不同工艺给水厂对典型微囊藻毒素的去除研究

针对常规处理和深度处理给水厂,研究夏季水源高藻期和冬季水厂各工艺段微囊藻毒素的浓度变化,讨论不同水处理工艺对微囊藻毒素的去除效果。研究结果:深度处理对微囊藻毒素的去除率为38.97%~100%,出厂水藻毒素总浓度为3.91~7.31ng/L;常规处理对微囊藻毒素的去除率为-684.54%~68.13%,出厂水藻毒素总浓度为7.43~237.80ng/L。常规处理对微囊藻毒素的去除效果有限,在夏季原水藻类较多时,预氧化至砂滤工艺段出水的微囊藻毒素浓度显著增高,此时常规处理出厂水微囊藻毒素浓度高于进厂水,尤其是MC-LR和MC-RR,出厂水浓度为进厂水的2~6倍。深度处理的臭氧氧化对微囊藻毒素的平均去除率为76.08%~100%,活性炭工艺的去除率为6.41%~88.78%,紫外消毒去除效果不明显。给水厂处理中,针对微囊藻毒素建议采用臭氧活性炭为主的深度处理工艺。另外,原水高藻期的水厂滤池反冲洗水中微囊藻毒素总浓度高达1 477.06ng/L,应关注滤池反冲洗水的安全处理。     

水环境中微囊藻毒素的检测现状概述

针对蓝藻暴发所产生的微囊藻毒素,分别阐述了其含义、结构特点及理化性质,综述了目前国内外有关水体中微囊藻的检测标准和限值,对两种常用的微囊藻毒素检测方式进行了对比,并简要介绍了微囊藻毒素在海河流域的检测概况.     

蓝藻暴发期给水厂微囊藻毒素应急去除技术研究

微囊藻毒素-LR是蓝藻暴发期常见的毒素,其毒性大、分布广、结构稳定,且难以通过饮用水常规工艺去除,成为饮用水中的潜在危害物质.针对此情况,对南太湖S水厂原水中微囊藻毒素-LR的发生情况进行了监测,对各制水工艺去除微囊藻毒素-LR的效果进行了分析,同时结合室内试验,对该水厂的微囊藻毒素-LR应急去除技术进行了初步探索.     

青草沙水库水体微囊藻毒素的分布特征及与环境因子的关系

对青草沙水库水体中微囊藻毒素(MC-LR、MC-RR、MC-YR)进行3年连续监测,探讨微囊藻毒素的时空变化特征,分析其与营养盐、藻类生物量等环境因子的关系。结果表明:微囊藻毒素的月平均总浓度为5.66~456.08ng/L,主要为MC-LR,MC-LR的月平均浓度为1.02~319.11ng/L。水库通水初期2012年的微囊藻毒素浓度最高(14.46~456.08ng/L),实施水力调控措施后,2014年藻类和微囊藻毒素降低(5.66~16.96ng/L),年均值较运行初期降低88.86%。微囊藻毒素总浓度夏秋季较高(5.66~456.08ng/L),冬春季较低(6.15~33.72ng/L)。库区北侧和下游区域浓度相对较高。水中微囊藻毒素与各环境因子的相关性分析表明,微囊藻毒素与水温、COD_(Mn)、藻细胞总数呈极显著正相关,与溶解性总氮、硝酸盐氮呈极显著负相关,与氨氮、锰呈显著正相关。     

拉曼光谱在微囊藻毒素检测中的应用

拉曼光谱已经广泛应用于许多领域,但在检测环境毒物方面的应用还比较少.在论述了微囊藻毒素的特性及其现行检测方法的基础上,对拉曼光谱应用于微囊藻毒素检测的可行性及特点进行了分析,并对此方法做了展望.     

硅藻土对水中微囊藻毒素的吸附性能研究

富营养化是我国湖库面临的共性问题,藻类水华造成的藻毒素污染严重威胁到湖库型饮用水水源地的供水安全。选择硅藻土吸附去除水中微囊藻毒素(MC-LR),研究其吸附性能及稳定性。结果表明,硅藻土对水中微囊藻毒素(MC-LR)的平衡吸附量随着温度的升高而增大,最大能达到4.4μg/g,相同温度下,平衡吸附量随微囊藻毒素(MC-LR)起始浓度的增加而增加。硅藻土对微囊藻毒素(MC-LR)的吸附符合Langmuir等温吸附模型。吸附过程较符合一级速率方程,反应速率由多种因素共同控制。选择典型湖库自然水体,验证硅藻土对微囊藻毒素的吸附性能,1 h内可将微囊藻毒素(MC-LR)浓度降至1.0μg/L以下。通过对示范工程进出水跟踪监测,进一步验证了硅藻土对自然水体中微囊藻毒素具有良好的去除效果。     

艾溪湖水华蓝藻多样性探讨

本文首次阐明了艾溪湖水华蓝藻的种类、形态及分类学特征,对艾溪湖水华蓝藻的组成和多样性指数进行了分析,并对艾溪湖水华蓝藻种类在全国的分布特征和产毒能力进行了讨论.艾溪湖水华暴发时蓝藻丰度占据绝对优势并导致藻类多样性急剧下降,严重抑制其它藻类生长.显微镜检后发现优势水华蓝藻7种,分别是惠氏微囊藻、挪氏微囊藻、阿氏浮丝藻、螺旋浮丝藻、拉氏拟浮丝藻、依沙矛丝藻、紧密长孢藻.艾溪湖优势水华蓝藻存在季节演替,春季水华蓝藻优势种是微囊藻,夏季是拉氏拟浮丝藻和螺旋浮丝藻.部分种类能够产生微囊藻毒素、神经毒素等藻毒素,对艾溪湖水生态安全具有重大威胁.     

