基于大型无脊椎动物完整性的赤水河健康评价体系构建

作为长江上游珍稀鱼类国家自然保护区的核心区,赤水河流域水系的健康状况虽颇受关注,但相关评价工作却较少。笔者结合现场调查(2016年)和历史数据(2007年),初步构建基于大型无脊椎动物群落的健康评价体系,对赤水河干流和部分支流的不同季节(春季和秋季)和不同河段(上中下游)的健康状况进行评估。指标筛选结果显示:赤水河上游河段在春季和秋季分别包括6、2个核心参数,中游河段分别包括5、4个,下游包括3、2个核心参数。通过四分法将健康状态划分为4个等级:健康、亚健康、一般和不健康。从整体上看,赤水河处于亚健康状态,且春季和秋季河流不同采样点健康状况有所差异,春季健康状况好于秋季。回归分析显示,BOD_5、COD_(Mn)以及NH~+_4-N是影响赤水河健康的主要环境因子。研究所构建的B-IBI评价指标较好地评估了赤水河的健康状况,可作为赤水河流域水体环境监测的有效手段之一。     

河流生态环境健康评价技术体系构建及应用

科学合理的河流生态环境健康评价体系不仅能够客观真实地反映河流的生态环境状况，还能为河流管理者提供决策依据，指明管理方向。基于国内外河流健康评价经验，构建了以水环境、水生态和水资源“三水”为系统层，包含水质、富营养化、水生生物、生境状况和水资源5个指标层的河流生态环境健康评价体系。将层次分析法和综合评估方法相结合，计算河流健康得分。以大运河(天津段)为例，评价结果显示，大运河(天津段)总体评价结果为中等水平。该评价体系考虑了多项影响河流生态功能的指标，能够客观真实地反映河流生态健康状况，同时能够为河流管理提供基础数据和决策依据。     

成都市河流生态健康评价

研究以成都市域内河流为研究对象,通过采样分析得到水质、生境状况、浮游藻类、底栖动物等相关指标,利用综合指标体系法,评价成都市域内河流生态系统健康状况,并结合成都市人口、土地利用、地区生产总值等因素分析人类活动与河流生态健康的关系。结果表明:成都市河流浮游藻类以硅藻和绿藻为主,部分中下游采样点出现以蓝藻为主的情况;底栖动物以指示有机污染的颤蚓科出现的频率最高,约48%的采样点以颤蚓科为优势种;约74%的河流生态健康状况为"差"或"很差",河流生态健康状况整体呈现中上游优于下游、城市周边优于市区的特征;人口密度、人类活动用地比例与河流中氨氮呈显著正相关,人类活动会显著影响河流生态系统健康。     

成都府南河叶绿素a和氮、磷的分布特征与富营养化研究

通过对成都市府南河上中下游共21个断面叶绿素a和总溶解态氮(TDN)、总溶解态磷(TDP)含量的测定,绘制时空分布图,并应用SPSS 13.0统计软件分析了3个指标之间的相关性,初步评价了府南河的富营养化状况。结果表明,府南河叶绿素a含量不高,磷污染较为严重;相关性分析显示叶绿素a和TDP含量呈显著正相关关系,氮是河水富营养化的主要限制因子;按照叶绿素a的含量判定府南河基本属于贫营养化型,但按照氮、磷含量评价已达到富营养化水平。这对评价城市河流的富营养化状态及生态环境整治和恢复有着积极意义。     

河流水生态环境质量评价方法研究与应用进展

河流生态质量的监测和评价是从河流生态系统健康状况的角度对河流质量进行的评价。河流生态健康的评价已经向多要素多指标综合、多种评价方法(预测模型法、生物完整性指数、多要素综合评价)、流域尺度方向发展。该文重点介绍了国外评价体系产生的背景和研究基础,分析了广泛应用的几类评价方法的特点、在不同国家和流域的应用情况以及各方法的应用前景,分析了国内开展河流生态质量评价研究的发展过程、阶段性研究进展和应用案例,并根据目前研究基础评述了我国评价体系现存问题及应用前景,为河流生态质量评价体系的建立及发展方向提供建议和参考。     

萍水河水质监测点的优化

城市内河流水质监测点位的优化,是全面掌握河流水质状况的关键。文章采用贴近度法对萍乡市萍水河2005—2015年水质及监测点位变化进行分析评价,并提出优化建议。根据萍水河水质污染特征,选择化学需氧量、五日生化需氧量、氨氮、总磷、总氮和高锰酸钾盐指数作为评价指标,结果表明:2005—2015年,萍水河水环境质量整体情况较好,但在2010年后呈下降趋势;监测点布设方案的调整有一定合理性,也有欠妥之处;对目前监测点位进行删减,得到了水质优化监测布点方案。     

基于多级灰关联法的博斯腾湖水生态健康评价

采用生态系统健康结构和功能指标建立了由物理化学指标体系、生态指标体系2个二级指标体系组成的生态系统健康评价指标体系。将多级灰关联理论引入系统综合评价之中,采用多级灰关联评价方法和综合营养状态指数评价方法相结合,对博斯腾湖自2001年以来水生态健康变化情况进行了综合评价与分析。评价结果显示,自2001年以来博斯腾湖的生态系统健康状态总体情况为中等,自2007年以来生态系统健康综合指数呈一定的下降趋势,并找出了导致水环境恶化的主要原因。     

