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Showing 8 results for Filter
Effect of Rapid Sand Filter on Copper and Zinc Metal Removal in Different Presence of Phosphate Concentration
N Daneshi, H Banejad, R Pirtaj Hamedani, H Farajee,
Volume 3, Issue 3 (10-2010)
Abstract

Backgrounds and Objectives: Due to copper and zinc elements toxicity, a greatly attention to removal of those in order to reduce environmental pollution exist. This experiment was conducted to investigate the study of the effect of gravity single layer rapid sand filter on heavy metals (zinc and copper) removal efficiency in aquatic condition in different phosphate concentration.
Materials and Methods: this study applied a gravity single layer rapid sand filter with silica sand media. Experiments conducted for all of the states of Cooper and Zinc concentration in 25, 75, 125 and 175 ppm at different phosphate concentration present by varied discharge. Each state of Solutions pumped on top of the bed and discharge adjusted. Samples taken fromeffluent then acidified immediately with nitric acid. Metals concentration perused by atomic emission spectrometer with ICP source. Collected data analyzed by SPSS software.
Results: Founds from this study shown that maximum removal efficiency for copper and zinc was 98.89%and 78.60%respectively effect of discharge,metal concentration and phosphate concentration factors in removal efficiency of zinc and cooper, discharge and phosphate concentration bilateral effect on cooper removal efficiency, phosphate concentration andmetal concentration bilateral on zinc removal efficiency, are significant in 1%. In addition, phosphate concentration and discharge bilateral effect, metal concentration and discharge bilateral effect are significant on zinc removal efficiency in 5%. Finally, bilateral effects of discharge and metal concentration also metal concentration and phosphate concentration have not significant effect on cooper removal efficiency.
Conclusion: Gravity single layer of rapid sandy filter with silica sand media in order to cooper removal in low concentration can be used successfully. This method in high concentration of cooper and also different concentration of zinc had not successful result but in this condition, may be use

 

 

of a series of filter with more depth


Upgrading of the Mono Media Filters in Water Treatment Plants by Changing Filter Media
V Alipour, L Rezaei,
Volume 3, Issue 4 (1-2011)
Abstract

Background and Objectives:Dual media filters have two different layer beds consist of sand and Anthracite. Advantage of dual media filters is longer run duration and more filtration rate. The purpose of this study was to achieve a performable model to improve single media Filters in water treatment plants.
Materials and Methods: in this cross-sectional study, two pilots mono and dual media were made and in a 5 month period samples taking were done. Total samples taken from input and output of each pilot, was 40. The samples then introduced for the measurment of turbidity and total organic carbon. Meanwhile the filters head loss also quantified in 40 times head loss measurement was done.
Results: Average turbidity removal in mono and two layer pilots were 63 and 65 percent respectively. Average removal of Total Organic Carbon in mono and two media pilots were 40 and 66 percent respectively. Head loss in dual and single media pilots were 0 .68 and 1.15 m respectively.
Conclusion: Although average torbidity removal disparity between two pilots was not significant the amount of total organic carbon removed was considerable. Average head loss in single media pilot was more than dual media type. Ratio of UFRV in dual media to mono media filter was 51:30 it shows that filtration rate capacity will be improved up to70 percent by changing media type.


Comparation  of Mono Layer Filter (Sand) Dual Media Filter (Anthracite and Leca) and Performance in Removal of Organic Matter and Turbidity
N Delbazi, M Ahmadi Moghadam, A Takdastan, N Jaafarzade Haghighi Fard,
Volume 4, Issue 3 (10-2011)
Abstract

Backgrounds and Objectives: Improvement of water quality standards and inability of mono layer filters in producing such quality caused researchers attended to multi layer filters. Due to specific characteristics of anthracite and leca can improve removal of organic materials and Surface over flow rate. The aim of this research was evaluation performance of dual media filters (anthracite/leca) in removing of organic materials and turbidity from Ahvaz Water treatment plant
Materials and Methods: In this study two pilots built for investigation of mono layer filter and dual media filter performance. The researcher used sand in structure's media of mono layer filter and composition of anthracite, sand and leca in structure's media of dual media filter, respectively.  In this study single and dual layer filter pilot examined in term of organic matter and turbidity removal efficiency. 
Results: Results indicated that removal of organic matter by single layer filter (sand), dual media filter (anthracite,  and sand), dual media filter (leca and sand) was 7%,12%,4/2% respectively. And also Turbidity removal by single layer filter(sand), dual media filter (anthracite and sand), dual media filter (leca and sand) was also  69%, 80%, 74% respectively.
Conclusion: Results of this study showed that upgrading of Single layer to dual layer with anthracite and leca media can‘t show a significant affect in TOC removal.


