A/O系统处理低C/N奶牛场废水中的抗生素

为处理奶牛场废水中常检出抗生素,考察了小试规模缺氧/好氧(A/O)系统对低C/N奶牛场废水中常规污染物和抗生素的处理效果。当进水COD、总氮、氨氮和总磷分别在1 242～4 350、830～1 367、818～1 291和6～12 mg·L~(-1), A池和O池水力停留时间(HRT)分别为3～4 d和2.05～5.4 d时,系统出水COD400 mg·L~(-1)、氨氮10 mg·L~(-1)、总氮去除率为40%～60%(无外加碳源)、总磷基本没有去除;通过调节硝化液回流比(1.0∶1～1.3∶1)可在进水COD/总氮≥3.1时实现碱度的自给自足;对11种磺胺类和8种β-内酰胺类抗生素研究发现,共检出9种磺胺类和1种β-内酰胺类抗生素(总浓度为5.89～17.31μg·L~(-1)),系统对抗生素的总去除率大于93%;先后2次向进水中人为添加8种磺胺类抗生素(每种浓度先后为50μg·L~(-1)和200μg·L~(-1))不会影响系统运行的稳定性,且抗生素的总去除率大于90%,A池和O池的抗生素去除率分别为15.0%～34.2%和69.1%～91.4%;在O池中的HRT降低50%时,系统对抗生素的总去除率基本不变。除甲氧苄啶外,其余7种磺胺类抗生素主要在O池中均得到去除,这与其分子结构中的S—N键有关。以上结果对奶牛场废水处理后还田具有重要的参考价值。     

高校环境与可持续发展教育研究综述

本文首先分析了目前高校中环境与可持续发展教育的国内外研究现状,在此基础上,揭示了高校环境与可持续发展教育研究存在的问题,并提出了提高高校环境与可持续发展教育研究意识,深化高校环境与可持续发展教育研究内容,协调高校环境与可持续发展教育研究比例等建议。     

油气管道位移光纤安全监测技术定位理论及预警信号特征研究

管道安全分布式光纤监测系统利用分布式光纤振动传感器两端检测信号的时间差确定管道沿线所发生事件位置,时间差的精度决定对异常事件事发点的定位精度;系统拥有较高的灵敏度,可对1.5 km内敲击、落石、滚石及人工挖掘等威胁管道安全的事件进行报警;事件的定位有一定的误差,对抢修有一定的指导意义。     

多维灰色评估方法在煤与瓦斯突出预测中的应用

影响煤与瓦斯突出的因素很多,并且其信息多具有灰色性。本文将瓦斯压力、瓦斯放散初速度、煤的坚固性系数、破坏类型以及综合指标K这5个因素综合起来考虑,应用基于灰色系统理论的多维灰色评估方法,对几个典型矿井进行煤与瓦斯突出预测分析,本方法突出了灰色系统理论可以进行定量分析的特点,具有能够动态预测、可靠性高等优点。研究结果表明,该方法能准确预测煤与瓦斯突出,可以为矿井的安全生产提供帮助。     

中国典型滨海湿地转变为养殖塘对土壤细菌多样性及群落结构的影响

以我国黄河口碱蓬湿地、九龙江口桐花树湿地、东寨港木榄湿地为研究样地,借助高通量测序技术探究这3个典型滨海湿地转变为养殖塘前、后土壤细菌多样性及群落结构的变化.结果表明：①天然湿地转变为养殖塘后,土壤细菌群落多样性与丰富度均有所下降;②天然湿地转变为养殖塘未显著改变细菌门水平群落组成,湿地优势细菌门主要为变形菌门（Proteobacteria）、绿弯菌门（Chloroflexi）、拟杆菌门（Bacteroidetes）、酸杆菌门（Acidobacteria）、厚壁菌门（Firmicutes）;③天然湿地转变为养殖塘改变了土壤优势细菌属,九龙江口和东寨港湿地转变后,寡养单胞菌属（Stenotrophomonas）相对丰度均有所升高,东寨港湿地转变后土壤中假单胞菌属（Pseudomonas）相对丰度也有所增加,并新增了气单胞菌属（Aeromonas）;4环境因子对湿地土壤细菌相对丰度有显著影响,寡养单胞菌属（Stenotrophomonas）与含水量呈显著负相关（p<0.05）,与容重和pH呈显著正相关（p<0.01）;Sulfurimonas、Woeseia等细菌属与土壤容重呈显著负相关（p<0.01）.由此可见,湿地围垦养殖对土壤微环境产生了较大影响,养殖户在进行养殖作业时需格外注重生态环境的健康与可持续发展.     

