iran
7 Social Determinants of Health Research Center, Yasuj University of
Medical Sciences, Yasuj, Iran
8 Research Center for Environmental Pollutants, Qom University of
Medical Sciences, Qom, Iran
9 Department of Environmental Health Engineering, Faculty of Health,
Bushehr University of Medical Sciences, Bushehr, Iran
10 The Persian Gulf Marine Biotechnology Research Center, The
Persian Gulf Research Center, Bushehr University of Medical
Sciences, Bushehr, Iran
11 Hyperlipidemia Research Center, Department of Laboratory
Sciences School of Paramedical Sciences, Ahvaz Jundishapur
University of Medical Sciences, Ahvaz, IR, Iran
12 Environmental Research Institute, Academic Center for Education,
Culture and Research (ACECR), Rasht, Iran
13 Department of Anaesthesiology, Faculty of Medicine, Ahvaz
Jundishapur University of Medical Sciences, Ahvaz, Iran
14 Occupational Hazards Control Research Center and Department of
Environmental Health Engineering, School of Public Health
Environmental, Shahid Beheshti University of Medical Sciences,
Tehran, Iran
15 Faculty of Food Science & Technology, Tehran University,
Tehran, Iran
16 Student Research Committee, Department of Environmental Health
Engineering, Ahvaz Jundishapur University of Medical Sciences,
Ahvaz, Iran
Environ Sci Pollut Res
DOI 10.1007/s11356-016-7447-xoutputs presented in term of hospital admissions respiratory
cases. Based on our result, the highest mean and maximum of
seasonal and annual levels for sulfur dioxide were observed in
2013. We concluded that obnoxious quality of fuel and some
deficiencies in maintenance and operation of industries lead to
worse quality of ambient air especially in 2013. Cumulative
cases of HARD attributed to sulfur dioxide level at central of
relative risk (RR) were estimated 24, 25, and 30 persons for
2011, 2012, and 2013, respectively. The finding of this study
showed that total mean of sulfur dioxide was higher than
standard concentration. We also noticed that wintertime concentrations
of sulfur dioxide during three successive years
were higher than of those levels in summer
Enhancing the Performance of Solar Water Disinfection with Potassium Persulfat: Laboratory Study with Enterococcus faecalis
Background & Aims of the Study: The safe drinking water providing is one of the most crucial objections in these centenaries. Bacterial water contamination and high rate of morbidity and mortality is crucial health threat. Efficiency of potassium persulfat (KPS) associated solar disinfection as a novel water disinfection technology was evaluated in batch scale experiments, using Ent. faecalis (ATTCC 29212).
Material and Methods: This research is a descriptive and experimental study which done on Tehran city, Iran. Ent. faecalis (ATTCC 29212) was provided in standard form from reference laboratory. Desired bacterial density in water was prepared by Mc Farland method. Water specimens were exhibited with solar radiations from 10 a.m to 16 p.m of Tehran local time. All experiments were conducted into 1.5 L volume of Damavand bottled water. Non-injured bacteria cells were detected by plating onto Bile Esculin azide agar media. Turbid water samples were provided by spiking of sterile slurry. Contact time (1-6 h), turbidity (30-200 NTU), KPS concentration (0.1, 0.7, 1.5 and 2 mMol/l), Ent. faecalis density(1000 and 1500 cell/ml) and UV intensity were independent and disinfection efficiency was a dependent variable, respectively.
Results: Intensity of UVA solar irradiation varied from 3770 to 6263.3 µW/Cm2, with the highest value was measured on 13.30 p.m. In single SODIS and 1 hour contact time, increasing of bacterial closeness from 1000 to 1500 cell/ml implied disinfection performance decreasing in which, the vital bacteria was 10 and 20 cell/ml, respectively; but beyond of this contact time, a complete disinfection was occurred. Disinfection of Ent. faecalis was achieved within 2 h with single solar irradiation but KPS associated solar disinfection with applied dosage of KPS provide completely disinfection in 1 h in which the process efficiency was not influenced by increasing of bacterial density and turbidity up to 200 NTU.
Conclusion: Association of KPS with SODIS enhancing water disinfection which can be used in remote area and emergency status
Study of Kinetic coefficients of a Membrane Bioreactor (MBR) for municipal wastewater treatment
Background & Aims of the Study: In order to design membrane bioreactors (MBR) properly, it is essential to comprehend the behavior of microorganisms in such wastewater treatment processes.
Materials & Methods: In this study, a lab-scale MBR process was operated to determine the biokinetic coefficients of the MBR system under different MLSS concentrations of 6800, 7000, 7400, and 7800 mg/l and organic loading rates of 0.5 kg COD/m3/day.
Results: The results of this study showed that the yield of microorganisms (Y), the endogenous decay coefficient (kd), the maximum specific growth rate (μmax) and the saturation constant (Ks) were in the range of 0.67 g VSS/g COD, 0.56 d−1, 1.86 d−1 and 6.65 mg COD/l, respectively.
