硝化细菌的培养及包埋固定化中试

为实现硝化细菌规模化富集及包埋固定化技术的工业化应用.以污水厂回流污泥为菌源,利用工业级生物发酵罐,连续投加并逐渐提高底物浓度,控制FA和FNA实现硝化细菌的快速增长,实现了氨氧化速率118 mg·(L·h)~(-1)的高表达.高通量种群分析结果表明,回流污泥生物多样性较大,具有硝化作用的Nitrosomonas比例仅为0.53%;富集培养后污泥多样性明显降低,Nitrosomonas比例上升至10.27%,相较于驯化前,比例提高了20倍.以此为菌源,用PVA(聚乙烯醇)进行包埋固定化,包埋填料填充率为30%,通过连续流的方式进行包埋填料的活性恢复,仅用27 d填料的硝化速率达到62mg·(L·h)~(-1),证明包埋填料活性恢复.     

安全文化在复杂社会技术系统安全控制中的作用

随着复杂社会技术系统的发展 ,安全文化对于系统的安全运行越来越重要。安全文化是人们关于安全问题的价值观、态度及行为方式的集合体。人们往往在态度与价值观层次上利用问卷调查的形式探讨安全文化的维度结构 ,从而指导实践。安全文化在个体层面上通过影响安全绩效的决定因素来影响安全绩效 ,而从组织事故发生的路径来看 ,不良安全文化影响各级防御措施中的人与设备 ,是造成各种潜在失效和现行失效的根因。系统的安全控制应该充分利用安全文化进行管理 ,积极地推动安全文化建设 ,引导组织控制向社会控制转变 ,并且合理地应用安全文化评估进行组织前馈 ,从而更好地预防事故的发生     

基于交通文化的交通安全策略

以往对于交通安全的研究 ,很少有人从交通文化的深度进行分析 ,而对交通文化的研究确实具有现实意义和深远的战略价值。笔者针对这一问题 ,在阐述了交通文化的定义、特征的基础上 ,构建了交通文化系统的结构 ,说明了交通文化与交通安全的关系 ,提出了基于交通文化的驾驶员素质培训和安全教育、培养交通参与者交通安全意识、重视交通安全技术的研究和应用、加强道路交通管理和重视交通道德建设等交通安全策略。     

现代企业安全工作中的问题及对策

对现代企业安全工作中存在的问题做了简要的阐述，并通过对当前安全形势的分析，提出了现阶段安全工作中应采取的对策。     

煅烧阴离子粘土(LDO)对低浓度活性艳橙X-GN的吸附研究

以不同Mg/Al比(物质的量比)的合成阴离子粘土为原料,在500℃条件下煅烧制备了煅烧阴离子粘土(LDO),研究其对低浓度活性艳橙X-GN的吸附行为,并用XRD、FTIR、XRF、BET等对LDO进行表征,通过研究解吸行为验证其吸附机理.实验表明,Mg/Al比为4∶1的LDO的吸附效果比2∶1的LDO好,Mg/Al比为...     

碳酸钾-二乙烯三胺复合溶液吸收烟气中CO2实验研究

热钾碱溶液在工业脱除二氧化碳中已获得较广泛的应用,但存在吸收速率差、再生负荷高等缺点-开发新型热钾碱溶液成为目前研究热点.采用搅拌实验装置,研究碳酸钾溶液及不同配比的碳酸钾-二乙烯三胺(DETA)复合溶液对烟道气中二氧化碳的吸收和解吸性能,揭示了吸收速率、吸收容量和酸碱度与时间之间的内在联系;对CO2初始逸出温度,试液...     

Ecosystem evolution of seal colony and the influencing factors in the 20th century on Fildes Peninsula,West Antarctica

As the topmost predator in Antarctica, the seal is a unique indicator of Antarctic environment and climate changes. In this study, we collected a sediment core from the Fildes Peninsula of West Antarctica, and used cholesterol, cholestanol, epicoprostanol, coprostanol, and seal hair numbers as the proxy indicators of seal population size and phytol as of general vegetation, and we reconstructed the 20th century history of variation of the seal population and vegetation abundance on this island. The sealing industry in the early 20th century caused the dramatic decline of seal population, and the ban of seal hunting since the 1960s led to its recovery of seal population. The seal population during the past century was primarily controlled by human activities and krill density. The reconstructed relation between seal population and vegetation abundance may oifer new insights into Antarctic environment and ecology.     

Hormetic response of cholinesterase from Daphnia magna in chronic exposure to triazophos and chlorpyrifos

In vivo activity of cholinesterase (ChE) in Daphnia magna was measured at di erent time points during 21-day exposure to triazophos and chlorpyrifos ranging from 0.05 to 2.50 g/L and 0.01 to 2.00 g/L, respectively. For exposure to triazophos, ChE was induced up to 176.5% at 1.5 g/L and day 10 when measured by acetylthiocholine (ATCh), whereas it was induced up to 174.2% at 0.5 g/L and day 10 when measured by butyrylthiocholine (BTCh). For exposure to chlorpyrifos, ChE was induced up to 134.0% and 160.5% when measured by ATCh and BTCh, respectively, with both maximal inductions detected at 0.1 g/L and day 8. Obvious induction in terms of ChE activity was also detected in daphnia removed from exposures 24 hr after their birth and kept in a recovery culture for 21 days. Results indicated that the enzyme displayed symptoms of hormesis, a characteristic featured by conversion from low-dose stimulation to high-dose inhibition. In spite of that, no promotion in terms of reproduction rate and body size was detected at any tested concentrations regardless of whether the daphnia were collected at end of the 21-day exposure or at end of a 21-day recovery culture. This suggested that induction of ChE caused by anticholinesterases had nothing to do with the prosperity of the daphnia population.     

混合填料生物接触氧化法处理生活污水的研究

采用混合型(火山岩和陶瓷环)填料生物接触氧化工艺处理实际生活污水,研究了混合型填料挂膜情况,不同HRT、DO和进水COD浓度对水质净化效果的影响。实验结果表明:混合型填料挂膜效果好,15 d后反应器达到稳定状态,对COD的去除率达到75%以上;在水温为20~32℃,HRT为12 h,DO为5~6 mg/L的条件下,对COD、氨氮、TN和TP的平均去除率分别达到了75.8%、71.8%、45.9%和35.7%;当进水COD浓度为100~400 mg/L时,各个指标的去除率随着COD浓度的升高而升高,可见进水COD浓度会对污水净化效果产生影响。     

Safety climate in university and college laboratories: impact of organizational and individual factors

INTRODUCTION: Universities and colleges serve to be institutions of education excellence; however, problems in the areas of occupational safety may undermine such goals. Occupational safety must be the concern of every employee in the organization, regardless of job position. Safety climate surveys have been suggested as important tools for measuring the effectiveness and improvement direction of safety programs. Thus, this study aims to investigate the influence of organizational and individual factors on safety climate in university and college laboratories. METHOD: Employees at 100 universities and colleges in Taiwan were mailed a self-administered questionnaire survey; the response rate was 78%. RESULTS: Multivariate analysis of variance revealed that organizational category of ownership, the presence of a safety manager and safety committee, gender, age, title, accident experience, and safety training significantly affected the climate. Among them, accident experience and safety training affected the climate with practical significance. RECOMMENDATIONS: The authors recommend that managers should address important factors affecting safety issues and then create a positive climate by enforcing continuous improvements.