城市污水处理厂微生物气溶胶污染和粒径分布特征

城市污水处理厂微生物气溶胶的污染与控制逐渐成为人们关注的热点问题。为明确城市污水处理厂微生物气溶胶浓度和粒径分布特征,选择鄂尔多斯市某城市污水处理厂的格栅间、配水池、氧化沟、二沉池、污泥脱水间和厂区门口6个功能区为对象,对各功能区产生的异养细菌、真菌和放线菌气溶胶浓度分布、污染特性和微生物粒子粒径分布特性进行研究。结果表明,该污水处理厂不同功能区内异养细菌、真菌和放线菌的浓度分布存在显著性差异,其中二沉池和污泥脱水间产生的异养细菌和放线菌浓度均较高,真菌浓度较高的区域为厂门口和二沉池;根据相关微生物气溶胶污染评价标准,污泥脱水间逸散的异养细菌浓度均达到污染级,二沉池、氧化沟和厂门口逸散的异养细菌浓度达轻微污染级,格栅间和配水池未受污染,而真菌浓度在各个功能区均未受到污染;各功能区产生的异养细菌、真菌和放线菌粒子粒径分布无明显差异,异养细菌、真菌和放线菌粒子粒径分别集中在第1、4级,第3、4级和第1、2、3级,大体上均呈正态分布;各功能区均逸散出一定比例的可以直接吸入人体呼吸道的微生物粒子,可能对人体健康具有一定的潜在风险。研究结果可为城市污水处理厂运行过程中微生物气溶胶的污染控制提供科学依据。     

大气微生物粒子与飘尘粒子的关系

用ＡＮＤＥＲＳＥＮ生物粒子采样器和光散射气溶胶粒子计数器，在北京西单对大气细菌、真菌和飘尘粒子的浓度、粒度分布及它们之间的关系进行了观测和研究。结果表明，大气细菌的粒度是负偏态分布，大气真菌是对数正态分布，飘尘是正偏态分布。大气细菌浓度与飘尘浓度的比值冬季大，为１１９５３８；夏季小，为２４２１７；年平均比值为６７５１７，＞２．０μｍ的菌尘比值为１５２５３８７，２．０μｍ～８．２μｍ的菌尘比值为３３１８，＞８．２μｍ的菌尘比值为３９４。大气真菌浓度与飘尘浓度的比值冬季大，为２１２７７０；夏季小，为６５５８５；年平均比值为１３５３４４，＜２．０μｍ的菌尘比值为９５２６９８，２．０μｍ～８．２μｍ的菌尘比值为５３４３，＞８．２μｍ的菌尘比值为２６３２。     

青岛地区大气气溶胶中微量金属的时空分布

于 2 0 0 1年 4月— 2 0 0 2年 5月在青岛近海三个采样点采集了 1 0 0多个大气气溶胶样品 ,用ICP AES测定了Al,Fe ,Mn ,Cu ,Pb和Zn的浓度 ,讨论了这几种元素的时空分布特征及其来源 .结果表明 ,六种元素浓度的时空分布特征为 :沧口 >八关山 >仰口 ,TSP(总体悬浮颗粒物 )与Al,Fe ,Mn的浓度呈明显的季节变化 :春季 >冬季 >秋季 >夏季 ,而Cu ,Pb ,Zn的季节变化比较复杂 .六种元素中Al,Fe,Mn主要由自然过程输入 ,而Cu ,Pb ,Zn主要是人为来源 .     

