饮用水源中挥发性有机物分析方法的优化和应用

采用吹扫捕集—气相色谱—质谱联用技术分析水中的24种挥发性有机物。通过优化分析条件,改善了各组份的分离效果,节省了分析时间,得到各组份检测限为0.001-0.099μg/L,相对标准偏差为2.3%-5.6%,加标回收率为91.2%-107.6%,方法具有较好的精密度、准确度和低检测限。同时对漳州市饮用水源中的24种挥发性有机物进行监测分析,结果均低于检测限。     

塔里木油田三甘醇脱水装置参数优化研究

文章通过三甘醇脱水工艺的第三套三甘醇注醇量调整,第三套再生温度的调节、汽提气注入量调整、贫液进塔温度调整运行参数的优化,得出:当三甘醇脱水工艺循环量在3840kg/h左右时,再生效果最好,贫液浓度最高,所获得的干气水露点最低;三甘醇脱水工艺再生温度在190～200℃之间温度越高,再生效果越好;三甘醇脱水工艺再生装置在汽提气量30Nm3/h左右时,再生效果最好,贫液浓度最高,所获得的干气水露点最低。     

西柏坡电广烟气脱硫装置的运行诊断及优化

以西柏坡电厂一期2×300MW烟气脱硫工程为例,对吸收塔运行状况进行运行监测及化学分析,在不进行大规模改造的前提下,通过CFD技术模拟不同工况下的吸收塔烟气流场,通过增加导流板优化吸收塔烟气流场的分布,达到了提高脱硫效率的目的,对已建成的吸收塔进行后期优化改造,有良好的借鉴作用.     

基于瓦斯涌出量预测的近距离煤层群开采顺序优化选择

随着中厚煤层资源的枯竭,近距离薄煤层群开采成为我国资源的重要补充。煤层群开采时合理的采掘部署是防止工作面瓦斯集中涌出的关键,本文通过分析近距离煤层群开采时各回采顺序下工作面瓦斯涌出量,建立了以工作面瓦斯涌出量预测为基础的近距离煤层群开采优化模型,利用计算机编程实现了模型的可视化操作。该模型通过对比分析全部种回采顺序方案,选择整个回采期间瓦斯涌出量最均衡的方案为最优方案。对翔升煤矿进行了实例分析,结果显示合理的回采方案可以使工作面最大瓦斯涌出量大大减小,使整个回采期间工作面瓦斯涌出量趋于均衡。为煤层群开采优化技术中的瓦斯环节提供了理论依据。     

Monitoring and optimizing the co-composting of dewatered sludge: a mixture experimental design approach

The management of dewatered wastewater sludge is a major issue worldwide. Sludge disposal to landfills is not sustainable and thus alternative treatment techniques are being sought. The objective of this work was to determine optimal mixing ratios of dewatered sludge with other organic amendments in order to maximize the degradability of the mixtures during composting. This objective was achieved using mixture experimental design principles. An additional objective was to study the impact of the initial C/N ratio and moisture contents on the co-composting process of dewatered sludge. The composting process was monitored through measurements of O(2) uptake rates, CO(2) evolution, temperature profile and solids reduction. Eight (8) runs were performed in 100 L insulated air-tight bioreactors under a dynamic air flow regime. The initial mixtures were prepared using dewatered wastewater sludge, mixed paper wastes, food wastes, tree branches and sawdust at various initial C/N ratios and moisture contents. According to empirical modeling, mixtures of sludge and food waste mixtures at 1:1 ratio (ww, wet weight) maximize degradability. Structural amendments should be maintained below 30% to reach thermophilic temperatures. The initial C/N ratio and initial moisture content of the mixture were not found to influence the decomposition process. The bio C/bio N ratio started from around 10, for all runs, decreased during the middle of the process and increased to up to 20 at the end of the process. The solid carbon reduction of the mixtures without the branches ranged from 28% to 62%, whilst solid N reductions ranged from 30% to 63%. Respiratory quotients had a decreasing trend throughout the composting process.     

