二氨基联苯胺分光光度法测定水质中硒的方法改进

采用3.3＇-二氨基联苯胺分光光度法对测定水质中硒的方法进行改进，主要研究了样品中硒的测定条件，通过对不同显色波长、酸碱度显色条件、显色剂用量、酸碱度比色条件的研究，得出比较理想的定量分析条件。采用该方法测定硒，显色稳定，准确度、精密度均能达到要求。     

实验室测定二氧化硫影响因素的探讨

空气中二氧化硫的测定对实验室测定条件比较敏感。通过实验表明显色时间、显色温度、PRA纯度、蒸馏水质量等实验条件均对其校准曲线的斜率和空白值有影响，所以在实验分析过程中，必须严格把握操作条件，严格遵循操作步骤。     

苯胺类标准曲线线性影响因素的探讨

温度和pH值对苯胺类测定中标准曲线的线性关系产生影响，在室温较低的条件下，只有通过改变温度条件，同时以酸度计作为调节pH的测试手段，方可产生良好的线性关系；显色所生成的紫红色物质稳定性良好，充分显色后的溶液，比色时间不会影响测定结果。     

异烟酸——吡唑啉酮显色液的改进

本文采用水代替二甲基甲酰胺溶解吡唑啉酮及以2％氢氧化钠溶液溶解异烟酸的混合溶液作显色液(简称改进显色液)以降低试剂毒性,作了某些条件试验,并对标准物质及电镀工业废水中氰作了对比测定,结果都较为满意。     

金属盐中硫化物分析方法的探讨

通过对金属盐类中的硫化物预处理及显色条件的探讨 ,证明在浓硫酸介质中气化 ,以 Na OH-EDTA为吸收液 ,用对氨基二甲基苯胺光度法测定 ,具有重现性好 (CV2 0 % ) ,测定周期短等特点。     

工业废水六价铬测定的前处理方法

工业废水中的六价铬,如用二苯碳酰二肼分光光度法直接显色测定,废水中的色度、有机和无机还原性物质、重金属离子等均干扰测定,为此需对水样进行前处理。 本文针对毛纺废水色度深的特点,采用活性炭脱色,以除去色度和一些有机物的干扰;对电镀、制革等行业的废水,用沉淀分离法将三价铬和六价铬分离后直接显色测定,或再经酸性条件下高锰酸钾氧化,破坏有机和无机还原性物质,过滤后显色测定。以上方法经实测和验证,结果较满意。     

总磷测定过程中的几点体会

地表水总磷测定中 ,样品消解时间通常需保持 3 0 min,通过进行缩短时间的试验 ,确认消解时间由 3 0 min缩短至 1 0 min,总磷测定结果符合要求。水中总磷测定时 ,标准系列需加 4ml5 % ( m/v)过硫酸钾溶液消解 0 .5 h,对校准曲线制备方法进行改进 ,省略了加热氧化操作步骤 ,样品测定结果无显著差异。地表水总磷测定中显色温度对显色时间存在很大影响 ,而且它们之间存在着一定的线性关系 ,经对低浓度水样进行显色试验 :在室温 1 5℃时 ,显色时间需 1 5 min,显色持续时间可达 3 0 min;而在室温 3 0℃时 ,显色时间仅需 5 min,显色持续时间为 2 0 …     

甲醛法测定二氧化硫问题研究

《环境监测技术规范》(简称“规范”),《环境空气监测质量保证手册》(简称“手册”),对斜率控制范围均作了明确规定。但在实际工作中,有时会出现校准曲线斜率不在规定范围的情况。出现这种情况是标准溶液、试剂质量或操作人员的问题呢?还是其它原因?其次,在SO_2的测定中,其显色条件要求温度控制在20±2℃,显色15min进行测定。这对于在夏季     

用正交试验确定游离性余氯最佳测定条件

在用DPD光度法测定水中余氯时，对水样的pH值、显色时间、显色剂用量和反应温度进行了研究，通过正交试验系统地分析了各因素影响测定结果准确性的程度，并获得最佳的反应条件，表明在该条件下测定水中余氯的准确性优于其他条件下测定的结果。     

氰化物分析中显色后稀释测定方法

氰化物分析中显色后稀释测定方法陈勤，厉莲（江苏扬州市环境监测站，扬州２２５００２）用异烟酸－吡唑啉酮光度法测定水中氰化物，对显色后才知其浓度已超出标准曲线线性范围的样品，无须重新取样测定，只须用零浓度空白管内显色后的试液作为稀释液对显色后样品进行稀释...     

