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Showing 3 results for Filtration
Survey of Nano filtration Performance for Hexavalent Chromium Removal fromWater Containing Sulfate
B Mortazavi, B Barikbin, Gh.r Moussavi,
Volume 3, Issue 3 (10-2010)
Abstract

Backgrounds and Objectives: Geological situation and/or anthropogenic contamination contain an increased concentration of ions such as hexavalent chromium as well as some other dissolved components such as sulfate in the upper of the establishedMCLs (50µg/L). In this paper, simultaneous removal of Cr (VI) and sulfate from water was investigated using nanofiltration as a promising method for reaching drinking water standards.
Materials and Methods: For varying pressure, pH , anion and cation solution effect, Sulfate and Cr (VI) concentration which have chosen were levels found in drinking water sources (Cr=0.1- 0.5mg/L) and (SO4-2= 100-800mg/L).Experiments were performed using NaCl, Na2SO4,K2 Cr2O7and anhydrous CrCl3. 6H2O which prepared with de mineralized water on procedure detailed in standard methods. All salts were purchased from Merck Corporation with purity over 99'.
Results: The results for hexavalent chromium experiments showed that when the concentration decreases, the chromate anions were given a better retention to 4 bars (96'). But when the concentration increases, concentration polarization led to increased removal of Cr (VI) (98'). For Cr (III) the influences of the ionic strength as well as the concentrations were strongly dependant on rejection but operating pressure were found weak. In addition, with increasing total dissolved solids, perfect rejection of chromium was seen. The effect of pH showed that better retention was obtained at natural and basic pH.
Conclusion: This study indicates that the nature of anions and cations, driven pressure and pH have significant effect on nano filtration operation. Research findings show that it seems nano filtration is a very good promising method of simultaneous removal of Cr (VI) and sulfate from water.


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.

The treatment of papermaking effluent with the hybrid process of coagulation-ozonation-membrane filtration in order to recycle and reuse
Mahdi Elyasi Kojabad, Ali Aghdami,
Volume 18, Issue 2 (9-2025)
Abstract
Background and Objective: The paper industry is one of the most water-intensive sectors, generating a large volume of wastewater. Proper management of this waste—including its treatment, recycling, and reuse—can help prevent environmental pollution and conserve the country's water resources. In this study, a three-step process consisting of coagulation, ozonation, and membrane filtration was employed to treat papermaking wastewater.
Materials and Methods: A three-step process involving coagulation, ozonation, and membrane filtration was employed to treat the wastewater. In the first stage, polyaluminum chloride (PAC) was used to remove larger particles. This was followed by ozonation to degrade complex organic compounds. The final stage involved membrane filtration to further purify the water. At each stage, the chemical oxygen demand (COD) of the wastewater was measured and analyzed for comparative evaluation.
Results: Each stage played a critical role in the treatment process. Coagulation effectively removed a substantial amount of suspended particles, while ozonation addressed issues related to color and the breakdown of complex compounds. The final stage, membrane filtration, was instrumental in eliminating extremely fine suspended particles. Despite these efforts, the treated effluent exhibited a higher COD than the initial sample, possibly due to the release of intermediate compounds during treatment. However, the process successfully reduced the concentration of crude oil by 66%.
Conclusion: The membrane flux analysis revealed that at pH levels of 11 and 14, the effluent’s membrane flux closely approached that of pure water. This finding highlights the potential effectiveness of the proposed purification method for the treatment and recycling of papermaking wastewater.
 

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