Human and organizational error data challenges in complex,large-scale systems

In complex, large-scale systems, event analyses are constrained by the quality of the data gathered, the maturity of the associated reporting system, and the training and background of the investigator and reporter. Such constraints place limits on the adequacy and strength of analyses conducted with the data. In this paper, we focus on the challenges of measuring performance variability in complex systems, using the lens of human and organizational error modeling. This paper begins with an overview of human and organizational error assessments, and then introduces the particular challenges of data needs in human reliability analyses. A case study of human and organizational error analysis in a complex, large-scale system, marine transportation in Puget Sound, is used to illustrate the impact of the data challenges on risk assessment processes. Suggestions for future research conclude the paper.     

Bioavailability of PCBs from field-collected sediments: application of Tenax extraction and matrix-SPME techniques

Two chemical approaches, Tenax extraction and matrix solid phase microextraction (matrix-SPME), were evaluated for their potential to improve the prediction of bioavailability by equilibrium partitioning theory (EPT) across sediments with various characteristics. Biota-sediment accumulation factors (BSAFs) and body residues were quantified by exposing Lumbriculus variegatus to three PCB-contaminated field sediments. The concentration of PCBs in biota was positively correlated to the total PCB sediment concentration, the PCB concentration in the rapidly desorbing fraction estimated using Tenax extraction, and the PCB concentration on the SPME fibers. Results showed EPT was acceptable for estimating bioavailability from the tested sediments with sum PCB BSAFs of 1.18-2.47; however, it overestimated PCB bioavailability from sandy sediment. Both Tenax extraction and matrix-SPME, which take sequestration into account, reduced variability in prediction of PCB bioavailability across sediments, including the sandy sediment, and could be used as cost- and time-efficient alternatives for bioassay. Matrix-SPME was considered the better technique due to its ability to directly predict PCB body residues in the exposed biota and its potential use with in situ applications in the field.     

城市灾害风险的基本构成要素

对城市灾害风险管理以及城市灾害和城市灾害风险的构成要素进行了分析研究,从构成要素角度解析了城市灾害的形成和城市灾害风险的形成。     

贵州土地复垦发展现状及其对策研究

详细分析了贵州省土地复垦的发展现状以及近年来所做的工作及成效,研究了矿山开采等活动对贵州省土地资源造成的破坏及生态危害,提出了具体的土地复垦的技术措施.为了实现能源、环境、社会、人口和经济的可持续发展,土地复垦是必然选择.     

AFB的活性污泥中发酵细菌的分离及其初步鉴定

从处理啤酒废水的厌氧流化床的活性污泥中分离纯化到了发酵细菌,并对其培养条件进行了研究,实验表明,该发酵细菌最佳培养温度为37～42℃,最佳培养时间为28 d,同时对其进行了生理生化和形态鉴定。将该发酵细菌反加到AFB反应器中,能有效降低反应器的启动时间,能提高反应器处理啤酒废水的处理效率约8%。     

核桃壳吸附剂对水中Pb2+的吸附

采用自制核桃壳吸附剂,利用静态吸附法,处理模拟含Pb²⁺废水。实验结果表明：当初始Pb²⁺的质量浓度20.00 mg/L、初始废水pH=5.5、吸附剂加入量12 g/L、吸附剂粒径1.60~2.50 mm、吸附时间120 min时,核桃壳吸附剂对Pb²⁺的去除率为91.7%;吸附剂对Pb²⁺的吸附行为满足拟二级吸附动力学方程,吸附等温线满足Langmuir等温方程,饱和吸附量达到3.903 mg/g;吸附饱和的吸附剂可用浓度 0.1 mol/L的硝酸解吸,经解吸后的吸附剂可重复利用3次。     

污泥土地利用生态风险评价初探

生态风险评价是污泥环境风险评价的重要组成部分。本文通过对美国污泥土地利用生态风险评价的研究，阐述了污泥土地利用生态风险评价过程中涉及的基本概念和定量研究方法，并对存在的困难进行了探讨。文章建议我国应借鉴国外污泥土地利用生态风险评价的研究方法，尽快建立适合我国污泥处置的生态风险评价标准方法和指南，以发挥其在环境保护和管理中的作用。     

省域水环境保护政策实施效果评价的指标体系构建与实证研究

本文以湖北省"十二五"环境规划的水环境保护指标为主要依据,采用压力—状态—响应(PSR)模型,从污染排放强度、水质改善效果、水资源利用和污染减排效率三个维度出发,建立湖北省"十二五"水环境保护政策评价指标体系,对政策的实施效果进行量化评估。结果表明:湖北省"十二五"期间水环境保护政策实施效果呈逐年上升趋势,从二级指标来看,政策实施在污染排放强度以及水资源利用和污染减排效率两方面均取得较好的成效,但在水质改善方面效果不明显甚至有所下降。建议湖北省在"十三五"期间以至接下来更长的一段时期内,首先要重点加强省内各局部区域的水环境承载能力评估,并依据评估结果对现有的产业布局进行有效的调整;其次应进一步强化环境监测和管理力度,以减少可能的非法排污。本文构建的指标体系对进一步促进省域水环境保护政策实施效果评价的规范化、合理化不无借鉴意义。     

双氰胺对污泥堆肥过程中酶活性和细菌群落演变的影响

鉴于氮肥增效剂在农田中的保氮经验,研究其对堆肥中氮素的保持具有重要意义.因此,本研究以氮肥增效剂-双氰胺(Dicyandiamide,DCD)为添加剂,脱水污泥为堆肥原料,进行了 20 d的堆肥试验,探讨DCD对堆肥过程中氮素转化和酶活性变化及其细菌群落演变的影响.结果表明,DCD的添加降低了堆肥高温期的温度,延长了高...     

基于主成分分析法的渭河陕西段水环境质量评价

主成分分析法能够在保证原始数据信息损失最小的情况下,以少数的综合变量取代原有的多维变量,使数据结构大为简化,并且客观地确定变量权数,避免了主观随意性。应用主成分分析法对渭河水环境进行质量评价,评价结果表明,渭河陕西不同地段水质状况不同。总的来讲,渭河污染十分严重。