Nutrient removal performance of an anaerobic–anoxic–aerobic process as a function of influent C/P ratio

The laboratory scale anaerobic–anoxic–aerobic (A²O) process fed with synthetic brewage wastewater was designed to investigate the effects of changing feed C/P ratio on the performance of biological nutrient removal (BNR) processes. In the experiment, the influent chemical oxygen demand (COD) concentration was kept at approximately 300 mg L^?1 while the total phosphorus concentration was varied to obtain the desired C/P ratio. Results showed that when the C/P ratio was lower than 32, phosphorus removal efficiency increased as C/P ratio increased linearly, while when the C/P ratio was higher than 32, the P removal efficiency was maintained at 90–98%, and effluent P concentration was lower than 0.5 mg L^?1. However, regardless of the C/P ratio, excellent COD removal (90% or higher) and good total nitrogen removal (75–84%) were maintained throughout the experiments. It was also found that very good linear correlation was obtained between COD uptake per unit P released in the anaerobic zone and C/P ratio. In addition, the P content in the wasted activated sludge increased with the decrease in the C/P ratio. Based on the results, it was recommended that the wastewater C/P ratio and its effects be incorporated into BNR design and operational procedures, appropriate C/P ratios were used to achieve the effluent treatment goals. Copyright © 2005 Society of Chemical Industry     

Comments on “Is the cause of size effect on structural strength fractal or energetic-statistical?” by Ba?ant & Yavari [Engng Fract Mech 2005;72:1-31]

Aim of this letter to the Editor is at replying to the criticisms raised by Ba?ant and Yavari [Ba?ant ZP, Yavari A. Is the cause of size effect on structural strength fractal or energetic - statistical? Engng Fract Mech 2005;72:1-31] against the fractal approach to the size-scale effects on the mechanical properties of materials and the concept of the Multi-Fractal Scaling Law presented by Carpinteri [Carpinteri A. Scaling laws and renormalization groups for strength and toughness of disordered materials. Int J Solids Struct 1994;31:291-302]. These criticisms will be analysed thoroughly, showing how they also contain some mistakes and misunderstandings. The presented elucidations should redirect the discussion to a more correct scientific debate.     

原油集输太阳能加热节能技术的应用

在油田的采油、集输等过程中,传统技术使用燃烧煤、油、天然气和电加热方法来实现原油加热,造成大量的能源消耗和严重的环境污染。原油集输太阳能加热计算机控制节能系统,为油田的采油、集输开辟了节能新途径。该系统不仅具有自动化、智能化的特点,而且节能效果显著,实际节气率超过40%。文章介绍了该系统的结构、工作原理、功能特点以及应用效果。     

光声耦合与光子Cooper对

文中研究了光声耦合所导致的光子Cooper对的形成机制，计算了光子Cooper对的能隙（0.01eV）和尺度（10^-5m)以及内禀角动量（奇数），并简要讨论了几十开低温下介质中光的超流效应的可能性。由于在低温下， 光子Cooper对不容易受到热运动的激发，因此有可能存在光的超流现象。     

降温集油技术在朝阳沟油田的应用

精确界定油井温度界限值,对回油温度进行自动控制是降低气耗、能耗的有效措施。首先推导了单井温度界限数值模型,然后针对朝阳沟油田的实际情况对油井进行了分类,并选择了有代表性的单(环)井进行了试验。通过现场实测值与利用模型计算的预测值比对,符合率达到了70%以上。在此基础上利用温度界限分析仪进行了进一步的验证试验,结果符合预期。在单(环)井上加装了掺水量自动控制装置,实现了回油温度的自动控制。     

Geothermal reservoir simulation

This paper is intended to be a state of the art review of geothermal reservoir simulation. Its recent application to the modelling of real geothermal reservoirs is described and put in the context of an emerging general approach to reservoir modelling. The use of computer simulation for geothermal well test analysis is described. One of the main recent uses of reservoir simulators has been for conducting numerical experiments aimed at improving the understanding of geothermal reservoir physics. Such studies on fractured reservoirs, the thermal structure of reservoirs and the effects of non-condensable gases and dissolved salts are outlined.     

降低氧化铝生产中熟料折合比的探讨

在氧化铝生产过程中，熟料折合比是烧结法一项重要的综合性指标，本文通过对熟料折合比的定义、计算公式的剖析，分析了生产过程中影响熟料折合比的主要因素，对有效降低熟料折合比的措施进行了探讨。     

Communications on energy: Fighting London's cold war

This communication illustrates the work of the London Energy and Employment Network. LEEN has the twin aims of promoting a rational energy policy for London and, in the process, generating much needed employment. In cooperation with Hackney, one of Britain's poorest boroughs, LEEN organized Hackney's Cold War — a series of initiatives showing the practical measures, informational back-up and funding sources necessary for a local energy policy. LEEN intends to repeat this project in other London Boroughs, with the eventual aim of helping to persuade central government to adopt a more comprehensive approach to energy conservation nationally.     

节能设计在医院综合病房楼建筑工程中的应用

医院建筑能耗高,如在设计阶段对建筑、供暖与通风、给排水、电器照明等各环节进行节能设计,可以起到事半功倍的效果.文中结合工程实践,提出了各种具体节能措施.     

中国炼铁系统的节能与环境保护

回顾了20世纪90年代以来,中国炼铁系统的节能和环境保护的进展.指出由于高炉喷煤技术的开发和推广,大大减少了焦炉的建设投资,真正从源头减少了铁前系统的能耗和污染.基于对炼铁系统二次能源的分析,从节能和减排温室气体来看,淘汰落后的小烧结、小高炉, 大力推广高炉TRT、高效干式除尘和利用高炉煤气发电及烧结余热回收利用等,将是今后工作的重点.