水解酸化-改良UASB工艺处理玉米酒精废水

采用一种新的工艺技术方法即水解酸化-改良UASB工艺处理玉米酒精废水。结果表明,在改良UASB运行60 d顺利启动完成后,进水COD在5 470～7 910 mg/L之间,TN在70～107 mg/L之间,TP在115～187 mg/L之间,SS在864～1 490 mg/L之间的条件下,水解酸化对COD和SS的去除率分别达50%和51%,NH3-N经过水解酸化后升高。改良UASB对COD的去除率达80%,对NH3-N、TN和TP也有一定去除,去除率分别为12%、17%和20%,经过水解酸化及改良UASB处理利于后续好氧处理。     

高浓度悬浮液的混凝实验及机理研究

进行了高浓度悬浮液的混凝实验研究。为研究混合阶段渐变剪切速率对混凝沉降效果的影响,在混合阶段分别采用固定搅拌转速和渐变搅拌转速进行实验。在混合阶段采用固定搅拌转速,当搅拌转速为210r/min时,絮体二维分形维数最高为1.8847,悬浮液浊度最低为118NTU。采用渐变搅拌转速的方法,由210r/min开始逐渐降低搅拌转速,絮体二维分形维数最大,为1.9205,处理后悬浮液浊度最小,为107NTU。在一般混凝沉降过程的规律及模型的基础上,提出了高浓度悬浮液混凝沉降过程的物理模型。     

中国露天生物质燃烧的温室气体排放及秸秆禁燃政策的协同减排效应

露天生物质燃烧是温室气体(CO₂、CH₄、N₂O)的重要排放源之一,这些排放可影响本地、区域和全球的大气化学和气候变化,并带来一系列生态环境问题,进而对人类及其他生物的生存环境产生影响.本研究采用卫星火点排放清单(FINN),对2010—2019年中国露天生物质燃烧温室气体排放进行研究,并分析秸秆禁燃政策对温室气体排放的影响,对后续秸秆禁燃政策的制定具有重要参考价值.结果表明,我国2010—2019年平均年温室气体排放量为1.53×10⁸t(将CH₄和N₂O的温室效应换算为同等效应的CO₂当量单位),总体呈波动性下降趋势.温室气体排放量最大的植被类型是森林(7.43×10⁷t)和农作物(3.19×10⁷t),分别占总排放量的48.7%和20.9%.从月分布来看,露天生物质燃烧排放的温室气体集中在2—6月,3月是高峰值.从空间分布上看,排放主要集中在华南、西南和华东地区,占总排放量的72.9%...     

Assessing the visual quality of green landscaping in rural residential areas: the case of Changzhou, China

Changzhou is a typical waterside municipality with approximately 2,500 years of history located south of the Yangtze River. It was an agriculturally oriented region but is becoming an industrialized region. Rural green landscaping in this region possesses characteristics of traditional Chinese gardens. This paper presents a methodology for assessing the visual quality of green landscaping in rural residential areas through public perception-based and expert/design approaches. The former approach enables us to rank green landscaping based on a survey of public preference; the latter weighs the contributions of the attributes contained in a photograph to its overall scenic beauty via correlation, regression, and factor analyses. The photographs used in the survey included road greenways, riparian greenways, residential public gardens and green landscaping around houses, with each type of landscape represented by seven photographs. In total, 141 college students and 41 other participants ranked photographs of each landscaping type from highest to lowest preference. The results indicate that the preferences of students are similar to those of the general public. Examples of green landscaping depicted in the “best” four photographs possessed more attractive qualities regarding the variety of vegetation, richness of colors and a selection of human additions compared to those depicted in the “worst” photographs. The perceived visual quality was positively influenced by, in decreasing order of importance, the variety of vegetation, color contrast, the openness of green spaces, the area of vegetation, and positive man-made elements; conversely, it was negatively influenced by the type of topography. Moreover, some suggestions were offered for future rural greening regarding perceived visual beauty.     

城市低频环境噪声烦恼度研究

噪声对人的影响程度不但与它的响度大小有关,而且和它的频率高低有关.当前城市噪声源中有相当一部分为低频噪声,其对人的影响具有与通常的中高频噪声不同的特点.为分析噪声频率与烦恼度的关系,进行了8个不同频率的纯音在等响度级情况下的主观烦恼度的影响研究,由17位实验评价者对4组不同等响度级的纯音所引起的烦恼程度进行了成对比较评价,对评估矩阵进行误差分析和有效性的统计分析.结果显示,等响度级条件下,在63 ～ 250 Hz的低频段,烦恼度随着频率的升高而降低;而在1 000～8 000 Hz的中高频段,烦恼度则随着频率的升高而增大;评价者对中高频声的烦恼反应要高于低频声,但低频段的烦恼影响仍不可忽视.     

