升流式污泥床对无机废水中氮硫转化及相互影响

采用无机含氨和硫酸盐(SO₄^2-)废水作为升流式污泥床(USB)反应器进水,研究了其对铵(NH₄⁺)和SO₄^2-的去除以及不同高度污泥层含氮、硫元素的转化途径.结果表明在反应器进水口处由于进水自含氧(外源性氧)和兼性厌氧菌受到氧化应激产生过氧化氢(内源性氧),两种“氧”共同存在下,反应器内生物脱氨量(以氮计)最高达40mg/L左右,且在USB反应器不同高度污泥层含氮化合物和含硫化合物的转化途径不同.在反应器底部污泥层,颗粒污泥表面氨氧化菌利用O₂将氨(NH₄⁺)氧化成亚硝酸盐(NO₂^-),在颗粒污泥内部厌氧氨氧化菌利用NH₄⁺和NO₂^-生成氮气(N₂)和硝酸盐(NO₃^-);同时,O₂     

鱼类加工废水絮凝床─SBR处理技术的应用

在鱼类加工废水蛋白质资源回收利用基础上,应用絮凝床预处理技术（ＣＦＢ） Ｅ以简单的ＳＢＲ生化法成功地处理了该类废水,实验表明,以ＣＦＢ技术为主线开发的鱼类加工废水处理工艺,具有技术先进、处理效果好、运行稳定可靠、管理简便、经济实用等特点,在实际应用中有广阔的前景。     

丝状菌污泥膨胀的影响因素与控制

本文系统地介绍了近一、二十年来国际上关于丝状菌污泥膨胀的最新研究成果。从丝状菌的种类与特性、丝状菌污泥膨胀的机理、引起污泥膨胀的污水性质和运行条件等方面全面地论述了污泥膨胀的影响因素与控制方法,通过对国内外污泥膨胀研究现状与存在问题的分析,提出了该课题今后的研究方向。     

企业电力负荷计算机安全管理系统

采用无线数据传输和上下位分布式计算机系统结构,设计了一种工矿企业电力负荷计算机安全管理系统,介绍了该系统的硬件构成、软件结构和工作原理。实际运行表明该系统对提高企业电力负荷安全管理水平具有显著作用。     

Removal capacity and pathways of phenolic endocrine disruptors in an estuarine wetland of natural reed bed

Phenolic compounds are partly known as endocrine disruptors with various harmful effects including feminization and carcinogenesis at very low concentrations. Consequently, the pathways and removal of these compounds in natural and artificial sewage treatment systems such as wetlands have received wide concern. In this paper, a natural reed bed wetland with an area of 695 ha located in the Liaohe River estuary in Northeast China was employed as a demonstration site to study the retention and removal efficiency of phenolic compounds including 4-nonylphenol (4-NP), bisphenol A (BPA), 4-t-octylphenol (4-t-OP), and 2,4-dichlorophenol (DCP), and to evaluate their purification capacity via water and mass balance analyses during an irrigation period from May 9 to September 8, 2009. The results showed that the phenolic compounds could be retained in the wetland system and removed through various processes. On average, 27.5% of phenolic compounds could be retained by the wetland substrate during the initial three-day irrigation period with a retention capacity order of 4-t-OP > 4-NP > BPA > DCP. During the following 120 d irrigation period, the phenolic compounds could be efficiently removed with an average percentage of 91.6%. It is estimated that 1.76 kg d⁻¹ of phenolic compounds could be removed by the Liaohe River estuarine wetland (∼8 × 10⁴ ha). The reed bed wetland system therefore provides a feasible mitigation option for phenolic pollutants in sewage and wastewater.     

青海省光伏电站接入电网调度模式探讨

青海省太阳能资源丰富,开发利用潜力巨大。根据青海省柴达木盆地＂千万千瓦级＂光伏发电基地发展规划,预计2010年青海省光伏发电总装机容量将达到20万kW,2020年远景规划装机容量超过750万kW,2030年远景规划总装机容量达到2 000万kW。但是,青海省光伏发电也面临着诸如光伏电站调度困难等技术、经济问题,必须妥善解决。针对青海省光伏电站接入电网调度模式开展相应工作,意图对青海省并网光伏电站及电网的安全、稳定、运行提供有益指导。     

Will PM control undermine China's efforts to reduce soil acidification?

