近50年宁夏极端气温事件的变化研究

随着全球变暖,极端气候事件频繁发生,由此造成气象灾害的数量日益增加。深入研究极端气候的变化特征,能够为预测和预防极端事件灾害提供参考依据。采用线性倾向估计法、反距离加权法和R/S分析法,选取10个极端气温指标研究了宁夏近50年来极端气温事件的时空变化特征,并在此基础上尝试预测了未来该地区极端气温变化的情形。结果发现:全天极端高温天数、白天极端高温天数、夜间极端高温天数、生物生长季和夏季天数分别以0.76、0.48、0.67、0.35和0.29 d/a的趋势明显增加,而全天极端低温天数、白天极端低温天数、夜间极端低温天数和最大连续霜冻天数分别以-0.40、-0.25、-0.66和-0.30 d/a趋势显著减少,极端气温年较差也呈下降趋势(-0.02℃/a),且空间差异明显;除极端气温年较差外,其它各极端气温指标与年平均气温均有很好的相关性;年极端冷指标和极端气温年较差在未来将继续下降,极端暖指标在未来将继续上升;宁夏气象灾害所造成的影响和损失将进一步增大。     

港东联合站外排污水深度处理工艺研究

为解决港东联合站外排污水2010年前达标排放的问题,需在现有氧化塘生化处理工艺的基础上,进行工艺优化和深度处理。通过对港东联合站外排污水的分析,发现现有处理系统的问题,并结合水质特性和现有处理工艺进行试验研究。结果表明:采用曝气生物滤池工艺,以兼性塘进水为水源,流量150L/h,BAF对CODCr的去除率为68.1%;采用活性炭吸附技术,在水力负荷不超过2.1m3/(m2.h)情况下,活性炭出水CODCr平均值为27.3～37.4mg/L,对CODCr的去除率在60%以上;曝气生物滤池与活性炭吸附工艺对CODCr、石油类、悬浮物的处理指标都达到了天津市地方标准DB12/356-2008《污水综合排放标准》的要求。     

Preparation and Properties of Thermoplastic Starch/Montmorillonite Nanocomposite Using N-(2-Hydroxyethyl)formamide as a New Additive

N-(2-Hydroxyethyl)formamide (HF) was synthesized efficiently and used as a new additive to prepare thermoplastic starch/montmorillonite nanocomposite (TPS/MMT). Here, HF acted as both plasticizer for TPS and swelling agent for MMT. The hydrogen bond interaction among HF, starch and MMT was proven by Fourier-transform infrared (FT-IR) spectroscopy. By scanning electron microscope (SEM), starch granules were completely disrupted. Atomic force microscopy demonstrated that partially exfoliated TPS/MMT nanocomposite was formed. The crystallinity of corn starch, MMT, HF-plasticized TPS (HTPS) and TPS/MMT nanocomposite was characterized by X-ray diffraction (XRD). Thermal stability of HTPS and TPS/MMT was determined by thermogravimetric analysis (TGA). The water resistance of TPS/MMT nanocomposite increased compared with that of pure HTPS. Tensile strengths of TPS/MMT nanocomposites were higher than those of HTPS, but just the reverse for elongations at break.     

黄河兰州段悬移质泥沙对氨氮的吸附特性

实验研究了黄河兰州段不同粒径的悬浮泥沙对氨氮的吸附行为,拟阐释黄河兰州段水质自净的机制。通过分析探讨了含沙量、氨氮初始浓度、泥沙粒径和化学成分对氨氮吸附过程的影响。结果表明,准二级动力学方程和Langmuir模型能够较好地描述黄河兰州段不同粒径泥沙的吸附动力学和等温吸附过程(R20.9);含沙量对泥沙吸附氨氮作用具有显著影响,且氨氮吸附量和平衡时间与含沙量呈明显负相关性;氨氮初始浓度与氨氮吸附量及平衡时间呈正相关性;同时,泥沙颗粒越细,吸附氨氮的能力越强,吸附容量越大,反应的自发程度越高。此外,泥沙有机质、Fe2O3、Al2O3和MgO的含量随粒径减小而增大,它们对单位质量泥沙最大吸附量(Sm)具有正效应。泥沙的吸附在黄河兰州段水质自净过程中起着一定的促进作用。     

