Potential for wastewater reuse in irrigation: case study from Aden (Yemen)

Wastewater treatment with waste stabilization ponds (WSP) is a very efficient, low cost and low maintenance operation. The treated wastewater from WSP should be considered as a valuable resource for reuse by water resources managers. Yemen’s water resources are currently experiencing a crisis, because all surface water and groundwater resources are exploited beyond the level of recharge. Promoting water reuse of treated wastewater for irrigation could mitigate this water crisis. This paper assesses the performance of a WSP in the city of Aden by examining the quality of treated sewage predominantly of domestic origin. A comparison with international guidelines reveals that it is possible to use the final effluent to a limited extent in irrigation. This paper includes an outline of the social, religious and political reasons for the water crisis, and explores the idea of reuse of effluent for different irrigation practices.     

Fouling Inhibition of Membrane Separation by H2O2/UV Pre-oxidation for Color Filter Effluent Reuse

This study evaluated the feasibility of treating color filter effluent by H₂O₂/UV pre-oxidation and membrane postseparation for in-house reuse. The effluent qualities were TOC of 5.8–34 mg/L, color of 46–138 ADMI, and conductivity of 1020–3500 μS/cm. Although the RO separation could directly remove TOC, color, and conductivity effectively, the serious fouling problem still existed. Through H₂O₂/UV pre-oxidation (UV = 13 W, H₂O₂ = 200 mg/L), organic and biofouling were inhibited to increase the normalized flux decline from 5% to 77%. That is, H₂O₂/UV pre-oxidation could mitigate the permeate flux decline as well as to improve the water quality for water reuse.     

Effects of porosity,dry unit weight,cement content and void/cement ratio on unconfined compressive strength of roof tile waste-silty soil mixtures

One of the conventional ways to improve the mechanical behavior of soils is to mix them with cementing agents such as cement, lime and fly ash. Recently, introduction to alternative materials or sub-products that can be adopted to improve the soil strength is of paramount importance. Therefore, the present study aims to investigate the effects of porosity (η), dry unit weight (γ_d) of molding, cement content (C) and porosity/volumetric cement content ratio (η/C_iv) or void/cement ratio on the unconfined compressive strength (q_u or UCS) of silty soil–roof tile waste (RT) mixtures. Soil samples are molded into four different dry unit weights (i.e. 13 kN/m³, 13.67 kN/m³, 14.33 kN/m³ and 15 kN/m³) using 3%, 6% and 9% cement and 5%, 15% and 30% RT. The results show that with the addition of cement, the strength of the RT–soil mixtures increases in a linear manner. On the other hand, the addition of RT decreases q_u of the samples at a constant percentage of cement, and the decrease in porosity can increase q_u. A dosage equation is derived from the experimental data using the porosity/volumetric cement content ratio (η/C_iv) where the control variables are the moisture content, crushed tile content, cement content and porosity.     

浅析旧工业建筑的改造与再利用

旧工业建筑是一个城市历史文化不断发展的见证,对旧工业建筑的改造和再利用是城市有机更新的重要组成部分。本文深入剖析了旧工业建筑改造和再利用的经济、环境、历史、文化、社会意义。以成都的“东郊记忆”为例,阐述了具有现实意义的,旧工业建筑改造和再利用开发设计模式,并引发了对于目前改造存在问题的思考。     

探讨一种再生的开发设计方式--工业建筑的改造利用

当今可持续发展已成为热门话题,在城市改造和建筑设计中该如何体现这一原则和思想？许多学者已开始从事此问题的研究,试图对工业建筑的再利用－“再生”进行探讨,寻求一种有价值和现实意义的设计方式。     

基于构件/构架整体叶轮IUMCAM系统的研制

通过对计算机辅助制造(CAM)专项领域可复用构件/构架的研究,针对整体叶轮CAM软件,设计了一个功能划分合理、复用性较强的构件/构架体系模型IUMCAM,从而可以大幅度地降低开发成本,提高软件的生产率以及软件质量。     

风景园林——城市基础设施再利用的重要手段

发达国家已呈现城市基础设施的相对"过剩",废弃的基础设施成为人们脱离自然、记忆失落以及丧失公共空间的祸首。发达国家的诸多实践案例证明了风景园林在重新定义基础设施并使其重现活力方面具有重要的先导意义,是城市基础设施利用的重要手段,这给我国城市基础设施建设和发展提供了有益的借鉴。     

稠油废水处理再生后回用于热采锅炉的研究

介绍了国内稠油废水处理再生的现状。在着重考察了胜利油田工业化生产和新疆油田中试中存在的问题后 ,对以稠油废水处理再生水为原水的锅炉给水水质指标给予了补充和修改。最后 ,提出了目前国内稠油废水处理再生后回用于热采锅炉中几个值得探讨的问题     

邯郸市东污水处理厂再生水回用工程设计与运行

邯郸市东污水处理厂再生水回用工程总设计处理规模为5万m3/d,其中一期工程规模为3万m3/d.该工程以东污水处理厂二级出水为原水,采用"高密度沉淀池+V型滤池"处理工艺.介绍了工程的设计与运行情况,着重介绍了高密度沉淀池的设计参数与构造.运行结果表明,工艺运行情况稳定,出水水质达到设计要求,主要回用于城市杂用水及景观环境用水,部分回用于工业用水.     

自由形特征复用曲面的设计与研究

在产品设计开发过程中,特征复用技术呈现出逐步增长的趋势.本文针对传统CAD系统中的参数化(如:B-Spline、 NURBS)曲线和曲面设计和修改困难、耗时且繁琐等问题,基于小波技术对自由形特征复用几何建模进行了研究.通过小波技术的时域与频域变换特性,实现了自由形特征信号的分解和合成复用.自由形特征作为基本几何基元的高层抽象避免了设计时对底层基元的操作,从而极大地加速了产品的设计开发效率.