生物气溶胶研究进展:环境与气候效应

生物气溶胶是大气气溶胶的一个重要组成部分,在大气中的扩散、传播会引发人类的急慢性疾病以及动植物疾病。生物气溶胶还可以间接影响全球气候变化,并对大气化学和物理过程有着潜在的重要影响。相关研究已成为国际研究的热点,也逐渐得到更广泛的关注。生物气溶胶中的几类生物体(如真菌、细菌和藻类)都被鉴别出是有效的云凝结核(CCN),并在以活性CCN的形式存在。当生物气溶胶与有机物(OC)碰撞接触时可以改变大气中OC的化学组成并改变其CCN特性,从而影响云量并间接影响全球气候变化。空气中的微生物也是影响空气质量的重要因素之一,相关研究主要集中于室内空气细菌、病毒、真菌等生物体的监测及来源调查。而对生物气溶胶的准确测定依赖于采样的有效性,为了减少采样中的误差和活性损失,近年来开发了一些具有应用前景的在线采集、分析技术,如自动拉曼光谱、时间飞行质谱等。分布在大气中的生物气溶胶同样可以遵从传输路线进行长距离传输,而且不同类型的生物气溶胶在大气中具有不同的浓度和时空分布模式。文章对国内外学者近年来在大气生物气溶胶环境效应、样品采集、监测分析以及分布和传输方面的研究进展作了较系统的综述。     

中国东北地区10座城市室内外细颗粒物渗透系数及细菌组分、多样性、来源研究

生物气溶胶不仅在生态系统中发挥着重要的作用,与雾霾形成也有一定关系.本研究以中国东北地区十座城市的居住建筑为对象,在非供暖季与供暖季对室内外细颗粒物浓度进行测试,并采用16S rDNA技术分析细颗粒物中细菌的组分和α多样性,预测细菌来源.研究结果表明,在非供暖季10座城市室内外细颗粒物的渗透系数在0.7128—0.8367之间,各城市间相差不大,其原因是非供暖季居住建筑以自然通风为主;在供暖季10座城市室内外细颗粒物渗透系数在0.4303—0.698之间,各城市间存在较大差异,其原因与不同城市的产业结构、空气污染状况、建筑结构特点等因素有关.细菌组分分析表明,在非供暖季10座城市中变形菌门为优势菌种;在供暖季10座城市主要的优势菌种为变形菌门、拟杆菌门、厚壁菌门、放线菌门.α多样性分析显示,供暖季细菌物种总数是非供暖季的10倍,原因可能是室外细颗粒物浓度和紫外线强度不同所致.来源预测表明,非供暖季10座城市细菌群落来源分布较相似,主要来源为土壤、水源、粪便和腐败有机物等;供暖季10座城市细菌主要来源为粪便、土壤、水源、植物等,由于气候原因水源占比大幅下降.     

古尔班通古特沙漠生物结皮中土壤微生物垂直分布特征

对新疆古尔班通古特沙漠主要沙丘类型———沙垄的不同部位、不同类型生物结皮中土壤微生物数量变化特征进行研究,结果表明:(1)微生物总数从垄顶至垄间低地呈递增趋势,在沙垄不同部位0~20cm土层中的垂直分布有差异.(2)土壤微生物各类群数量垂直变化规律为:细菌数量在垄顶0~10cm土层中递减,到10~20cm有所回升;在迎风坡和背风坡的0~10cm土层中递增,到10~20cm有所下降;在垄间低地0~20cm土层中呈递增趋势.放线菌数量在各部位均随土层加深而递减.真菌数量在垄顶和迎风坡0~20cm土层中的垂直变化与细菌在垄顶的垂直变化一致,在垄间低地和背风坡,真菌数量均在2~5cm土层中出现峰值,然后随土层加深递减.(3)微生物类群的组成表现为:细菌数量>放线菌数量>真菌数量.在垄间低地细菌所占微生物总数比例相对垄顶有所增加,而放线菌和真菌相应减少.(4)土壤微生物的数量变化特征与生物结皮的类型、分布以及土壤有机质含量等因子有一定相关性.图5表1参34     