辽宁省畜禽养殖业抗生素排放特征及减排路径分析

抗生素作为新兴环境污染物,已成为国内外研究的热点问题.以磺胺类和四环素类抗生素为研究对象,运用物质流分析方法,对辽宁省畜禽养殖业抗生素的排放特征进行系统分析,并通过情景分析法对各减排路径进行了比较分析.结果表明：2017年辽宁省畜禽养殖业两类抗生素的消耗总量为712 t,排放总量为280 t;排泄物中的抗生素有39.34%进入养殖废水,60.66%进入养殖粪便,废水和粪便中抗生素的去除率分别为7.50%和8.15%;从排放去向看,土壤环境抗生素的负荷量明显高于水环境;2000—2014年,辽宁省畜禽养殖业抗生素排放总量呈逐年增加趋势,2015年略有下降,2017年出现明显下降,抗生素排放量主要受养殖数量影响;饲料"禁抗"情景可使抗生素排放量削减18.02%,改善废物资源化利用情景和加强废物末端治理情景抗生素排放量可分别削减13.05%和25.29%,全过程优化情景抗生素排放量可削减46.99%.     

双酚A及其活性炭催化微波照射降解液对牛血清白蛋白的作用

采用UV-vis光谱和荧光光谱法研究双酚A(BPA)与牛血清白蛋白(BSA)的相互作用.结果显示,BPA的加入能使BSA肽链伸展,导致色氨酸,酪氨酸和苯丙氨酸等残基的芳杂环裸露,紫外光谱表现为明显的增色效应.在三个给定的温度(25℃,37℃和42℃)下,BPA对BSA的荧光猝灭方式均为静态猝灭,结合位点数(n)均为1,作用距离(r)均小于7 nm.BPA与BSA的相互作用是自发进行的,主要为疏水作用.同步荧光光谱表明,BPA对BSA的色氨酸残基微区的影响大于对酪氨酸残基微区的影响.酸度和离子强度的增加促进BPA与BSA的相互作用.另外,通过UV-vis光谱和高效液相色谱(HPLC)研究了活性炭催化微波照射下BPA的降解液对BSA的作用.结果表明,此法可有效地降解BPA,但其降解液仍然对BSA作用.而且即使经过较长时间(5.0 min)微波照射和多次稀释方式处理的BPA降解液仍然对BSA具有一定的作用.     

Plastic materials and water sources actively select and shape wastewater plastispheres over time

● Wastewater MPs exhibited resistomes and therefore health threats. ● High density of alkB gene indicates both HDPE and PET can be utilized by microbes. ● Plastics and waters actively selected and shaped the plastispheres over time. ● A broader phylogenetic spectrum of MHET-degrading microorganisms was annotated. The daily use of plastics presents a serious pollution issue due to their extremely slow degradation. Microplastics and the biofilm that grows on plastics (i.e., the plastisphere) are important subsets of plastic wastes. Many studies have been conducted to reveal the structures of the plastispheres, the driving factors for the formation of the plastisphere, and the ability of the plastispheres to degrade plastics in a variety of water bodies. However, the plastispheres related to wastewater are understudied. In this study, we used a microcosmic strategy to study the evolution of the plastispheres associated with microplastics (MPs) over time in wastewater. We found that plastic materials and water sources did not actively select and shape the plastispheres at an early stage, but the active selection for a unique niche of the plastisphere occurred after 14 d of growth. In addition, we confirmed that the alkB gene was densely present, and metagenomics showed some additional chemical reactions, which suggests that MPs are consumed by the microbes in the plastispheres. Additionally, metagenomics identified some metagenome-assembled genomes (MAGs) associated with high-density polyethylene (HDPE) and polyethylene terephthalate (PET). The identification of HDPE-associated MAGs and PET-associated MAGs further supports the notion that the selection for a unique niche of the plastisphere is driven by plastic materials and water sources (in this study, after 14 d of growth). Our discoveries bring new views on the behavior of the wastewater-associated plastisphere, especially how long it takes a wastewater plastisphere to form.     

Effects of anthropogenic landscapes on population maintenance of waterbirds

Anthropogenic impacts have reduced natural areas but increased the area of anthropogenic landscapes. There is debate about whether anthropogenic landscapes (e.g., farmlands, orchards, and fish ponds) provide alternatives to natural habitat and under what circumstances. We considered whether anthropogenic landscapes can mitigate population declines for waterbirds. We collected data on population trends and biological traits of 1203 populations of 579 species across the planet. Using Bayesian generalized linear mixed models, we tested whether the ability of a species to use an anthropogenic landscape can predict population trends of waterbird globally and of species of conservation concern. Anthropogenic landscapes benefited population maintenance of common but not less-common species. Conversely, the use of anthropogenic landscapes was associated with population declines for threatened species. Our findings delineate some limitations to the ability of anthropogenic landscapes to mitigate population declines, suggesting that the maintenance of global waterbird populations depends on protecting remaining natural areas and improving the habitat quality in anthropogenic landscapes. Article impact statement: Protecting natural areas and improving the quality of anthropogenic landscapes as habitat are both needed to achieve effective conservation.     

Urinary heavy metals in residents from a typical city in South China: human exposure and health risks

Environmental Science and Pollution Research - Although heavy metal pollution has developed into a major global environmental problem, most research has focused on specific elements, especially...