土壤全氮的快速测定

本方法是过硫酸盐氧化消化样品的基础上测定土壤中全氮的光度法.采用碱性过硫酸钾溶液(0.37mol/L K_2S_2O_3,0.375N NaOH)消化土壤样品,然后用百里酚光度法进行测定,具有准确、灵敏、快速、简便等优点,适用于常规和大量样品的分析.     

连续流动分析仪测定环境水样中的硝酸盐氮

应用连续流动分析仪对环境水榈的NO3^--N进行了分析，简述了试剂浓度的确定原则和编写运行程度的方法。通过对标准样品的多次测定，测定值均在其保证值范围内，相对标准差为0．7％，准确度高，精密度好。方法检测限可达0.003mg/L NO3^--N，环境水样回标回收率在94％－102％之间，样品分析速率可达50个/h。     

水质凯氏氮标准样品的研究

提出了水质凯氏氮标准样品的研究方法。在研究过程中，完成了样品的配制、均匀性、稳定性等工作。经过多家实验室协作定值，确定了样品的标准值及不确定度，并提供使用。     

戴氏合金还原法同时测定废水中硝酸盐氮和亚硝酸盐氮

应用戴氏合金还原法测定废水中硝酸盐氮和亚硝酸盐氮。结果表明 ,对标准样品所测硝酸盐氮和亚硝酸盐氮的相对标准差分别为 2 8%和 2 0 %。废水样的加标回收率 ,硝酸盐氮和亚硝酸盐氮分别为 90 %～ 95 %和 96 %～ 10 0 %。     

气相分子吸收光谱法在海水无机氮测定中的适用性研究

为探究气相分子吸收光谱法在海水无机氮测定中的适用情况,在检出限的10～20倍、30～50倍、50～100倍3个浓度范围内开展了准确度、加标回收率和方法比对试验。结果表明,采用气相分子吸收光谱法测定海水亚硝酸盐氮(0～0.100 mg/L)、硝酸盐氮(0～0.400 mg/L)、氨氮(0～0.200 mg/L)时,标准曲线均具有很好的线性,线性拟合度均在0.999 3以上,检出限依次为0.000 8、0.004、0.004 mg/L,且该方法不具有盐效应,适用于海水样品的检测。当样品浓度太低时,气相分子吸收光谱法测定结果的准确度较低,因此,建议仅在亚硝酸盐氮浓度高于0.030 mg/L、硝酸盐氮浓度高于0.100 mg/L、氨氮浓度高于0.090 mg/L时使用该方法,对应的海域为河口及近岸等无机氮含量较高的海域。此外,为保证测定结果的准确度,每个样品需平行测定2～3次。     

安徽淮北矿区地表水氮的富营养化特征及来源解析

为探索淮北临涣矿区地表水体中氮的分布和来源,采集研究区河流和沉陷积水区样品,测试分析其水化学指标和氮、氧同位素特征值,并采用IsoSource模型计算不同端源氮的污染贡献率。结果表明:研究区地表水处于中度富营养化状态,矿区地表水中氮的输入源受含氮肥料、土壤有机氮和粪肥污水共同影响,所发生的硝化及反硝化作用微弱;矿区河水中氮的主要输入源为粪肥污水,贡献率达66.6%,沉陷积水区氮主要受含氮肥料输入的影响,贡献率达52.0%。     

土壤中全氮分析方法的研究进展

土壤中的氮是衡量土壤肥力的主要指标之一。基于对国内外文献的调研,系统地归纳了现阶段土壤中全氮分析方法(凯氏法、红外光谱技术、杜马斯燃烧法)的原理和应用。对不同的测定方法进行比较,总结不同分析方法的优缺点。提出自动化分析、高灵敏度、高准确度、低成本、便捷的检测技术是土壤中全氮分析的重要发展方向。     

连续流动分析用于总磷在线监测的可行性研究

以连续流动-钼酸铵分光光度法为基础,探究连续流动检测流程和蠕动泵泵速,建立总磷连续流动在线监测方法。该方法线性范围为0~2.00 mg/L,方法检出限为0.002 mg/L,方法相对标准偏差RSD为0.4%。将该法应用于实际水样测定,并通过加标回收率对分析结果进行验证,加标回收率为79.7%~109.4%,质控样品测定结果满足生态环境部标准样品研究所的误差允许范围,可用于地表水总磷在线监测。     