太湖蓝藻暴发应急处理方案研究

总结了课题组针对近期太湖蓝藻暴发的应急处理技术所做的一些研究工作.研究结果表明,此次水体中致臭物质为烯烃类等极性亲水性有机物质,普通活性炭对其吸附效果较差;选择的特种粉末活性炭可以有效吸附水中的致臭物质,20 mg/L的特种活性炭可以有效去除水的臭味、微囊藻毒素,而且具有明显的助凝作用;高锰酸钾预氧化在较高投量时对水的臭味有一定的改善作用,但存在着氧化的中间产物性质难以确定、出水锰离子可能超标等问题,需投加粉末活性炭和粉末沸石来保证出水水质.臭氧氧化是一种有效的除臭技术,可以作为以富营养化水体为水源的自来水厂的储备技术.     

超高效液相色谱-串联质谱法测定水中8种微囊藻毒素

微囊藻毒素主要是由水中蓝绿藻凋亡后产生的一类常见的环肽肝脏毒素,对水生生物及人体健康具有非常大的危害性。建立准确、快速检测微囊藻毒素的方法对中国民众饮水安全非常重要。对固相萃取、色谱和质谱等条件进行优化,建立了超高效液相色谱-串联质谱同时检测水中8种微囊藻毒素(LR、RR、YR、WR、LW、LA、LF、LY)的方法。该方法检出限为0.002～0.006μg/L,定量限为0.006～0.018μg/L,加标回收率为85.3%～107.5%,相对标准偏差小于11%。该方法可为地表水中微囊藻毒素的日常检测提供技术支持。     

微囊藻毒素的毒性和去除研究进展

目前水体富营养化现象日益严重,蓝藻是造成富营养化的主要藻类,它所产生的微囊藻毒素具有遗传和致癌毒性.介绍了微囊藻毒素的毒性及其去除研究现状,对比分析了各个技术的去除效能,并在总结国内外研究的基础上,提出了微囊藻毒素去除领域今后研究的主要方向和需解决的问题.     

环保式过鱼水轮机发展及研制探讨

现代水轮机的开发与设计起始于20世纪初,受当时观念及各方面技术的限制,在设计时没有将保护洄游鱼类安全通过水轮机的问题纳入设计的考虑范畴。通过相关文献调查,介绍了鱼类通过水轮机流道时所受的伤害及受伤机理,并分析总结了现有的过鱼水轮机设计理念和相应的设计实践。从机械结构、流体动力学、鱼类生物特性方面提出了针对上述设计理念的认识和思考。可为我国“过鱼水轮机”（也称“亲鱼型水轮机”）的进一步研究与设计提供参考。     

金沙江一期工程对保护区生态环境的影响与对策

 金沙江一期工程实施后,将给长江上游河道演变、水文情势等带来一系列的变化,对长江合江-雷波段珍稀鱼类国家级自然保护区生态环境产生严重影响。根据工程特点,结合保护区生态环境现状,从生态学角度探讨分析了工程实施后对长江上游珍稀鱼类、特有鱼类、经济鱼类以及相关栖息生态环境的综合影响,并提出了相应的保护对策。     

光电催化技术在污水处理中的应用研究

水电工程在建设过程中有大量的污水需要处理，而有毒有机物的降解方法很多，如传统的气浮法、吸附法等，近年来发展了一些氧化技术，如化学氧化法、光化学氧化法、催化氧化法等。为了进一步提高有机物降解效率，合理利用资源，将光化学氧化(光催化)和电化学氧化方法结合起来，达到协同效应的光电结合技术是目前氧化法研究的新的热点。光电催化法能将水中有害物质完全矿化，或者通过控制条件将其分解为有用成分，这是其他方法所无法比拟的。在当今水污染日趋严重的情况下具有很好的推广应用价值。     

爆破荷载对隧洞围岩稳定的影响研究

该文以数值模拟为主要手段,研究隧洞爆破开挖施工引起的围岩动力响应及其对围岩稳定性的影响.研究表明,隧洞爆破开挖施工时,爆炸冲击荷载会在短时间内造成围岩的破坏,随后主要以爆破振动的形式作用于近区围岩.     

