合并带异步注入-流动注射分光光度法快速测定地热水中高浓度硅酸盐  

Fast determination of High Concentration Silicate in Geothermal Water Based on An Asynchronous-Injection Merging Zone Flow Injection Spectrophotometry

作　　者：钟红生[1] 李永生[1] 张红[1] 张淑娟[1] 

机构地区：[1]四川大学化学工程学院,成都610065

出　　处：《分析化学》2010年第11期1629-1633,共5页Chinese Journal of Analytical Chemistry

基　　金：四川大学214人才引进振兴计划基金(No.0082204127067)资助项目

摘　　要：去除地热发电的废水回补管道中硅酸盐结垢是个难题。若能连续监测地热水中高浓度的硅酸盐含量、控制硅垢抑制剂的添加量,就可控制硅垢产生。本实验采用直接自动测定地热水中高浓度硅酸盐的合并带异步注入流动注射分光光度法,并优化了测定条件:2%(w/V)钼酸铵,0.1mol/L NaOH,1.0%草酸,预混合盘管长度350cm,反应盘管长度160cm,干扰掩蔽盘管长度300cm,载流流量2.0mL/min。本方法每次测定所需样品用量仅为25μL,显色剂用量仅为120μL,测定范围为25～800mg/L(SiO2),相对标准偏差小于1.96%,回收率为94.1%～110.5%,每小时可分析60个样品;本方法重现性好、分析速度快、测定成本极低,测定高浓度硅酸盐时无需预稀释处理。Forming silica scale on reinjection wells are a serious problem at geothermal power plants. If we can continuously monitoring the high concentrations of silicate in geothermal waters and control the dosage of silica-scale prevention reagents,the creating of the silica scale can be avoided. Consequently,based on a new merging zones mode of the asynchronous injection,we established a flow injection spectrophotometry for directly determining the high concentrations silicate in geothermal waters. The optimized various conditions were as follows： concentrations of ammonium molybdate,sodium hydroxide and oxalic acid were 2% （ w/V） , 0. 1 mol/L,and 1% （ w/V） ,respectively; lengths of premixing,reaction and masking coils were 350 cm, 160 cm,and 300 cm,respectively; total flow rate was 2. 0 mL/min. Only 25 μL of the sample and 120 μL of the reagent were consumed per time in this method,the determination range was 25 800 mg/L（ SiO2 ） , relative standard deviation was less than 2. 0% ,recovery ranges were 94. 1% 110. 5% ,about 60 samples can be analyzed per hour. Merits of the system were good reproducibility,fast speed,less cost,and no needing pre-dilution for determination of high concentrations silicate.

关 键 词：流动注射分析 分光光度法 高浓度硅酸盐 地热水 

分 类 号：X132[环境科学与工程—环境科学]