青藏高原希夏邦马冰芯中阴阳离子的研究

本文对希夏邦马浅冰芯的资料进行了分析,发同离子含量变化显示强烈的周期性变化,反映了季节变化的特征。离子浓度高低变化将指示气候的冷暖变化。并与降水量变化有着反相关关系,与δ＾１８Ｏ存在着对应关系,但δ＾１８Ｏ对气候变化的反映没有各咱郭反映灵敏。     

烟气净化双流体喷嘴雾化特性实验

在烟气净化装置喷雾干燥塔内,进行双流体喷嘴喷雾特性试验,实验研究了影响喷雾粒度、角度以及液滴均匀度的主要因素。实验证明,气液质量比、浆液密度为影响双流体喷嘴雾化特性的重要因素。通过改变运行参数,可以得到合适的液滴粒径以及喷雾角度,该喷嘴用于喷雾干燥烟气中酸性气体的净化,可提高净化效率。     

六盘山生态旅游区旅游步道对人类践踏干扰的响应研究

从生态系统响应和游客主观认知的双重视角,对六盘山旅游区旅游步道对人类旅游践踏干扰的响应进行了研究。结果表明:①自然状态下旅游践踏干扰主要集中在旅游步道边缘1~3m范围内,但不同生态系统差异较大。在调查的3个景区中,小南川景区乔灌草生态统主要集中在旅游步道1m左右;凉殿峡景区高山草甸生态系统集中在1~2m之间;野荷谷景区华北落叶松林下生态系统则达到3m左右;②采用地表覆盖物响应指数(Index of Land Cover Impact,ILCI)和游客可接受改变限度(Limits of Acceptable Change,LAC)来衡量受干扰旅游步道响应程度,在1m范围内各调查样区ILCI均达到4级或5级严重冲击程度;1~2m间以凉殿峡景区ILCI值较高(39%),介于1~2级之间,而小南川与野荷谷景区ILCI值属1级轻微影响;3m及以外三者影响基本较小。游客对游道沿线土壤裸露度可接受改变限度为55.7%,3个调查样区1m范围内植被覆盖减少率(CR)均超过此水平;③调查样区旅游步道响应强弱与游道坡度、边坡坡度以及游道宽度具有一定相关性;④地表覆盖物响应指数因与其它各响应变量间显著相关,可作为评估旅游干扰系统响应的一项简易而有效的指标。研究结果也表明,目前旅游践踏干扰已对游道沿线环境以及游客游憩体验产生了一定的负面影响。因此,改变目前景区开发无序状态,加强旅游步道规划设计和游客行为规范,建立长期环境监测系统,将对制定防治游憩冲击策略,促进六盘山生态旅游区可持续发展具有重要指导价值。     

含油污泥中石油降解菌的分离及其降解特性

从渤海油田含油污泥中分离出3株石油烃降解菌,通过16S rRNA基因序列鉴定RS1、RS2和RS3分别为棒状杆菌、短杆菌和假单胞菌。经单因素实验确定,3株细菌对石油的最适降解条件分别为37℃、盐度3%、pH 8;32℃、盐度1%、pH 8;42℃、盐度1%、pH 6。降解实验结果表明,3株细菌30 d内对含油污泥中总石油烃的降解率分别为39.69%、31.13%和53.29%,而混合菌的降解效果明显高于单一菌株,降解率为58.08%;不同菌株对原油中不同组分的降解能力不同,其中,RS1对饱和烃的降解率最高,达20.74%,RS3对芳香烃的降解率最高,达到8.08%;GC-MS分析表明,混合菌对n-C12~n-C34等正构烷烃均有明显降解,且对萘、苊、屈和苯并[b]荧蒽等多环芳烃的降解能力较强。     

城市污泥过热蒸汽与热风干燥特性

为研究城市污泥过热蒸汽和热风干燥特性,研制了一套常压内循环式干燥实验装置。以4 mm和10 mm污泥薄层为研究对象,在160~280℃温度下进行过热蒸汽和热风干燥特性实验。实验结果表明,随着温度升高过热蒸汽与热风干燥时间越来越接近,当温度达到280℃时,过热蒸汽干燥与热风干燥时间大致相同;过热蒸汽干燥初期存在凝结过程,4 mm和10 mm污泥在160~280℃下凝结量范围为3.39~1.07 g和9.71~3.62 g,凝结现象的出现导致干燥速率出现负值,但随着温度升高凝结过程对整个干燥时间影响愈来愈轻。从干燥结束后污泥的表观形态可以观察到过热蒸汽干燥的污泥表面裂纹密集、质地疏松,没有发生燃烧炭化的现象,能够避免污泥干燥时可能发生燃烧和爆炸的危险。     

