Separation of Chromium from Tannery Effluent by Reverse Osmosis

2003 ◽  
Author(s):  
Biman Mukherjee ◽  
Asit Kumar Mitra
Keyword(s):  
Reverse Osmosis ◽  
Tannery Effluent

scholarly journals Tannery Effluent Treatment by Nanofiltration, Reverse Osmosis and Chitosan Modified Membranes

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 378
Author(s):  
Asmaa Zakmout ◽  
Fatma Sadi ◽  
Carla A. M. Portugal ◽  
João G. Crespo ◽  
Svetlozar Velizarov
Keyword(s):  
Reverse Osmosis ◽  
Fourier Transforms ◽  
Divalent Cations ◽  
Appropriate Technology ◽  
Effluent Treatment ◽  
Polymeric Membrane ◽  
Tannery Effluent ◽  
Reflectance Ftir ◽  
Environmentally Sound ◽  
Water Pollutant

The objective of this work is to develop an appropriate technology for environmentally sound membrane-based purification of a tannery effluent assuring, simultaneously, the recovery of chromium, considered as the most hazardous inorganic water pollutant extensively used in leather tanning. A comparison between the permeate fluxes obtained during treatment of a synthetic tannery effluent through nanofiltration (NF270 and NF90 membranes) and reverse osmosis (BW30 and SW30) membranes was first performed. Then, a dedicated polymeric membrane was prepared by coating chitosan (cs) on a polyethersulfone (PES) microfiltration membrane (cs-PES MFO22) support. The resulting membrane was characterized by Fourier Transforms Infrared Spectroscopy Attenuated Total Reflectance (FTIR-ATR), Emission Scanning Electronic Microscopy (SEM) to confirm the process of surface modification and cross-linking of chitosan with glutaraldehyde. This membrane was found to be highly effective for chromium removal (>99%), which was more than eight times higher in reference to monovalent cations (e.g., Na+ and K+) and more than six times higher in reference to the divalent cations (Mg2+ and Ca2+) studied. The reverse osmosis permeate conforms to local Algerian regulations regarding being discharged directly into the natural environment (in this case, Reghaia Lake) or into urban sewers linked to wastewater biological treatment stations. While the SW30 membrane proved to be the most effective for purification of the tannery effluent, the chitosan modified membrane proved to be appropriate for recovery of chromium from the reverse osmosis concentrate.

Desalination of Mixed Tannery Effluent with Membrane Bioreactor and Reverse Osmosis Treatment

2005 ◽  
Vol 39 (21) ◽  
pp. 8505-8511 ◽  
Author(s):  
W. G. Scholz ◽  
P. RougÉ ◽  
A. BÓdalo ◽  
U. Leitz
Keyword(s):  
Reverse Osmosis ◽  
Membrane Bioreactor ◽  
Tannery Effluent

scholarly journals Recovery of Cr(III) from Tannery Effluents by Diafiltration Using Chitosan Modified Membranes

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2598
Author(s):  
Asmaa Zakmout ◽  
Fatma Sadi ◽  
Svetlozar Velizarov ◽  
João G. Crespo ◽  
Carla A. M. Portugal
Keyword(s):  
Reverse Osmosis ◽  
Ionic Species ◽  
Tannery Wastewater ◽  
Tannery Effluent ◽  
Proof Of Concept ◽  
Tannery Effluents ◽  
Selective Recovery ◽  
Preferential Adsorption ◽  
Tanning Process ◽  
First Time