室外空气细菌群落特征研究进展

着重论述了空气细菌的来源、粒子特征、群落特征、浓度的时空变化及其群落结构的影响因素.国内外研究结果表明:空气细菌主要来源于自然界的土壤、动植物、人类和水体,另外一些非自然的人类活动也是其重要来源;空气细菌的粒径主要在 0. 3~15. 0μm间变化,海岸边细菌气溶胶的粒径相对较小,而其他地方 84%或更多的细菌粒子的粒径≥2. 1μm;空气中革兰氏阳性细菌占绝大多数,无论在森林、海岸、城市还是乡村,芽孢杆菌 (Bacillus)都是优势菌属;一年中空气细菌浓度夏季最高,冬季最低,一天中则可以明显的划分为 5个阶段: (ⅰ )午夜细菌浓度最低, (ⅱ )日出时细菌浓度达到高峰, (ⅲ)正午细菌浓度积累逐渐上升, (ⅳ)下午后期细菌浓度降低, (ⅴ )晚上到午夜细菌浓度较低;人类活动频繁,动植物较多的地方空气细菌浓度较高.此外,空气细菌不仅与各种环境因素有关,还受到各种污染因子的影响. 表 2参 53     

生物肥料对香蕉枯萎病及土壤微生物的影响

香蕉枯萎病是真菌引起的一种土传病害,它的蔓延已经严重影响到香蕉产业的正常发展.将腐熟的有机肥与3种生防细菌(枯草芽胞杆菌、胶质芽胞杆菌和巨大芽胞杆菌)结合,组合成生物复混肥和生物有机肥,将它们施用在香蕉上,研究其对枯萎病病害防治效果.盆栽香蕉试验结果显示,2种肥料不仅能抑制香蕉枯萎病(防病效果分别为61.5%和53.8%),同时也引起土壤微生物群落发生变化,真菌数量明显下降,放线菌明显升高,细菌变化较小.通过相关分析发现,生物肥料中3种生防细菌总数与土壤中枯萎菌和普通真菌呈显著负相关,而与防病效果呈极显著正相关,有机肥中细菌与土壤细菌和放线菌含量也呈显著正相关.     

黄土高原土壤细菌和真菌群落结构及其多样性对菌糠有机肥响应机制研究

为了明确黄土高原农田土壤细菌群落和真菌群落对菌糠有机肥的响应机制,基于高通量测序技术,分析了施用菌糠有机肥和施用化肥(对照)后土壤细菌和真菌群落物种组成、多样性指数、群落结构差异及其主要分异作用的微生物.结果表明,土壤细菌和真菌群落对外源养分的响应机制不同.添加菌糠有机肥改变了土壤细菌菌群的结构,厚壁菌门、奇古菌门相对...     

临安本底站大气气溶胶水溶性离子浓度变化特征

为研究我国长江三角洲地区气溶胶污染的区域特征,2008年4月、7月、10月和2009年1月,在临安区域本底站利用安德森(Andersen)分级采样器进行了大气气溶胶采样,样品用离子色谱(IC)进行了分析.结果表明,临安区域本底站SO24-、NH4+、K+的浓度在粒径0.43—1.1μm出现峰值;Ca2+、Mg2+的浓度在粒径3.3—5.8μm出现峰值;NO3-、Cl-、Na+的浓度在粒径0.43—1.1μm和3.3—5.8μm出现峰值.气溶胶各个粒径段上的阳、阴离子电荷比均小于2.在降水过程个例分析中,降水之后临安区域本底站的总离子浓度增加了10.9μg·m-3;粒径分布除SO24-和K+有明显变化以外,其它离子没有明显变化.通过霾日和非霾日的浓度变化分析发现,细粒子中SO24-、NH4+的浓度的增加是造成霾天气的主要原因.     

