高氯离子废水COD的吸收测定方法研究

本法基于可定星测定Ｋ２Ｃｒ２Ｏ７和Ｃｌ－的反应产物Ｃｌ２这一原理，在用吸收装置吸收Ｃｌ２后．用碘量法测定余氯，从而消除氯离子的干扰。本法具有较高的准确度和精密度。     

对饮用水中游离性余氯测定条件的研究

系统研究了反应时间、水温、显色剂的用量及pH对游离性余氯测定的影响,优化选择最佳测定条件为控制水样pH<8,水温25℃,显色剂用量2.5 ml,加入显色剂后立即比色测定游离性余氯。在此条件下,测定3种生活饮用水游离性余氯,回收率为96.7%~99.8%,测定结果与《生活饮用水标准检验法》(GB 5750-85)中37.3滴定法颇为一致。     

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。     

氢化物发生——原子吸收法测定人发中砷

应用自制氢化物发生才电加热石英管原子吸收仪测定人发中砷。用硝酸－高氯酸进行消解，加入碘化钾溶液、抗坏血酸－硫脲混合液，消除了各种元素的干扰。方法简便快速、灵敏度高。发样砷的方法检测限为０．０３ｍｇ／ｋｇ，相对标准偏差在２．５％以内。     

选择双波长分光光度法测定水中余氯

余氯在pH6.5条件下与PADA发生显色反应,本文根据稳定悬浮颗粒对光的吸收行为研究选择波长测定水体中余氯,实验证明在450～515nm波长范围内任意选择两波长比色按照推导公式和模型计算余氯浓度,测定方便结果准确,且计算模型稳定,几乎不受操作环境影响。适合于废水和天然水的监测。     

溴百里酚蓝测定水中余氯的方法研究

提出了测定水中余氯的一个新方法.余氟将溴百里酚蓝氧化而褪色,在碱性介质中为蓝色.λmax=616nm,ε=9.17×104L/mol·cm.检出限(4.6SD)为0.6mg/L.用于测定自来水中余氯,相对标准偏差为1.76%,加标回收率为97.22%～104.2%.     

火焰原子中收光度法测定汽油中铅

用一氯化碘萃取汽油样中听铅,加入过量碘化钾,生成碘化铅络合物,以抗坏血酸还原碘,再用甲基异丁基甲酮反萃取碘络合物,以空气－乙炔火焰原子吸收分光光度法测定。检测限为０．２９１ｍｇ／Ｌ。     

停流──诱导动力学光度法测定微量钒

Ｃｒ（Ⅳ）－Ⅰ－淀粉体系的氧化还原反应可被Ｃｒ（Ⅳ）－Ｖ（Ⅳ）反应所诱导，本文据此提出了一种测定微量钒（Ⅳ）的停流－诱导动力学光度法，并建立了测定最佳条件。常见离子中，除Ｆｅ２＋，Ｔｒ１＋，Ｓｅ４＋，Ａｓ３＋以外，大部分不干扰测定。本法测定钒（Ⅳ）的线性范围为０～１．８μｇ／ｍｌ；测定了土壤中微量钒，六次测定的ＲＳＤ＝２．４５％。     

DPD分光光度法测定水中游离余氯的探讨

采用DPD分光光度法测定水中的游离余氯，验证了用高锰酸钾替代氯制剂配制标准溶液的有效性，方法在0 mg/L～0.800 mg/L范围内符合朗伯-比尔定律，检出限为0.01 mg/L。使用次氯酸钠标准体系和高锰酸钾标准体系分别测定废水样品及其加标样，并用硫酸亚铁铵滴定法作比对验证，结果显示3种方法具有可比性。     

碘淀粉比色法测定环境样中微量碘

试验了碘的倍增反应用于微量碘的测定，用淀粉指示剂显色，最大吸收峰位于６２０ｍｍ，摩尔吸光系数可达１×１０５Ｌ·ｍｏｌ－１·Ｃｍ－１．０～６μｇ碘／１０ｍｌ符合比耳定律，可用于盐湖水、矿泉水、油田水和食盐、海产品中微量碘的测定．     

水中余氯测定方法进展

综述了水体中余氯的分析方法研究进展,对每种分析方法的原理、测定条件、干扰因素及其消除方法、检测限、线性范围及应用对象做了较为详细的论述。     

膜分离紫外光度法连续测定二氧化氯的应用

利用 Cl O2 能透过微孔性聚四氟乙烯膜 (PTFE)而制成 Cl O2 连续流动分离装置 ,建立了膜分离紫外光度法连续测定二氧化氯的测试方法。用此方法测定江苏某水厂净水流程线上各采样点的二氧化氯浓度 ,并对测定结果进行显著性检验 ,确定当水中二氧化氯浓度大于或等于 0 .0 8mg/ L时 ,此方法与美国 Vulcan公司推荐的连续碘量法无显著性差异     