热分解法与紫外分光光度法测定总氮的方法比对

地表水中总氮测定方法按照《过硫酸钾氧化紫外分光光度法》(GB 11894-1989),该方法的前处理较为繁琐,人工耗时较长,对测定用的试剂、工具也有一定污染,给分析工作带来不便.TOC-VCPH总有机碳测定仪(简称热分解法),可以将样品中的氮化合物经过加热分解成为氨氮,通过再生成氮,转变为亚硝酸盐氮后,根据吸收峰值定量氮的质量,可以求出样品中总氮质量浓度.     

凯氏氮测定前处理方法的改进

根据GB11891-1989水质凯氏氮的测定方法，消解时以汞盐为催化剂，蒸馏时有黑色络合物产生，馏出液浑浊，影响分析结果，故改用硫酸铜溶液作为催化剂消解，效果较好，经过实验对比，可用于水质样品的分析．     

流式细胞术在水质检测领域的研究进展

流式细胞术作为一种新兴技术,具有检测快速简便、灵敏度高等优点,在水环境突发污染事件及水处理工艺的评价中正发挥着重要作用。随着荧光染色及配套技术的突破性发展,流式细胞术在水环境领域的研究和应用得到逐步拓展。笔者系统评述了流式细胞术检测原理及技术特点、水环境检测影响因素及其应用进展等,并对该技术在水质检测评价中的推广应用提出建议。     

流动注射分析方法概述

介绍了流动注射分析法在自动分析方面的应用及美国水和废水标准分析方法中的流动注射分析法。     

Characterization and source apportionment of water pollution in Jinjiang River, China

Characterizing water quality and identifying potential pollution sources could greatly improve our knowledge about human impacts on the river ecosystem. In this study, fuzzy comprehensive assessment (FCA), pollution index (PI), principal component analysis (PCA), and absolute principal component score–multiple linear regression (APCS–MLR) were combined to obtain a deeper understanding of temporal–spatial characterization and sources of water pollution with a case study of the Jinjiang River, China. Measurement data were obtained with 17 water quality variables from 20 sampling sites in the December 2010 (withered water period) and June 2011 (high flow period). FCA and PI were used to comprehensively estimate the water quality variables and compare temporal–spatial variations, respectively. Rotated PCA and receptor model (APCS–MLR) revealed potential pollution sources and their corresponding contributions. Application results showed that comprehensive application of various multivariate methods were effective for water quality assessment and management. In the withered water period, most sampling sites were assessed as low or moderate pollution with characteristics pollutants of permanganate index and total nitrogen (TN), whereas 90 % sites were classified as high pollution in the high flow period with higher TN and total phosphorus. Agricultural non-point sources, industrial wastewater discharge, and domestic sewage were identified as major pollution sources. Apportionment results revealed that most variables were complicatedly influenced by industrial wastewater discharge and agricultural activities in withered water period and primarily dominated by agricultural runoff in high flow period.     

恒压氮气隔断连续流动分析法测定水中化学需氧量

为建立恒压氮气隔断连续流动分析法测定水样化学需氧量的分析方法,将连续流动分析法恒流空气隔断改为恒压氮气隔断,优化试剂配方和反应模块,结果表明：恒压氮气隔断法注入氮气的压力是0.06 MPa,仪器稳定时间是20～35 min,持续分析样品时间大于4 h,指标均优于恒流空气隔断法;标准曲线在2.5～40.0 mg/L范围内,相关系数大于0.999,方法检出限为0.44 mg/L,相对标准偏差为0.2%～2.6%,加标回收率在93.8%～103.8%之间,检出限优于恒流空气隔断法,精密度和正确度满足质量控制要求;实样和标样方法比对测定结果相对标准偏差小于5%,结果精密度优于标准的手工法。恒压氮气隔断连续流动分析法适用于大批量低浓度水样化学需氧量的快速检测,对于密度大、黏度大液流恒压氮气隔断具有更好的稳定性、灵敏度和正确度。     