森林土壤固碳机理研究进展

全球碳平衡中,土壤有机碳储量为2000 Pg,植被碳储量500 Pg,大气碳储量785 Pg,土壤中有机碳变化是影响大气温室气体含量的重要因素。中国人工林总量世界第一,可以通过造林树种的选择,增加森林土壤的碳汇功能,它主要通过4种机理来实现,包括稳定性有机-矿物复合体的形成、持久性封存的深层碳的增加、耐分解有机物成份的积累、以及土壤团聚体结构中碳的物理性保护。中国近年来对木材的需求上升,导致大量短轮伐期人工林的种植,采伐、火烧炼山、施肥与整地等营林措施对土壤碳汇功能形成重大影响。因而,通过加强对中国人工林土壤固碳机理的研究,通过人为措施实现具有较强固碳能力的森林类型,从而提高人工森林生态系统的固碳能力,它对中国减排增汇战略具有重要意义,而加强对不同营林措施对碳汇功能影响的研究是中国当前面临的重大课题。     

Evaluating losses in ecosystem services in nature reserves in Sichuan,China

Nature reserves have developed rapidly over the decades in China and play a significant role in the function of ecosystem services. The function of ecosystem services in nature reserves, however, has tended to decline in recent years due to natural hazards and human activities. Based on land use, the variation of ecosystem services value (ESV) during 2000–2010 in national nature reserves in Sichuan was evaluated. We analyzed the comprehensive effects of natural disasters and human activities on the decline of ESVs. Total ESV in the national nature reserves in Sichuan was approximately 2741.35 million US$ in 2000, 2616.81 million US$ in 2005, and 2499.06 million US$ in 2010, representing a decrease of 242.29 million US$, or 8.84%, in the decade. Forestland, grassland, wetland, and water bodies played vital roles in the function of ecosystem services, with an aggregated ESV of 99% of the total. The largest proportion of the total ESV was the protection of biodiversity at 48.6%. ESV of all land use types and single ecosystem services continued to decline during 2000–2010. A mechanism of adaptable risk prevention should be established, and unreasonable human activities should be avoided to protect ecosystems and to improve the functions of ecosystem services.     

中国水稻土碳循环研究进展

文章首先分析了水稻土在碳循环研究中的地位和重要性，进而对我目水稻土碳循环的研究现状作了较为详尽的阐述，对其主要研究结论进行了深入的剖析。中国大而积的水稻土自1980年以来显示出有机碳库增加现象，说明水稻田对大气CO2可能产生汇效应。水耕熟化过程足有机碳的积累过程，水稻土的碳密度是早作土碳密度的2-3倍。水稻土的同碳能力与土壤的微团聚体的粒径有关。但对于水稻土中有机碳的分布和结合状态与农业管理措施、水稻土质量变化、农业生态环境变化的关系仍不清楚。因而建议就这一问题从土壤物理学、化学和生物学的相互作朋与土壤微团聚体中矿物质、有机质和微生物的相互结合关系的层面上进行多学科研究。同时提出了今后我困水稻土碳循环的重点研究方向和领域，即从整体和系统的角度来研究碳循环和平衡，从不同的时空区域来研究碳循环的过程和强度。     

生物扰动在水层-底栖界面耦合中的作用

综合评述了生物扰动在水层-底栖界面耦合中的作用研究进展和热点问题,并进行了展望。国际上十分重视水层-底栖界面耦合过程的研究并已有一定基础,生物扰动作为海洋生态学的重要内容之一早在20世纪50—60年代就已开展了工作,但直到10余年前才真正开始定量研究,进入了实验模拟、现场观测与建立模型相结合的新阶段。国内的生物扰动研究尚处于起步阶段,加上技术方法落后,一直未能取得突破性进展。目前国内外关于水层-底栖界面生物扰动效应研究基本上都在海洋中开展,尤其在河口、近岸和浅海水域进行,湖泊和河流研究明显薄弱。作为水生态动力学的重要分支和前沿领域,生物扰动研究具有广阔前景。急需针对我国水域特点,引进先进的现场观测和室内测试手段,进一步揭示水层-底栖界面耦合过程中的生物扰动机制,更精准和更详细地掌握水域中各种物质的生物地球化学循环的全过程,为控制水体内源污染释放、富营养化治理和生态建模等提供科学依据。     

