Chemical cleaning of fouled PVC membrane during ultrafiltration of algal-rich water

• Published in: Journal of environmental sciences (China) Vol. 23; no. 4; pp. 529 - 536
• Main Authors: Zhang, Yan, Tian, Jiayu, Liang, Heng, Nan, Jun, Chen, Zhonglin, Li, Guibai
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.2011; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
• Subjects: algal-rich water; atomic force microscopy; Biofouling - prevention & control; chemical cleaning; Cleaning; EDTA; EDTA (chelating agent); Electronics; Eukaryota - drug effects; Eukaryota - growth & development; Fouling; Fourier transform infrared spectroscopy; membrane fouling; membrane permeability; Membranes; Membranes, Artificial; Microscopy, Atomic Force; Microscopy, Electron, Scanning; NaClO; NaOH; Organic Chemicals - analysis; poly(vinyl chloride); Polyvinyl Chloride - chemistry; Polyvinyl Chloride - pharmacology; Polyvinyl chlorides; PVC膜; Restoration; scanning electron microscopy; Sodium Chloride - pharmacology; sodium hydroxide; sodium hypochlorite; Sodium Hypochlorite - pharmacology; Solutions; Spectroscopy, Fourier Transform Infrared; Surface Properties - drug effects; Ultrafiltration; Ultrafiltration - methods; Water - parasitology; Water Purification - methods; 傅立叶变换红外光谱仪; 化学清洗; 原子力显微镜分析; 氢氧化钠溶液; 碳水化合物类; NaOH; membrane fouling; chemical cleaning; NaClO; algal-rich water
• ISSN: 1001-0742; 1878-7320
• DOI: 10.1016/S1001-0742(10)60444-5

Cleaning of hollow-fibre polyvinyl chloride (PVC) membrane with different chemical reagents after ultrafiltration of algal-rich water was investigated. Among the tested cleaning reagents (NaOH, HC1, EDTA, and NaClO), 100 mg/L NaClO exhibited the best performance (88.4% ± 1.1%) in removing the irreversible fouling resistance. This might be attributed to the fact that NaClO could eliminate almost all the major foulants such as carbohydrate-like and protein-like materials on the membrane surface, as confirmed by Fourier transform infrared spectroscopy analysis. However, negligible irreversible resistance (1.5% ± 1.0%) was obtained when the membrane was cleaning by 500 mg/L NaOH for 1.0 hr, although the NaOH solution could also desorb a portion of the major foulants from the fouled PVC membrane. Scanning electronic microscopy and atomic force microscopy analyses demonstrated that 500 mg/L NaOH could change the structure of the residual foulants on the membrane, making them more tightly attached to the membrane surface. This phenomenon might be responsible for the negligible membrane permeability restoration after NaOH cleaning. On the other hand, the microscopic analyses reflected that NaClO could effectively remove the foulants accumulated on the membrane surface.