Use of a flow deflector to protect rheophilic fish spawning grounds during hydropeaking

Rheophilic fishes are one of the ecological groups of fishes declining most quickly in number due to various habitat modifications and discharge regulations. Artificial rapid increases and decreases in discharge (hydropeaking) can cause severe damage to the eggs of rheophilic fishes. We investigated whether the effects of a water increase in hydropeaking on a spawning ground may be mitigated by a deflector installed at the top of the weir that diverts flow to other sections. At the research site, rheophilic asp (Leuciscus aspius) spawn annually in early spring, and their success might be affected by hydropeaking, with base discharge ranging from 3 to 7 m³ × s⁻¹ and peak discharge ranging from 16 to 25 m³ × s⁻¹ occurring 4 to 7 times during the asp spawning season and egg development period. To protect the adhesive eggs from detachment during peak discharge, a flow deflector (a wooden wall at the selected part of the weir) was installed to regulate discharge on the protected spawning ground. This measure allowed normal discharge under base flow conditions. During peak flow, a significant portion of the additional water was directed to the part of the river channel where egg abundance was lower and to the mill channel, where asp spawning was not present. While the total discharge increased 4.1 times compared to the base flow, the water discharge in the protected spawning ground increased only 2.7 times. This resulted in more than half of the asp eggs being retained in the protected channel. Although the use of such a measure is limited to specific local conditions where eggs are located just downstream of the weir, it can be a valid solution in highly fragmented rivers with hydropeaking and can lead to higher recruitment of rheophilic fishes.     

Cumulative effects of dams on migratory fishes across the conterminous United States: Regional patterns in fish responses to river network fragmentation

Globally, dams fragment river networks, threatening migratory fishes which require access to distinct habitats to complete their life cycles. Efforts to understand how cumulative effects of multiple dams affect migratory fishes across large regions, such as a country or continent, could help to identify locations for connectivity-enhancing actions to conserve migratory fishes. To address this, we evaluated cumulative effects of dams on migratory fishes in rivers across nine ecoregions of the conterminous USA. First, using fish data from thousands of sites (N = 45,989), we summarized ecoregional patterns in assemblages, quantifying the number of migratory species comprising assemblages, showing the prominence of potamodromous species across the large region as well as differences in migratory life history traits among ecoregions. Next, we compared the importance of a set of river network fragmentation metrics that captured influences of multiple dams in networks versus other anthropogenic landscape stressors and natural landscape factors that impact migratory fishes by ecoregion. We found that migratory fishes were more sensitive to cumulative dam effects than other stressors including urbanization and agriculture in the eastern USA. To further identify specific effects of environmental variables on potamodromous fishes, we conducted Boosted Regression Trees analysis in the eastern ecoregions. Our results suggested that the key natural influences on river fishes included catchment area as well as river baseflow and air temperature, suggesting that migratory fishes may be affected by changing climate. Additionally, we found that downstream dams were more influential than other human stressors to potamodromous fishes, underscoring the importance of enhancing connectivity within river networks to conserve migratory fishes. Collectively, our results provide new insights in identifying threats to migratory fish species across the USA, providing information that can aid in conserving this vulnerable but ecologically and socioeconomically important group of fishes.     

长江流域的渔业与湿地保护

长江流域拥有丰富的湿地资源,孕育了丰富的鱼类资源和发达的渔业.长江渔业在中国淡水渔业中占举足轻重的地位,在种质、苗种、名特优鱼类上具有资源优势.介绍了长江流域的湿地,渔业及天然渔业资源的概况,渔业的现状及存在的问题.近年来,由于渔业资源的衰退与长江湿地资源受到严重破坏,长江捕捞渔业严重衰退,而养殖渔业有较大的发展.长江在我国淡水渔业中的地位是基因库、原种基地和珍稀物种的乐园而不应是天然渔场,应大力发展养殖渔业,捕捞渔业应退出长江,为湿地的合理利用和保护发挥重要作用.     

Numerical study on propulsive performance of fish-like swimming foils

1. INTRODUCTION The study of the movement of fishes can be very informative in exploring mechanisms of unsteady flow control because movements in fish is a result of many millions of years of evolutionary optimization. Previous studies have shed light on …     

Recognizing the importance of scale in the ecology and management of riverine fish

Processes affecting fish populations range in scale from local to global. Fish response is also scale‐dependent, with some activities varying locally while others depend on large‐scale connectivity within or between watersheds. These issues are still only partly recognized, with large‐scale research often affected by non‐independent sampling, weak inference, poor model testing or model over‐extrapolation. Available multi‐scale studies can reach different conclusions about factors affecting fishes from local studies, but results vary between examples. Potential explanations are (i) effects on fishes are context‐dependent; (ii) different species or life‐stages are limited in different ways; (iii) multi‐scale studies are too few for generalization. We advocate improved use of geostatistical tools to guide sampling or interpret the spatial extent of management problems, and we illustrate this using brown trout in Welsh streams. Our strongest recommendation is that fish ecologists recognize the importance of interactions across scales in quantifying effects on fishes so that management decisions can be better based on evidence rather than judgement or extrapolation. Copyright © 2006 John Wiley & Sons, Ltd.