• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>2011 Membrane technology conference amp; exposition. >Extended Abstract for AWWA 2011 Membrane Technology Conference Exposition 28-31 March 2011 in Long Beach, CA
【24h】

Extended Abstract for AWWA 2011 Membrane Technology Conference Exposition 28-31 March 2011 in Long Beach, CA

机译：2011年3月28日至31日在加利福尼亚州长滩举行的AWWA 2011膜技术会议和展览的扩展摘要

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The development of safe new sources of high-quality water to keep up withrnsoaring water demand is of paramount importance. Due to improvements in membranerntechnology over the last decades, recycling wastewater by treating it to an acceptablernstandard using membrane technology, such as reverse osmosis (RO) or nanofiltrationrn(NF) is becoming a more and more widely accepted option. RO and NF are increasinglyrnused for the treatment of recycled waters to the necessary standards due to theirrnefficiency in removing a broad range of dissolved contaminants. However, studies havernshown that NF and RO membranes are permeable for certain, relatively small tracernorganic contaminants, including many pharmaceuticals and personal care products, thernpresence of which might pose risks to human health and the environment.rnIn most cases, currently available membrane technology can achieve a high levelrnof treatment for many microconstituents. The more fundamental issue is identifying thernappropriate balance between the desired level of treatment and the financial and energyrncost of achieving it. The currently prevalent practice is to employ higher-pressurernmembranes as a general “catch-all,” designed to remove as many compounds as possiblernbut at higher financial and energetic cost. However, if one considers the mechanisms forrnthe membrane removal of microconstituents, it may be possible to reduce the cost ofrntreatment by selecting a lower-pressure system but operating with particular membranesrnand under treatment conditions that are more favorable for removal of the one, or smallrngroup of, “problem” microconstituents at any particular location.rnRejection of small molecules by reverse osmosis and nanofiltration membranes isrnthought to be controlled by three main effects: size exclusion or sieving, chargernrepulsion, and the less tangible but no less important “solute-membrane affinity.” Thernfirst effect, size exclusion, is relatively straightforward: All else being equal, the larger arnmolecule, the better it will be removed by a membrane. The second, charge repulsion, isrnin principle no more complicated: The feed-size surface of reverse osmosis andrnnanofiltration membranes are generally negatively charged. Ionic compounds with arnnegative charge are therefore repulsed from the membrane surface, and those with arnpositive charge are retained as well due to an overall requirement for charge neutrality.
机译：开发高质量的安全新水源以跟上不断增长的用水需求是至关重要的。由于近几十年来膜技术的进步，通过使用膜技术（例如反渗透（RO）或纳滤（NF））将废水处理至可接受的标准来回收废水正变得越来越广泛。 RO和NF因其去除大量溶解污染物的效率越来越高而被用于将再生水处理至必要标准。但是，研究表明NF和RO膜对于某些相对较小的微量有机污染物（包括许多药品和个人护理产品）是可渗透的，其存在可能对人体健康和环境构成风险。在大多数情况下，当前可用的膜技术可以实现对许多微量成分的高水平处理。更根本的问题是确定所需治疗水平与实现该治疗所需的财务和能源成本之间的不适当平衡。当前普遍的做法是采用高压膜作为通用的“全包”产品，旨在去除尽可能多的化合物，但要付出较高的财务和精力成本。但是，如果考虑去除微量成分的膜的机制，则可以通过选择低压系统但使用特定的膜来操作，并在更有利于去除其中一种或一小部分的处理条件下降低处理成本。在任何特定位置都存在“问题”微成分。rn应该通过三个主要作用来控制反渗透和纳滤膜对小分子的排斥：尺寸排阻或筛分，电荷排斥，以及不太明显但同样重要的“溶质膜亲和力”。 ”第一效应，尺寸排阻是相对简单的：在所有其他条件相同的情况下，纤细分子越大，被膜去除的效果就越好。第二，电荷排斥原则上不再复杂：反渗透和纳米过滤膜的进料尺寸表面通常带负电荷。因此，带有负电荷的离子化合物会从膜表面排斥，由于对电荷中性的总体要求，带有正电荷的离子化合物也会保留下来。

著录项

相似文献

  • 外文文献
  • 中文文献
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号