赤泥碱性调控研究进展

赤泥是氧化铝工业生产过程产生的强碱性固体废弃物,资源化利用难、环境风险高,严重制约了氧化铝行业的可持续发展.赤泥土壤化是实现规模化处置赤泥的一种可行方法,而碱性调控则是赤泥土壤化的关键环节.论文在综述氧化铝生产过程碱性物质形成过程的基础上,从可溶性碱和化学结合碱角度分析了赤泥碱性物质的赋存状态,阐述了国内外化学调碱法和生物调碱法的研究进展和碱性转化机制,剖析了赤泥碱性调控方面存在的问题,提出了赤泥碱性调控研究的发展方向.这将为赤泥规模化处置和堆场生态重建、保障氧化铝工业的健康发展提供科学参考.     

生物吸附/MBR/硫铁自养反硝化组合工艺运行特性及蛋白质源污泥增量研究

为实现污水处理的深度脱氮除磷及蛋白质源污泥增量,进行了生物吸附/MBR/硫铁自养反硝化组合工艺处理城镇污水的试验研究.结果表明,生物吸附池可以快速富集进水中的大部分有机物,COD平均去除率为55.1%,剩余污泥采用厌氧发酵方式处理,用于生产优质碳源.通过组合工艺系统中的硝化、硫自养反硝化及铁屑除磷作用,出水氨氮、总氮和总磷分别达到1、5和0.4 mg·L~(-1)以下.优质碳源投加到MBR工艺段,碳源环境的改善使得污泥增长率从0.17 g VSS/g COD提高至0.49 g VSS/g COD,进水中总氮的同化比例从40%提高至59%.此外,污泥中蛋白质及氨基酸含量也显著增长,增长率分别为18.3%和19.7%.组合工艺在获得高排放标准水质的同时,实现了高蛋白质源污泥的增量,可为污泥资源化利用提供优质原料.     

后脱贫时期可持续生计研究展望

在"后脱贫时代",规避返贫风险、实现持续稳定脱贫将是精准扶贫政策的逻辑延续,更是促进乡村长期振兴的重要基础.长期以来,可持续生计分析框架在贫困治理过程中发挥了重要的指导作用,但在新的情势下也迫切需要做出系统总结与展望.本文在整理社会学、经济学、地理学、环境科学等关联学科研究成果的基础上,系统梳理了可持续生计研究在返贫治...     

A directional passive air sampler for monitoring polycyclic aromatic hydrocarbons (PAHs) in air mass

A passive air sampler was developed for collecting polycyclic aromatic hydrocarbons (PAHs) in air mass from various directions. The airflow velocity within the sampler was assessed for its responses to ambient wind speed and direction. The sampler was examined for trapped particles, evaluated quantitatively for influence of airflow velocity and temperature on PAH uptake, examined for PAH uptake kinetics, calibrated against active sampling, and finally tested in the field. The airflow volume passing the sampler was linearly proportional to ambient wind speed and sensitive to wind direction. The uptake rate for an individual PAH was a function of airflow velocity, temperature and the octanol-air partitioning coefficient of the PAH. For all PAHs with more than two rings, the passive sampler operated in a linear uptake phase for three weeks. Different PAH concentrations were obtained in air masses from different directions in the field test.     

污泥龄对LSP & PNR污泥减量新工艺运行效能的影响

通过研究分析污泥龄(SRT)对富磷污水除磷的LSP&PNR污泥减量新工艺运行效果的影响,结果发现,延长污泥龄有利于提高系统的厌氧释磷能力,但不影响其总的除磷率,同时磷的回收比例增大,当SRT=50 d时,磷回收率取得最大值70.4%;LSP&PNR系统污泥龄增加,还有利于污泥产率的降低.试验还发现,排富磷污水除磷的长污泥龄LSP&PNR系统的除磷效率与污泥产率之间不存在制约关系,即系统可以同时获得优异的污泥减量与生物除磷效果,当SRT=50 d时,每降解1 kg COD仅产生0.143 kg污泥,而除磷率达最高值92.8%;LSP&PNR系统中SRT、DO与SVI之间存在一定的相关性,在供氧充足(DO=0.8～1.5 mg/L)条件下,SRT增加,SVI越高,但对于SRT为50 d的LSP&PNR系统,稳定运行时没有污泥膨胀之虞.     