Conclusions: The kinetic coefficients in this study can be used to improve the operation and design the MBR system in full scale
Modelling of Disinfection by-products formation via UV irradiation of the water from Tajan River (source water for Sari drinking water, Iran)
Background & Aims of the Study Irradiation with ultraviolet light (UV) is used for the disinfection of bacterial contaminants in the production of potable water. The main objective of the study was to investigate and model Disinfection By-Products (DBPs) formation due to the UV Irradiation of the Tajan River water under different Irradiation conditions. Materials & Methods: Water samples were collected throughout September 2011 to August 2013. Transportation of the sample to the laboratory was done on ice in a cooler, and physiochemical analysis was conducted immediately within one day. Dissolved organic carbon (DOC) was determined by a TOC analyzer. Irradiation experiments were conducted in a series of 25 mL glass serum bottles with Teflon septa. The present study adopts an orthogonal design. The design involved irradiation with UV at a UV/DOC ratio of 0.5–3.0 and incubating (headspace-free storage) for 5–25 sec. A 1 mM phosphate buffer maintained the pH at 6, 7, or 8 respectively, and an incubator maintained the temperature (Temp) at 15, 20, or 25 °C respectively. The development of empirical models for DBPs formation used a multivariate regression procedure (stepwise) which applied the SPSS System for Windows (Version 16.0). Results: The results showed that the total DBPs formation ranged between 12.3 and 67.4 mg/l and that control of the levels was primarily due to the reaction time and the dissolved organic carbon level (DOC) in the water. Conclusions: Reaction time and level of DOC concentrations in water exerted a dominant influence on the formation of DBPs during the UV irradiation of water from the Tajan River. The relationships between the measured and predicted values were satisfactory with R 2 values ranging from 0.89 (for Octanal)–0.92 (for Formaldehydes). The DOC level in water is the key factor in controlling DBPs formation
Arsenic Removal from Aqueous Solution Using Titanium Dioxide Nanoparticles (Anatase)
Background and Objectives: Groundwater sources, as strategic sources of water supply, are of particular importance for human beings. Arsenic is a toxic and carcinogenic contaminant that has been reported to be widely found in groundwater sources. In recent years, adsorption property of nanoparticles has been used to remove arsenic. The present study was performed with the aim of assessing the arsenic reduction process in the aqueous environment under groundwater-like conditions using titanium dioxide (TiO2) nanoparticles (anatase).
Methods: In this experimental study, using batch experiments, the effect of changes of time, nanoparticles concentration, and pH factors, were investigated on the changes in arsenic concentration in aqueous solution. The specific surface area of the adsorbent was 200-240m2/g. Data were statistically analyzed by measures of central tendency.
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Results: In this study, more than 90% of arsenic concentration in the solution, was absorbed after about 30 minutes of exposure to anatase nanoparticles, however, it took 60 minutes to reach drinking water standard level of arsenic (10µg/L). Increasing adsorbent concentration caused an increase in arsenic adsorption. In natural pH range of groundwater, TiO2 nanoparticle can absorb near 100% of arsenic (200µg/l), but, increase in pH increased this ability. Also, adsorption of arsenic by anatase nanoparticles was more consistent with the Freundlich isotherm.
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Conclusion: The results of the current study showed that TiO2 nanoparticles are efficient adsorbents for removal of arsenic from aqueous solutions under natural groundwater conditions
Photocatalytic Degradation of Ciprofloxacin pharmacy pollutant in Batch Photoreactor
Background & Aims of the Study: Pharmaceutical compounds have a variety of forms and applications. Specific amounts of toxic organic compounds in the process of their manufacturing and utilization cause environmental pollution problems. So, degradation and removal these compounds are necessary. The aim of this paper is the study photocatalytic degradation of ciprofloxacin drug in aqueous solution using photo-Fenton process in a batch photoreactor.
Materials and methods: This is an experimental study on a laboratory scale. Fe2+ ions as a homogeneous catalyst applied for the degradation of ciprofloxacin in aqueous solution. The study was performed on synthetic wastewaters that contain ciprofloxacin as a pollutant. The effect of operational parameters such as pH, Fe2+ concentration and H2O2 concentration on reaction kinetics were studied and the optimum conditions were determined for the photocatalytic degradation of ciprofloxacin using one factor at the time (OFAT) experimental design method.
Results: The optimal conditions were obtained at pH =3, Fe2+ concentration at 35 ppm and H2O2 concentration at 25 ppm. A first order reaction with rate constant (k=0.0291 min−1) was observed for the photocatalytic degradation reaction. The chemical oxygen demand (COD) analysis of the ciprofloxacin under optimum conditions showed 92% reduction COD in a 49 min period.
Conclusions: The results showed that the photo-Fenton process can be a suitable alternative method to degradation of pharmaceutical compounds from synthesis wastewaters
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