The Development of Nanofibrous Media Filter Containing Nanoparticles for Removing Particles from Air Stream
S Farhang Dehghan, B Maddah, F Golbabaei,
Volume 8, Issue 4 (3-2016)
Abstract

Background and Objectives: The goal of the present study was to develop nanofibrous media filters containing MgO nanoparticles for future application in removing particles from gas stream.

Materials and Methods: Electrospun nanofibers were fabricated using experimental design prepared by Response Surface Methodology. Optimization of electrospinning parameters was conducted for achieving the desired filter properties including fiber diameter, porosity, and bead number. After taking SEM images, the determination of fiber diameter and number of beads were performed through Image Analysis and the calculation of porosity percent was performed by MATLAB. A filter media was produced based on the optimized conditions of electrospinning and it was certified by the HEPA filter performance test.

Results: In terms of morphological quality of fibers including fiber uniformity, absence of branching and lower numbers of beads, experiment standard No. 2 (STD 2: concentration 16 wt%, voltage 10 kV, and distance 15 cm) had the best combination. Maximum fiber diameter was also observed in STD 2. Among the electrospinning, the highest correlation coefficient was observed between solution concentration and response variables and the relationship between concentration and both fiber diameter and porosity percent was statistically significant (p <0.05 and p <0.01, respectively). A weak positive correlation was found between fiber diameter and porosity percent (r=0.29, p>0.05) and a weak negative relationship was seen between fiber diameter and bead number (r=-0.2, p>0.05).

Conclusion: Solution concentration was found as the most affecting factor on the filter properties, so that the higher concentration leaded to the lower bead number and greater fiber diameter. Increase in fiber diameter resulted in larger pore size and higher porosity. Quadratic models were known for understudy variables. Efficiency of the optimized filter was comparable with the HEPA filter and it had the lower pressure drop.


Identification and Study of Antibiotic Resistance of Bacteria in Membranes of Household Water Filter Systems in Ahvaz
L Kiyani, Se Rezatofighi, H Motamedi,
Volume 9, Issue 4 (3-2017)
Abstract

Background and Objective: The use of household water filter systems has been widely increasing in recent years because of water pollution.  In water filter systems, bacterial biofilm forms on the surface of the membranes, thereby increasing the possibility of transferring antibiotic resistance among bacteria and allowing their entry into the human body. This study analyzed the types of bacteria that grow in the membranes of water filter systems and their antibiotic resistance.

Materials and Methods: For this study, samples were collected from 80 membranes of household water filter systems. Bacteria grown on these membranes were identified using biochemical and molecular methods. Resistance against antibiotics including penicillin, tetracycline, erythromycin, gentamycin, cephalexin, and trimethoprim-sulfamethoxazole was evaluated by disk diffusion method.

Results: The detected bacteria included Pseudomonas, Rhodococcus, Bacillus, Sphingomonas, Zymomonas, Aeromonas, Klebsiella, Citrobacter, Drexia and Achromobacter. Majority of the isolates were identified as Pseudomonas aeruginosa. The antibiogram test showed that most of these bacteria exhibited multi-drug resistance (MDR). Maximum resistance was observed toward cephalexin and the least resistance was toward gentamicin.

Conclusion: The results revealed that membranes of household water filter systems were suitable environments for the growth of bacteria. In these conditions, MDR bacteria presumably could transfer antibiotic resistance genes to bacteria and microflora of the human body through water. Therefore, membranes should be designed in such a manner that not only they can remove the bacteria from water but also kill them.


