胶州湾海水淤泥密度指数影响因素研究

超滤+反渗透组合的双膜法在海水淡化中已经得到广泛应用,然而反渗透膜的污染问题严重影响了正常生产。淤泥密度指数（SDI）已经成为评价反渗透进水水质的主要指标。通过对超滤出水水质进行检测分析并对反渗透膜主要污染物进行分析,探讨目前胶州湾海水淡化过程中反渗透进水SDI的影响因素及各因素影响程度,结果表明：微生物作为自然水体中广泛存在的生物,其随季节和温度变化造成的总量变化是影响SDI的最主要因素;水体中的硫酸盐以及Si、Al、Fe胶体是造成膜污染的主要无机污染物;此外,浊度与水样的SDI没有相关关系,也不能在反渗透过程中对水质情况进行有效衡量。最后,针对影响SDI的微生物因素的研究以及膜表面无机胶体的清洗提出未来发展方向。     

一种基于膜污染指数的超滤膜污染评价方法

利用浸没式中空纤维膜小试系统,基于膜污染指数（FI）建立超滤膜污染的评价和试验方法。通过试验考察超滤膜污染变化规律,以及运行周期对膜污染指数计算的影响,并确定计算膜污染指数的运行周期;并对膜污染指数评价方法的可重复性进行检验：对化学清洗前后膜污染指数进行比较。试验表明,在过滤初期,滤饼污染和吸附污染并存,所以初期水力不可逆膜污染指数（HIFI）增长较快;中期超滤膜的吸附能力不断减弱,膜污染主要是滤饼污染,所以膜污染较为稳定：后期跨膜压力过大,压缩滤饼层,减小滤饼孔隙率,增加滤饼阻力,所以HIFI有所增加。同时短期的膜污染试验可以用来反映长期的膜污染情况,该超滤膜污染的评价方法重复性好,污染后的超滤膜经过化学清洗后。可以重复利用。     

反渗透膜元件胶体污染的预防

胶体污染是膜元件污堵的主要原因之一。它不仅严重影响膜元件的使用性能：如产水量的急剧下降、系统压差的增加及脱盐率的降低等等,而且还会降低膜元件的使用寿命,以及给用户带来生产上的诸多不便。为此,有效预防膜元件的胶体污染对反渗透系统的正常运行有很大的益处。     

超滤膜出水污染密度指数测试方法研究

水污染密度指数(SDI)是重要的水质参数,可以有效评价超滤膜预处理效果和反渗透进水水质。结合ASTM标准D4189-07,介绍了SDI的标准测试方法,开展了不同水体系中SDI测试研究,进行了手动和在线自动两种测试方法的比较。结果表明,全自动SDI仪的测试数据准确可靠,精密度高,完全可以满足日常测试水体SDI的要求,为SDI测试提供了新的途径。     

超滤膜污染指数模型及其在工程设计中的应用

本文提出了超过滤的模型,通过对苯二甲酸悬浮液的超滤浓缩数据的线性回归,提出了对该体系的污染方程系数,利用此模型计算了操作参数变化对超滤通量的影响曲线,求出了最佳操作条件。本模型对类似体系的超滤工程设计有参考价值。     

反渗透膜的污染及清洗

介绍了RO膜污染的类型及污染的形成,讨论了RO膜的清洗方法及配方。     

反渗透系统的污染及清洗

反渗透作为水处理领域的一种高新除盐技术应用日益广泛，如何防止膜元件的污染及污染后的清洗是当前反渗透技术应用中的一个难点，本文结合长铝公司400t/h反渗透系统的运行和清洗经验就该问题进行一些探讨。     

超滤技术在水处理中的膜污染及控制

膜污染是超滤技术应用在水处理中的最主要限制因素,超滤膜污染和控制是近年来的研究热点。通过阐述超滤膜污染过程,分类膜污染形式,识别典型的膜污染物,深入了解超滤膜污染。通过混凝、吸附、氧化和生物处理等控制技术,可以在不同程度上减轻膜污染,未来实施集成预处理方法,追求最优化的膜污染控制手段,从而加速超滤技术的収展。     

反渗透膜的污染及在线清洗

随着反渗透装置的投运,反渗透膜的污染因其预处理工艺、预处理效果以及各地水源水质的不同,会产生各种各样的污染。反渗透膜污染到一定程度,就必须进行清洗。而反渗透膜的清洗,尤其是在表洗是我国反渗透应用中的一大难题。文中主要介绍了卷式反渗透膜污染的原因、特征以及在线清洗配方的选择、操作注意事项和清洗实例等,以供同行参阅。     

超滤膜的制备及其截留率与产水SDI值之间的关系

以聚醚砜（PES）为膜材料,N甲基2吡咯烷酮（NMP）为溶剂,分别选用不同分子量的聚乙烯吡咯烷酮（PVP K10、PVP K30、PVP K50、PVP K70）为添加剂,利用相转化法制备了PES平板超滤膜。研究了制备条件对膜结构及性能的影响。当PES含量为18 %（质量分数,下同）,PVP K30添加量为6 %时,超滤膜平均水通量和平均截留率最佳,分别为90.7 L/（m2·h）、95.1 %。实验进一步测定了5组膜片对1 g/L牛血清蛋白（BSA）溶液的截留率以及它们对取自生活饮用自来水和泳池水样滤出水的污染密度指数（SDI）值。结果表明,PES超滤膜对生活饮用水滤出水的SDI5 min值随着截留率的升高而降低;针对泳池滤出水,随着超滤膜截留率的升高,其滤出水的SDI5 min值没有明显变化。     

