The Application of the Nanofiltration Membrane NF270 for Separation of Fermentation Broths

Abstract

The potential for nanofiltration (NF) in removing both relatively low molecular weight (MW) organic species and charged solutes from complex media is noteworthy. The main aim of the current work was to improve understanding of the separation mechanisms of fermentation broths components in the NF process. For this purpose, the experimental investigations were performed using the commercial polyamide NF270 membrane. The feed solution was ultrafiltered 1,3-propanediol (1,3-PD) broths. The separation results were analyzed and discussed in light of the detailed characteristics of both the membrane and the broth components. It has been noted that the membrane ensured the complete 1,3-PD permeability and significant rejection of some feed components. A thorough analysis showed that the retention of carboxylic acids was based on both the Donnan effect and sieve mechanism, according to the following order: succinic acid > lactic acid > acetic acid > formic acid. Indeed, acids retention increased with increasing charged acids ions valency, Stokes radius (rS) as well as MW, and decreasing diffusion coefficient (D). In turn, for ions, the following orders retention was determined: SO42− = PO43− > Cl− and Ca2+ > Na+ > NH4+ ~ K+. It indicated that the ions retention increased with increasing ions charge density, hydrated radius (rH), and hydration energy (Eh). It showed that the separation of the ions was based on the Donnan exclusion, sieving effect, and dielectric exclusion.

Removal of total phosphate and sulfate from industrial wastewater by recirculating flow in nanofiltration

“…The total phosphate and sulfate that can be removed is the total phosphate that is insoluble in water so that it can undergo the sieving and Donnan exclusion mechanism [14]; [15]. The sieving mechanism is based on size, where a membrane with a certain pore size allows smaller molecules to pass through and blocks larger molecules, while the Donnan exclusion mechanism is based on the selective permeability of charged ions.…”

Study of the removal of nitrate and dissolved iron pollutants from industrial wastewater to become raw water using nanofiltration

“…The probability value above 0.05 (p value > 0.05) did not, however, result in any appreciable variations in nitrate removal due to variation in intersection. Nitrate is a pollutant that tends to have a negative charge, so the Donnan exclusive mechanism can work in this case in conjunction with the filtering mechanism [13]. Based on Figure 3., represents the removal of dissolved iron from the industrial wastewater of PT.…”

“…where Qp is the value of the permeate flow rate and Qo is the feed water flow rate [13]. The data is used to calculate the flow rate using a rotameter.…”

“…where Cp is the treated water's concentration value and Co is the feed water's concentration value [13]. Samples are taken at the reservoir (inlet) and after they have passed through the membrane (outlet) in order to measure the amounts of nitrate and dissolved iron.…”

Research Progress of Water Treatment Technology Based on Nanofiber Membranes

“…NF is an energy-saving, environmentally friendly, and simple separation technology with the unique ability to remove low-molecular-weight organics and charged solutes [ 67 , 68 , 69 , 70 ]. NF membranes are usually neutral or negatively charged membrane materials [ 71 ] with a microporous structure with a pore size less than 2 nm and molecular weight cut-off in the range from 200 to 1000 Da [ 72 , 73 ].…”