MODIFIED CARRAGEENAN MEMBRANE WITH POLYVINYL ALCOHOL (PVA) FOR METHYLENE BLUE DYES SEPARATION

• Main Author: Majid Madani, Anwar
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/64821
• Institution: Institut Teknologi Bandung

Membrane filtration is a wastewater treatment technology that has the potential to be developed because its application is quite simple, fast and very efficient. Membrane fouling is a critical problem of this technology. An alternative that can be used is the use of biopolymer as a membrane material because it can increase the hydrophilicity of the membrane. Carrageenan is an anionic polygalactose biopolymer with a fairly high sulfate ester functional group (15-40%). The presence of sulfate ester groups and their gel-forming characteristics make carrageenan potential to be used as a material for membrane manufacture for the application of methylene blue cationic dye separation. Methylene blue itself is a contaminant in textile industry waste that can have a negative impact on the surrounding environment. Carrageenan membranes were successfully fabricated using ?-carrageenan biopolymer and the addition of polyvinyl alcohol (PVA) as an additional polymer and PEG as a porogen. The membrane was formed after immersion in a solution of KCl-boric acid as a crosslinker. The functional groups and specific binding of the CarS-PVA membrane were identified on IR characterization. At 1240 cm-1 there is a peak of the symmetric stretching vibration of the O=S=O sulfate ester bond, at 1068 cm-1 there is a peak of the C-O-C glycosidic bond vibration, at 921 cm-1 there is a peak originating from the 3,6-anhydro?-D-galactose ring structure. and at 844 cm-1 there is a peak of the stretching vibration of the C– O–SO3 bond on the D-galactose-4-sulfate ring. The PVA polymer was identified at 1732 cm-1 from the vibration of the C=O acetyl group. Crosslinks with boric acid were identified at 1131 cm-1 from the bending vibration of the C-O-B bond and 664 cm-1 from the O-B-O strain vibration. The membrane formed has a hydrophilic character with a contact angle of 48,9o and has a swelling degree of 12,25%. CarS-PVA membrane has a high rejection rate for methylene blue, which is >98%, but has a relatively low water flux value of 4,24 L/m2 hour. The CarS-PVA membrane has an FRR 1 value of 165.17% and a fouling phenomenon is observed at an FRR 2 value of 78.09%. Reusability test showed CarS-PVA membrane can be used with good enough performance for 2 cycles with KCl-boric acid solution pH 1 as the washing solution. The selectivity test with a mixture of methylene blue, congo red and reactive yellow 145 dyes showed that the membrane could be used to separate a mixture of cationic and anionic dyes. The pH effect test showed that there was a change in the structure of ?-carrageenan at low pH which caused a change in the rejection value and water flux.