Influence of Operating Parameters on Biomass Conversion under Sub‐ and Supercritical Water Conditions

The influence of reaction pressure, reaction time, reaction temperature, and biomass‐to‐water mass ratio R on the conversion of miscanthus biomass to biofuels under sub‐ and supercritical water (SCW) conditions was investigated. The highest total conversion was obtained under SCW conditions and the heating value increased under subcritical and SCW conditions. The findings herein show that near‐supercritical and supercritical water at 400 °C and high pressure can be an effective reaction medium for converting biomass to oils with relatively low oxygen contents in high yields.     

聚乙烯密度测试影响因素的研究

分别对聚乙烯材料密度测试中是否采用熔条、是否水煮以及熔融挤出时采用的载荷对测试结果的影响进行了系统的研究与分析，并指出了不同的试样类型、不同的试样处理方法及不同的测试条件对聚乙烯密度测试结果的影响。     

PVDF树脂在水处理领域的应用现状

主要介绍了聚偏氟乙烯（PVDF）树脂在水处理领域的应用情况,比较了市场上常用的PVDF树脂性能,并对由上述树脂制备的水处理膜性能进行对比。     

高密度沉淀池在火力发电厂中的应用

介绍了高密度沉淀池的结构特点、工作原理及其作为火力发电厂原水预处理设施的优点,并将其与传统原水预处理设施进行了综合比较,结果表明:高密度沉淀池对浊度和有机物的去除率高,对水质突变适应能力强,运行成本低。     

An assessment of the Silt Density Index based on RO membrane colloidal fouling experiments with iron oxide particles

RO membrane colloidal fouling experiments were performed in the laboratory under well controlled and realistic conditions. Iron oxide was selected as a typical inorganic colloidal foulant, due to its importance, as evidenced from well known manufacturer recommendations on iron concentrations in feed waters and from frequently encountered problems in membrane installations. A range of iron concentrations was identified where a linear relationship existed between flux reduction rate and concentration. The performance of the Silt Density Index (SDI) was tested on the basis of the RO fouling data obtained. The range of iron concentrations where measurable and meaningful SDI values could be obtained was remarkably close to membrane manufacturer recommendations. A notable sensitivity of the SDI was also observed with particles for which retention is negligible. However, on the basis of the RO fouling data obtained, it appears that the SDI is not conservative enough. Furthermore, since the SDI cannot predict fouling rates, it cannot discriminate between different types of membranes.     

Silt Density Index and Modified Fouling Index relation, and effect of pressure, temperature and membrane resistance

Particulate matter present in feed water of reverse osmosis and nanofiltration membrane elements tends to deposit on the membrane surface and spacers. This type of fouling results in permeate flux decline, loss of product quality and membrane damage. To characterize the fouling potential of RO feed water the Silt Density Index (SDI) and the Modified Fouling Index (MFI0.45) are commonly applied. SDI is applied worldwide for many years on a routine basis by operators since it is a simple and cheap test.Unfortunately, the SDI has several deficiencies e.g. it is not based on any filtration mechanism, has no linear relation with particulate matter and is not corrected for temperature, pressure and membrane resistance. This might explain the frequently reported erratic results obtained in practice, e.g. water treated with ultrafiltration showed in several cases high SDI values, which could not be attributed to failures of the UF membrane elements or systems. To overcome these deficiencies the MFI0.45 has been developed. This test is based on the occurrence of cake filtration during a substantial part of the test, has a linear relation with particulate matter content, and is corrected for pressure and temperature. However the manual procedure of measuring an MFI0.45 is somewhat more complicated and for this reason less suitable for application on a routine basis in practice.Fully automated equipment, measuring SDI and MFI0.45 at the same time is on the market.In this study a mathematical relation between SDI and MFI0.45 has been successfully developed, assuming that cake filtration is the dominant filtration mechanism during the tests. Based on the developed mathematical relation and experiments with an artificial colloidal suspension of aluminum oxide spheres (0.6 μm) as model water, it could be demonstrated that the SDI depends on pressure, temperature and membrane resistance. The effect of temperature and membrane resistance explains to a large extent the erratic results from the field. It is recommended to correcting SDI for temperature and membrane resistance and/or to making the guideline formulated by ASTM for the allowable range of membrane resistances much more stringent.     

饱和热水塔的工作状态分析

应用PRO-Ⅱ软件模拟计算饱和热水塔的工作状态。计算结果表明，控制系统循环水量、增加饱和热水塔的填料理论板数、控制热水塔出口变换气温度、控制较低的汽气比均可使饱和热水塔更高效地回收热量。     

均匀设计法研究聚硅硫酸铁制备条件

将均匀设计应用于聚硅硫酸铁复合共聚生产工艺,得到最显著影响因素以及各因素的最佳水平：铁硅比6．0～10.0;硫酸铁浓度24%～36％;酸化温度45℃～60℃;酸化pH值4．5～5．5。用此条件制备PFSS并处理巢湖水样,平均剩余浊度为0．5NTU,平均除浊率99．5％。对实验数据的多元回归分析得到了可对不同实验条件所得产品絮凝效果进行预测的回归方程。