In situ lifetimes and kinetics of a reductive whey barrier and an oxidative ORC barrier in the subsurface

Permeable reactive barriers (PRB) are being used to engineer favorable field conditions for in-situ remediation efforts. Two redox adjustment barriers were installed to facilitate a 10-month research effort on the fate and transport of MTBE (methyl tert-butyl ether) at a site called the Michigan Integrated Remediation Technology Laboratory (MIRTL). Thirty kilograms of whey were injected as a slurry into an unconfined aquifer to establish an upgradient reductive zone to reduce O2 concentration in the vicinity of a contaminant injection source. To minimize the impact of contaminant release, 363 kg of oxygen release compound (ORC) were placed in the aquifer as a downgradient oxidative barrier. Dissolved oxygen and other chemical species were monitored in the field to evaluate the effectiveness of this technology. A transient one-dimensional advective-dispersive-reaction (ADR) model was proposed to simulate the dissolved oxygen transport. The equations were solved with commonly encountered PRB initial and constant/variable boundary conditions. No similar previous solution was found in the literature. The in-situ lifetimes, based on variable source loading, were estimated to be 1,661 and 514 days for the whey barrier and ORC barrier, respectively. Estimates based on either maximum O2 consumption/production or measured O2 curves were found to under- or overestimate the lifetime of the barriers. The pseudo-first-order rate constant of whey depletion was estimated to be 0.303/d with a dissolution rate of 0.04/d. The oxygen release rate constant in the ORC barrier was estimated to be 0.03/d. This paper provides a means to design and predict the performance of reactive redox barriers, especially when only limited field data are available.     

高阻隔PET瓶的最新技术

一、国外高阻隔材料和处理技术 对于啤酒容器来说,一些潜在技术的应用带给PET瓶供应商新的机遇。以啤酒用包装材料来看,过半数的业者在3～10年间有1～5％啤酒容器将会被塑料包装材料所取代。 ＊Eastman化学公司针对啤酒、果汁、蕃茄酱产品用的包装材料,开发出具高阻隔PET用的聚合物Nanocomposites。使用此聚合物不需改变加工成形的过程,利用现有吹瓶成形机即可生产各种形状的瓶子。使用少量的Clay platelets可维持瓶身透明且无色。     

磷化钢丝绳生产技术论证

磷化是防止钢丝绳微动损伤措施之一。磷化钢丝绳专利技术是将制绳钢丝进行磷化处理并将磷化膜面质量控制在3~60 g/m2,使用磷化后的钢丝捻股合绳。磷化膜与润滑脂共同作用,可以大幅提高钢丝间的润滑效果和钢丝的耐磨损防氧化能力。对比拉拔用磷化钢丝和制绳用磷化钢丝的技术要求,指出制绳用磷化钢丝属于重膜磷化,磷化膜面质量控制在15~30 g/m2,磷化温度一般在90~95℃。由于钢丝力学性能在磷化前后无明显变化,磷化钢丝绳几乎适用于所有种类的钢丝绳产品,尤其是对耐疲劳性能有较苛刻要求的产品。介绍制绳用磷化钢丝的生产及磷化废水的主要处理方法。     

DOE/NETL's phase II mercury control technology field testing program: preliminary economic analysis of activated carbon injection

Based on results of field testing conducted by the U.S. Department of Energy's National Energy Technology Laboratory (DOE/NETL), this article provides preliminary costs for mercury control via conventional activated carbon injection (ACI), brominated ACI, and conventional ACI coupled with the application of a sorbent enhancement additive (SEA) to coal prior to combustion. The economic analyses are reported on a plant-specific basis in terms of the cost required to achieve low (50%), mid (70%), and high (90%) levels of mercury removal "above and beyond" the baseline mercury removal achieved by existing emission control equipment. In other words, the levels of mercury control are directly attributable to ACI. Mercury control costs via ACI have been amortized on a current dollar basis. Using a 20-year book life, levelized costs for the incremental increase in cost of electricity (COE), expressed in mills per kilowatt-hour (mills/kWh), and the incremental cost of mercury control, expressed in dollars per pound of mercury removed ($/lb Hg removed), have been calculated for each level of ACI mercury control. For this analysis, the increase in COE varied from 0.14 mills/kWh to 3.92 mills/kWh. Meanwhile, the incremental cost of mercury control ranged from $3810/lb Hg removed to $166000/lb Hg removed.     

中国新兴大豆食品业寻找发力点——大豆食品营养科普工程启动

2008年9月26日,由CIFST中国大豆食品学会发起,中国营养学会临床营养分会、儿童食品学会、中国三农研究院等各行业协会团体支持,展太农庄承办,人民网健康频道全程支持的大豆食品营养科普工程在北京正式启动.该项工程提出了"读一本科普书,听一堂营养课,吃一份大豆食品"的口号.     

移动互联网技术在食品生产许可现场核查中的应用探索

目的介绍基于移动互联网技术的食品生产许可现场核查系统,探讨食品生产许可审查信息化建设的新思路、新模式。方法应用智能手机、计算机、互联网技术,制作包括PC页面端和Android移动端的食品生产许可现场核查系统,为现场核查提供评分记录、影像采集、信息上传等服务。结果该核查系统使现场核查工作更加公正、便捷,给许可审批有关部门和企业提供便利的信息渠道。结论基于移动互联网的现场核查系统的应用,有助于提高食品生产许可审查工作效率和质量,树立高效、公平、公正的行业形象。     

基于移动互联网的食品生产许可现场核查系统的应用效果

目的分析评价基于移动互联网的核查系统移动应用软件(APP)在食品生产许可现场核查工作中的应用效果。方法选择48家企业开展核查系统测试,将审查员随机分为实验组和对照组,实验组采用有核查系统APP进行核查工作,对照组则采用传统纸质评分表格进行核查工作。比较2组的工作用时、资料完整性和差错概率方面的差异。结果与对照组比较,实验组在现场核查工作用时、资料完整性和差错性的差异均有统计学意义。实验组和对照组在实用性和公平性的评价差异有统计学意义,在规范性的评价差异无统计学意义。结论食品生产许可现场核查系统APP实用性强,在保证现场核查工作程序规范性的前提下,提高了工作效率、质量和公平性,值得推广应用。     

透过率检测技术在食品包装材料阻隔性分析中的应用

食品包装对食品安全有很大影响,包装材料的氧气和水蒸气阻隔性是保护食品品质的重要因素。本文对国家标准及相关文献进行综述,详细阐述了食品包装材料的氧气及水蒸气阻隔性的各种检测方法原理,并对其进行比较,总结方法的适用性。氧气透过率检测有压差法和库仑计法2种方法,压差法的成本和精准度相对较低,库仑计法的成本和精准度均相对较高;水蒸气透过率的检测有红外检测器法和电解传感器法,其中红外检测器法优于电解传感器法。最后对透过率检测在食品包装材料领域的应用进行了介绍,同时对今后阻隔性研究的发展方向进行了展望。     

News: DOE cleanup office to fund long-term basic research

Funding.