湿法氧化提取水中碳的方法优化  

Optimization of carbon extraction from water by wet oxidation

作　　者：李磊 刘卫[2] 马玉华[2] 李志强[1] 邓珂[2] 曾林林[2] 徐勇 LI Lei;LIU Wei;MA Yuhua;LI Zhiqiang;DENG Ke;ZENG Linlin;XU Yong(Hengyang Normal University,Hengyang 421010,China;Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China)

机构地区：[1]衡阳师范学院,衡阳421010 [2]中国科学院上海应用物理研究所,上海201800

出　　处：《核技术》2024年第3期47-54,共8页Nuclear Techniques

基　　金：上海市青年科技英才扬帆计划项目(No.22YF1457800)资助。

摘　　要：水中碳的提取是液闪谱仪测量环境水中14C的重要预处理步骤。本研究采用过硫酸钠与Fenton试剂相结合的湿法氧化体系以及磷酸酸化、氮气鼓泡的方法,对体积10 L已知碳组分(去离子水+蔗糖)和未知碳组分的两种水样进行湿法氧化碳提取的实验,同时对未知碳组分水样进行湿法氧化与185 nm紫外氧化相结合的碳提取实验。通过实验确定试剂最佳投放时间与顺序,优化试剂投放量及配比。在优化条件下,90℃水温反应3 h后,已知碳组分(去离子水+蔗糖)的有机碳提取率高于96%;未知碳组分的水中总碳提取率为(96.8±0.3)%,其中无机碳的提取率>98.5%、有机碳提取率为(93.4±0.2)%,其中单宁酸类有机物氧化率仅有(88±0.2)%。湿法氧化+185 nm紫外氧化联用后,未知碳组分的总碳提取率提升至(98.3±0.5)%,其中无机碳提取率≥99%、有机碳提取率达到(95.6±1.4)%。由此表明,湿法氧化法不能用典型有机物的碳回收率来代表实际水样中的碳回收率,湿法氧化与185 nm紫外氧化联用是水中碳提取的更好方法。[Background]Extraction of carbon from water is a crucial preprocessing step for measuring 14C in environmental waters using liquid scintillation spectrometry.[Purpose]This study aims to explore the optimal technological conditions for extracting carbon from water using wet oxidation method.[Methods]A wet oxidation system combining sodium persulfate and Fenton's reagent,along with phosphoric acid acidification and nitrogen bubbling,were employed for the wet oxidation carbon extraction experiments on two types of water samples with known(deionized water+sucrose)and unknown carbon components,each with a volume of 10 L.Simultaneously,carbon extraction experiments were conducted on the water samples having unknown carbon component,using a combination of wet oxidation and 185 nm ultraviolet(UV)oxidation so as to determine the optimal timing and sequence of reagent addition,as well as the optimized reagent dosage and ratio.Further experiments under optimized conditions were conducted to obtain more results for deep analysis.[Results]Under the optimized conditions,after a 3-h reaction at 90°C,the organic carbon extraction rate for the known carbon component(deionized water+sucrose)exceeds 96%.The total carbon extraction rate from the unknown carbon component water is(96.8±0.3)%,with an inorganic carbon extraction rate>98.5%,and an organic carbon extraction rate of(93.4±0.2)%,while the oxidation rate of tannic acid-type organic compounds is only(88±0.2)%.After the combination of wet oxidation and 185 nm UV oxidation,the total carbon extraction rate for the unknown carbon component increases to(98.3±0.5)%,with an inorganic carbon extraction rate≥99%and an organic carbon extraction rate that can reach(95.6±1.4)%.[Conclusions]Results of this study indicate that wet oxidation alone cannot represent the carbon recovery rate in actual water samples using typical organic compound carbon recovery rates.The combination of wet oxidation and 185 nm UV oxidation proves to be a more effective method for carbon extraction from

关 键 词：水中14C 湿法氧化 紫外 有机碳 无机碳 

分 类 号：TL751[核科学技术—辐射防护及环境保护]