珠三角典型河道49种抗生素污染现状及风险评估

为评估抗生素在珠三角地表水中的生态及健康风险,在石岐河布设20个监测点位,分别采集丰水期和枯水期样品,用固相萃取/超高效液相色谱-质谱法对4大类共49种抗生素进行检测。结果显示,在丰水期和枯水期样品中共检出抗生素30种,检出种类和抗生素总浓度都呈现出枯水期明显大于丰水期的现象。从总量上看,喹诺酮类是影响石岐河生态环境安全的主要抗生素类别。石岐河抗生素浓度在枯水期主要受污水处理设施出水的影响,在丰水期主要受沿岸养殖业排水的影响。采用风险熵法对生态风险进行评估,发现枯水期生态风险高于丰水期,头孢匹啉、克林霉素、诺氟沙星3种抗生素处于高生态风险级别,罗红霉素、磺胺二甲异恶唑和奥索利酸3种抗生素处于中等生态风险级别,另有4种抗生素处于低生态风险级别,应引起重视。采用健康风险评价模型对人群健康风险进行评价,发现石岐河抗生素致癌风险和非致癌风险皆处于可接受的健康风险范围内。     

基于模糊综合模型的湿地沉积物重金属污染评价

应用模糊综合-加权模型,以及温州市3个典型湿地沉积物中7种重金属含量数据,对温瑞塘河重金属污染进行评价。模糊综合评价结果表明,温州市居民区河流三垟湿地沉积物属于Ⅴ级重金属污染水平,主要污染元素为Zn和Cd;山前上游河段卧龙河沉积物为Ⅲ级污染,主要污染物是Cd。工业区河流牛桥底河沉积物虽然也是Ⅴ级,但是Cu、Cr、Ni、Zn和Cd 5种重金属污染分值为1.0,小于前2个典型河段的1.2和3.3。内梅罗指数法和潜在生态危害系数法评价结果显示,沉积物的重金属污染程度为牛桥底河三垟湿地卧龙河,这与模糊综合评价结果相符。     

广东省某河段健康状况调查、监测与评价

为掌握河流健康状态，精准施策，研究组按照目标层、指标层及准则层逐层加权的方法，从“盆”、“水”、生物、社会服务功能对广东省某河段健康状况进行调查、监测与评价。最终赋分77.67,形态结构完整性、水生态完整性与抗扰动弹性、生物多样性、社会服务功能可持续性等方面良好，处于健康状态；部分指标如“生态流量满足程度”的赋分过低，应加强区域生态环境需水量的研究，并制定科学合理的取用水规划和管理措施。     

锅炉烟尘测试中锅炉负荷率的计算方法探讨

GB5468 -91规定 ,锅炉烟尘测试时 ,必须对锅炉的运行负荷进行测试 ,而实际监测过程中 ,许多锅炉房不具备测试的计量条件 ,为了解决这一问题 ,文章提出利用烟气量和空气过剩系数计算锅炉负荷率。在实际监测工作中 ,该方法方便、易于操作 ,所得结果和标准规定方法所得结果有很好的一致性     

城市空气质量周报效用分析

介绍了世界上一些发达国家的空气污染预报的做法和采取的措施,阐述了我国开展空气质量预报的方针和方法,指出了周报是预报的基础工作。叙述了我国空气质量周报的污染参数的选取、污染指数的分级及其浓度限值和污染指数计算及确定,分析并总结了开展城市空气质量周报所发挥的效用是提高公众的环保意识,加大了治理污染的力度,转变了环境监测的职能,促进了环境监测事业的发展     

水中总硬度测量不确定度的评定

采用EDTA滴定法测定水质总硬度的测量不确定度评定。充分考虑测量重复性、标准溶液的配制、滴定等过程对测量的影响,计算水中总硬度的测量相对合成标准不确定度为1·81×10-3。     

贵州黔东南州三板溪水库春季拟多甲藻水华特征

2011年3月13日对贵州省黔东南州三板溪水库进行春季浮游植物调查的结果表明,三板溪水库Ⅱ号采样点(下革东)发生以佩纳形拟多甲藻为优势种的拟多甲藻水华,细胞密度高达1.15×10⁷cell/L;板溪水库总氮的最低值为2.09 mg/L,总磷的最低值为0.95 mg/L,三板溪水库的总氮、总磷含量较丰富,不存在总氮或总磷是限制性因子;通过SPSS16.0统计软件分别进行Pearson 积距相关系数分析表明,氮磷比是三板溪水库发生拟多甲藻水华的主要影响原因。     

Environmental Assessment of the Impact of Ozone to the Neuston of the Sea-Surface Microlayer of the Gulf of Mexico

