磁河流域污染物的包气带中赋存规律研究

通过对河北平原磁河流域包气带不同浓度取样并对污染物含量的测定，确定了主要污染物及其在包气带中的分布规律。结果表明：包气带可以将有机质吸附、降解；Cr（Ⅵ）和Cl^-迁移能力强；SO4^2-浓度较低；NH4－N虽然在包气带中能够得到一定的降解，但由于其浓度较高，降解不完全，可能已对包气带构成污染。     

垃圾渗滤液中污染物在包气带运移模拟实验及预测

为揭示垃圾渗滤液中污染物在包气带中的迁移转化规律,通过静态吸附、静态降解、动态土柱和数学模型预测等方法进行模拟实验。结果表明,包气带对污染物的吸附过程是线性的,即S=KdC,吸附系数Kd=0.0976;降解曲线符合一级动力学方程,即C=C0e-λt,降解系数λ=0.0324d-1;弥散过程符合对流-弥散迁移转化模型,弥散系数D=0.00435m2·d-1,由此确定了污染物迁移数学模型。通过动态土柱实验验证了模型的可靠性,并利用模型对垃圾渗滤液中有机污染物(COD)的时空分布进行预测。     

垃圾污染质在粉质粘土包气带中运移情况的调查

在我国填埋仍是垃圾处理的主要方式.垃圾产生的渗滤液量大、组分复杂,重金属及有机物含量极高,对土壤及地下水环境污染严重[1].渗滤液污染地下环境的过程主要包括污染物质在包气带中的垂向运移和透过包气带后在含水层中的侧向运移.因此,包气带是阻止渗滤液污染含水层的天然屏障,可以通过对污染物质的阻截和自然衰减,起到削弱污染、保护含水层的作用.因此研究垃圾渗滤液污染物,特别是在不同岩性包气带介质中的迁移转化十分必要.     

矿山废水中重金属离子在包气带中的吸附特征

受矿山废水排放的影响,金昌市地下水的污染物以重金属离子为主.同时金昌地区有着巨厚的包气带,其物质组成由砂砾石、亚粉土、亚粘土为主.本文在对污染组分进行取样分析的基础上,对包气带的吸附能力进行研究,结论认为其对重金属离子有着较强的吸附能力,可以有效降低地下水的污染水平.     

新疆焉耆盆地平原区地下水有机污染特征初步分析

在新疆焉耆盆地平原区采集了42组地下水水样,检测有机污染物共计39项.对所有水样测试结果的统计显示,焉耆盆地平原区地下水中检出的有机污染物共有3种,分别是三氯甲烷、1,2-二氯乙烷和1,2-二氯苯,检出率分别为30.95%、2.38%和2.38%,检出的3项有机污染物含量均低于饮用水标准;不同含水层类型的有机污染物检出率为潜水(50.00%)深层承压水(33.33%)浅层承压水(27.27%);不同土地利用类型的有机污染物检出率为牧草地(42.86%)耕地(34.48%)建设用地(16.67%);有机污染物14个检出点大部分分布在包气带岩性为亚黏土(41.18%)与亚砂土(40.00%)的区域,其余分布在包气带岩性为砂砾石(20.00%)的区域;地下水中检出的有机污染物不是来自于地表水的补给;深层承压水检测出有机污染物是由于有机污染物垂向渗透污染以及地下水混合开采、止水不佳所致.     

水热法制备PbMoO4微晶体及其光催化降解灭幼脲

以水热法合成的PbMoO4微晶体为催化剂,考察了反应溶液pH、污染物初始浓度和催化剂用量对光催化降解灭幼脲的影响,研究了光催化降解过程的反应动力学和作用机理.结果表明,最佳反应溶液pH 6.0、污染物初始浓度20 mg.L-1、催化剂用量0.4 g.L-1.反应4 h灭幼脲降解率达99.96%,矿化率达66.4%,降解反应符合一级动力学.通过加入自由基清除剂对比实验发现,PbMoO4微晶体主要通过空穴和.OH的氧化作用使灭幼脲降解,其中空穴起主要作用.     