非煤矿山安全检查存在的问题及对策

安全检查是企业安全管理的一项基础工作。通过系统分析目前我国非煤矿山安全检查存在的主要问题,提出了有针对性的对策措施,供我国非煤矿山企业改进安全检查工作参考。     

高原湖泊流域水环境特征与污染防治综合整治研究

在深入分析玉溪市抚仙湖、星云湖、杞麓湖水质现状、污染源贡献、污染成因以及存在问题的基础上,探索基于流域系统的源头削减、过程控制、末端治理相结合的良好型湖泊保护与污染防治型湖泊综合整治的全过程治理思路,提出高原湖泊资源“优先保护、协调发展、限量开发、强化管理”的保护与开发管理全新理念.以经济社会发展与资源环境承载能力相适应为基础,提出适应“大玉溪”新形势发展需求下的高原湖泊流域水环境保护与综合整治措施.     

基于生命周期的废旧纺织品全过程管理体系构建

针对我国目前废旧纺织品处理中存在的问题,从纺织产品生命周期的视角对其生产、流通、消费、回收使用、收集转运和末端处理6个环节进行了分析。在此基础上,建立了由"源头管理"、"中间管理"和"末端管理"3个部分构成的废旧纺织品全过程管理体系。     

活性炭/聚丙烯腈纤维对溶液中的甲基橙染料吸附动力学研究

采用自制添加活性炭的聚丙烯腈纤维为吸附剂,吸附染料甲基橙溶液,考察了活性炭含量、温度及溶液pH值等因素对纤维吸附染料甲基橙吸附量和吸附速率的影响.结果表明,活性炭/聚丙烯腈纤维吸附甲基橙染料符合表观二级动力学方程.吸附过程的限速步骤为甲基橙染料向活性炭/聚丙烯腈纤维中活性炭颗粒内部微孔扩散,自制的活性炭/聚丙烯腈纤维对甲基橙染料具有较大的吸附容量和较快的吸附速率,可作为甲基橙等染料废水治理的理想材料.     

Photodegradation of bisphenol Z by UV irradiation in the presence of beta-cyclodextrin

In this work, the formation of the inclusion complex of bisphenol Z (1,1-bis(4-hydroxyphenyl)cyclohexane, abbreviated as BPCH) with beta-cyclodextrin (beta-CD) has been studied, 1:1 inclusion complex can be obtained, the formation constant of the beta-CD/BPCH complex is 5.94x10(3)M(-1). The photodegradation behavior of BPCH was investigated under monochromatic UV irradiation (lambda=254 nm). The photodegradation rate constant of BPCH in aqueous solutions with beta-CD showed a 9.0-fold increase, and simultaneously the mineralization of BPCH can be enhanced by beta-CD. The influence factors on photodegradation of BPCH were also studied and described in details, such as concentration of beta-CD, initial concentration of BPCH, organic solvent and pH. The photodegradation of BPCH in the presence of beta-CD includes the direct photolysis and the photooxidation of BPCH during the photochemical process. Some predominant photodegradation products are 4-(2,4,5-trihydroxy-phenyl)-4-(4-hydroxyphenyl) butanoic acid, 5,5-bis(4-hydroxyphenyl)pentanoic acid, meta-hydroxylated BPCH, ortho-hydroxylated BPCH and 4-(1-(4-hydroxyphenyl)pentyl)phenol respectively. The enhancement of photodegradation of BPCH mainly results from moderate inclusion depth of BPCH molecule in the beta-CD cavity. This kind of inclusion structure allows BPCH molecule sufficient proximity to secondary hydroxyl groups of the beta-CD cavity, and these hydroxyl groups could be activated and converted to hydroxyl radicals under UV irradiation, which can enhance the photooxidation of BPCH.     

Effects of organic loading rate and temperature fluctuation on the microbial community and performance of anaerobic digestion of food waste

Environmental Science and Pollution Research - Semi-continuous anaerobic fermentation of food waste was carried out using a solar-assisted heat reactor to explore effects of temperature fluctuation...