西安市自来水中铁锰来源的分析

分析了影响西安市供水系统铁、锰含量的主要因素,包括水文地质条件、气候条件、污染程度及水质稳定性等,指出其主要来源,并提出通过加强水源保护等措施来控制水中的铁锰含量.     

对某商品混凝土搅拌站强度检测结果异常值的分析

对异常值的深入分析，常常能发现一些很重要的线索，可找出试验上重大误差发生的原因、次数、误差范围等线素。因此我们必须慎重地对待检测中出现的异常值。本文从一起混凝土强度检测的异常值中发现是由检测中的差错引起的，同时发现此差错是检测中的普遍现象，望大家对此引起重视。     

氧弹燃烧灰化法测定聚丙烯中铁的含量

用氧弹燃烧灰化法对有机物中铁的含量进行测定,方法操作简便、快速,实验过程无污染,测定结果可靠。     

严格控制玻璃中铁的含量提高器皿玻璃的白度

随着人民生活水平的提高,人们对高白度器皿玻璃的要求越来越高。我厂无色器皿玻璃基本上有两种,一种是钠钙玻璃,另一种是铅晶质玻璃。所谓高白度的器皿玻璃必须是在正常光线下目视感觉看不出玻璃有颜色,玻璃透明度好、亮度高,铅晶质玻璃还需要有一定指标的氧化铅含量和较高的折射率。要想达到用户要求的高白度器皿玻璃,必须严格控制玻璃中铁的含量。     

介绍一种快速测定铁矿石中铁含量的方法

介绍一种快速测定铁矿石中铁含量的方法赵洪东卢加珠（平邑万寿宫水泥有限公司）窦兆祥（山东省水泥质检站）１前言水泥企业控制进厂铁矿石的质量，常采用全分析的方法测定含铁量，虽然十分准确，能有效地控制进厂铁矿石的质量，但这种方法比较费时，大半天才能出结果，不...     

基于监测数据的马坪滑坡稳定性分析

滑坡位移变形的产生及演变,对于滑坡安全稳定性的评价至关重要。本文以德化县马坪滑坡为例,利用位移监测数据,并结时间序列模型分析滑坡体的位移变化,在此基础上结合降雨、地下水等影响因素分析对今后滑坡的稳定性进行了预测。结果表明基于位移监测数据的时间序列模型具有较高精度,对了解边坡位移的发展趋势以及研究边坡的动态稳定性是有效可行的。     

竖井开挖引起地表沉降时空变化趋势研究

对竖井开挖引起的地表沉降时间序列自相关系数的计算分析表明,这些时间序列具有非平稳性特征,即地表沉降量存在确定性趋势。对于竖井开挖引起的地表沉降,时间和空间是不可分割的两个变量,把沉降量的确定性趋势δ、时间t及空间x三者建立起相应联系,构建三者的函数关系模型:δ=f(x,t),使之能预测预报施工引起的地表沉降。     

高强砖的砌体抗压试验研究

我国高强砖的砌体抗压数据偏少,现提供我院曾进行的3批高强砖的砌体抗压试验数据,可供结构设计者和研究者参考。     

基于时间序列分析的工程造价指数预测

准确的工程造价指数预测可以帮助承包商将工程费用的波动纳入预算之中,避免低于成本价或超过拦标价中标的现象等。利用1996年1月～2012年12月香港路政署的工程造价指数,基于ARIMA构建工程造价指数预测模型进行样本内和样本外预测,并对预测结果总结分析,并指出了进一步的研究方向。     

Subsurface iron and arsenic removal for shallow tube well drinking water supply in rural Bangladesh

