Reuse of reverse osmosis membranes in advanced wastewater treatment

In areas where tap water has a high salt content, wastewater is not appropriate for reuse in agriculture, particularly for sensitive crops. One alternative is reduction, via desalination, of the brackish character to the secondary effluent. A filtration stage is also required before desalination. On the other hand, used reverse osmosis membranes can be recycled and used as filters in the advanced treatment stage in order to reduce suspended matter contained in the secondary effluent—one advantage being the environmental recovery of solid waste. Used membranes can be treated with strong chemical oxidants to peel off the active separation layer in order to transform them into microfiltration or ultrafiltration elements. Preliminary tests have been carried out with 8″ elements, aimed at comparing membrane performance before and after the peeling process. An index denoted as peeling effectiveness (high flux, high salt passage) is used for comparison. It was soon observed that potassium permanganate was more effective than others, together with sodium hydroxide. Doses around 1000 mg/L KMnO₄ provided the best results. It was also concluded that membrane cleaning, done with sodium bisulphite prior to peeling, was better when recirculating the cleaning solution around the membrane rather than soaking it. Next steps in the research will test the actual filtration capability of the peeled membranes in actual wastewater.     

Nanocellulose-based reusable liquid metal printed electronics fabricated by evaporation-induced transfer printing

Reusable electronics have received widespread attention and are urgently needed. Here, nanocellulosebased liquid metal(NC-LM) printed circuit has been fabricated by the evaporation-induced transfer printing technology. In this way, the liquid metal pattern is embedded into the nanocellulose membrane, which is beneficial for the stability of the circuit during use. Besides, the NC-LM circuit is ultrathin with just tens of microns. In particular, the finished product is environmentally friendly because it can be completely dissolved by water, and both the liquid metal ink and the nanocellulose membrane can be easily recollected and reused, thereby reducing waste and pollution to the environment. Several examples of flexible circuits have been designed to evaluate their performance. The mechanism of evaporation-induced transfer printing technology involves the deposition, aggregation, and coverage tightly of the nanosized cellulose fibrils as the water evaporated. This study provides an economical and environmentally friendly way for the fabrication of renewable flexible electronics.     

1970年以后欧美建筑再利用的学术发展概览

本文介绍了西方关于建筑再利用的理论研究和教学概况,以期为国内更好地理解建筑再利用问题以及将来开展相关研究、教学和项目实践提供些许参考。本文第一部分介绍了建筑再利用的理论研究,从建筑学领域和遗产保护领域这两个方面分开阐述,建筑学领域关于建筑再利用的理论研究主要分为类型学、技术派、建筑策略和室内设计等方向,遗产保护领域关于建筑再利用的专门讨论是近几年才开始的,主要包括适应性再利用、可持续再利用和共同演变式再利用等方向。第二部分介绍了建筑再利用的教学情况,首先以米兰理工大学为例介绍了建筑学科下关于建筑再利用的专业课程教学,接着以美国罗德岛设计学院和比利时哈瑟尔特大学等高校为代表介绍了关于建筑适应性再利用的专业硕士培训项目,最后介绍了欧盟关于现代主义建筑再利用以及其他高校关于建筑再利用的硕士培训项目。     

Effective practices in design transfer

The notion of transferring existing design solutions to new design problems is a basic one. Transfer provides a means of tackling increasing complexity, of limiting risks and costs, and of capitalizing on experience. In practice, in design organizations, it can be hard to judge the outcome of transfer because there can be several, often obscure benefits and drawbacks. This work is therefore an attempt to identify effective practices towards transfer on the part of designers and design managers. It is based on a qualitative analysis of 50 unstructured interviews carried out with members of two commercial design organizations. The practices were classified inductively in 15 main categories, of which the most heavily populated were associativity-improving, criteria-broadening, effort-reducing, environment-influencing, error-averting and motivation-addressing. The results have both a practical relevance (since most of the effective practices could be readily taught to novice designers) and a more theoretical relevance (showing what designers believe makes design transfer problematic).     

Life Cycle Simulation System for Life Cycle Process Planning

To realize closed loop manufacturing, it is essential to design product life cycles and to plan life cycle processes property. Life cycle simulation has been recognized as an effective tool in this direction. In this paper, we present a life cycle simulation system developed as a general tool for life cycle design and management. The system includes functions for modelling and controlling each life cycle process in a flexible manner. The system maintains usage history of products and parts independently taking the reuse of parts into account. Examples of the simulation are shown for both a rapid life cycle scenario and for a part sharing scenario over the product generations.     

城市污水处理工艺设计——以某污水处理厂为例

废物资源化利用是污水处理发展的必然趋势。以某污水处理厂为例,在技术力量与经济能力有限的地区,因地制宜、科学合理地设计污水处理工艺,较为详细地阐述了污水处理工艺流程,合理地确定了本次设计的水质指标,并简要探索其回用途径,真正实现污水无害化以及废物资源化利用。     

Control of residual organic matter to reduce bacterial regrowth potential for wastewater reuse

Several problems have been reported about accumulated microorganisms in reclaimed water distribution systems. This paper presents the results of residual organic matter (OM) removal and apparent bacterial regrowth potential of treated wastewater obtained from laboratory-scale experiments using advanced biological treatments: two immobilization processes in series and a membrane bioreactor (MBR) process. Furthermore, a nanofiltration (NF) membrane process was applied to effluents of both advanced biological treatments. The immobilization process removed large molecular weight (MW) fractions >5,000 since immobilized microorganisms had sufficiently acclimated. The NF membrane was more effective in rejecting large MW fractions in the effluents of the immobilization and the MBR treatments. But it was difficult to reject small MW fractions <1,000 by NF. Neutral hydrophilic fraction of DOC was reduced by both advanced biological processes, and it can be thought that the microorganisms in the advanced processes could decompose and grow on some part of the neutral hydrophilic fraction. Quantity of attached microorganisms in the second immobilization reactor was significantly reduced compared to that in the first immobilization reactor. This suggests that apparent bacterial regrowth potential is controlled by the accumulation of effective microorganisms in the first reactor.     

皮带定量配料系统在焦粉再利用中的应用

基于目前工业废弃焦粉回收再利用生产过程中生产效率低、配比不准确、生产合格率低等问题,设计了电子皮带定量配料系统.该系统采用闭环反馈控制与PID控制相结合的方式来进行物料配比.通过采集安装有该配料系统的某厂区的现场数据进行验证,结果表明焦粉回收再利用的生产效率和产品合格率得到极大提高.经过现场调试,系统日产量可达300t/16h,整个过程物料配比精确,满足焦粉回收再利用的生产要求.     

代码重用技术在财务管理系统开发中的应用

本文结合作者在多个财务管理系统开发中积累的经验,讨论了当前财务管理系统开发中代码重用方法,详细分析了利用VC＋＋进行财务软件开发过程中实现代码重用的技术和方法,通过代码重用,提高了财务软件开发的生产率,降低了财务软件开发难度和成本,缩短了开发周期。同时,可重用技术有利于改善财务软件质量,有利于财务软件的升级与维护。