Substantial amounts of NOx (146 000 t/y) and total hydrocarbons (294 000 t/y) are released to the marine atmosphere by the large number of oil and gas operations over Federal waters of the Gulf of Mexico (GOM). Under appropriate meteorological conditions these emissions react to form ozone (0–54 g/m3 over-water) which can affect the marine environment. Using a dry deposition model, this work examines the amount of ozone derived from oil and gas offshore operations and deposited in the sea surface of the Gulf of Mexico, and assesses its impact on the neuston of the sea-surface microlayer. Surface integrated estimates of ozone deposited from oil and gas operations over the sea surface ranges from 400 kg to 1800 kg which results in sea surface concentrations of 15 g/m3. This estimate and the actual toxic ozone levels suggest no acute, toxic impacts to the neuston. However, indirect effects may occur through changes to the pelagic foodwebs and organic carbon pathways. Another potential pathway for ozone impacting the environment is through the production of bromate. Based on the concentrations and time scales (11–139 days) only sublethal effects appear to occur, but uncertainties associated with this assessment need to be further studied. From an ecological perspective, the environmental impacts and risks of NOx and VOC discharges from offshore platforms need to be assessed for neuston and other components of the marine ecosystem.     

二乙氨基二硫代甲酸银试剂质量对测砷的影响

用简单合成了二乙氨基二硫代甲酸银试剂，并比较了自制和市售的二乙氨基二硫人 银对测砷的影响。结果表明，采用自制的二乙氨基二硫代甲酸银能大大降低试剂空白，提高方法的灵敏度和降低检出限，试剂质量明显优于市售产品。     

氨氮测量不确定度的评定

采用纳氏试剂光度法测定水质氨氮的测量不确定度评定,应该考虑工作曲线、测量重复性、标准溶液、仪器读数分辨率等对测量的影响.     

Fractionation of heavy metals and assessment of contamination of the sediments of Lake Titicaca

Chemical weathering is one of the major geochemical processes that control the mobilization of heavy metals. The present study provides the first report on heavy metal fractionation in sediments (8–156 m) of Lake Titicaca (3,820 m a.s.l.), which is shared by the Republic of Peru and the Plurinational State of Bolivia. Both contents of total Cu, Fe, Ni, Co, Mn, Cd, Pb, and Zn and also the fractionation of these heavy metals associated with four different fractions have been determined following the BCR scheme. The principal component analysis suggests that Co, Ni, and Cd can be attributed to natural sources related to the mineralized geological formations. Moreover, the sources of Cu, Fe, and Mn are effluents and wastes generated from mining activities, while Pb and Zn also suggest that their common source is associated to mining activities. According to the Risk Assessment Code, there is a moderate to high risk related to Zn, Pb, Cd, Mn, Co, and Ni mobilization and/or remobilization from the bottom sediment to the water column. Furthermore, the Geoaccumulation Index and the Enrichment Factor reveal that Zn, Pb, and Cd are enriched in the sediments. The results suggest that the effluents from various traditional mining waste sites in both countries are the main source of heavy metal contamination in the sediments of Lake Titicaca.     

Evaluation of method of preparation of passive diffusion tubes for measurement of ambient nitrogen dioxide

This study was carried out in response to suggestions that the measurement of NO(2) by Palmes-type passive diffusion tubes (PDT) is affected by the method of preparation of the triethanolamine (TEA) absorbent coating on the grids. The following combinations of factors were investigated: TEA solvent (acetone or water), volume composition of TEA in solvent (50% or 20%), and grid coating method (dipping in solution prior to assembly or pipetting solution on after assembly). Duplicate PDTs prepared by each of the 8 methods were exposed in parallel, in urban air, for a total of 80 separate 1 week exposures. NO(2) concentrations derived from PDTs prepared by pipetting methods were significantly less precise than concentrations from dipping methods, with mean RSDs for duplicate measurements of 13.8% and 8.5%, respectively (n= 316 each category). Pipetting methods using solutions of 50% TEA composition were particularly imprecise (mean RSD 17.2%). Data from PDTs prepared by pipetting methods were systematically more poorly correlated with each other and with data from co-located chemiluminescence analysers, than corresponding data from PDTs prepared by dipping methods, indicating that more consistent accuracy was also obtained by the latter PDTs. The statistical evidence suggested that PDTs prepared by pipetting 50% TEA in water generally gave lower NO(2) concentrations. Although this is in agreement with a previous study, it is also possible that such an observation here may be a statistical artefact given the demonstrably poorer precision of this method. The general tendency of PDTs to show positive bias in NO(2) measurement in urban air in 1 week exposures was again evident in this study (mean biases at roadside and urban centre locations of +35% (n= 475) and +18% (n= 112), respectively) consistent with augmentation of within-tube NO(2) flux by chemical reaction between co-diffusing NO and O(3). Overall, it is recommended that the pipetting method of PDT grid preparation is avoided, or at least investigated further, because of the apparent degradation in precision and accuracy of NO(2) measurement. Potential reasons for the effect are discussed.     

污染物总量控制中载体水流量的测定

示踪剂法测定河水流量是较为准确的办法 ,利用河流动力模型计算出示踪剂投放点 ,利用示踪剂投放量与测定浓度之间的关系可方便地获得河水流量结果