scholarly journals SELECTIVE HYPERFILTRATION OF HEAVY METAL IONS. ION-ASSOCIATION SORPTION AND PERMEATION OF METAL COMPLEXES ON CELLULOSE ACETATE MEMBRANES

1985 ◽  
Vol 14 (6) ◽  
pp. 829-832
Author(s):  
Takashi Hayashita ◽  
Motohiro Hamada ◽  
Makoto Takagi
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Metal Complexes ◽  
Cellulose Acetate ◽  
Heavy Metal Ions ◽  
Ion Association ◽  
Cellulose Acetate Membranes

scholarly journals Cellulose acetate-Sn(IV) molybdophosphate: A biopolymer supported composite Exchanger for the removal of selected heavy metal ions

2020 ◽  
Vol 34 (2) ◽  
pp. 259-276
Author(s):  
A. M. Taddesse ◽  
T. T. Ketema ◽  
E. Teju
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Cellulose Acetate ◽  
Heavy Metal Ions ◽  
Sol Gel ◽  
Basic Medium ◽  
Separation Potential ◽  
Toxic Heavy Metal ◽  
Gel Method ◽  
Sol Gel Method

Cellulose acetate-tin(IV) molybdophosphate (CATMP) composite exchanger was prepared by mixing biopolymer celluloseacetate with its inorganic counterpart tin(IV) molybdophosphate (TMP) using sol‑gel method. The physical characterization of the as synthesized exchanger was carried out by FTIR, XRD, BET, TGA-DTG and SEM-EDX techniques. Chemical properties such as ion exchange capacity, chemical stability, pH and distribution behavior were carried out. The average IEC of the composite material, as determined by batch equilibrium, was found to be 2.43 meq/g for Na+ ion; higher than its inorganic counterpart, i.e. 1.41 meq/g. This exchanger was also found to be stable in water, acids and organic solvents, but unstable in basic medium. The distribution study (Kd) of the exchanger in different solvent systems showed promising separation potential of the exchanger towards metal ions of analytical interest from a given mixture of toxic heavy metal ions. The sorption studies revealed that the material was selective for Cr(III) and Cd(II) ions and moderately selective for Co(II) ion in solvents employed in this work. Its selectivity was examined by achieving some important binary separations of metal cations on its column indicating its promising application in environmental pollution abatement.                     KEY WORDS: Cation exchanger, Biopolymer, Organic-inorganic hybrid, Sol–gel method, Binary distribution   Bull. Chem. Soc. Ethiop. 2020, 34(2), 259-276 DOI: https://dx.doi.org/10.4314/bcse.v34i2.5

Composite membranes with cellulose acetate surface layer for water treatment

2021 ◽  
Vol 2 ◽  
pp. 32-40
Author(s):  
D. D. Fazullin ◽  
◽  
L. I. Fazullina ◽  
G. V. Mavrin ◽  
I. G. Shaikhiev ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Cellulose Acetate ◽  
Heavy Metal Ions ◽  
Tap Water ◽  
Substrate Surface ◽  
Composite Membranes ◽  
Specific Productivity ◽  
Absorption Bands ◽  
Ultrathin Layers

Microporous composite membranes containing from one to three ultrathin layers were obtained by multistage immersion of a paper base in a solution of cellulose acetate in acetone. The physicochemical properties of membranes have been studied and the parameters of membrane separation of heavy metal ions from tap water have been determined. An increase in the particle size and a decrease in the absolute value of the ζ-potential with an increase in the concentration of cellulose acetate in acetone were revealed. It was found that the porosity of the membranes increased from 47 % to 51 % depending on the number of ultrathin cellulose acetate layers on the substrate surface. A decrease in the moisture absorption of composite membranes and an increase in the contact angle of wetting with distilled water from 30.0° to 68.8°, depending on the number of ultrathin layers, were noted. Microscopic examination of the membrane surface showed that the ultrathin layer consists of many pores with sizes less than 1 micron. The absorption bands in the IR spectra of cellulose acetate and the surface of the composite microporous cellulose acetate (MAC) membrane are identical. The retention capacity of MAC composite membranes, determined by iron ions from an iron (III) chloride solution, ranged from 47.5 to 97.4 % depending on the number of cellulose acetate layers on the substrate surface with a specific productivity of 27.9 to 7399 dm3/(m2·h) and a pressure of 0.35 MPa. A high selectivity of a microporous membrane of three layers of cellulose acetate (MAC3) with respect to heavy metal ions contained in tap water was established: Cr3+ (96 %) > Cu2+ (92 %) > Fe3+ (90 %) > Mn2+ (45 %).

Phase Studies and Efficient Recovery of Inorganic Metal Salts from the Microemulsion System Using a Sugar-Based Non-Ionic Surfactant

2021 ◽  
Vol 58 (4) ◽  
pp. 265-270
Author(s):  
Shehnaz H. Solanki ◽  
Sandeep R. Patil
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Metal Complexes ◽  
Heavy Metal Ions ◽  
Potassium Thiocyanate ◽  
Ionic Surfactant ◽  
Microemulsion System ◽  
Recovery Efficiency ◽  
Nickel Ions ◽  
Efficient Recovery

Abstract In the present work, the phase behaviour of the microemulsion system formulated by using water, organic solvent, and a sugar-based non-ionic surfactant was investigated in detail. We have used a sugar-based non-ionic surfactant for formulation of microemulsion, as it is a greener alternative for the formulation of a microemulsion system, owing to the following aspects: a) better physicochemical properties as compared to that of the conventional non-ionic surfactants, b) non-toxicity, and c) biodegradability. The extraction of heavy metal ions from the metal complexes as well as the recovery efficiency of heavy metal ions using a microemulsion system has been investigated. The maximum absorbance values of metal ions, after recovery from the metal complexes, were measured. Moreover, the UV-Visible spectrophotometric studies revealed that the absorbance increases with an increase in metal ion concentration in the aqueous phase while its value decreases with an increase in the concentration of potassium thiocyanate in the aqueous phase after the extraction of the metal ions from the metal complexes. Furthermore, it has also been evaluated that 4.0 mol/L potassium thiocyanate is the optimum concentration required for efficient recovery of 0.05 mol/L cobalt ion as well as nickel ions. The recovery efficiency of cobalt ions was found to be 97%, whereas that of nickel ions was determined to be 94% respectively. In addition to being an environmentally friendly approach, the present work is an economically viable option too, as it deals with the studies related to the extraction and efficient recovery of metal ions.

Effects of heavy metal ions on N-nitrosodimethylamine (NDMA) formation

RSC Advances ◽  
2016 ◽  
Vol 6 (74) ◽  
pp. 70474-70479
Author(s):  
Yameng Liu ◽  
Yongdong Liu ◽  
Rugang Zhong ◽  
Bin Peng ◽  
Henry F. Schaefer, III
Keyword(s):  
Density Functional Theory ◽  
Heavy Metal ◽  
Metal Ions ◽  
Metal Complexes ◽  
Heavy Metal Ions ◽  
Density Functional ◽  
Functional Theory

The mechanism of NDMA formation as affected by heavy metal complexes [MONO]+ (M = Cd, Pb, Hg) was investigated using density functional theory (DFT). Three possible NDMA formation pathways are discussed.

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