甲氧苄啶在有机酸络合Fe~(2+)活化过硫酸钠体系中的降解机制

在有机酸(OAS)/Fe~(2+)/过硫酸钠(PDS)体系中生成的具有强氧化能力的硫酸根自由基(SO_4~(·-)),可以降解水中难降解污染物甲氧苄啶(TMP).分别探讨了柠檬酸(CA)浓度、Fe~(2+)浓度、PDS浓度、p H值对甲氧苄啶降解的影响,以及不同浓度的4种有机酸在不同p H值下对TMP降解的影响.结果表明,当TMP浓度20μmol·L~(-1),p H=7,温度25℃,反应时间30 min,摩尔比CA∶Fe~(2+)∶PDS∶TMP=5∶15∶40∶1时,TMP的降解率高达82.55%;柠檬酸和EDTA有促进TMP降解作用,焦磷酸钠和草酸起抑制TMP降解作用.猝灭实验证实了TMP的降解是SO_4~(·-)和·OH共同作用的结果,SO_4~(-·)起主导作用;液相色谱质谱检出5种中间产物,推测TMP的降解路径涉及羟基化反应、脱甲氧基化反应和裂解反应.     

SnWO_4可见光催化降解甲基橙研究

采用溶剂热法合成了可见光催化剂SnWO4,以甲基橙溶液为目标污染物,研究了催化剂的用量、溶液的初始浓度、盐效应等因素对光催化降解效果的影响.结果表明,甲基橙溶液初始浓度为20 mg.L-1、催化剂的最佳投加量为1.5 g.L-1,SnWO4的催化活性最好,光照反应90 min对目标污染物的去除率可达99.37%;溶液中...     

腐殖质的光化学降解及其对环境污染物环境行为的影响

腐殖质是地表环境中最重要的有机组分,也是生态环境中最主要的吸光物质之一,对环境污染物的形态、迁移、毒性和生物可利用性有着重要的影响。文章综述了腐殖质的结构特征和光化学降解反应过程和机理,指出腐殖质的光敏化和光化学降解过程对环境污染物的环境行为和归宿有重要的影响。通常,腐殖质的光敏化作用在低质量浓度下,尤其在一定铁离子的协同作用下可促进有机污染物的降解,但高质量浓度的腐殖质由于其本身的吸光作用以及参与自由基的竞争则抑制有机污染物的降解。腐殖质的光化学降解过程降低了环境体系的pH和腐殖质的分子量、破坏了腐殖质的芳环结构、改变了紫外和可见光区域的吸收等,导致其与重金属离子和有机污染物结合能力的下降,造成水体或颗粒态中游离的污染物质量浓度增加,对生态系统将造成更大的危害。目前对腐殖质和环境污染物本身的光化学降解机理已较为清晰,今后应加强对自然水体或土壤系统中腐殖质光化学降解的影响因素,腐殖质光化学降解过程中结构特性的变化机理,以及腐殖质的结构特性与环境污染物结合性质之间的构效关系等方面的研究。特别是随着平流层臭氧空洞的增加,增强了到达地球表面的紫外线强度,研究紫外线增强对腐殖质和有机污染物的降解以及对生态系统的影响可进一步深刻理解太阳光辐射对污染物环境行为和归宿的影响。     

焦化厂多环芳烃污染场地的环境评价实证研究

通过实地调查某焦化厂污染场地污染现状,结果表明：该场地土壤和地下水以多环芳烃（PAHs）有机类污染为主,土壤中苯并（仅）芘和多环芳烃污染以1．5m以内表层土污染为主,随着深度的增加浓度逐渐降低,弱透水层表现出良好的阻隔作用。沿着地下水流动方向,地下水中多环芳烃浓度逐渐降低,经过约400m的迁移,由17296μg／L降至111μg/L;苯并（α）芘经过200m的迁移,由18．3μg／L降至0,地下水流动导致污染物在包气带横向扩散。1号孔、3号孔和4号孔所在地表层土壤中苯并（α）芘的单个污染物的致癌风险分别为0．0278、0．0209和1．496,远远超出可接受水平,因此上述孔位所在地附近表层土壤需重点治理。     

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。     

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.     