Subsurface iron and arsenic removal has the potential to be a cost-effective technology to provide safe drinking water in rural decentralized applications, using existing shallow tube wells. A community-scale test facility in Bangladesh was constructed for injection of aerated water (∼1 m³) into an anoxic aquifer with elevated iron (0.27 mmol L⁻¹) and arsenic (0.27 μmol L⁻¹) concentrations. The injection (oxidation) and abstraction (adsorption) cycles were monitored at the test facility and simultaneously simulated in the laboratory with anoxic column experiments.Dimensionless retardation factors (R) were determined to represent the delayed arrival of iron or arsenic in the well compared to the original groundwater. At the test facility the iron removal efficacies increased after every injection-abstraction cycle, with retardation factors (R_Fe) up to 17. These high removal efficacies could not be explained by the theory of adsorptive-catalytic oxidation, and therefore other ((a)biotic or transport) processes have contributed to the system’s efficacy. This finding was confirmed in the anoxic column experiments, since the mechanism of adsorptive-catalytic oxidation dominated in the columns and iron removal efficacies did not increase with every cycle (stable at R_Fe = ∼8). R_As did not increase after multiple cycles, it remained stable around 2, illustrating that the process which is responsible for the effective iron removal did not promote the co-removal of arsenic. The columns showed that subsurface arsenic removal was an adsorptive process and only the freshly oxidized adsorbed iron was available for the co-adsorption of arsenic. This indicates that arsenic adsorption during subsurface treatment is controlled by the amount of adsorbed iron that is oxidized, and not by the amount of removed iron. For operational purposes this is an important finding, since apparently the oxygen concentration of the injection water does not control the subsurface arsenic removal, but rather the injection volume. Additionally, no relation has been observed in this study between the amount of removed arsenic at different molar Fe:As ratios (28, 63, and 103) of the groundwater. It is proposed that the removal of arsenic was limited by the presence of other anions, such as phosphate, competing for the same adsorption sites.     

原水铁锰含量对细菌除铁除锰效能的影响

将从水厂成熟锰砂中分离出来的细菌进行驯化和增殖培养,通过改变原水中铁锰含量来改变细菌生长环境,考察了不同条件下混合细菌对铁锰的去除效果.结果表明:在有Fe2+存在的情况下,铁锰氧化细菌维持着正常的活性,对铁锰始终具有高效而稳定的去除能力;Fe2+的存在与否也影响着Mn2+的氧化速率;原水中锰的存在对细菌除铁影响较小.     

Biological iron oxidation by Gallionella spp. in drinking water production under fully aerated conditions

Iron oxidation under neutral conditions (pH 6.5-8) may be a homo- or heterogeneous chemically- or a biologically-mediated process. The chemical oxidation is supposed to outpace the biological process under slightly alkaline conditions (pH 7-8). The iron oxidation kinetics and growth of Gallionella spp. - obligatory chemolithotrophic iron oxidizers - were assessed in natural, organic carbon-containing water, in continuous lab-scale reactors and full-scale groundwater trickling filters in the Netherlands. From Gallionella cell numbers determined by qPCR, balances were made for all systems. The homogeneous chemical iron oxidation occurred in accordance with the literature, but was retarded by a low water temperature (13 °C). The contribution of the heterogeneous chemical oxidation was, despite the presence of freshly formed iron oxyhydroxides, much lower than in previous studies in ultrapure water. This could be caused by the adsorption of natural organic matter (NOM) on the iron oxide surfaces. In the oxygen-saturated natural water with a pH ranging from 6.5 to 7.7, Gallionella spp. grew uninhibited and biological iron oxidation was an important, and probably the dominant, process. Gallionella growth was not even inhibited in a full-scale filter after plate aeration. From this we conclude that Gallionella spp. can grow under neutral pH and fully aerated conditions when the chemical iron oxidation is retarded by low water temperature and inhibition of the autocatalytic iron oxidation.     

对村庄水系统规划编制内容的探讨

在分析了我国农村水系现状问题的基础上,构建了村庄水系统规划的编制内容,包括水系治理规划、河道保护规划、给水设施规划和排水设施规划,并对四个方面的要点、标准进行了详细阐述,以期指导村庄水系统工程规划建设。     

Morphological and physicochemical characteristics of iron corrosion scales formed under different water source histories in a drinking water distribution system

