尽管能够从废水中生产高质量的可重复使用的水，但该领域的大量 RO 回收装置都遇到了困难的操作问题。
这些问题包括过滤率差、脱盐率降低、频繁的膜清洗和膜过早失效。这些问题导致高运营成本和在许多情况下生产过程的关闭。
造成这种不希望或不可接受的性能的主要原因是反渗透膜对水中各种不相容成分的耐受性低。这些物质如果不去除，将导致反渗透膜结垢、结垢或永久降解。
这些问题加上不断增加的水回收需求，推动了下一代高通量管式膜微滤 (MF) 技术的发展，以提高废水回收过程中的 RO 性能。
由于其多功能性、坚固性和高滤液质量，管式微滤可以很好地替代传统设备，包括重力澄清器、介质过滤器、石灰软化器和离子交换器，作为 RO 预处理以去除不可接受的物质。
高通量管状 DFLOW德氟龙管式MF 过滤系统制造过程开始于制备由聚偏二氟乙烯 (PVDF) 聚合物和其他成膜增强化学品组成的化学溶液。
独特的溶液配方和应用程序有效地： (1) 消除了所有不需要的大孔，(2) 每平方英寸膜表面产生更多的孔，以及 (3) 在 PVDF 膜和聚合物管之间形成强大的间隙锚定表面。均匀亚微米孔径的第一个特征能够完全去除有害成分，并产生 NTU (<1.0) 和 SDI (<3.0) 值的流流，完全符合 RO 给水标准。
增加孔数的第二个特征解释了该膜能够以两倍于其他类似 MF 膜的操作通量持续运行的能力。
此功能将允许设计采用一半的德氟龙膜来过滤相同数量的加仑废水。形成强表面结合的第三个特征产生了高度耐用的 MF 过滤材料，可以延长连续运行 5 到 10 年而无需更换膜。PVDF 非凡的耐化学性允许使用范围广泛的化学品 - 酸、碱和溶剂，以有效清洁顽固的污垢物质，如果不去除这些物质，即使不是不可能，也很难从 RO 膜上清除。此功能将允许设计采用一半的膜来过滤相同数量的加仑废水。
形成强表面结合的第三个特征产生了高度耐用的 MF 过滤材料，可以延长连续运行 5 到 10 年而无需更换膜。PVDF 非凡的耐化学性允许使用范围广泛的化学品 - 酸、碱和溶剂，以有效清洁顽固的污垢物质，如果不去除这些物质，即使不是不可能，也很难从 RO 膜上清除。此功能将允许设计采用一半的膜来过滤相同数量的加仑废水。形成强表面结合的第三个特征产生了高度耐用的 MF 过滤材料，可以延长连续运行 5 到 10 年而无需更换膜。PVDF 非凡的耐化学性允许使用范围广泛的化学品 - 酸、碱和溶剂，以有效清洁顽固的污垢物质，如果不去除这些物质，即使不是不可能，也很难从 RO 膜上清除。
Despite its capability to produce high-quality re-usable water from wastewater, a large number of RO recycling installations in the field have experienced difficult operational problems. These problems include poor filtration rate, decrease in salt rejection, frequent membrane cleaning, and premature membrane failure. These problems result in high operating cost and in many cases shut down of production processes. The primary cause for such an undesired or unacceptable performance is that RO membrane has low tolerance for a broad range of incompatible components in water. These substances, if not removed, will cause scaling, fouling or permanent degradation of the RO membrane. Such issues coupled with the ever-increasing water recycle demand have driven the development of the next generation of high-flux tubular membrane microfiltration (MF) technology to augment the RO performance in the wastewater recycling process. Because of its versatility, robust nature and high filtrate quality, tubular microfiltrationcould well replace traditional equipment including gravity clarifiers, media filters, lime softeners and ion exchangers as RO pretreatment for removal of unacceptable substances.
The high-flux tubular MF filter fabrication process starts with preparation of a chemical solution consisted of a Polyvinylidene Fluoride (PVDF) polymer and other membrane formation enhancing chemicals. The unique solution formula and application procedures have effectively (1) eliminated all undesired large pores, (2) generated a much larger number of pores per square inch of membrane surface, and (3) formed strong interstitial anchorages between the PVDF membrane and polymeric tube surfaces. The first feature of uniform sub-micron pore size enables complete removal of the detrimental components and generates a flow stream with NTU (<1.0) and SDI (<3.0) values in full compliance with the RO feed water criteria. The second feature of increasing pore number explains the ability of the membrane to consistently operate at twice the operating flux of other similar MF membranes. This feature will allow the design to take one half as many membranes to filter the same number of gallons of waste water. The thirdfeature of forming strong surface bond produces a highly durable MF filter material that can extend a continuous operation for 5 to 10 years without membrane replacement. The extraordinary chemical resistant property of PVDF permits the use of a wide range of chemicals - acids, bases and solvents for effective cleaning of the persistent fouling substances which are very difficult, if not impossible, to be cleaned from the RO membrane if not removed.
To learn more about how the Tubular Membranes work, and how they can help improve the efficiency of a wastewater treatment or water recovery systems, read the full article.