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.     

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。     

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.     

硝基芳香化合物的植物作用研究进展

硝基芳香化合物是环境中难以降解的污染物之一。因其用途广泛,大量残留于土壤,水体和大气中,造成的环境污染日趋严重。多种植物对该类污染物具有吸收、富集和代谢降解作用,利用植物对其环境污染进行治理是一种有效的方法。文章在总结国内外有关硝基芳香化合物的植物作用研究基础上,重点阐述了植物对硝基芳香化合物的吸收、转运和代谢过程,分析了吸收、代谢机理以及影响吸收的因素;硝基芳香化合物的理化特性、浓度和植物自身特性及其它外界条件都会影响植物对该类化合物的吸收,植物可以通过体内降解、体外联合代谢、根部释放酶催化的机制实现该类化合物的降解。目前,硝基芳香化合物进入植物细胞膜的机理认知不足,模拟模型缺乏有力数据验证;代谢机制中参与反应的酶、化合物等体系和反应产物环境特性仍不明确,植物修复可行性缺乏有力证据。未来将在模型预测构建、降解机理和修复工程的实际应用方面作进一步探究,以形成系统的认知,为硝基芳香化合物污染土壤和农产品的生态风险评价以及植物修复提供理论依据。     

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.     

Bioavailability of trace metals in brownfield soils in an urban area in the UK

Thirty-two brownfield sites from the city of Wolverhampton were selected from those with a former industrial use, wasteland or areas adjacent to industrial processes. Samples (<2 mm powdered soil fraction) were analysed, using inductively coupled plasma–atomic emission spectrometry (ICP–AES) for 20 elements. Loss on ignition and pH were also determined. A five-step chemical sequential extraction technique was carried out. Single leach extraction with 0.12 M hydrochloric acid of Pb, Cu and Zn in soil was determined as a first approximation of the bioavailability in the human stomach. Some of the sites were found to have high concentrations of the potentially toxic elements Pb, Zn, Cu and Ni. The partitioning of metals showed a high variability, however a number of trends were determined. The majority of Zn was partitioned into the least chemically stable phases (steps 1, 2 and 3). The majority of Cu was associated with the organic phase (step 4) and the majority of Ni was fractionated into the residue phase (step 5). The majority of Pb was associated with the residue fraction (step 5) followed by Fe–Mn oxide fraction (step 3). The variability reflects the heterogeneous and complex nature of metal speciation in urban soils with varied historic histories. There was a strong inverse linear relationship between the metals Ni, Zn and Pb in the readily exchangeable phase (step 1) and soil pH, significant at P < 0.01 level. There was a significant increase (P < 0.05) in the partitioning of Cu, Ni and Zn into step 4 (the organic phase) in soils with a higher organic carbon content (estimated by loss on ignition). Copper was highly partitioned into step 4 as it has a strong association with organics in soil but this phase was not important for the partitioning of Ni or Zn. The fractionation of Ni, Cu and Zn increased significantly in step 3 when the total metal concentration increases (P < 0.01). The Fe–Mn oxide fraction becomes more important in soils elevated in these metals, possibly due to the scavenging of metals by oxides. Cu and Pb extracted by HCl was statistically similar to the sum of the metals in steps 1 to 4 (P < 0.01) and HCl available Zn was statistically similar to the sum of Zn in steps 1 to 3 (P < 0.01). Step 4 (the organic phase) was not an important phase for Zn, so it was concluded that any Cu, Zn and Pb present in soil in a nonresidue phase would be potentially available for uptake into the human system once soil has been ingested.