气相分子吸收光谱法测定海水中氨氮的干扰因素识别及预处理方法研究

采用气相分子吸收光谱法测定海水样品中的氨氮,重点考察海水中共存离子对氨氮测定结果的影响规律,识别测定过程中主要的干扰因素,并提出消除干扰的预处理方法.研究结果表明,碘离子会对氨氮的测定产生负干扰,当样品中碘离子质量浓度达到0.0765 g/L时,氨氮的测定结果与标准值相比明显降低,且在碘离子质量浓度达到0.1910 g...     

测定游离氯和总氯样品保存方法研究

建立了游离氯和总氯样品保存方法。用氢氧化钠溶液作为固定剂,现场固定含有游离氯和总氯的水样,使水样pH>12。结果表明,样品经4℃低温避光保存,5 d内测定,测量结果没有显著变化,方法检出限(以Cl2计)为0.004mg/L,加标回收率为96.7%～104%。     

Monitoring of Coliforms and chlorine residual in water distribution network of Rawalpindi, Pakistan

The present study was undertaken to examine the drinking water quality of Rawal Treatment Plant, Rawalpindi and its distribution network by collecting samples from eight different locations. The aim was to determine potential relationship between the presence of microorganisms and chlorine residual in the distribution network. Quantification of chlorine residual, turbidity, standard plate count (SPC), fecal and total coliforms by Most Probable Number (MPN) was performed. Three different forms of chlorine were measured at each sampling station such as free chlorine, residual chlorine, chloramines and total chlorine residual. A critical evaluation of data presented indicated that pH generally ranged from 7.02–7.30; turbidity varied from 0.34–2.79 NTU; conductivity fluctuated from 359–374 μS/cm; and TDS values were found to be ranging between 180–187 mg/l. Station # 7 was found to be most contaminated. The value of total chlorine was found to be 0.86 to1.7 mg/l at Station # 3 and 6, respectively. Highest standard plate count was 62 CFU/ml at Station # 7. Total coliforms were less than 1.1 MPN/100 ml at almost most of the stations except at Station # 3 where it was found to be greater than 23.0 MPN /100 ml. Overall aim of this study is to create awareness about contamination of drinking water in the water distribution networks and to make recommendations to provincial agencies such as EPA, CDA and WASA that regular monitoring should be carried out to ensure that the chlorine residual is available at consumer end.     

Monitoring of Pathogenicity of Effluents from the UASB Based Sewage Treatment Plant

We researched the behavior of pathogenic microbes in a treated wastewater reuse system to acquire knowledge for establishing new standards for the reuse of treated wastewater. Based on the results that showed occasional growth of total coliforms but barely any growth of Escherichia coli in the supply tank, we found that the total coliform, which includes bacteria that also breed in the soil, etc., is not necessarily suitable as the index bacteria for indicating pollution by excrement. We also clarified that it is possible to decrease the heterotrophic plate count to a specified level in cases where combined residual chlorine is more than 0.3 mg/l, and that the standard value for residual chlorine should be set at 0.3 mg/l or more. At the same time, we found that applying sand filtration treatment to water used for toilet flushing, sprinkling and landscaping, and sand filtration treatment plus coagulation treatment to water for recreational use lowers the annual risk of infection by Cryptosporidium to less than 10⁻⁴. The standard for viruses must be examined in the future because Noroviruses were sometimes detected even in the reclaimed water, although we could not establish the standard at this time due to problems with the virus detection method.     

快速测试管法现场测定水中总余氯

余氯在水中极不稳定 ,需现场测定。通过研制一种测试管 ,从而能快速、简便地测水中的总余氯。常规法测定时间需要 3～ 5小时 ,而该测试管法仅需 1 0分钟。分析成本也大为降低     

分光光度法测定水中活性氯的方法研究与改进

研究了N,N-二乙基-1,4-苯二胺分光光度法和便携式光度计测定水中活性氯的精密度和准确度,结果表明:便携光度测定法同实验室测定方法具有等效的准确度和精密度。对N,N-二乙基-1,4-苯二胺分光光度法研究结果表明,显色剂于4℃下保存应不超过7d;对于标准曲线测定时碘酸钾的反应时间,应由1min更改为30min。