污水生物脱氮过程中N_2O的释放途径和影响因素

为了更好地理解和掌握污水处理过程中N 2O的释放规律,结合近年来已经发表的研究结果,就传统的污水生物脱氮过程(全程硝化反硝化过程)和新型污水生物脱氮过程(同步硝化反硝化、短程硝化反硝化和厌氧氨氧化)中N2O的释放途径以及影响因素进行了综述。通过综述发现,硝化和反硝化过程均有可能导致N2O的释放,且硝化过程更易产生N2O;与传统的脱氮过程相比,同步硝化反硝化等新型脱氮过程产生N2O的概率更大;影响N2O释放的因素主要有DO浓度、NO-2浓度、进水氨氮负荷、SRT和COD/N等运行工况和细菌种类及其活性。最后,展望了该领域的研究方向。     

Evaluating the blank contamination and recovery of sample pretreatment procedures for analyzing organophosphorus flame retardants in waters

Organophosphate esters (OPEs), used as flame retardants and plasticizers, are widely present in environmental waters. Development of accurate determination methods for trace OPEs in water is urgent for understanding the fate and risk of this class of emerging pollutants. However, the wide use of OPEs in experimental materials results in blank interference, which influences the accuracy of analytical results. In the present work, blank contamination and recovery of pretreatment procedures for analysis of OPEs in water samples were systematically examined for the first time. Blank contaminations were observed in filtration membranes, glass bottles, solid phase extraction cartridges, and nitrogen blowing instruments. These contaminations could be as high as 6.4–64 ng/L per treatment. Different kinds of membranes were compared in terms of contamination levels left after common glassware cleaning, and a special wash procedure was proposed to eliminate the contamination from membranes. Meanwhile, adsorption of highly hydrophobic OPEs on the inside wall of glass bottles was found to be 42.4%–86.1%, which was the primary cause of low recoveries and was significantly reduced by an additional washing step with acetonitrile. This work is expected to provide guidelines for the establishment of analysis methods for OPEs in aqueous samples.     

富里酸在水体多环芳烃光化学降解中的作用

以氙灯作为模拟光源,对水相中5种不同来源、不同浓度富里酸(FA)在5种PAHs光解中的作用进行了比较分析;并通过活性氧的捕获探讨了FA在PAHs光解中的作用.结果表明,不同来源FA的结构及其对PAHs光解的影响具有较高的一致性.在低浓度(1.25 mg·L-1)体系中FA对二氢苊、芴、菲的光解表现出不同程度的抑制作用,而对荧蒽和芘的光解则表现出一定的促进作用;随着体系中FA浓度的升高,其对PAHs的光解总体上呈抑制趋势.FA的存在一方面促进了单线态氧和羟基自由基的生成,强化了PAHs的活性氧光解进程;另一方面FA也可以参与PAHs分子的能量竞争.     

繁殖期白头鹤觅食地活动的时间分配和日节律

2004年4~6月在黑龙江大沾河湿地自然保护区内,采用野外直接观察法对野生白头鹤在觅食地的活动节律进行了研究.结果表明:①繁殖期白头鹤在觅食地各种行为活动有一定的时间分配规律.在繁殖前期,雌、雄白头鹤全天(5:30~18:00)成对在觅食地活动,雄性个体以取食、警戒、游走、保养和求偶为主要行为,雌性个体以取食、警戒、游走和保养为主要行为;到繁殖后期,雌、雄白头鹤每天有两个时间段单独在觅食地活动(4:00~6:00和17:00~19:00),无论雌雄个体,均无求偶行为.②白头鹤雌、雄个体间保养行为差异极显著(P<0.001),警戒和求偶行为差异显著(P<0.05),取食、游走行为具有一定的差异.③在麦田和池塘2种微地貌之间,白头鹤的取食、求偶行为具极显著差异(P<0.001),警戒行为具显著差异(P<0.05).④在繁殖期的不同阶段以及不同的天气情况下白头鹤的各种行为均具有一定差异.图1表2参15