高温后钢管再生混凝土短柱的理论分析与试验研究

首先进行了高温后钢管再生混凝土轴压短柱的试验研究,在分析试验结果的基础上提出了高温后核心再生混凝土的应力一应变关系模型,模型考虑了再生粗骨料取代率和曾经历的最高温度的影响;然后采用数值方法对高温后钢管再生混凝土轴压短柱的荷栽一变形全过程关系曲线进行了计算分析,数值计算结果得到试验结果的验证;最后利用数值方法系统分析了再生粗骨料取代率、曾经历的最高温度和约束效应系数等参数对高温后钢管再生混凝土短柱轴压强度系数的影响,并提出了相应的简化计算公式,轴压承载力的简化计算结果与试验结果基本吻合。     

混凝土轴压方柱满足目标抗火可靠指标的建议截面

对混凝土轴压柱抗火计算所用荷载比与其常温设计荷载比的换算关系进行了推导和分析,分别针对耐火等级一级和二级情况下的柱耐火极限要求,给出了四面受火轴压方柱满足目标抗火可靠指标的最小截面取值。研究表明:①常温设计荷载比大致为抗火计算所用荷载比的2～5倍,一般混凝土柱可近似取2.5倍;②荷载比小于0.2时,现行规范给出的300mm×300mm截面柱,在抗火可靠指标不小于目标抗火可靠指标的情况下可以满足二级耐火要求;③荷载比和耐火等级是影响轴压柱最小截面取值的主要因素。     

场地土壤六价铬污染治理试验研究

为深入研究唐山市老自行车厂场区六价铬污染机理和确定治理方案,本文通过一系列的浸泡和土柱试验,查明了六价铬在场地包气带中的污染原理和硫酸亚铁还原固定治理土壤六价铬污染的可行性与相关参数。试验结果表明:污染场地内包气带中六价铬的运移主要受吸附和解析作用的控制。使用PH值为3.0,质量浓度为2.4%的硫酸亚铁溶液作为治理药剂,可将污染场地包气带中93.24%的六价铬去除。     

Diagnosis of dissolved organic matter removal by GAC treatment in biologically treated papermill effluents using advanced organic characterisation techniques

Granular activated carbon (GAC) exhaustion rates on pulp and paper effluent from South East Australia were found to be a factor of three higher (3.62 cf. 1.47 kg m⁻³) on Kraft mills compared to mills using Thermomechanical pulping supplemented by Recycled Fibre (TMP/RCF). Biological waste treatment at both mills resulted in a final effluent COD of 240 mg L⁻¹. The dissolved organic carbon (DOC) was only 1.2 times higher in the Kraft effluent (70 vs. 58 mg L⁻¹), however, GAC treatment of Kraft and TMP/RCF effluent was largely different on the DOC persisted after biological treatment. The molecular mass (636 vs. 534 g mol⁻¹) and aromaticity (5.35 vs. 4.67 L mg⁻¹ m⁻¹) of humic substances (HS) were slightly higher in the Kraft effluent. The HS aromaticity was decreased by a factor of 1.0 L mg⁻¹ m⁻¹ in both Kraft and TMP/RCF effluent. The molecular mass of the Kraft effluent increased by 50 g mol⁻¹ while the molecular mass of the TMP/RCF effluent was essentially unchanged after GAC treatment; the DOC removal efficiency of the GAC on Kraft effluent was biased towards the low molecular weight humic compounds. The rapid adsorption of this fraction, coupled with the slightly higher aromaticity of the humic components resulted in early breakthrough on the Kraft effluent. Fluorescence excitation-emission matrix analysis of the each GAC treated effluent indicated that the refractory components were higher molecular weight humics on the Kraft effluent and protein-like compounds on the TMP/RCF effluent. Although the GAC exhaustion rates are too high for an effective DOC removal option for biologically treated pulp and paper mill effluents, the study indicates that advanced organic characterisation techniques can be used to diagnose GAC performance on complex effluents with comparable bulk DOC and COD loads.     

五莲县石材废料的资源化利用

石材工业是资源加工型产业,加工过程会产生大量的石材废料.我国对石材加工废料的研究起步较晚,应用技术不成熟.介绍了目前国内外对石材废料的几种主要资源化利用方式,并结合五莲县石材产业基地石材加工实际工艺及废料资源化处理方式,研究石材废料的资源化利用.     