基于正交试验的煤矿安全开采充填材料配比优化研究

针对目前我国"三下"压煤的现状,以及煤矿固体废弃物以煤矸石、粉煤灰为主的情况,结合岱庄煤矿膏体充填工程实践,以水泥为胶结料,煤矸石和粉煤灰为粗细骨料,运用正交试验的方法定量确定了水泥、粉煤灰和煤矸石不同配比和膏体浓度对煤矸石膏体充填各性能指标的敏感程度,以及各指标随各因素的变化趋势。结果表明:提高水泥掺量可以缩短膏体的凝结时间并提高膏体的强度;膏体的塌落度即流动性主要通过调节其浓度来实现;加入适量的粉煤灰可以提高膏体的流动性,但随着粉煤灰的增多,分层度和泌水率都有所增加。当水泥∶粉煤灰∶煤矸石为1∶2.22∶4.44,浓度为75%时,充填膏体的可泵性和强度都达到最佳,充填效果显著,有助于煤矿安全开采。     

Revealing the effect of preparation parameters on zeolite adsorption performance for low and medium concentrations of ammonium

The effect of preparation parameters on the performance of zeolite for ammonium(20–300 mg N/L) adsorption from simulated wastewater is reported. It was found that the ratios of Na_2O/SiO_2 and Si/Al had a more important influence than crystallization time on zeolite adsorption properties. Relatively low Na_2O/SiO_2 ratios were beneficial for fabrication of zeolites with high proportions of micropore area and volume, which led to the surface adsorption mechanism being dominated by surface free energy and pore effects. However,with decreasing Si/Al ratios, the effect of ion-exchange was more prominent due to the high negative surface potential of zeolite. In addition, the concentration of weak acid sites on the zeolites was increased with lower ratios of Na_2O/SiO_2 and Si/Al, which may promote ammonium removal. Therefore, the most effective zeolite for ammonium removal, which was fabricated at Na_2O/SiO_2= 1.375, Si/Al = 4 and crystallization time of 48 hr, exhibited the cooperative effects of adsorption, ion-exchange and a large amount of weak acid sites. The maximum ammonium adsorption capacity(35.06 ± 0.98 mg/g) and the removal efficiency(94.44% ± 4.00%) were obtained at the dosage of 4.0 g/L zeolite NaX at ammonium concentrations of 300 mg N/L and 20 mg N/L, respectively. The Freundlich isotherm and pseudo-first-order kinetics models provided excellent fitting for the ammonium adsorption process. In addition, zeolite NaX showed about 1.23–3.2 times the ammonium adsorption capacity of clinoptilolite. The stable and efficient reusability of zeolite NaX after five regeneration cycles demonstrated that this adsorbent has considerable potential for practical industrial applications.     

Developing China's roadmap for air quality improvement: A review on technology development and future prospects

Air pollution control policies in China have been experiencing profound changes, highlighting a strategic transformation from total pollutant emission control to air quality improvement, along with the shifting targets starting from acid rain and NO_x emissions to PM_2.5 pollution, and then the emerging O₃ challenges. The marvelous achievements have been made with the dramatic decrease of SO₂ emission and fundamental improvement of PM_2.5 concentration. Despite these achievements, China has proposed Beautiful China target through 2035 and the goal of 2030 carbon peak and 2060 carbon neutrality, which impose stricter requirements on air quality and synergistic mitigation with Greenhouse Gas (GHG) emissions. Against this background, an integrated multi-objective and multi-benefit roadmap is required to provide decision support for China's long-term air quality improvement strategy. This paper systematically reviews the technical system for developing the air quality improvement roadmap, which was integrated from the research output of China's National Key R&D Program for Research on Atmospheric Pollution Factors and Control Technologies (hereafter Special NKP), covering mid- and long-term air quality target setting techniques, quantitative analysis techniques for emission reduction targets corresponding to air quality targets, and pathway optimization techniques for realizing reduction targets. The experience and lessons derived from the reviews have implications for the reformation of China's air quality improvement roadmap in facing challenges of synergistic mitigation of PM_2.5 and O₃, and the coupling with climate change mitigation.     

GSK-XGBoost模型在井底风温预测中的应用*

为防治矿井热害,针对矿井井底风温在预测过程中精度较低的问题,提出1种网格搜索法结合K折交叉验证优化XGBoost的预测模型。通过分析确定影响井底风温的主要因素,使用网格搜索算法结合K折交叉验证,进行迭代缩小搜索范围并调参,选取最优参数配置,实现对XGBoost模型的优化,得到预测结果并与其他模型进行比较。研究结果表明:初始参数经优化后,当最大回归树深度为3且学习速率为0.1时,XGBoost回归模型性能最佳,与随机森林模型、BP神经网络模型、T-S模糊神经网络模型相比,平均相对误差分别降低了2.12%,0.88%,0.3%,均方根误差分别降低了0.66,0.24,0.11 ℃。     

反渗透预处理技术探讨

反渗透是当今先进的水处理技术，为了满足反渗透膜对水质的要求，原水进入膜之前必须进行妥善的预处理，本文详细探讨了反渗透装置之前的各种预处理技术，并对其存在问题提出了优化思路。