scholarly journals EFFECT OF pH ON FLUX DECLINE DURING FRACTIONATION OF GLUCOSE FROM CELLULOSE HYDROLYSATE THROUGH A POLYSULFONE MEMBRANE

2016 ◽  
Vol 20 (6) ◽  
pp. 1413-1420 ◽  
Author(s):  
Abdul Wahab Mohammad
Keyword(s):  
Polysulfone Membrane ◽  
Effect Of Ph ◽  
Flux Decline ◽  
Cellulose Hydrolysate

Effect of pH on flux during ultrafiltration of sweet whey and buttermilk

1995 ◽  
Vol 62 (3) ◽  
pp. 441-449 ◽  
Author(s):  
Harohally G. Ramachandra Rao ◽  
Michael J. Lewis ◽  
Alistair S. Grandison
Keyword(s):  
Concentration Polarization ◽  
Combined Effects ◽  
Ph Change ◽  
Deposit Formation ◽  
Effect Of Ph ◽  
Flux Decline ◽  
Sweet Whey ◽  
Effects Of Ph

SummaryThe flux patterns for sweet whey and buttermilk were strongly influenced by pH. Increasing the pH of buttermilk from 6·6 to 8·0 tended to reduce initial flux values and reduce deposit formation on the membrane as indicated by lower values for the fouling coefficient. Flux was mostly controlled by concentration polarization. Reducing the pH below 6·6 increased the flux but caused more deposit on the membrane as indicated by high fouling coefficient values. Almost the opposite was found for sweet whey. The initial flux increased as pH increased, followed by considerable flux decline, which was linked to greater fouling of the membrane. Reducing the pH reduced the initial flux considerably but also reduced further fouling. These changes are thought to be brought about by the combined effects of pH change on the proteins and minerals, and in particular on calcium.

Separation of oil–water emulsion from car washes

2000 ◽  
Vol 41 (10-11) ◽  
pp. 109-116 ◽  
Author(s):  
S. Panpanit ◽  
C. Visvanathan ◽  
S. Muttamara
Keyword(s):  
Water Usage ◽  
Polysulfone Membrane ◽  
Water Emulsion ◽  
Oil Emulsion ◽  
Toc Removal ◽  
Flux Decline ◽  
Nonionic Emulsifier ◽  
Oil Water ◽  
Membrane Type ◽  
Competitive Ions

The potentials of UF and NF membrane processes have been evaluated for separation of oil water emulsion generated from car washing operations. Using membranes, wastewater can be effectively recycled and fresh water usage could be reduced. The parameters studied were membrane type, emulsifier types, pressure and competing compounds. Both an-ionic and non-ionic emulsifiers were used for the experimental runs. The Ca2+ and Mg2+ were used as the main competitive ions. Results indicate that a polysulfone membrane caused more flux reduction than the cellulose acetate and thin film polyamide membranes. Higher concentrations of emulsifier presented negative flux decline in both UF and NF membranes. However, the presence of nonionic emulsifier in oil emulsion caused more significant flux reduction than an anionic emulsifier. The NF membrane produced higher TOC removal and less fouling than UF. The results indicate that increased competitive Ca2+ and Mg2+ ions resulted in significant positive NF flux and TOC removal.

scholarly journals Novel Carbon Quantum Dots/Silver Blended Polysulfone Membrane with Improved Properties and Enhanced Performance in Tartrazine Dye Removal

Membranes ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 175
Author(s):  
Jin Yee Gan ◽  
Woon Chan Chong ◽  
Lan Ching Sim ◽  
Chai Hoon Koo ◽  
Yean Ling Pang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Dye Removal ◽  
Pure Water ◽  
Water Flux ◽  
Carbon Quantum Dots ◽  
Lemon Juice ◽  
Surface Charges ◽  
Polysulfone Membrane ◽  
Flux Decline ◽  
Dye Rejection

This study produced a novel polysulfone (PSF) membrane for dye removal using lemon-derived carbon quantum dots-grafted silver nanoparticles (Ag/CQDs) as membrane nanofiller. The preparation of CQDs was completed by undergoing hydrothermal treatment to carbonize the pulp-free lemon juice into CQD solution. The CQD solution was then coupled with Ag nanoparticles to form Ag/CQDs nanohybrid. The synthesized powders were characterized in terms of morphologies, functional groups and surface charges. A set of membranes was fabricated with different loadings of Ag/CQDs powder using the nonsolvent-induced phase separation (NIPS) method. The modified membranes were studied in terms of morphology, elemental composition, hydrophilicity and pore size. In addition, pure water flux, rejection test and fouling analysis of the membranes were evaluated using tartrazine dye. From the results, 0.5 wt % of Ag/CQD was identified as the optimum loading to be incorporated with the pristine PSF membrane. The modified membrane exhibited an excellent pure water permeability and dye rejection with improvements of 169% and 92%, respectively. In addition, the composite membrane also experienced lower flux decline, higher reversible fouling and lower irreversible fouling. This study has proven that the addition of CQD additives into membrane greatly improves the polymeric membrane’s properties and filtration performance.

