Removal of potassium chloride by nanofiltration from ion-exchanged solution containing potassium clavulanate

Abstract

In this study, nanofiltration with NF200 membrane was employed to remove KCl from ion-exchanged solutions containing potassium clavulanate. The pore radius of NF200 membrane was estimated to be around 0.39 nm. The effects of operating pressure on separation performance were investigated in a range of 100-400 psig. The influences of cross-flow velocity (0.14-0.70 cm/s), temperature (4-25 degrees C), and feed composition were also investigated. In all experiments, clavulanate rejection showed high levels from 0.91 to 0.99, while chloride rejection ranged from 0.06 to 0.54. In a case at an operating pressure of 50 psig and 25 degrees C, as much as 94% of clavulanate was retained while 94% of chloride was removed, indicating that NF200 membrane was a suitable choice for selectively removing KCl. NF200 membrane also showed a stable performance in the operational stability test with an ion-exchanged solution obtained by treating actual fermentation broth.

Energy barriers to anion transport in polyelectrolyte multilayer nanofiltration membranes: Role of intra-pore diffusion

“…4A). The pressure effect was thus more pronounced as the need for ion dehydration was higher, in agreement with reported observations [25,62]. The energy barrier to fluoride transport decreased significantly with pressure (p < 0.001), while no pressure effects on the energy barriers to bromide transport were observed at the operating pressures applied here, suggesting that bromide transport was largely convection-controlled.…”

“…An increase in the two operating parameters led to an increase in bromide flux. Generally, solute flux increases at higher pressure (up to a certain critical pressure) mostly due to enhanced convective flow [25,60], while higher temperature leads to increased diffusion, decreased water viscosity, and potentially altered membrane pore structure (e.g., due to fusion of adjacent pores) [61][62][63]. The effect of temperature on the PEM pore sizes and water viscosity was investigated by comparing the calculated energy barriers for water and ion transport through the membranes (Fig.…”

Quantifying barriers to monovalent anion transport in narrow non-polar pores

“…32,33 In nanofiltration membranes, energy barriers to salt transport evaluated experimentally with the Arrhenius relationship have been reported in the range of 2.3-12.9 kcal mol À1 . [34][35][36][37] Conventionally, selectivity in nanofiltration is evaluated using retention. The general ordering of the retention of these salts is fluoride 4 chloride 4 nitrate 4 nitrite.…”

“…[34][35][36][37] Conventionally, selectivity in nanofiltration is evaluated using retention. The general ordering of the retention of these salts is fluoride 4 chloride 4 nitrate 4 nitrite.…”

Experimental Energy Barriers to Anions Transporting through Nanofiltration Membranes

“…Energy barriers can be overcome by any driving force, such as directional pressure, flow and concentration, − , and nondirectional temperature. An increase in system temperature increases internal energy, solute diffusion, and polymer chain mobility, reduces solvent viscosity, and can lead to changes in pore size/membrane structure. ,,− Temperature is the standard driving force used to quantify energy barriers via the Arrhenius method and has been used to determine energy barriers in membranes. ,,,− The temperature dependence of the flux of a specific solute through a membrane can be described by the Arrhenius relationship if it is linear. The energy barriers represent the net energetic expense of solute transport and thus include contributions from all acting mechanisms.…”