Chemical characterization of blue stains in domestic fixtures in contact with drinking water

Bluish green staining in domestic fixtures was observed in three to 9-year-old houses in the city of Talca, located 256 km. south of Santiago, the capital of Chile. The houses contained copper pipes which were exposed to soft well water, with low pH and low buffer capacity. The aim of this paper is to establish the chemical composition of the stains and to determine the conditions by which they were formed. X-ray diffraction analysis of the stains revealed the presence of malachite, a copper compound that caused green coloring in kettles and water boilers. Dioptase, which is deep green in coloring, was identified in a bathtub tile. In one house, where blue stains were found in a toilet bowl, the presence of chrysocolla was suggested by means of X-ray fluorescence. In the field conditions studied it was concluded that the bluish green stains in bathroom home appliances were generated by the precipitation of copper compounds in places were leakages occur.     

砷化氢-钼蓝光度法测定环境样品中砷

介绍了用砷化氢 -钼蓝光度法测定水质、土壤和沉积物样品中砷 ,对测定条件中的砷化氢反应时间、显色酸度、碘 -碘化钾溶液用量、钼酸铵用量和干扰物质等进行了试验。方法检测限为 7μg/L ,平均回收率在 97%～ 10 5 %之间 ,相对标准差为 2 5 % ,摩尔吸收系数为 2 4× 10 4 。     

Application and evaluation of kriging and cokriging methods on groundwater depth mapping

Groundwater and water resources management play a key role in conserving the sustainable conditions in arid and semi-arid regions. Applying some techniques that can reveal the critical and hot conditions of water resources seem necessary. In this study, kriging and cokriging methods were evaluated for mapping the groundwater depth across a plain in which has experienced different climatic conditions (dry, wet, and normal) and consequently high variations in groundwater depth in a 12 year led in maximum, minimum, and mean depths. During this period groundwater depth has considerable fluctuations. Results obtained from geostatistical analysis showed that groundwater depth varies spatially in different climatic conditions. Furthermore, the calculated RMSE showed that cokriging approach was more accurate than kriging in mapping the groundwater depth though there was not a distinct difference. As a whole, kriging underestimated the real groundwater depth for dry, wet, and normal conditions by 5.5, 2.2, and 5.3%, while cokriging underestimations were 3.3, 2, and 2.2%, respectively; which showed the unbiasedness in estimations. Results implied that in the study area farming and cultivation in dry conditions needs more attention due to higher variability in groundwater depth in short distances compared to the other climate conditions. It is believed that geostatistical approaches are reliable tools for water resources managers and water authorities to allocate groundwater resources in different environmental conditions.     

对比分析法在环境空气质量预报业务中的应用

通过分析京津冀及周边区域环境空气质量预报的实际案例,从实时监测、污染源、大气条件以及数值预报模拟4个方面阐述了对比分析法在空气质量预报业务中的应用,帮助预报员比较类似污染源排放条件下的大气条件变化或者类似大气条件下的污染源变化,以便进一步开展量化分析。研究结果显示:利用时间同比、空间比较和大气条件对比的分析方法,能够判断在类似污染源排放和相似大气条件下,主要污染物的浓度水平、重污染发生、影响范围、持续时间、严重程度等污染特征以及污染物的水平传输影响等;采用污染源变化对比分析法,能够获得在类似大气条件下,污染源排放的减少或剧增对主要污染物浓度水平的影响程度;通过数值预报模式结果对比分析,能够获得在类似的污染源排放条件下,大气环流形势的稳定程度和变化情况,从而判断其对污染物浓度水平的影响。对比分析法是开展京津冀及周边区域环境空气质量预报业务中的重要环节,有利于持续提高空气质量预报的准确率,供全国空气质量预报员开展辖区空气质量预报时参考。     