The selective recovery of chromium remaining in tannery effluents after the leather tanning process is highly desirable to potentiate its reuse, simultaneously minimizing the ecotoxicity of these effluents. To the best of our knowledge, this work evaluates for the first time the ability of a chitosan-based membrane for selective recovery of chromium from a tannery wastewater by subsequent diafiltration and selective chromium desorption, envisaging their integration after tannery wastewater treatment by reverse osmosis (RO). A polyethersulfone (PES) microfiltration membrane top-coated with a chitosan layer (cs-PES MF022) was used for selective recovery of Cr(III), from concentrate streams obtained by treatment of synthetic and real tannery effluents through reverse osmosis (RO), through a diafiltration process. The diafiltration of the RO concentrates was conducted by an intermittent addition of water acidified to pH 3.6. The prepared cs-PES MF022 membranes were able to retain 97% of the total mass of Cr(III) present in the RO concentrates, from a real tannery effluent, with a selectivity of 4.2 and 5 in reference to NH4+ and Cl−, respectively, 12.9 and 14.6 in reference to K and Na, and > 45 in reference to Mg, Ca, and S. Such a high selectivity is explained by the preferential adsorption of Cr(III) onto chitosan, and by the relatively high permeability of cs-PES MF022 membranes to the other ionic species. Proof of concept studies were performed to investigate the desorption of Cr(III) at pH 2 and 5.8. A higher Cr(III) desorption degree was obtained at pH 2, leading to a final solution enriched in Cr(III), which may be re-used in tannery operations, thus improving the process economy and reducing the hazardous impact of the effluents discharged by this industry.

Cellulose Acetate Reverse Osmosis Membrane Structure

1972 ◽  
Vol 30 ◽  
pp. 528-529
Author(s):  
H. K. Plummer ◽  
E. Eichen ◽  
C. D. Melvin
Keyword(s):  
Cellulose Acetate ◽  
Reverse Osmosis ◽  
Membrane Structure ◽  
Freeze Drying ◽  
Dense Layer ◽  
Water Removal ◽  
Reverse Osmosis Membrane ◽  
Correct Interpretation ◽  
Electron Image ◽  
Scanning Electron

Much of the work reported in the literature on cellulose acetate reverse osmosis membranes has raised new and important questions with regard to the dense or “active” layer of these membranes. Several thickness values and structures have been attributed to the dense layer. To ensure the correct interpretation of the cellulose acetate structure thirteen different preparative techniques have been used in this investigation. These thirteen methods included various combinations of water substitution, freeze drying, freeze sectioning, fracturing, embedding, and microtomy techniques with both transmission and scanning electron microscope observations.It was observed that several factors can cause a distortion of the structure during sample preparation. The most obvious problem of water removal can cause swelling, shrinking, and folds. Improper removal of embedding materials, when used, can cause a loss of electron image contrast and, or structure which could hinder interpretation.

Performance Study of Some Reverse Osmosis Systems for Removal of Uranium and Total Dissolved Solids in Underground Waters of Punjab State, India

2014 ◽  
Vol 4 (2) ◽  
pp. 467-476
Author(s):  
Nisha Sharma ◽  
Jaspal Singh ◽  
Barjinder Kaur
Keyword(s):  
Drinking Water ◽  
Reverse Osmosis ◽  
State Government ◽  
Total Dissolved Solids ◽  
Internal Exposure ◽  
Drinking Water Source ◽  
Performance Study ◽  
Dissolved Solids ◽  
Underground Waters ◽  
High Concentrations

Radionuclides (uranium, thorium, radium, radon gas etc.) are found naturally in air, water, soil and rock. Everyday, we ingest and inhale these radionuclides through the air we breathe and through food and water we take. Out of the internal exposure via ingestion of radionuclides, water contributes the major portion. The natural radioactivity of water is due to the activity transfer from bed rock and soils. In our surveys carried out in the past few years, we have observed high concentrations of uranium and total dissolved solids (TDS) in drinking waters of some southern parts of Punjab State exceeding the safe limits recommended by national and international agencies. The main drinking water source is the underground water procured from different depths. Due to the highly saline taste, disorders in their digestive systems and other ailments, people are installing reverse osmosis (RO) systems in their houses. Some RO systems have been installed on commercial basis. The state government is also in the process of installing community RO systems at the village level. As high values of uranium are also undesired and may pose health hazards due to radioactivity and toxicity of uranium, we have conducted a survey in the field to study the performance of various RO systems for removal of uranium and TDS. Water samples from about forty RO systems from Faridkot, Mansa, Bathinda and Amritsar districts of Punjab State were collected and analyzed. Our results show that some RO systems are able to remove more than 99% of uranium in the underground waters used for drinking purposes. TDS values are also reduced considerably to the desired levels. So RO systems can be used to avoid the risk of unduly health problems posed by high concentrations of uranium and TDS in drinking water.

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