Iono-molecular Separation with Composite Membranes II. Preparation and characterization of polysulphone and composite nanoparticles

2017 ◽  
Vol 68 (2) ◽  
pp. 203-209
Author(s):  
Hussam Nadum Abdalraheem Al Ani ◽  
Anca Maria Cimbru ◽  
Corneliu Trisca-Rusu ◽  
Szidonia Katalin Tanczos ◽  
Adriana Cuciureanu ◽  
...  
Keyword(s):  
Chemical Species ◽  
Composite Membranes ◽  
Ammonium Persulfate ◽  
Operating Pressure ◽  
Polysulfone Membrane ◽  
Polymeric Nanoparticle ◽  
Molecular Separation ◽  
Copper Complexation ◽  
Molecular Separations ◽  
Methyl Pyrrolidone

This paper illustrates the possibility of producing iono-molecular separations using ionic colloidal ultrafiltration membrane of polysulfone synthetic solutions of cupric ions and nitro phenols through ultrafiltration assisted by polymeric nanoparticle composites based on polysulfone. In the present work, in order to reduce the operating pressure and increase the flow of water we are using the process of ultrafiltration through a polysulfone membrane in N-methylpyrrolidone 10% prepared by coagulation in isopropanol. The nanoparticles needed in colloidal ultrafiltration had been obtained through the immersion technique of precipitation of a solution of 5% PSf in N-methyl pyrrolidone containing 3% aniline in lower alcohols: methanol, ethanol, and isopropanol, followed by the oxidation of the remaining aniline in a solution of 10% hydrochloric acid and ammonium persulfate. The Nanoparticles of polysulfone (NP-PSf) and The three obtained variants of nanoparticles composites (NP-PSf-PANI) were morphologically (SEM) and (AFM), structurally and compositionally (FTIR) characterized and the results show that nanoparticles polysulfone have a much lower range than the composites. The Possibility of copper complexation by both nitrophenols, and by nanoparticle surface probably lead to the formation of more stable aggregates in the supply, which can sufficiently justify the increased retention. The Retentions of the chemical species in question use in all the tests made the same series:R NP-PSf-PANI-M] R NP-PSf-PANI-E] R NP-PSf-PANI-P] R NP-PSf

Effect of pH and NH4NO3 as a Spray Additive on Penetration of NAA Through Isolated Tomato Fruit Cuticle

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 550a-550 ◽  
Author(s):  
Royal G. Fader ◽  
Martin J. Bukovac
Keyword(s):  
Direct Measurement ◽  
Sodium Citrate ◽  
Tomato Fruit ◽  
Initial Slope ◽  
Control Effect ◽  
Solution Ph ◽  
Ph Change ◽  
Effect Of Ph ◽  
Spray Droplets ◽  
Partition Behavior

We have reported that NH4NO3 (AN, 8 mM, pH 4.2), applied as simulated spray droplets, enhanced penetration of 14C-NAA through isolated leaf and fruit cuticles. One explanation for this response is that AN depresses NAA (pKa= 4.2) dissociation, increasing the nondissociated moiety, which penetrates more readily than the anion (NAA'). Direct measurement of AN (concn. 0-800 mM) effect on NAA (215 μM) dissociation as indexed by change in solution pH revealed no significant effect, with a pH change from 4.19 to 4.05. This change is not sufficient to account for the observed enhancement. When 14C-NAA, buffered (20 mM sodium citrate) at pH 3.2, 4.2, 5.2, 6.2, was partitioned against chloroform, there was a marked increase in NAA partitioning into chloroform as pH was decreased. AN (8 mM) did not alter this partition behavior, also indicating no effect on NAA dissociation. However, in cuticle penetration studies, using a finite dose system with 14C-NAA buffered at pH 3.2, 4.2, 5.2, 6.2, and in the presence and absence of 8 mM AN, there was no marked or consistent pH or AN (-70 to + 232 % of no AN control) effect on penetration as indexed by initial slope (4-12 h) or penetration after 120 h. The possible effects of AN and buffer on penetration of 14C-NAA from the droplet deposit will be discussed.

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