烟气排放连续监测技术的发展及应用前景

回顾了烟气排放连续监测系统及其分析技术的发展与应用历程,对直接测量法、抽取测量法和遥感测量法等3种主要连续监测技术的应用情况、技术特点进行了介绍和对比分析。指出烟气连续监测技术有由抽取测量法向直接测量法发展的趋势,进而向遥感测量法发展;分析技术则以光学技术为主导,向全谱分析和线状光谱技术方向发展;测量范围逐渐向低浓度发展,追求更高的准确度和精密度;监测因子更多,除常规烟尘、SO2、NOx外,CO2、H2S、HC l、HF、Hg等物质也将逐步纳入监测范围;技术可靠、系统简洁、操作简便是连续监测技术的发展方向,具有广阔的应用前景。     

连续流动分析法测定地表水中总氮

采用50 mm流动检测池,建立了连续流动分析法测定地表水中总氮。方法检出限为0.02 mg/L,水样加标回收率为100%~101%,平行样品相对偏差为0.10%~0.27%,精密度(RSD,n=6)为0.72%~1.10%。实验结果表明,该方法准确可靠、灵敏度高、重现性好、分析速度快、操作简便,适用于地表水中总氮的分析。     

全流稀释风道机动车排放颗粒物采集系统的集成及其流量控制和调节

以机动车排放颗粒物采集和分析为主要目的,开发了全流稀释风道机动车排放颗粒物采集系统.文章阐述了全流稀释风道的系统集成以及流量控制系统的设计和调节,其中包括设计应用范围、主要技术参数、系统检定等.流量控制系统采用的关键技术,即文丘里管组合装配方式具有控制流量范围广、变更灵活的特点,可以适应小到摩托车,大到重型柴油车等不同类型车辆检测的需要.     

跨界水体联合监测中总磷测定的问题探讨

研究了不同分析方法、去浊度手段和预处理方式对地表水总磷测定的影响。结果表明:钼酸铵分光光度法在跨界水体联合监测中较连续流动分析法、氯化亚锡还原光度法、孔雀绿-磷钼杂多酸分光光度法更为适用;在水样没有色度的情况下,采用浊度-色度补偿法和离心法都能有效消除浊度干扰,相对误差±10%;预处理方式的不同是导致各监测单位测定结果可比性差的最关键因素。     

Long-term monitoring of streambed sedimentation and scour in a dynamic stream based on streambed temperature time series

This study presented the monitoring and quantification of streambed sedimentation and scour in a stream with dynamically changing streambed based on measured phase and amplitude of the diurnal signal of sediment temperature time series. With the applied method, changes in streambed elevation were estimated on a sub-daily scale with 2-h intervals without continuous maintenance of the measurement system, thus making both high temporal resolution and long-term monitoring of streambed elevations possible. Estimates of streambed elevation showed that during base flow conditions streambed elevation fluctuates by 2–3 cm. Following high stream stages, scouring of 2–5 cm can be observed even at areas with low stream flow and weak currents. Our results demonstrate that weather variability can induce significant changes in the stream water and consequently sediment temperatures influencing the diurnal temperature signal in such an extent that the sediment thickness between paired temperature sensors were overestimated by up to 8 cm. These observations have significant consequences on the design of vertical sensor spacing in high-flux environments and in climates with reduced diurnal variations in air temperature.     

Groundwater geochemistry and identification of hydrogeochemical processes in a hard rock region, Southern India

Hydrogeochemical investigations were carried out in Chithar River basin, Tamil Nadu, India to identify the major geochemical processes that regulate groundwater chemistry. For this study, long-term (1991–1997) and recent water quality data (2001–2002) for 30 groundwater wells spread over the study area were used to understand the groundwater geochemistry and hydrogeochemical process regulating groundwater quality. Groundwater quality data obtained from more than 400 water samples were employed. Results of electrical conductivity and chloride express large variation between minimum and maximum values and high standard deviation, which suggests that the water chemistry in the study region is not homogeneous and influenced by complex contamination sources and geochemical process. Nitrate and depth to water table expose the influences of surface contamination sources, whereas dissolved silica, fluoride and alkalinity strongly suggest the effect of rock–water interaction. In the study region, weathering of carbonate and silicate minerals and ion exchange reactions predominantly regulate major ion chemistry. Besides, the concentrations of sulphate, chloride and nitrate firmly suggest the impact of agricultural activities such as irrigation return flow, fertiliser application, etc on water chemistry in the study region.