用高浓度苯酚贮备液省略标定过程的探讨

采用精确称量苯酚制高浓度贮备液，可省略标定过程，并能获得准确的分析结果。     

亚硝氨标准贮备液浓度确定方法的改进

采用亚硝酸钠标准试剂干燥后直接配制确定贮备液浓度,代替亚硝酸钠标准贮备液标定法,可省时、省力、减少标准液污染环节,并能满足环境监测分析质量要求.     

垃圾渗出液中酚类物质的气相色谱分析

建立了一种用气相色谱法准确、快速测定垃圾渗出液中酚类物质的新方法。外标法定量分析 4 -甲基苯酚及苯酚。采用填装了 80～ 1 0 0目 Chromosorb WAW DCMS的玻璃填充柱 ,担体上涂渍了 2 % OV-1 7,2 .5% QF-1的固定液 ,分离酚类物质效果较好 ,线性范围为 1 0 0～ 1 50 0 mg/ L,相关系数为 0 .9996,方法回收率为 94 .7%。     

假丝酵母菌对高浓度苯酚的降解效果及SDS对其生长影响

从含酚废水处理池污泥中驯化得到苯酚降解菌——假丝酵母菌FD-1,通过试验考察FD-1对高浓度苯酚废水的降解效果,以及十二烷基磺酸钠(SDS)对高浓度苯酚废水中FD-1菌株生长的影响。试验表明,假丝酵母菌FD-1对苯酚的最大降解质量浓度为1 500 mg/L,降解时间为30 h。当苯酚质量浓度不超过1 000 mg/L时,添加适量的SDS可以显著提高苯酚降解速率,进而缩短苯酚降解时间,SDS的最佳投加量为100 mg/L,超过150 mg/L时FD-1生长受到抑制。     

中性高锰酸钾贮备液稳定性探讨

对不同温度下的高锰酸钾贮备液进行多次定量稀释并标定,实验结果表明,高锰酸钾浓度基本不变。     

中性高锰酸钾溶液稳定性研究

不同温度条件下,多次将高锰酸钾贮备液进行定量稀释并标定,发现其浓度基本不变,稳定性较好。     

在线液膜萃取富集流动注射分光光度法测定水中痕量对硝基苯酚

介绍了选用无毒性的磷酸三丁酯为流动载体,煤油为膜溶剂的支撑液膜萃取体系,建立了支撑液膜在线萃取富集流动注射分光光度法测定水中痕量对硝基苯酚的新方法。通过对实验条件的优化选择,得出该方法的检测限为0．002mg／L,线性范围为0．005mg／L～0．05mg／L。该方法应用于废水中对硝基苯酚的检测,结果满意。     

苯酚标准溶液的稳定性探讨

通过对苯酚标准溶液(浓度10μg／m^3)经过实验发现在一定条件下至少可稳定100d,无需使用当天配制．     

H103大孔树脂吸附苯酚性能研究

通过静态吸附试验,研究了不同条件下H103大孔树脂对水中苯酚的吸附性能。结果表明,树脂对水中苯酚的吸附速率较快,60min内基本达到平衡。树脂对水中苯酚的吸附量随其初始浓度的增加而增加,并呈线性关系。Freundlich模型能很好地描述H103大孔树脂对苯酚的吸附性能。动态处理某精细化工含酚废水结果表明,在室温下,固定床流速为3BV/h时,水中苯酚去除率接近91.9%,CODcr去除率≥69.3%。采用5%NaOH再生,再生率为86.5%,实现了酚的回收。     

硫化钠标准溶液稳定性试验报告

硫化钠标准溶液的不稳定性增加了硫化物测定的困难和费时。每ml含1mg硫的贮备液,实践证明不能久贮,在贮存一定时间后,且可以出现因氧化、聚合等作用而导致下述现象:若用碘量法测定尚有一定浓度,但稀释成使用液后,出现加显色试剂不显色,或所显色泽不是亚甲兰色而是紫红色。由贮备液稀释成使用液后,即时显色和相隔七小时后显色就存在明显差异,若硫化物浓度在4.0～40.0μg范围内,吸光度降低可达7～30％。 文献记载硫化钠标准溶液用除气过的稀醋酸锌溶液来配制的比单独用除气过的水配制来得稳定,所用醋酸锌浓度为0.05％(W/V)左右。本实验以亚甲兰法为测定方法,探讨用稀醋酸锌溶液配制的硫化钠标准使用液的均匀性和稳定性。     

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。     

实验室质量管理体系内部审核的实施

在实施GB/T15481-2000 idt ISO/IEC17025:1999标准《检测和校准实验室能力的通用要求》的过程中,通过实验室质量管理体系内部审核的实践与系统分析,识别出内部审核实施阶段的关键环节,提出召开首次会议、收集审核证据、确定审核发现和召开末次会议的技术方法,对提高内部审核的质量和有效性、获得可靠的审核结论具有重要意义。     

“湖泛”恶臭物质分析及来源浅析

介绍了中国南方"湖泛"中的恶臭物质及检测情况,采用常规分析和气相色谱-质谱(GC-MS)对"湖泛"水样进行检测,认为"湖泛"恶臭物主要是氨和硫醚类物质。根据"湖泛"发生的时间及频次,结合南方地区农业水稻秧田的农药使用情况,推断氨基甲酸酯类农药的使用可能是"湖泛"发生的诱因。     

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.     

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.     

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.