A review of approaches to direct reverse osmosis membrane recycling: a technical, economic and environmental assessment
Seyedeh Elahe Mahdavian, Seyedeh Masumeh Ghaseminezhad,
Volume 13, Issue 2 (8-2020)
Abstract
Background and Objective: Global market growth of reverse osmosis (RO) has led to an increase in annual disposal of membrane wastes. Therefore, evaluation of membrane waste management strategies is important to reduce their adverse environmental impacts. Due to the widespread domestic RO membrane market and their economic considerations, this study aims at investigation the direct recycling methods of RO membranes to extend their life cycles.
Materials and Methods: Academic search engines and citation databases such Scopus and PubMed was used to retrieve relevant papers. Selected documents were analyzed and compared in three aspects of technical, economic and environmental issues. 
Results: Direct recycling of RO is performed with fouling removal and degradation of polyamide layer (PA) using oxidizing agents like KMnO4 and NaOCl. The degradation rate of the PA layer is controlled by optimizing the oxidant concentration during the oxidation process. Factors such as the type of membrane used, its storage conditions, the operating units’ conditions and the final expected product will determine the required concentration-time values. Strategies to reduce these values are very important from an economic and environmental point of view. Decreasing the concentration of oxidizing agent reduces the chlorinated and halogenated compounds emitted from the oxidizing unit which subsequently lessen their harmful environmental impacts and reduces the energy consumption required for treatment.
Conclusion:  The conversion of RO membranes to porous filters is technically possible by optimizing the conditions. In addition, the proper choice of RO membrane and final product type lead to economic and environmental productivity.

Evaluating the efficiency of a baffled-filter system with sponge media on removal of turbidity, microbial agents, and total organic carbon from water
Zahra Amirilagmuj, Gholamreza Moussavi,
Volume 14, Issue 2 (9-2021)
Abstract
Background and Objective: Access to safe water is critical for protecting human health. Turbidity is one of the main physical parameters that affect the quality of water from both health and aesthetical points of view. Therefore, waters should be treated based on the standards set for turbidity before consumption. This study was performed to determine the performance of a bench-scale baffled filter system for removing the turbidity, microbial population, and total organic carbon (TOC) from the contaminated water.
Materials and Methods:  A lab-scale Plexiglas baffled filter consisting of five compartments with a total working volume of 2 L was designed and constructed. The polyurethane foam cubes were used as filter media. The effect of turbidity (10, 50, and 100 NTU) and surface overflow rate (SOR: 7.5, 10 and 15 m/h) was investigated on the performance of the developed system.
Results: A direct relationship between turbidity, TOC, and microbial density was observed in the inlet water. The efficiency of the baffled filter in the removal of turbidity and the period of the filter operation run both enhanced as the SOR was either decreased or the inlet turbidity was increased. In addition, almost complete removal of TOC from the inlet water was noticed.
Conclusion: The results of the present study indicated that the baffled filter system with sponge media can be a novel and effective method for the removal of turbidity, microbial contaminants and TOC from the natural surface water.

Investigating the factors of pollution and the health risk caused by heavy metals in the dust inside the cabin and air filter of different cars in Ahvaz city
Alireza Zarasvandi, Maryam Delphi, Nadia Azizi, Fatima Rastmanesh, Gazelle Zarasvandi,
Volume 16, Issue 3 (12-2023)
Abstract
Background and Objective: During the last few decades, heavy metal pollution in indoor dust has been widely studied; While, the quality of the environment inside the cars has not been considered enough. Therefore, the specific objectives of this study generally include investigating the levels of selected heavy metals in the dust of private cars collected from Ahvaz city, as well as evaluating the health risk of carcinogenesis and exposure to the dust inside these cars through ingestion, inhalation, and skin absorption.
Materials and Methods: 10 cars were selected for this study. The condition of choosing the cars was not to wash the car for a week. Then, samples were collected and coded from the dust of the air conditioner filter and the cabin of each car. To determine the composition of heavy metals, spectroscopic analysis (ICP) was performed on the samples.
Results: The study of non-carcinogenic risk index (HI) in the present study indicates that the values of more than 1 and the health risk is high. The sequence of HI index values for heavy metals was obtained as  Pb>Cu>Cr> Fe> Zn> Cd> Ni. Evaluated risks from different pathways in children was HQing < HQinhder while in adults follows HQingder< HQinh process. Additionally, the values of enrichment factor of the studied samples showed the maximum and minimum values for Cu (4.3) and Ni (8.3), the maximum and minimum geoaccumulation index for Fe (12.75) and Ni (1.9) and the amount of integrated pollution and pollution index were estimated to be 1.34+E27 and 2.07+E9, respectively, indicating the average range for the studied heavy metals.
Conclusion: According to this study, the risk of non-carcinogenic risk of heavy metals (except Fe and Cu) for children is estimated to be higher than that of adults. Furthermore, the investigation of the CR index for the three carcinogenic heavy metals (cadmium, chromium, and arsenic) has exceeded the safe level, which indicates ingestion and inhale as the target pathways for the worst adverse effects of heavy metals in children andadults, respectively. In the present study, the amount of heavy metals studied is more than the set standards. The results of the current study showedthe more enrichment of heavy metals in the car filter as compared with  the cabin.
 

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