溶液pH值不仅影响溶质的电荷等表面性质,同时也影响膜表面的特性,从而影响溶质与膜表面之间的相互作用和溶质在膜面的沉积量及膜通量.胞外多糖(Extracellular POlvsac-charides,EPS)是膜生物反应器(Membrane Bioreactor,MBR)中主要的膜污染物质之一,从实际MBR膜污染层中分离纯化得到的EPS,在EPS引起膜污染机理分析的基础上,以过滤阻力、EPS在膜表面沉积量及膜通量为评价指标,综合分析不同溶液pH对EPS污染特征的影响,可为揭示MBR中EPS膜污染的成因和机理以及污染膜的清洗提供参考.结果表明,MBR膜污染层EPS的膜污染过程较好地符合沉积阻力模型,EPS在膜表面的污染主要是EPS沉积引起的;EPS溶液的pH越高,其与膜之间的排斥力越大,沉积量越少,沉积阻力越小,膜通量越高.pH为7.0时,沉积阻力为3.34×10~(11) m~(-1),沉积量为1.25 g/m~2,初始相对膜通量为9.8%.
Solution pH influences the surface charge and structure of solute as well as those of membrane, consequently heavily affects the interaction between solute and membrane, deposited amount of solute on membrane surface and membrane flux. Extracellular polysaccharides (EPS) are one of important foulants of membrane sur face in membrane bioreactor (MBR). EPS were obtained from membrane fouling layer of treating wastewater MBR. Based on the determination of membrane flux, filtration resistances and deposited amount of EPS on the membrane surface as well as the mechanism analysis of membrane fouling, the influence of solution pH on the PVDF membrane fouling of EPS obtained was investigated. The membrane fouling caused by EPS in MBR fol-lows the model of deposition resistance. EPS deposition on membrane surface leads to membrane fouling. As pH of EPS solution increases, the repulsion between EPS and membrane surface goes up, depositing resistance of filtration goes down and deposited amount of EPS increases. When pH is 7.0, deposited resistance of filtration,deposited amount of EPS and flux are 3.34 × 10~(11) m~(-1), 1.25 g/m~2 and 9.8% , respectively.
参考文献
| [1] | Ma H M;Christopher N B;Robert H D .Membrane fouling by backwashing and surface modification[J].Journal of Membrane Science,2000,173:191-200. |
| [2] | Martinez F.;Pradanos P.;Calvo JI.;Palacio L.;Hernandez A.;Martin A. .Protein adsorption and deposition onto microfiltration membranes: The role of solute-solid interactions[J].Journal of Colloid and Interface Science,2000(2):254-261. |
| [3] | Chang I S;LEE C H.Membrane filtration characteristics in membrane-coupled activated sludge system-the effect of physiological states of activated sludge on membrane fouling[J].Desalination,1998(120):221-233. |
| [4] | Lee W;Lang S;Shin H .Sludge characteristics and their contribution to microfiltration in submerged membrane bioreacters[J].Journal of Membrane Science,2003,216:217-227. |
| [5] | Johnson C A;Wu P;Lenhoff A M .Electrostatic and van der Waals contributions to protein adsorption 2.Modeling of ordered arrays[J].LANGMUIR,1994,10:3705-3713. |
| [6] | Jucker C;Clark M .Adsorption of aquatic humic sub-stances on hydrophobic ultrafiltration membranes[J].Journal of Membrane Science,1994,97:37-44. |
| [7] | Fane A G;Fell C J D;Suki A .The effect of pH and ionic environment on the ultrafiltration of protein solutions with retentive membranes[J].Journal of Membrane Science,1983,16:195-210. |
| [8] | KoMK;Pellegrino J J;Nassimbene R et al.Characterization of the adsorption-fouling layer using globular proteins on ultrafiltration membranes[J].Journal of Membrane Science,1993,76:101-120. |
| [9] | Jeffrey Mueller;Robert H. Davis .Protein fouling of surface-modified polymeric microfiltration membranes[J].Journal of Membrane Science,1996(1):47-60. |
| [10] | Braghetta A .The influence of solution chemistry and operating conditions on nanofiltration of charged and uncharged organic macromolecules[D].University of North Carolina at Chapel Hill,1995. |
| [11] | 林红军,陆晓峰,段伟,沈飞.膜生物反应器中膜过滤特征及膜污染机理的研究[J].环境科学,2006(12):2511-2517. |
| [12] | 郑蕾,田禹,孙德智.pH值对活性污泥胞外聚合物分子结构和表面特征影响研究[J].环境科学,2007(07):1507-1511. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%