Treatment of silk production wastewaters by membrane processes for sericin recovery

Capar, Goksen
Aygun, S. Seylan
Gecit, M. Rusen
Sericin protein, although a valuable resource for many industries including cosmetics, pharmaceutical and biomedical, has been discarded as a waste in silk industry, causing environmental pollution. This paper describes determination of a membrane-based process for sericin recovery from cocoon cooking wastewaters (CCW) that will enable value-added utilization of waste sericin. The iso-electric point (pI) of sericin was found as 5-6, whose MW was distributed as 180-200, 70-80, 30-40 and 10-25 kDa. Prior to membrane filtration. sericin was separated from other impurities via centrifugation (CFG) followed by microfiltration (MF) in the pre-treatment stage, which also helped minimize post membrane fouling. Ultrafiltration (UF) and nanofiltration (NF) were adopted at a pH equal to pI of sericin. UF achieved partial recovery of sericin polypeptides at 37-60%, which was attributed to increased transmission of uncharged sericin polypeptides at their pI. On the other hand, NF achieved sericin recovery as high as 94-95%, containing all MW fractions. Severe flux decline was the major problem due to protein-membrane interactions and high sericin concentrations, where concentration polarization mainly had a dominant effect. Although flux declines were as high as 58-88% in UF and 70-75% in NF, flux recovery by at least 83% was achieved by chemical cleaning using NaOH and free chlorine.


Separation of sericin from fatty acids towards its recovery from silk degumming wastewaters
Capar, Goksen; Aygun, S. Seylan; Gecit, M. Rusen (Elsevier BV, 2009-10-15)
Sericin is a valuable protein, which is currently discarded as a waste in silk industry. Silk degumming wastewaters (SDW) are abundant sources of sericin, however, they contain impurities such as salts of fatty acids (soap) in conventional degumming processes. In this study, a process consisting of centrifugation (CFG), low temperature crystallization (LTC) and ultrafiltration (UF) was developed to separate sericin from fatty acids towards its recovery from conventional SDW. Complete removal of fatty acids ...
Reclamation of printing effluents of a carpet manufacturing industry by membrane processes
Capar, G; Yetiş, Ülkü; Yılmaz, Levent (Elsevier BV, 2006-06-01)
The effluent from the print dying process of a carpet manufacturing industry was subjected to nanotiltration (NF) and ultrafiltration (UF) processes aiming at water reuse. Three alternatives were adopted; (i) NF, (ii) loose UF (MWCO 20,000 Da) followed by NF and (iii) tight UF (MWCO 1000 Da) followed by NE The separation performances and flux decline levels were compared for the detemination of the best process. Printing effluent was chemically precipitated using alum and fed to a lab-scale plate-and-frame ...
ZIF filled PDMS mixed matrix membranes for separation of solvent vapors from nitrogen
Sahin, Fatma; TOPUZ, BERNA; Kalıpçılar, Halil (Elsevier BV, 2020-03-15)
The efficiency of chemical processes can be improved by recovering high value volatile organic compounds (VOCs). For this purpose PDMS based mixed matrix membranes were prepared by using ZIF-7, ZIF-8, ZIF-67, ZIF-71 and ZIF-L as filler for VOC removal from permanent gases. Membranes were characterized by separating pure or mixed solvent vapors of methanol (MeOH), ethanol (EtOH), isopropanol (IPA), n-propanol (PrOH) and ethyl acetate (EtAc) from nitrogen. The total VOC permeability and VOC/N-2 selectivity in...
Separation of silkworm proteins in cocoon cooking wastewaters via nanofiltration: Effect of solution pH on enrichment of sericin
ÇAPAR, GÖKŞEN (2012-02-01)
Cocoon cooking wastewater contains waste silkworm proteins including sericin, which is a valuable raw material for many industries including cosmetics and pharmaceuticals. Sericin can be recovered via nanofiltration (NF) with high efficiency; however the process conditions need to be optimized to maximize separation. In this study, the effect of solution pH on NF performance was investigated for separation of silkworm proteins towards sericin enrichment. Solution pH (3.5-9.0) slightly influenced sericin rej...
Development of enhanced ultrafiltration methodologies for the resolution of racemic benzoin
Olceroglu, Ayse Hande; Çalık, Pınar; Yılmaz, Levent (Elsevier BV, 2008-09-15)
In the scope of achieving the separation of chiral molecules, enzyme enhanced ultrafiltration (EEUF), a new method based on polymer enhanced ultrafiltration (PEUF), utilizing apoenzymes as ligands, was developed. Benzoin was chosen as the model chiral molecule. Bovine serum albumin (BSA) and apo form of benzaldehyde lyase (BAL) (E.C. were used as chiral ligands in PEUF and EEUF experiments, respectively. In order to bind to the target enantiomer well, the addition of ligand to the benzoin solution...
Citation Formats
G. Capar, S. S. Aygun, and M. R. Gecit, “Treatment of silk production wastewaters by membrane processes for sericin recovery,” JOURNAL OF MEMBRANE SCIENCE, pp. 920–931, 2008, Accessed: 00, 2020. [Online]. Available: