活性炭/氧化亚铜对聚乙烯醇废水的光催化效果研究

以活性炭为载体,采用液相还原法制备活性炭/氧化亚铜（ AC/Cu2O）光催化剂,利用傅立叶变换 红外光谱仪（IR）、扫描电子显微镜（SEM）、 X射线衍射仪（XRD）等对样品进行官能团分析、形貌观察和物相分析。利用该催化剂处理聚乙烯醇（PVA）废水,实验结果表明：在水样初始pH为5、PVA初始浓度75mg/L、催化剂 投加量4g/L、反应时间50min时PVA的去除率为90.60％;且水样初始pH对PVA的去除效果影响最显著。     

固定化尖镰孢菌去除水中蒽的试验研究

采用聚乙烯醇（PVA）-累托石复合载体包埋固定蒽高效降解菌（尖镰孢菌），用于去除水中的蒽，考察了pH值、蒽初始浓度、固定化尖镰孢菌用量及双氧水浓度对固定化尖镰孢菌除蒽效果的影响。结果表明，当蒽的初始浓度为40mg／L时，在pH值为7～8、固定化尖镰孢菌小球用量为8％～10％、双氧水浓度为20～50mg／L的条件下，可取得较好的去除效果。与未包埋尖镰孢菌的小球相比，固定化尖镰孢菌小球对水中的蒽有较强的去除能力，二次使用时，固定化尖镰孢菌小球对水中的蒽仍具有较好的去除效果。     

臭氧/生物活性炭深度处理密云水库水中试研究

采用臭氧／生物活性炭工艺（O3／BAC）对密云水库水进行深度处理中试研究，试验结果表明：臭氧／生物活性炭工艺的处理效果优于单独活性炭工艺（GAC），在最佳臭氧投加量（2．0mg／L）下，03／BAC对CODMn、UV254、BDOC的去除率分别比GAC工艺的高9．9％、30．5％、12．9％；同时，活性炭的结构特征对于生物降解作用有重要影响，破碎炭对BDOC的去除效果明显优于柱状炭的。     

改性膨润土吸附剂的制备及应用研究

以AlCl3为改性剂研究了制备改性膨润土水处理吸附剂的条件，探讨了影响改性膨润土吸附去除苯酚效果的因素。结果表明：当AlCl3投量为25g／100g原土、焙烧温度为450℃时，所制得改性膨润土吸附剂的比表面积和微孔总体积分别为350．21m^2／g和0．907cm^3／g。采用该吸附剂处理苯酚废水（苯酚浓度为200mg／L）的试验结果表明，在改性膨润土吸附剂投量为4g／L、溶液的pH值为8．5、反应时间为30min的条件下，对苯酚的去除率达到了92．2％；对数据的回归分析显示，改性膨润土对苯酚的吸附符合Freundish方程。     

Fenton/活化凹凸棒石工艺去除微污染水中的苯酚

采用Fenton试剂／活化凹凸棒石工艺去除模拟微污染水中的苯酚,考察了pH值、吸附时间、投加量等因素对苯酚去除效果的影响。结果表明,Fenton试剂与活化凹凸棒石联用对微污染水中的苯酚具有较好的去除效果,在苯酚浓度为10mg／L、pH=8、温度为25℃、活化凹凸棒石投量为8g／L、吸附时间为30min的条件下,对苯酚的去除率达94．4％;活化凹凸棒石对苯酚的吸附行为符合Langmuir吸附等温方程。     

两种微波——活性炭法对苯酚的去除效果及其效能比铰

以活性炭为吸附剂和吸波载体,对微波再生法和直接微波法去除水中的苯酚进行了对比试验研究。结果表明,在两种微波辐射方式下,活性炭都能有效去除水中的苯酚,其中微波再生法对活性炭的一次再生率可达96％,多次再生率为50％～70％;活性炭直接微波法对苯酚的去除率较单独活性炭吸附提高了7％～20％,在苯酚浓度较低（462mg／L）时对其去除率最高达93％。试验结果还表明,微波再生法的除污效能指标（P）值普遍高于直接微波法,且活性炭可重复利用,是一种更为经济有效的微波方法。     

高压脉冲放电氧化水处理中铁盐的催化作用

采用向高压脉冲放电反应器中投加铁盐的方式来强化降解苯酚的效果。试验中考察了Fe2＋、Fe2＋的投加量及待处理溶液浓度、pH值对苯酚处理效果的影响。在中性条件下,与单独高压脉冲放电进行比较,Fe2＋投量为0．05mmol／L时,苯酚的去除率可由15．45％提高到94．94％,Fe2＋投量为0．061mmol／L时,去除率提高到61．23％,比Fe2＋低。去除率提高,是由于Fe2＋和Fe2＋诱发放电过程中产生的H2O2发生芬顿和类芬顿反应生成·OH。使用Fe2＋催化时,当溶液的pH值为3左右时,苯酚的去除效果最好,大约处理60min就可达到90％以上;pH值在3～6时,去除率均可达到80％以上。     

混凝对微囊藻毒素的去除效果及机理研究

采用静态试验研究了混凝工艺对水源水中的细胞内和溶解性（细胞外）微囊藻毒素的去除效果，并初步探讨了其去除机理。试验结果表明，混凝剂投加量为25mg／L时，将原水pH值调节到5．5～6．0可有效地去除水中的细胞内微囊藻毒素，去除率可达97．4％；投加10mg／L的粉末活性炭对致嗅物质有一定的吸附效果。强化混凝工艺可显著提高对溶解性微囊藻毒素的去除效果，对MC-RR和MC-LR的去除率均达到60％～70％，原因为强化混凝工艺强化了对小分子弱疏水性有机物的去除效果。     

膜生物反应器去除原水中微量苯酚的研究

酚类化舍物普遍存在于生活污水、天然水和饮用水中。采用一体式膜生物反应器（MBR）进行去除微污染湖水中微量苯酚（2～150μg／L）的试验，结果表明：对苯酚的平均去除率为89．01％。连续试验显示，MBR在冬夏两季运行、当进水苯酚浓度分别在11．0μg／L和19．4μg／L以下时，出水苯酚浓度均低于2μg／L，满足饮用水卫生规范的要求。同时采用间歇试验对MBR去除苯酚的机理进行了研究，证实生物作用在苯酚的去除中起主要作用，MBR对苯酚的去除符合一级动力学过程，降解速率常数为0．0642min6-1。     

臭氧一生物活性炭工艺去除饮用水中AOC的研究

AOC是衡量饮用水生物稳定性的重要指标。研究发现,不同的臭氧投加量下砂滤出水的AOC变化不显著,考虑氧化作用和消毒效果,将最佳的臭氧投量确定为1～2mg／L。生物活性炭（BAC）滤池改善了臭氧氧化后出水的生物稳定性,对TAOC的去除率稳定在28％～65％,而对AOC—P17的去除效果优于AOC—NOX的,因而表现出一定的选择性。较长的空床接触时间（EBCT）并不能保证对AOC的良好去除,但有利于TOC的去除,同时水温的降低一定程度上影响了BAC对AOC的去除效果。     

Rate constants of reactions of ozone with organic and inorganic compounds in water—III. Inorganic compounds and radicals

Second-order rate constants for reactions of ozone with 40 inorganic aqueous solutes are reported. Included are compounds of sulfur (e.g. H₂S, H₂SO₃, HOCH₂SO₃H), chlorine (e.g. Cl⁻, HOCl, NH₂Cl, HClO₂, ClO₂), bromine (e.g. Br⁻, HOBr), nitrogen (e.g. NH₃, NH₂OH, N₂O, HNO₂) and oxygen (e.g. H₂O₂), as well as free radicals (e.g. O₂⁻, OH^•). Most of these compounds exhibit an increase in rate constant with increasing pH corresponding to their degree of dissociation. Rate constants are based on ozone consumption rates measured by conventional batch-type or continuous-flow methods (10⁻³-10⁺⁶ M⁻¹ s⁻¹ range) and determinations of stoichiometric factors. Also listed are data determined by pulse-irradiation techniques using kinetic spectroscopy (10¹⁰ M⁻¹ s⁻¹ range). Additional literature data are reviewed for completeness. Results are discussed with respect to water treatment and environmental processes.     

Formation of disinfection by-products in indoor swimming pool water: the contribution from filling water natural organic matter and swimmer body fluids

The contribution and role of different precursors in the formation of three class of disinfection by-products (DBPs) [trihalomethanes (THMs), haloacetic acids (HAAs), and halonitromethanes (HNMs)] in swimming pool waters were examined using filling waters obtained from five drinking water treatment plant (WTP) effluents and three body fluid analogs (BFAs). BFAs exerted higher chlorine demands as compared to natural organic matter (NOM) in filling waters. BFAs exhibited higher HAA formation potentials than THM formation potentials, while the opposite was observed for the filling water NOM. There was no appreciable difference in the HNM formation potentials of BFAs and filling water NOM. Different components in the BFAs tested exhibited different degree and type of DBP formation. Citric acid had significantly higher THM and HAA yields than other BFA components. The effect of temperature was greater on THM formation, whereas the effect of contact time had more impact on HAA formation. Experiments with filling waters collected from WTP effluents at three different times showed more variability in HAA than THM formation at the WTPs studied.     

Behavior of alkylphenol polyethoxylate metabolites during soil aquifer treatment

The attenuation of alkylphenol polyethoxylates (APEOs) metabolites was studied at a soil aquifer treatment (SAT) site located in Arizona, USA. Two parcels of water were monitored during infiltration; one parcel was predominantly oxic while the other was predominantly anoxic. In this study, only alkylphenol ethoxycarboxylates (APECs) and carboxyalkylphenol ethoxycarboxylates (CAPECs) were detected, no short-chained APEOs were observed-even under anoxic conditions. APEO metabolites were rapidly (<7 days) removed under both aerobic and anoxic conditions. In general, the length of the ethoxycarboxylate chain decreases with depth--at depths greater than 3m, only alkylphenoxy acetic acids (AP1ECs), carboxyalkylphenoxy acetic acids (CAP1ECs), and alkylphenols (APs) remain. Under aerobic conditions, octylphenol and nonylphenol concentrations decreased by approximately 80% (w/w) within 3m of the ground surface. Under anoxic conditions however, alkylphenol concentrations increased by approximately 200% during the first 1.5m and then decreased during the next 1.5m; overall, under anoxic conditions, alkylphenol concentrations increased by approximately 38% within 3m. During infiltration, APEC and CAPEC concentrations decrease by more than 95% within 3m of SAT. Alternate flooding and drying cycles appear to enhance overall APEO metabolite removal efficiencies.     

Removal of VUV pre-treated natural organic matter by biologically activated carbon columns

A potential alternative water treatment process using VUV (185 nm+254 nm) irradiation followed by a biological treatment is described. The system uses sufficient VUV radiation (16J cm(-2)) to significantly enhance the production of biologically degradable moieties prior to treatment with biologically activated carbon (BAC). Two similar activated carbons were used, one virgin and one taken from a water treatment plant with an established biofilm. The VUV-BAC process decreased the overall dissolved organic carbon (DOC) concentration of a natural water sample by 54% and 44% for the virgin carbon and previously used BAC, respectively. Furthermore, VUV-BAC treatment decreased the trihalomethane (THM) formation potential (THMFP) by 60-70% and the haloacetic acid (HAA) formation potential (HAAFP) by 74%. The BAC systems effectively removed the hydrogen peroxide residual produced by VUV irradiation. Although nitrite formation can result from VUV treatment of natural organic matter (NOM), none was detected before or after BAC treatment.     

