碱熔-离子选择电极法测定固体废物中氟  

Determination of fluorine in solid waste by alkali fusion-ion selective electrode method

作　　者：李静 关玉春 王琳 郭晶晶 刘跃 王记鲁 LI Jing;GUAN Yuchun;WANG Lin;GUO Jingjing;LIU Yue;WANG Jilu(Tianjin Eco-Environmental Monitoring Center,Tianjin 300191,China)

机构地区：[1]天津市生态环境监测中心,天津300191

出　　处：《冶金分析》2021年第8期84-90,共7页Metallurgical Analysis

基　　金：国家环境保护标准项目(2016-32)。

摘　　要：为实现固体废物中氟含量的准确测定,采用氢氧化钠熔融样品,建立了离子选择电极法测定固体废物中氟的分析方法。对碱熔温度、碱熔时间、碱熔剂组成、碱熔剂用量4因素进行了L_(9)(3^(4))正交试验,结果表明,这4个因素对碱熔过程的影响程度由大到小依次为碱熔温度、碱熔时间、碱熔剂用量、碱熔剂组成。通过对正交试验的结果进行直观分析和计算分析,得到两种优化的碱熔条件。选取除含氟量较高的废弃助熔剂和质地较为坚硬的电镀废渣为试验对象,进一步对这两种优化条件进行了比较试验,确定了适用于固废样品的碱熔条件为在样品表面覆盖3.0g氢氧化钠于600℃马弗炉中恒温熔融30min。以干扰最强的Al^(3+)对总离子强度调节缓冲溶液(TISAB)进行了筛选试验,结果表明柠檬酸钠相较于1,2-环己二胺四乙酸(CDTA)或钛铁试剂而言,掩蔽能力相对更强;且与柠檬酸组合使用的掩蔽能力要优于单独使用,因此,确定了柠檬酸钠与柠檬酸的组合作为TISAB。方法线性范围为0.10~10.0mg/L,相关系数为0.9999,检出限为0.02g/kg,定量限为0.08g/kg。按照实验方法测定生活垃圾、污水厂污泥、电镀污泥、垃圾飞灰和废弃助熔剂中氟,结果的相对标准偏差(RSD,n=7)和加标回收率分别在2.3%~8.3%和85%~105%范围内。选择含氟量较高的电镀污泥、垃圾飞灰以及废弃助熔剂,采用在线燃烧-离子色谱法进行方法比对,两种分析方法的测定结果吻合度良好。In order to realize the accurate determination of fluorine content in solid waste,an analysis method of fluorine content in solid waste by ion selective electrode was established after melting the sample with sodium hydroxide.L_(9)(3^(4))orthogonal tests were performed on four factors,including the temperature of alkali fusion,the time of alkali fusion,the composition of alkali fusing agent,and the dosage of alkali fusing agent.The results showed that the influence degree of 4 factors on the alkali fusion process was presented as below:the temperature of alkali fusion>the time of alkali fusion>the dosage of alkali fusing agent>the composition of alkali fusing agent.Through the intuitive analysis and computational analysis of orthogonal test results,two kinds of optimized alkali fusion were obtained.The electroplating waste slags except for waste flux with high fluorine content and hard texture were selected as the test objects to further compare two optimized conditions.It was found that the following conditions were applicable for the solid waste samples:3.0 g of NaOH was covered on sample surface followed by constant temperature fusion in a muffle at 600℃for 30 min.Then,a screen test was performed on total ionic strength adjustment buffer(TISAB)solution using Al^(3+)which had the strongest interference.The results revealed that sodium citrate had a stronger masking capacity than 1,2-cyclohexanediamine tetraacetic acid(CDTA)or Tiron.Furthermore,the combination use of sodium citrate and citric acid was superior to the use of single sodium citrate.Therefore,the combination of sodium citrate and citric acid was used as TISAB in experiments.The linear range of method was 0.10-10.0 mg/L with correlation coefficient of 0.9999.The limit of detection was 0.02 g/kg,and the limit of quantification was 0.08 g/kg.The contents of fluoride in household waste,sewage sludge,electroplating sludge,solid waste fly ash,and waste flux were determined according to the experimental method.The relative standard deviations(RSD,n=7)of

关 键 词：氟 碱熔 离子选择电极法 固体废物 

分 类 号：X502[环境科学与工程—环境工程] O657.1[理学—分析化学]