改进WQI在川中丘陵地区典型流域水质评价中的应用—以琼江流域上游段为例

水质指数（WQI）克服了传统水质评价方法无法同时满足定性评价与定量评价的缺点,但其所需指标较多,无法做到广泛运用。以琼江流域上游段为川中丘陵地区典型流域的代表,对其2018—2019年水质监测数据进行多元线性逐步回归分析,从25个水质指标中筛选出氨氮（NH₃-N）、化学需氧量（COD_Cr）、生化需氧量（BOD₅）、溶解氧（DO）4个指标建立改进WQI （WQI_min）模型,该模型评价结果与WQI高度相关,并且具有较好的预测性能（R²=0.81,PE=11.9%）。WQI_min评价结果表明：琼江流域上游段WQI_min均值为63.1±17.2,水质等级为好;干流WQI_min整体上呈沿程升高的趋势,流经安居区时,WQI_min明显降低,但能较快恢复至入城区前的水平;WQI_min由高至低依次为琼江干流>会龙河>玉丰河>蟠龙河>石洞河,主要支流水质均劣于干流,建议区域水污染治理的重点应逐步放到支流上。     

The impact of different voltage application modes on biodegradation of chloramphenicol and shift of microbial community structure

● Presented coupled system enhanced biodegradation of antibiotic chloramphenicol. ● HRT and electrical stimulation modes were key influencing factors. ● Electrical stimulation had little effect on the chloramphenicol metabolic pathway. ● Microbial community structure varied with the voltage application mode. Exoelectrogenic biofilms have received considerable attention for their ability to enhance electron transfer between contaminants and electrodes in bioelectrochemical systems. In this study, we constructed anaerobic-aerobic-coupled upflow bioelectrochemical reactors (AO-UBERs) with different voltage application modes, voltages and hydraulic retention times (HRTs). In addition, we evaluated their capacity to remove chloramphenicol (CAP). AO-UBER can effectively mineralize CAP and its metabolites through electrical stimulation when an appropriate voltage is applied. The CAP removal efficiencies were ~81.1%±6.1% (intermittent voltage application mode) and 75.2%±4.6% (continuous voltage application mode) under 0.5 V supply voltage, which were ~21.5% and 15.6% greater than those in the control system without voltage applied, respectively. The removal efficiency is mainly attributed to the anaerobic chamber. High-throughput sequencing combined with catabolic pathway analysis indicated that electrical stimulation selectively enriched Megasphaera, Janthinobacterium, Pseudomonas, Emticicia, Zoogloea, Cloacibacterium and Cetobacterium, which are capable of denitrification, dechlorination and benzene ring cleavage, respectively. This study shows that under the intermittent voltage application mode, AO-UBERs are highly promising for treating antibiotic-contaminated wastewater.     

Metabolites change of Scenedesmus obliquus exerted by AgNPs

With increasing emission of silver nanoparticles (AgNPs) into the environment, it is important to understand the effects of ambient concentration of AgNPs. The biological effects of AgNPs on Scenedesmus obliquus, a ubiquitous freshwater microalgae, was evaluated. AgNPs exerted a minor inhibitory effect at low doses. Non-targeted metabolomic studies were conducted to understand and analyze the effect of AgNPs on algal cells from a molecular perspective. During the 48?hr of exposure to AgNPs, 30 metabolites were identified, of which nine had significant changes compared to the control group. These include d-galactose, sucrose, and d-fructose. These carbohydrates are involved in the synthesis and repair of cell walls. Glycine, an important constituent amino acid of glutathione, increased with AgNP exposure concentration increasing, likely to counteract an increased intracellular oxidative stress. These results provide a new understanding of the toxicity effects and mechanism of AgNPs. These metabolites could be useful biomarkers for future research, employed in the early detection of environmental risk from AgNPs.     

锅炉屏式过热器近集箱处爆管原因分析及改进措施

某电厂锅炉屏式过热器管在近集箱处发生爆管,本文通过宏观形貌检查、化学成分分析、机械性能测试及金相组织分析等方法对其爆管原因进行了系统分析。根据分析结果推断:集箱或管子内异物堵塞,导致管子材质劣化,但仅更换炉内管段,未更换炉外材质劣化管段,最终在长期运行中发生爆管。最后针对具体失效原因,提出了普查屏过管、失效分析、清洁工程及加强监督等改进措施。     

Impact of waste of COVID-19 protective equipment on the environment,animals and human health: a review

Environmental Chemistry Letters - During the Corona Virus Disease 2019 (COVID-19) pandemic, protective equipment, such as masks, gloves and shields, has become mandatory to prevent person-to-person...