Fouling analysis for different ultrafiltration membranes in reactive dyeing wastewater treatment

Zaf, Ruken Dilara
Textile industry produces wastewater that is often very rich in salt and color, containing residues of dyes and other chemicals. Treating this wastewater to exceptionally high quality standards, typically for reuse purposes, necessitates advanced treatment methods among which membrane technology is a leading one. However, membrane fouling which can be caused by dissolved and particulate solids appears as the major limitation with the use of membranes in wastewater reclamation that leads to reduced efficiency and a shorter membrane life. In this branch of a more comprehensive project on water recovery from reactive dyeing wastewater (RDW), the relationship between membrane fouling and membrane type was investigated in ultrafiltration (UF) process. The aim of the work is pointing the most suitable membrane type for RDW treatment with regards to its fouling behavior and treatment performance. Within this context, commercial membranes such as polyether sulfone (PES), regenerated cellulose (RC), thin film composite (TFC) and poly(piperazine amide) (PPZ) were used. These membranes were compared based on their permeate flux changes, fouling tendencies/cleanabilities and color, total organic carbon (TOC), turbidity and conductivity treatment efficiencies. As a concurrent execution, in order to correlate membrane surface and fouling characteristics, the contact angles and roughness of these different UF membranes were investigated. The overall results achieved indicated that TFC membrane showed the best performance by providing lowest fouling tendency, acceptable cleanability and good treatment performance with the highest color removal among the tested membranes. In the meanwhile, 5 kDa RC membrane was found as the weakest one because of its smallest TOC and color removal whereas the cleanabilities of PES and 1 kDa RC membranes were observed as the lowest ones among all membranes. The highest flux decline was observed during PPZ membrane filtration which also had the highest average roughness (Ra) and contact angle.  
Citation Formats
R. D. Zaf, “Fouling analysis for different ultrafiltration membranes in reactive dyeing wastewater treatment,” M.S. - Master of Science, Middle East Technical University, 2017.