Subagjo

Determination of thermodynamic properties of polysulfone/PEG membrane solutions based on Flory-Huggins model

Flory-Huggins (F-H) model was used to study thermodynamic properties of polysulfone-based membrane solution that consists of water, dimethylacetamide (DMAC), polysulfone (PSf), and polyethylene glycol (PEG400). The thermodynamic properties of membrane solution were examined based on equilibrium composition in a ternary diagram of the membrane system, which known as binodal curve. The binary interaction parameters of each component in F-H model were predicted based on cloud point experiment at various PSf and PEG400 concentrations and used to calculate the binodal curve in ternary diagram. It was obtained that the binary interaction parameters in the membrane solution are: X13 (water–PSf) = 6.76, g14 (water–PEG400) = 0.51, g23 (DMAc–PSf) = 0.46, g24 (DMAc–PEG400) = 0.46, and g34 (PSf–PEG400) = −0.53. Based on the thermodynamic analysis in the ternary diagram, low solubility of membrane solution was achieved when 20 wt% of PSf was blended with a high concentration of PEG400 (20–30%). It means that the membr...

The effect of polymer concentration on flux stability of polysulfone membrane

The influence of various polymer concentrations on flux stability of polysulfone membranes was investigated. The polysulfone membrane was prepared by blending polysulfone in DMAc with 25%wt concentration of PEG400 and 4% wt concentration of acetone. It was found that the pure water flux was sharply decreased from 1230 to 7 Lm-2h-1, when the polysulfone concentration was increased from 14% to 24%wt. Furthermore, the increase of polysulfone concentration also affects the fouling behavior of the membranes, in which almost of 90% of FRR was achieved by the addition of 18 %wt of polysulfone concentration. It was suggested that fouling formed on the membrane surface was dominated by reversible fouling, thus it could be easily cleaned by flushing method. In addition, the applied transmembrane pressure (TMP) also plays an important role in fouling behavior of polysulfone membrane. It was observed that irreversible fouling of organic matter was deteriorated by the increase of TMP, which contributed to the reduction of water flux. More stable membrane flux performance was achieved although it was operated at high TMP, when 20% wt concentration of polysulfone was added into membrane solution.The influence of various polymer concentrations on flux stability of polysulfone membranes was investigated. The polysulfone membrane was prepared by blending polysulfone in DMAc with 25%wt concentration of PEG400 and 4% wt concentration of acetone. It was found that the pure water flux was sharply decreased from 1230 to 7 Lm-2h-1, when the polysulfone concentration was increased from 14% to 24%wt. Furthermore, the increase of polysulfone concentration also affects the fouling behavior of the membranes, in which almost of 90% of FRR was achieved by the addition of 18 %wt of polysulfone concentration. It was suggested that fouling formed on the membrane surface was dominated by reversible fouling, thus it could be easily cleaned by flushing method. In addition, the applied transmembrane pressure (TMP) also plays an important role in fouling behavior of polysulfone membrane. It was observed that irreversible fouling of organic matter was deteriorated by the increase of TMP, which contributed to the reductio...