Variation in male courtship costs in butterflies

A cost of mating is common to both sexes but has predominantly been examined in females. In species where males provide resources to females at copulation, male mating costs are expected to be high as nutrient provisioning enhancing female fecundity is assumed to carry costs. In addition, males frequently court females prior to mating, which is known to carry survival costs to both sexes. However, the magnitude and basis of variation in males’ mating costs remains largely unknown. Here, I examine the effect of nutrient provisioning and courtship on male longevity across full-sib families in the paternally investing green-veined white butterfly, Pieris napi. Copulating males suffered a survival cost as did courting males prevented from copulating, indicating the courtship component of mating is costly. Male P. napi release aphrodisiacs during courtship to promote mating, indicating that these compounds may also be costly to produce. Contrary to expectation, nutrient provisioning was not associated with reduced survival relative to males only allowed to court females, although it is possible that this could be masked by the potentially elevated courtship rates of courting males relative to mating males. Families differed in magnitude of reduced male survivorship, indicating a likely genetic basis to variation in costs of courtship and copulation. Male weight was unrelated to longevity and mating success, whereas longevity strongly influenced male mating success, indicating lifespan is an important male fitness trait in this species.     

Is the antipredatory response in behaviour reflected in stress measured in faecal corticosteroids in a small rodent?

Predation risk has been shown to alter various behaviours in prey. Risk alters activity, habitat use and foraging, and weight decrease might be a consequence of that. In mammals, studies on physiological measures affected by risk of predation, other than weight, are rare. We studied in two separate laboratory experiments foraging, hoarding behaviour and expression of stress measured non-invasively from the faeces in the bank vole (Clethrionomys glareolus), a common boreal rodent. Voles were exposed to predation risk using odours of the least weasels (Mustela nivalis nivalis). Distilled water served as control. In the first experiment, we found that foraging effort, measured as sunflower seeds taken from seed trays filled with sand, was significantly lower in trays scented with weasel odour. Both immediate consumption of seeds and hoarding were affected negatively by the weasel odour. Females hoarded significantly more than males in autumn. In the second experiment, the negative effect of weasel odour on foraging was consistent over a 3-day experiment, but the strongest effect was observed in the first night. Foraging increased over the time of the experiment, which might reflect either energetic compensation during a longer period of risk, predicted in the predation risk allocation hypothesis, or habituation to the odour-simulated risk. Despite decreased foraging under predation risk, stress measured as corticosteroid metabolite concentration in vole faeces was not affected by the weasel odour treatment. In conclusion, we were able to verify predation-risk-mediated changes in the foraging effort of bank voles but no physiological stress response was measured non-invasively, probably due to great individual variation in secretion of stress hormones.     

Employment of passive sampling in monitoring indoor air quality in selected residences in a Tri-city area in Poland

Time-weighted average concentrations of selected volatile compounds were measured in chosen residences in a Tri-City area of Poland by means of passive sampling. The results were compared to those obtained by dynamic technique – sorption tubes filled with Tenax TA sorbent. Results obtained by employing the two techniques were similar. Total volatile organic compound (TVOC) parameters were also determined. An attempt was also made to evaluate the influence of outdoor air pollutants on indoor air quality.     

中国公众参与环境管理的研究

回顾了中国公众参与环境管理的发展历程,分析了公众参与环境管理存在的问题。针对公众参与环境保护管理的有效性的影响因子,例如主观因素、传统背景、时效因素及执行技巧等进行一系列的探讨,并根据公众参与计划的设计构思、公众参与计划的关键两方面的讨论,提出增加公众参与环境保护管理有效性的一些建议。     

Lead in a residential environment in Jamaica

The background levels of lead in Jamaica in soils and sediments, estimated at 37 mg kg^–1, are relatively high compared with world averages. Several areas have values in excess of this due to mineralisation and pollution. One such is the residential Hope Flats/Kintyre area in which levels of lead up to 2.5% are found in the soils and up to 8 g kg^–1 in the water of the nearby Hope River. The blood lead levels of a sample of children were in the range 5.7–57 g dl^–1. The high lead levels suggest a potential health risk, particularly for the children. This can be minimised by programmes which include community education, case management and abatement to reduce the lead exposure.