污泥龄对LSP & PNR污泥减量新工艺运行效能的影响

通过研究分析污泥龄（SRT）对富磷污水除磷的LSP&PNR污泥减量新工艺运行效果的影响,结果发现,延长污泥龄有利于提高系统的厌氧释磷能力,但不影响其总的除磷率,同时磷的回收比例增大,当SRT=50 d时,磷回收率取得最大值70.4％;LSP&PNR系统污泥龄增加,还有利于污泥产率的降低。试验还发现,排富磷污水除磷的长污泥龄LSP&PNR系统的除磷效率与污泥产率之间不存在制约关系,即系统可以同时获得优异的污泥减量与生物除磷效果,当SRT=50 d时,每降解1 kg COD仅产生0.143 kg污泥,而除磷率达最高值928％;LSP&PNR系统中SRT、DO与SVI之间存在一定的相关性,在供氧充足（DO＝0.8～1.5 mg/L）条件下,SRT增加,SVI越高,但对于SRT为50 d的LSP&PNR系统,稳定运行时没有污泥膨胀之虞。     

吸力式桶形基础多桶组合结构承载力特性研究

海洋采油平台结构中一般采用多桶组合基础型式,然而迄今对多桶组合结构尚缺乏理论分析和实验研究。本文针对我国第一座吸力式桶形基础采油平台CB20B,基于单桶基础在复合加载模式下的承载力特性,建立了双桶、四桶组合基础的三维有限元数值计算模型,探讨了对称多桶基础结构与单桶基础结构的承载力特性之间的相互关系,阐述了不同桶间距的多桶组合结构地基破坏机制,为工程设计提供参考依据。     

Partitioning of hydrogen peroxide between the gas and liquid phases in the presence of surfactant

Gas-liquid phase partitioning is a key physical property that can predict the environmental fate of a compound between two phases. Several environmental factors have been known to affect the gas-liquid phase partitioning. We investigated the influence of surfactant on the gas-liquid phase partitioning of hydrogen peroxide (H(2)O(2)). The surfactant used was ammonium perfluorooctanoate (APFO). H(2)O(2) solution containing the surfactant was equilibrated in a closed system and gas phase H(2)O(2) concentration was measured by the peroxyoxalate chemiluminescence (PO-CL) method. Gas phase H(2)O(2) concentrations remained constant below the critical micelle concentration (CMC) and increased linearly with surfactant concentration above the CMC, which indicated that surfactant micelles influenced the gas-liquid phase partitioning of H(2)O(2). This result showed that H(2)O(2)-micelle interactions are less favorable than H(2)O(2)-H(2)O interactions. Surfactant monomers did not affect the gas-liquid phase partitioning of H(2)O(2) due to the absence of micelles. Solvent (methanol) effect was also investigated and showed that gas phase H(2)O(2) concentrations increased with the addition of solvent. This indicated the unfavorable interaction of H(2)O(2) with hydrophobic medium compared to hydrophilic one. It is consistent with the result that H(2)O(2)-micelles has a weaker interaction than H(2)O(2)-water because surfactant micelles are hydrocarbon-like organic phase rather than aqueous phase.     

上海与伦敦城市绿地的生态功能及管理对策比较研究

在资料收集及实地采样调查的基础上 ,文章对上海与伦敦城市绿地的生态功能及管理对策进行了比较分析 ,指出了上海城市绿地建设及管理中的一些优点及不足之处。     

塔里木河干流农田排水资源化研究

近几十年分析资料对比表明 ,农田排水对塔里木河干流水质盐化的影响不断加重。在塔里木河干流 ,农田排水资源化利用有如下几个有利条件 :( 1)农田排水有一定数量且渠网的延伸和改造难度不大 ;( 2 )荒漠可作为农田排水资源化利用的场所 ;( 3)农田排水仍可勉强适于耐盐植物生长。根据区域不同 ,利用农田排水拓展乔灌草防沙带、增加盐成土荒漠耐盐植被的盖度、使人工绿洲边缘的荒漠能够生长耐盐植物等都是农田排水资源化利用发展的方向