750kV GIS中金属氧化物避雷器对VFTO影响的研究

随着超高压气体绝缘变电站(GIS)的广泛使用,由隔离开关(DS)和断路器(CB)操作引起的快速暂态过电压(VFTO)的危害越加明显。以西北地区750 kV官亭GIS变电站为计算原型,利用电磁暂态程序(EMTP)对不同运行方式下GIS设备上的VFTO进行数值仿真计算和分析。重点在于对不同运行方式下金属氧化物避雷器(MOA)的限制过电压效果进行分析。计算结果表明:DS无分合闸电阻时,MOA防护效果更明显;MOA主要的抑制效果体现在MOA附近的设备上,对于远离MOA的设备上的VFTO的抑制效果较小;由于VFTO持续的时间极短,通过MOA的能量很小。     

膨润土对重金属离子Pb~(2+),Zn~(2+),Cr(VI),Cd~(2+)的吸附性能

试验研究了pH值、吸附时间和吸附剂用量对膨润土吸附重金属离子Pb2 ,Zn2 ,Cr(VI)和Cd2 的影响.结果表明,在本试验的pH值、吸附时间及吸附剂用量条件下,膨润土对Pb2 ,Zn2 ,Cd2 的吸附效果均优于其对Cr(VI)的吸附效果;pH值是影响上述吸附的重要因素,离子交换和表面络合是上述吸附的主要形式.     

建筑西向房间夏季室内热环境改善

以国内某大学综合实验大楼为例,实测了其中一间西向房间的室内外空气温度与壁面温度,分析了其夏季室内热环境。为了在经济合理地使用能源的情况下,满足它对夏季冷量与冬季热量的需求,根据实测的数据,利用建筑热平衡原理,对其夏季室内热环境特性进行了分析,指出了其热工设计缺陷,并对其进行了热舒适性的改造。通过软件模拟出改造后房间室内空气温度值,对比改造前后室内空气温度值,结果显示改造后的温度值明显降低,热舒适性得到了改善。     

An energy-based partial pushdown analysis procedure for assessment of disproportionate collapse potential

A disproportionate (or progressive) collapse is triggered by localized structural damage that propagates throughout a large portion of a structural system. The current guidelines issued by the US Department of Defense use the alternative path method to assess the vulnerability of a structural system to disproportionate collapse. In this method, the capability of a structure to sustain local damage is evaluated by notionally removing primary load-bearing elements and checking whether the local damage can be absorbed. The assessment can be performed using linear or nonlinear static structural models or a nonlinear dynamic model. Although nonlinear dynamic analysis gives the most accurate results, it is computationally intensive and requires considerable skill to implement properly. In this paper, the vulnerability of three steel frames to disproportionate collapse is assessed using an energy-based nonlinear static pushdown analysis. The predictions are sufficiently close to the results of a nonlinear dynamic time history analysis that the method would be useful for disproportionate collapse-resistant design of buildings with regular steel framing systems.     

聚硅铁混凝去除腐殖酸的研究

考察了聚硅铁(PSF)对腐殖酸(HA)的去除效果及影响因素,并与聚合硫酸铁(PFS)、硫酸铁[Fe_2(SO_4)_3]进行了比较.结果表明,当5相似文献   

Understanding soluble microbial products (SMP) as a component of effluent organic matter (EfOM)

Formation of soluble microbial products (SMP) during biological degradation of organic compounds in a sequencing batch reactor (SBR) was investigated using high performance liquid chromatography--size exclusion chromatography (HPSEC) as well as other organic matter characterization tools. Results showed that carbon compounds in a glucose feed solution were totally transformed to other organic products classified biomass-associated products (BAP). The SMP-BAP contained in the SBR effluent consisted mainly of high-molecular weight (MW) fractions of organic matter, possibly originating from cell lysis. These compounds exhibited a low specific ultraviolet absorbance (SUVA) and a hydrophilic character. In addition, the characteristics of bulk effluent organic matters (EfOM) samples from wastewater treatment facilities were studied. It was observed that EfOM consisted of humic-like and hydrophobic (HPO) compounds, derived from the corresponding drinking water source, in addition to SMP-BAP. A superimposition of SEC chromatograms of the SMP-BAP and humic-like compounds represented a fingerprint of EfOM.