Batik wastewater, in general, is colored and has high concentrations of BOD (biological oxygen demand), COD (chemical oxygen demand), and dissolved and suspended solids. Polysulfone (PSf)-based membranes with the addition of polyvinyl pyrrolidone (PVP) were prepared to treat batik industrial wastewater. PSf/PVP membranes were prepared using the phase inversion method with N-methyl-2 pyrrolidone (NMP) as the solvent. Based on the membrane characterization through FESEM, water contact angle, porosity, and mechanical tests showed a phenomenon where the addition of PVP provided thermodynamic and kinetic effects on membrane formation, thereby affecting porosity, thickness, and hydrophilicity of the membranes. The study aims to observe the effect of adding PVP on polysulfone membrane permeability and antifouling performance on a laboratory scale through the ultrafiltration (UF) process. With the addition of PVP, the operational pressure of the polysulfone membrane was reduced compared to that without PVP. Based on the membrane filtration results, the highest removal efficiencies of COD, TDS (total dissolved solid), and conductivity achieved in the study were 80.4, 84.6, and 83.6%, respectively, on the PSf/PVP 0.35 membrane operated at 4 bar. Moreover, the highest color removal efficiency was 85.73% on the PSf/PVP 0.25 operated at 5 bar. The antifouling performance was identified by calculating the value of total, reversible, and irreversible membrane fouling, wherein in this study, the membrane with the best antifouling performance was PSf/PVP 0.25.

Gas separation processes through membrane permeation have attracted the attention of researchers recently due to their promising applications. In this study, we modified the cellulose acetate (CA) membrane to improve the membrane performance of CO2/CH4 gas separation. The CA membrane was modified by adding polyethylene glycol (PEG) 400 as the carrier and N, N’-methylenebisacrylamide (MBA) as the cross-linking agent. Gamma-ray from cobalt 60 was used as a reaction initiator with variation in irradiation doses. The membrane characterization tests were conducted using scanning electron micrograph (SEM), Fourier transforms infrared (FTIR), and instron tensile strength tester. The permeability and selectivity of the membranes were tested against the single gases CO2 and CH4. The SEM analysis showed the morphology change in the membrane surface by gamma irradiation and a crosslinking agent. The spectra of FTIR showed a change in peak intensity on several polymer functional groups in the presence of gamma-ray irradiation. The tensile strength test showed that membranes with MBA have a higher mechanical strength than those without MBA. Based on the membrane permeability and selectivity tests, CO2 gas permeability was affected by pressure. The ideal selectivity of CO2/CH4 shows that the irradiated membrane has a higher selectivity than that of the non-irradiated membrane.