Analysis of foulant layer in all elements of an RO train
Analysis of foulant layer in all elements of an RO train
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DOI：
10.1016/j.memsci.2005.03.044
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发表时间：
2005-09
影响因子：
9.5
通讯作者：
R. Schneider;L. M. Ferreira;P. Binder;J. R. Ramos
中科院分区：
文献类型：
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作者：
R. Schneider;L. M. Ferreira;P. Binder;J. R. Ramos
从一套反渗透装置的第一级和第二级的所有反渗透元件(每个六种元件)中回收膜样品，用经过处理的地表水进料，以分析污层组成。化学和微生物数据是基于对每个元素的五个不同膜叶片样品的分析结果进行平均的，但由于污染层的均质性，每个元素只对一个膜样品进行电子显微镜检查。除第二阶段的最后一个元素外，所有元素的膜上都覆盖着一层厚厚、致密、附着、粘稠、浅棕色的污垢，其中含有微生物细胞，但没有盐沉积，在那里发现了一层片状但有时很厚的BaSO4晶体。两个阶段元素中微生物总数在105~106个/cm2之间变化。活菌数从第一阶段的前两个元素的105-106个菌落形成单位/cm2下降到后续元素的102-104个细胞/cm2。除阶段1中的元素1和元素4(分别为0.15和0.25 mg/cm2)外，所有元素的污垢层干重在0.15~0.20 mg/cm2之间变化。在第一阶段，有机质占干重的百分比从前两个元素中的约30%增加到元素4-6中的55%，并在第二阶段的所有元素中保持不变。有机组分的蛋白质含量从元素1的70%左右线性下降到元素6的40%左右，在阶段2的所有元素中保持不变。总碳水化合物在两个阶段的所有元素中所占的比例都是相同的。O、S、P、Si、Fe、Al等元素在各元素污秽层无机组分中的含量基本一致。BaSO4晶体在阶段1中从前部到后部呈线性增长，在阶段2中保持不变。BaSO4晶体仅在阶段2最后一个元素的污垢层中检测到。
Membrane samples were recovered from all RO elements of the first and second stage (six elements each) of a RO unit fed with pre-treated surface water to analyse fouling layer composition. Chemical and microbiological data were averaged based on the results obtained from analysis of samples from five different membrane leaves from each element, but electron microscopy was performed on a single membrane sample per element due to the homogeneity of the fouling layers. Membranes from all elements were covered by a thick, compact, adherent, slimy, lightly brown coloured fouling layer, which contained microbial cells but no salt deposits, except for the last element of the second stage, where a patchy but sometimes thick layer of BaSO4crystals was detected. Total microbial counts varied between 105and 106cells/cm2in the elements from both stages. Viable counts dropped from 105–106colony forming units/cm2in the first two elements of the first stage to 102–104cells/cm2in subsequent elements. Dry weight of the fouling layers varied between 0.15 and 0.20mg/cm2in all elements except elements 1 and 4 in stage 1 (0.15 and 0.25mg/cm2, respectively). The proportion of organic matter as a percentage of dry weight increased in the first stage from approximately 30% in the first two elements to 55% in the elements 4–6 and remained constant in all elements of the second stage. The protein content in the organic fraction decreased linearly from around 70% in element 1, stage 1 to about 40% in element 6, stage 1 and remained constant at the latter level in all elements of stage 2. The proportion of total carbohydrate in the organic fraction of about 3% was the same in all elements of both stages. The content of O, S, P, Si, Fe and Al was similar in the inorganic fractions of foulant layers from all elements. Ba and Sr increased linearly from the lead to the rear element in stage 1 and remained constant throughout stage 2. BaSO4crystals were detected in significant amounts only in fouling layers from the last element of stage 2.