Methodological advancements in Life Cycle Process Design: A preliminary outlook

This paper deals with the application of Life Cycle Assessment (LCA) methodology for process design, and presents the initial findings of this analysis qualitatively. The work identifies a need for a methodological development of Life Cycle Process Design (LCPD). This is underpinned by a broad literature review. The literature review shows that the application of LCA as an environmental design instrument is recognized in literature. In contrast to that there is hardly any hint which role Life Cycle Costing (LCC) could play within environmental process design. Most interesting in this line is, how LCA and LCC can be combined for environmental process design to be finally the core instruments of LCPD. The applicability of LCA and LCC within LCPD is shown on the example of a novel biorefinery process under development. Both instruments (LCA and LCC) are already applied during basic process development in this work, parallel to laboratory research. The aim is to identify potential environmental threats at an early stage of process design and also to give a hint on economic feasibility. Additionally a trade-off between environmental and economic issues can be drawn out. On the basis of this analysis the role of LCA during process development is highlighted as well as difficulties and challenges are emphasized. One of the major obstacles is data availability for LCA as well as LCC in the basic design stage of a biotechnological process. The findings of this paper serve as basis for the methodological development of LCPD. It is emphasized that conducting LCA and LCC during basic process development can reveal some relevant action areas for process engineers, which may influence technical as well as economic feasibility. The results presented have to be understood as a first outlook and provide key aspects for future research on the topic of accompanying basic process research projects with LCA and LCC to support future sustainable process design.     

Nitrogen Removal by Stormwater Management Structures: A Data Synthesis

A comprehensive synthesis of data from empirically based published studies and a widely used stormwater best management practice (BMP) database were used to assess the variability in nitrogen (N) removal performance of urban stormwater ponds, wetlands, and swales and to identify factors that may explain this variability. While the data suggest that BMPs were generally effective on average, removal efficiencies of ammonium (NH₄), nitrate (NO₃), and total nitrogen (TN) were highly variable ranging from negative (i.e., BMPs acting as sources of N) to 100%. For example, removal of NO₃ varied from (median ±1 SD) ?15 ± 49% for dry ponds, 32 ± 120% for wet ponds, 58 ± 210% for wetlands, and 37 ± 29% for swales. Across the same BMP types, TN removal was 27 ± 24%, 40 ± 31%, 61 ± 30%, and 50 ± 29%. NH₄ removal was 9 ± 36%, 29 ± 72%, 31 ± 24%, and 45 ± 34%. BMP size, age, and location explained some of the variability. For example, small and shallow ponds and wetlands were more effective than larger, deeper ones in removing N. Despite well‐known intra‐annual variation in N fluxes, most measurements have been made over short time periods using concentrations, not flow‐weighted N fluxes. Urban N export is increasing in some areas as large storms become more frequent. Thus, accounting for the full range of BMP performance under such conditions is crucial. A select number of long‐term flux‐based BMP studies that rigorously measure rainfall, hydrology, and site conditions could improve BMP implementation.     

精密离心机机箱设计研究

本机箱是精密离心机的重要组件,它可为离心机旋转平台提供良好的气流环境,为电容测微仪提供稳定支承,对保证离心机稳定可靠的运行有重要意义。针对10-6级精密离心机的使用要求,通过功能分析,确定了光滑环形整流罩形式的机箱结构。在此基础上,完成了机箱的结构设计和工艺分析,并进行了力学计算和试验测试。分析和试验结果表明,所设计的机箱可改善离心机风阻力矩和风阻波动,可有效降低风阻对离心机精度的影响。     

炼钢焙烧高温烟气湿法净化工程设计与实践

湿法除尘有独特优点和用途。介绍了石灰窑窑尾高温烟气湿法净化的设计要点和主要设备计算方法。除尘系统投产后运行良好。对工程设计和运行管理提供参考。     

基于安全疏散的高速铁路桥梁救援定点站台设计参数研究

应用安全疏散性能化设计的理论方法,研究了桥梁救援定点疏散站台的尺寸参数 ,以保证设计更为安全、经济、合理。首先,采用FDS软件模拟火灾警戒线随疏散时间 的发展趋势,分析ASET对站台长度的影响;其次,采用EVACNET4软件模拟了列车中部和 端部火灾情境下,乘客在站台的疏散运动,研究站台宽度对疏散时间的影响。结果表明 :从火灾警戒范围考虑,站台长度取值为450 m是经济合理的;有效宽度1.75 m为站台 疏散时间特征变化的分界点,有效宽度为1.75 m时的疏散时间均小于有效宽度为1.5 m 时的疏散时间,而当有效宽度大于1.75 m后,疏散时间的变化不大。研究成果可为救援 定点疏散站台的尺寸设计提供参考和依据。     