复杂岩溶条件下锰矿尾矿库地下水溶质运移特征数值模拟研究

受构造、地层等复杂地质情况综合影响的岩溶地区地下水,其溶质运移及流场模拟向来是水文地质、环境地质研究中的难点。以贵州省松桃县某锰矿尾矿库为例,在充分分析研究区周边水文地质、环境地质条件的基础上,建立地质模型,概化边界条件,利用有限元软件FEFLOW进行流场拟合。在此基础上,模拟特征污染物锰及氨氮的弥散情况。模拟结果表明,在不做任何防渗处理的情况下,特征污染物将在F201断层、地层产状等边界条件的影响下汇入地下暗河,最终流入地表水系及地下水系,流向东部的松江河。因此,必须对锰矿尾矿库采取防渗措施,从而降低其对地下水、地表水的污染风险。     

Effects of environmental conditions on historical buildings: lichens and NOx gases

Environmental conditions affect human life in various ways. One of the domains of environmental conditions is buildings, and amongst them, a major and important group is the historical buildings. To keep this inheritance alive, one needs to determine the effects of environmental conditions. In this work, effects of lichens and NOx on 7 historical buildings in Erzurum were investigated. Historical buildings are readily available for lichen growth, which takes a long time, and this growth was investigated as a sample of environmental effect that occurs through long periods of time. NOx, main source of which is traffic in Erzurum, were considered as the environmental effect of daily life.     

Comparison of two dynamic measurement methods of odor and odorant emission rates from freshly dewatered biosolids

Odor and odorant emission rates from freshly dewatered biosolids in a dewatering building of a Water Reclamation Plant (WRP) are measured using the EPA flux chamber and wind tunnel methods. Experimental results are compared statistically to test whether the two methods result in similar emission rates when experiments are performed under field conditions. To the best of our knowledge the literature is void of studies comparing the two methods indoors. In this paper the two methods are compared indoors where the wind velocity and air exchange rate are pertinent field conditions and can be measured. The difference between emission rates of odor and hydrogen sulfide measured with the two methods is not statistically significant (P values: 0.505 for odor, 0.130 for H(2)S). It is concluded that both methods can be used to estimate source emissions but selection of the most effective or efficient method depends on prevailing environmental conditions. The wind tunnel is appropriate for outdoor environments where wind effects on source emissions are more pronounced than indoors. The EPA flux chamber depends on the air exchange rate of the chamber, which simulates corresponding conditions of the indoor environment under investigation and is recommended for estimation of indoor pollution sources.     

餐饮业油烟排放监测模拟工况研究

在现行《饮食业油烟排放标准(试行)》(GB18483—2001)的执行过程中,工况难以控制,影响监测结果的准确性。在对不同餐饮业的主要烹饪方式(炸、煎、煮、炒)餐饮油烟的初始排放浓度进行实测的基础上,模拟出和以上4种烹饪方式相匹配的工况,分析各种类型餐饮业不同工况下的油烟排放规律,建立了一组能够由监测人员主动控制的油烟监测模拟工况。     

厂界无组织排放监测气象条件判定及布点问题对策研究

通过对现有技术要求的分析,指出大气污染物无组织排放监测主要技术依据中气象条件判定和监控布点存在监测时段选择不合理、条件设置不具代表性和不具可操作性等问题和难点。对此提出了相应对策,指出可通过滑动计算相关数值的方式将气象和监控布点设置条件扩展至监测全过程,使用气象条件和点位判定系统来解决上述问题和难点。对技术依据中未规定的多点和区域无组织排放源的有效监控区域确定提出了解决思路,探讨了监测全过程监控点位有效性的评价方式。通过实施示例对提出的对策进行了说明。     

空气质量监测中标准状态对测定结果的影响及建议

环境空气质量标准中各种污染物的浓度限值是评价、考核空气质量状况的基本依据。为了保证在不同时空、不同环境状况下监测数据的可比性,各个国家或组织在制定的空气质量标准中对标准状态(温度和压力)进行了定义。但是,由于标准状态定义不同,即使是同一环境状况下的同一实测结果进行标化计算后的污染物浓度也不相同,达不到可比性的基本原则。因此,建议中国在未来修订空气质量标准所采用的标准状态,进一步与国际接轨。