China’s strategies to control acidifying pollutants and particulate matter (PM) may be in conflict for soil acidification abatement. Acidifying pollutant emissions are estimated for 2005 and 2020 with anticipated control policies. PM emissions including base cations (BCs) are evaluated with two scenarios, a base case applying existing policy to 2020, and a control case including anticipated tightened measures. Depositions of sulfur (S), nitrogen (N) and BCs are simulated and their acidification risks are evaluated with critical load (CL). In 2005, the area exceeding CL covered 15.6% of mainland China, with total exceedance of 2.2 Mt S. These values decrease in the base scenario 2020, implying partial recovery from acidification. Under more realistic PM control, the respective estimates are 17.9% and 2.4 Mt S, indicating increased acidification risks due to abatement of acid-neutralizing BCs. China’s anthropogenic PM abatement will have potentially stronger chemical implications for acidification than developed countries.     

二级活性炭生物流化床深度处理有机胺废水研究

采用二级活性炭生物流化床工艺深度处理有机胺废水,研究了有机容积负荷、NH3-N容积负荷以及曝气间歇对COD、NH3-N去除效果的影响.结果表明:当有机容积负荷为0.94～2.38 kg COD/(m3·d)时,二级流化床对COD的去除率为80.6%～95.5%,比一级流化床的抗有机负荷冲击的能力更强;当NH3-N容积负...     

Bed Stability and Sedimentation Associated With Human Disturbances in Pacific Northwest Streams1

Abstract: To evaluate anthropogenic sedimentation in United States (U.S.) Pacific Northwest coastal streams, we applied an index of relative bed stability (LRBS*) to summer low flow survey data collected using the U.S. Environmental Protection Agency’s Environmental Monitoring and Assessment Program field methods in a probability sample of 101 wadeable stream reaches. LRBS* is the log of the ratio of bed surface geometric mean particle diameter (D_gm) to critical diameter (D*_cbf) at bankfull flow, based on a modified Shield’s criterion for incipient motion. We used a formulation of LRBS* that explicitly accounts for reductions in bed shear stress that result from channel form roughness due to pools and wood. LRBS* ranged from ?1.9 to +0.5 in streams within the lower quartile of human riparian and basin disturbance, and was substantially lower (?4.2 to ?1.1) in streams within the upper quartile of human disturbance. Modeling results suggest that the expected range of LRBS* in streams without human disturbances in this region might be generally between ?0.7 and +0.5 in either sedimentary or volcanic lithology. However, streams draining relatively soft, erodible sedimentary lithology showed greater reductions in LRBS* associated with disturbance than did those having harder, more resistant volcanic (basalt) lithology with similar levels of basin and riparian disturbance. At any given level of disturbance, smaller streams had lower LRBS* than those with larger drainages. In sedimentary lithology (sandstone and siltstone), high‐gradient streams had higher LRBS* than did low‐gradient streams of the same size and level of human disturbance. High gradient streams in volcanic lithology, in contrast, had lower LRBS* than low‐gradient streams of similar size and disturbance. Correlations between D_gm and land disturbance were stronger than those observed between D*_cbf and land disturbance. This pattern suggests that land use has augmented sediment supplies and increased streambed fine sediments in the most disturbed streams. However, we also show evidence that some of the apparent reductions in LRBS*, particularly in steep streams draining small volcanic drainages, may have resulted in part from anthropogenic increases in bed shear stress. The synoptic survey methods and designs we use appear adequate to evaluate regional patterns in bed stability and sedimentation and their general relationship to human disturbances. More precise field measurements of channel slope, cross‐section geometry, and bed surface particle size would be required to use LRBS* in applications requiring a higher degree of accuracy and precision, such as site‐specific assessments at individual streams.     

PCC桩水平承载特性足尺模型试验与数值模拟

通过进行大型模型槽足尺模型试验,根据桩身变形和桩身弯矩的试验结果,分析了水平荷载作用下现浇混凝土大直径管桩(以下简称PCC桩)的水平承载特性和桩-土共同作用性状。采用大型通用有限元软件ABAQUS对PCC桩的水平承载特性进行了数值模拟,计算结果与试验结果符合得较好,并进一步探讨了PCC桩水平承载特性的主要影响因素。结果表明:表层土体的弹性模量对水平受力性状影响较大,表层土体的厚度对桩身水平位移也有较大影响,因此可以通过改良表层土体来控制桩身水平位移,以达到工程设计要求;土体强度参数对水平承载特性也有影响,尤其是内摩擦角和粘聚力较小时更为明显。