低氧条件下好氧型微生物降解煤吸附甲烷实验

为了研究好氧型微生物对低氧气浓度环境条件下煤吸附甲烷的降解效能,培养、分离、初步鉴定了高效降解甲烷的好氧型甲烷氧化菌。并在高压容量法瓦斯吸附-解吸装置的基础上,自主开发了低氧环境下甲烷降解实验分析系统,研究了氧气浓度为0%、5%和15%三种条件下甲烷氧化菌的降解效能,通过对实验前后甲烷减少量,二氧化碳增加量,氧气减少量进行分析。结果表明:在氧气浓度（0%~15%）范围内,随着氧气浓度升高及降解时间的持续,甲烷的减少量可达130.5 cm3,二氧化碳的增加量最高可达25.7 cm3,同时最多消耗69.0 cm3氧气;在无氧条件下,好氧型甲烷氧化菌的生理活性受到了一定的限制,但最高仍然可以降解11.9 cm3的甲烷,生成二氧化碳3.5 cm3。     

Benzene removal by nano magnetic particles under continuous condition from aqueous solutions

Benzene removal evaluated using Fe304 nano continuous condition. A 44 initial benzene concentration, from aqueous solutions was magnetic particles （NM） in factorial design including NM dose, contact time and pH was investigated in 16 experiments （Taguchi OA design）. The results indicated that all factors were significant and the optimum condition was： pH 8, NM dose of 2000 mg.L-1, benzene concentrations of 100 mg.L-1 and contact time of 14min. The maximum benzene uptake and distribution ratio in the optimum situation were 49.4mg.g-1 and 38.4L.g-1, respectively. The nano particles were shown to capture 98.7% of the benzene in optimum batch condition and 94.5% in continuous condition. The isotherm data proved that the Bmnauer-Emmett-Teller model fit more closely and produced an isotherm constant （b） less than one, indicating favorable adsorption. Regeneration studies verified that the benzene adsorbed by the NM could be easily desorbed by temperature, and thereby, NM can be employed repeatedly in water and wastewater management.     

桥式起重机安全评估指标体系研究和系统设计

在对桥式起重机的设计、结构组成和常见事故故障资料进行调查研究的基础上,分析了桥式起重机在工程应用中遇到的不安全因素,建立了较完善的安全评估指标体系。设计了一种基于模糊神经网络的桥式起重机安全评估系统并对系统的软件功能设计进行了初步探讨。建立了模糊神经网络评估数学模型,利用MATLAB工具对模型进行了仿真验证,结果表明此模型是可行的。通过研究,为进一步针对桥式起重机展开定性、定量评估及安全管理与决策提供了有益参考     

Adsorptive removal of direct dyes by PEI-treated peanut husk biomass: Box–Behnken experimental design

This paper reports the application of Box-Behnken experimental design to illustrate the adsorption of direct dyes (Indosol Black NF and Indosol Orange RSN) using polyethyleneimine (PEI)-treated peanut husk biomass. The effect of three independent variables (initial dyes concentration, biosorbent dose and pH) was investigated during the study. Maximum biosorption capacity (141 and 98.2 mg/g) of PEI-pretreated biomass was achieved with 200 mg/L initial dye concentration and 0.05 g/50 mL biomass dose for Indosol Black NF and Indosol Orange RSN, respectively. Acidic pH was found to be favourable for maximum dyes removal. Characterisation of biosorbent was carried out through Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy, thermogravimetric analysis (TGA) and point of zero charge determination. FT-IR analyses confirmed the involvement of carboxylic and carbonyl groups. The desorption study was also conducted to check out the possibility of regeneration of dyes and adsorbent and it was found that 51.58 and 76.6% of Indosol Black NF and Indosol Orange RSN, respectively, can be desorbed from the loaded biosorbent by using 1 M NaOH solution. The results indicated that PEI-treated peanut husk biomass can be used as an efficient biosorbent for the removal of Indosol Black NF and Indosol Orange RSN dyes from aqueous solutions.