The corrosion scales on iron pipes could have great impact on the water quality in drinking water distribution systems (DWDS). Unstable and less protective corrosion scale is one of the main factors causing “discolored water” issues when quality of water entering into distribution system changed significantly. The morphological and physicochemical characteristics of corrosion scales formed under different source water histories in duration of about two decades were systematically investigated in this work. Thick corrosion scales or densely distributed corrosion tubercles were mostly found in pipes transporting surface water, but thin corrosion scales and hollow tubercles were mostly discovered in pipes transporting groundwater. Magnetite and goethite were main constituents of iron corrosion products, but the mass ratio of magnetite/goethite (M/G) was significantly different depending on the corrosion scale structure and water source conditions. Thick corrosion scales and hard shell of tubercles had much higher M/G ratio (>1.0), while the thin corrosion scales had no magnetite detected or with much lower M/G ratio. The M/G ratio could be used to identify the characteristics and evaluate the performances of corrosion scales formed under different water conditions. Compared with the pipes transporting ground water, the pipes transporting surface water were more seriously corroded and could be in a relatively more active corrosion status all the time, which was implicated by relatively higher siderite, green rust and total iron contents in their corrosion scales. Higher content of unstable ferric components such as γ-FeOOH, β-FeOOH and amorphous iron oxide existed in corrosion scales of pipes receiving groundwater which was less corroded. Corrosion scales on groundwater pipes with low magnetite content had higher surface area and thus possibly higher sorption capacity. The primary trace inorganic elements in corrosion products were Br and heavy metals. Corrosion products obtained from pipes transporting groundwater had higher levels of Br, Ti, Ba, Cu, Sr, V, Cr, La, Pb and As.     

钢铁中硅含量测定方法的研究

采用还原型硅钼酸盐光度法对钢铁中硅含量进行了实验测定,根据测定原理,介绍了试料分解和试液制备的方法,并对最低检出限、精密度、准确度进行了分析,指出实验测定值均在标准样品保证值范围内。     

管道直饮水系统设计初论

对管道直饮水处理工艺的设置、设计秒流量公式的选用进行了探讨,介绍了用概率法计算直饮水设计秒流量的方法,并与规范中的方法作了比较,说明该方法的合理性和简便性。     

Speciation and distribution of vanadium in drinking water iron pipe corrosion by-products

Vanadium (V) when ingested from drinking water in high concentrations (> 15 μg L^− 1) is a potential health risk and is on track to becoming a regulated contaminant. High concentrations of V have been documented in lead corrosion by-products as Pb₅(V⁵⁺O₄)₃Cl (vanadinite) which, in natural deposits is associated with iron oxides/oxyhydroxides, phases common in iron pipe corrosion by-products. The extent of potential reservoirs of V in iron corrosion by-products, its speciation, and mechanism of inclusion however are unknown. The aim of this study is to assess these parameters in iron corrosion by-products, implementing synchrotron-based μ-XRF mapping and μ-XANES along with traditional physiochemical characterization. The morphologies, mineralogies, and chemistry of the samples studied are superficially similar to typical iron corrosion by-products. However, we found V present as discrete grains of Pb₅(V⁵⁺O₄)₃Cl likely embedded in the surface regions of the iron corrosion by-products. Concentrations of V observed in bulk XRF analysis ranged from 35 to 899 mg kg^− 1. We calculate that even in pipes with iron corrosion by-products with low V concentration, 100 mg kg^− 1, as little as 0.0027% of a 0.1-cm thick X 100-cm long section of that corrosion by-product needs to be disturbed to increase V concentrations in the drinking water at the tap to levels well above the 15 μg L^− 1 notification level set by the State of California and could adversely impact human health. In addition, it is likely that large reservoirs of V are associated with iron corrosion by-products in unlined cast iron mains and service branches in numerous drinking water distribution systems.     

Observations on the use of iron(II) complexing agents to fractionate the total filterable iron in natural water samples

Analysis of filtered natural water samples using Fe(II) complexing agents (bathophenanthrolinedisulphonic acid, 2,2′-dipyridyl, ferrozine, TPTZ) and acetic acid-sodium acetate buffer (pH 4.6) showed that the absorbance of the iron(II) complex increased with time both in the presence and the absence of a reducing agent (ascorbic acid, hydroxylammonium chloride). Exposure of the samples to 0.1 M HCl (pH 1.3) for 1 h prior to the addition of the complexing reagents resulted in a stable iron concentration which was designated the acid-extractable fraction of the total filterable iron. The results have implications for the complexometric determination of iron fractions other than total iron after acid digestion.     

砂含水量对混凝土质量的影响

介绍了工程用砂含水量状况对混凝土质量和经营成本的影响 ,并就如何将砂子含水量对混凝土性能影响降低到最低程度的措施进行了阐述