Developing an anaerobic digester with external Zeolite filled column for enhancing methane production from swine manure – A feasibility study

ABSTRACT

Development of digesters with an external zeolite column facilitates the convenient removal of the zeolite with TAN, without disturbing the continuous anaerobic digestion process. A digester with an inside zeolite bed (In-Zeo) and digester without adding zeolite (No-Zeo) were employed to compare the process performance with digester with external zeolite column (EX-Zeo). The cumulative, CH₄ yields were 5% and 15% greater in the EX-Zeo, and the In-Zeo digesters respectively compared to the No-Zeo digesters. Also, the % VS reduction was 49%, 55% and 41%, respectively in the Ex-Zeo, In-Zeo and No-Zeo digesters. The results indicated that treatment with 7% zeolite during anaerobic digestion has the potential to improve biodegradation of swine manure. The addition of zeolite appeared to reduce TAN from the digestate, thereby enhancing the CH₄ yield. Zeolite could be used either internally or externally to enhance CH₄ production through anaerobic digestion of swine manure.     

Rapid determination of polar pesticides and plant growth regulators in fruits and vegetables by liquid chromatography/tandem mass spectrometry

ABSTRACT

A simple high-throughput liquid chromatography/tandem mass spectrometry (LC-MS/MS) multiresidue analysis method was developed for the simultaneous determination of polar pesticides, plant growth regulators and other polar compounds. These included amitrole, chlormequat, mepiquat, cyromazine, ETU, PTU, perchlorate, and daminozide using a mixed-mode column. A 10 g test portion was shaken with acidified methanol for 10 min. After centrifugation, the sample extract was injected and analyzed within 11 min by LC-MS-MS. This column eliminated the need for derivatization or the use of ion paring reagent. Two MS-MS transitions were monitored in the method for each target compound to achieve true positive identification. Eight isotopically-labeled internal standards corresponding to each analyte were used to correct for matrix suppression effect and/or instrument signal drift. The average recovery for all analytes at 20, 40, and 250 ng/g (n = 6) ranged from 73–136%, with a relative standard deviation of ≤ 20%.     

Fate of atrazine in a soil under different agronomic management practices

Agricultural management affects the movement of atrazine in soil and leaching to groundwater. The objective of this study was to determine atrazine adsorption in a soil after 20 years of atrazine application under agronomic management practices differing in tillage practice (conventional and zero tillage), residue management (with and without residue retention) and crop rotation (wheat-maize rotation and maize monoculture). Atrazine sorption was determined using batch and column experiments. In the batch experiment, the highest distribution coefficient K_d (1.1 L kg^?1) at 0–10 cm soil depth was observed under zero tillage, crop rotation and residue retention (conservation agriculture). The key factor in adsorption was soil organic matter content and type. This was confirmed in the column experiment, in which the highest K_d values were observed in treatments with residue retention, under either zero or conventional tillage (0.81 and 0.68 L kg^?1, respectively). Under zero tillage, the fact that there was no soil movement helped to increase the K_d. The increased soil organic matter content with conservation agriculture may be more important than preferential flow due to higher pore connectivity in the same system. The soil's capacity to adsorb 2-hydroxyatrazine (HA), an important atrazine metabolite, was more important than its capacity to adsorb atrazine, and was similar under all four management practices (K_d ranged from 30 to 40 L kg^?1). The HA adsorption was attributed to the type and amount of clay in the soil, which is unaffected by agronomic management. Soils under conservation agriculture had higher atrazine retention potential than soils under conventional tillage, the system that predominates in the study area.     

水中草甘膦和氨甲基膦酸的柱前衍生-液相色谱方法研究

建立柱前衍生-液相色谱-荧光检测法同时测定水中草甘膦和氨甲基膦酸的方法。水样经芴甲氧羰酰氯衍生化后取上清液进样,采用ODS C18柱,以水(5 mmol/L乙酸铵)-乙腈作为流动相进行梯度洗脱,采用荧光检测器进行检测。实验通过加入柠檬酸三钠,解决了实际水样中金属阳离子的干扰问题。草甘膦和氨甲基膦酸在一定范围内线性良好(r=0.997 3~0.999 0),回收率为92.2%~102%,相对标准偏差为4.3%~8.5%,方法检出限为1.29μg/L和1.84μg/L。     

毛细管柱气相色谱法测定工业废气和废水中N,N-二甲基甲酰胺

采用HP-INNOWAX毛细管柱、气相色谱氢火焰离子化检测器测定工业废气和废水中的N,N-二甲基甲酰胺,可能共存的丙酮、乙醇和乙酰丙酮均对测试无干扰.方法在0.939 mg/L～75.1 mg/L范围内线性良好,对工业废水、无组织排放工业废气和有组织排放工业废气中N,N-二甲基甲酰胺的检出限分别为0.47 mg/L、0.16 mg/m3和0.31 mg/m3,标准溶液平行测定的RSD为1.9％ ～2.2％,废水样品加标回收率为94％～ 97％.