title: Enzymatic treatment for controlling irreversible membrane fouling in cross-flow humic acid-fed ultrafiltration.
abstract: Exploring reasonable ways to remove foulant is of great importance in order to allow sustainable operation of ultrafiltration (UF) membranes in water/wastewater treatment technology. Compounds of organic and inorganic origin largely contribute to irreversible fouling. This study attempted to remove problem of UF membrane fouling by using four different enzymes including alpha-amylase, lipase, cellulase and protease. This investigation showed that none of the above mentioned enzymes was found to be effective for the removal of foulant when used alone. However, when these enzymes were used in combination with NaOH and citric acid, about 90% cleaning was achieved. The addition of non-ionic surfactant to the enzymatic solution appears to increase the efficiency of flux recovery by reducing the adhesion of foulant species to the membrane surface through the decrease of contact angle. Field emission gun scanning electron microscopy, Fourier transform infrared spectroscopy and atomic force microscopy (AFM) techniques were employed to qualitatively illustrate the foulant characteristics. The surface roughness through AFM was used to explain the potential mechanism for the enzymatic cleaning.
authors.affiliation: Department of Civil and Environment Engineering, Nanya Institute of Technology, Taoyuan, Taiwan, ROC.
authors.forename: Chien-Hwa
authors.initials: CH
authors.lastname: Yu
authors.forename: Lung-Chen
authors.initials: LC
authors.lastname: Fang
authors.forename: Shaik Khaja
authors.initials: SK
authors.lastname: Lateef
authors.forename: Chung-Hsin
authors.initials: CH
authors.lastname: Wu
authors.forename: Cheng-Fang
authors.initials: CF
authors.lastname: Lin
mesh_terms: D002480:Cellulase; D004868:Equipment Failure; D006812:Humic Substances; D006867:Hydrolases / Q000378:metabolism*; D008049:Lipase; D008567:Membranes, Artificial; D010447:Peptide Hydrolases; D014462:Ultrafiltration / Q000295:instrumentation* / Q000379:methods; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods; D000516:alpha-Amylases
chemical_list: D006812:Humic Substances; D008567:Membranes, Artificial; D006867:Hydrolases; D008049:Lipase; D000516:alpha-Amylases; D002480:Cellulase; D010447:Peptide Hydrolases