湿式氧化工艺对己内酰胺污泥处置效果与氧化液特征  

Effect of Wet Oxidation Process on Caprolactam Sludge Disposal and Characteristics of Oxidation Solution

作　　者：吴太行 李姝琪 秦树林 郑威城 刘新超[1,3] WU Taihang;LI Shuqi;QIN Shulin;ZHENG Weicheng;LIU Xinchao(College of Environmental Science and Engineering,Tongji University,Shanghai 200092,China;Hangzhou Research Institute of China Coal Technology&Engineering Group,Hangzhou 311201,China;Tongji Architectural DesignCo.,Ltd.,Shanghai 200092,China)

机构地区：[1]同济大学环境科学与工程学院,上海200092 [2]中煤科工集团杭州研究院有限公司,浙江杭州311201 [3]同济大学建筑设计研究院<集团>有限公司,上海200092

出　　处：《净水技术》2025年第4期134-140,196,共8页Water Purification Technology

基　　金：中国煤炭科工集团有限公司科技创新项目(2022-3-KJHZ001)。

摘　　要：【目的】己内酰胺生产废水处理过程中产生成分复杂的污泥,文章通过研究湿式氧化(WO)处理污泥在不同条件下的无害化和减量化效果以及氧化液中挥发性脂肪酸(VFAs)和溶解性有机质(DOM)随温度的组成变化规律可减少环境污染,提高资源利用率。【方法】测量WO反应前后己内酰胺污泥的总化学需氧量(TCOD_(Cr))和挥发性悬浮固体(VSS)来表示无害化和减量化效果,气相色谱(GC)搭配色谱柱和氢火焰离子化检测器(FID)对VFAs进行鉴定和定量分析,紫外可见吸收光谱(UV-Vis)耦合三维激发发射矩阵(3D-EEMs)-荧光区域积分(FRI)用于分析DOM组成及变化规律。【结果】结果表明,相比于86.8%含水率的污泥,97.8%含水率的污泥的TCOD_(Cr)和VSS去除率分别提高了23.3%和19.7%,在污泥含水率为97.8%,反应温度为260℃,反应时间为1 h,起始氧压为1 MPa的条件下,TCOD_(Cr)和VSS去除率最大分别可达到70%和95%以上。乙酸随反应温度的增加而积累,乙酸/挥发性脂肪酸最大达到89.6%。3D-EEMs结合FRI发现位于激发波长(E_(x))/发射波长(E_(m))=220~235 nm/375~410 nm和E_(x)/E_(m)=290~315 nm/375~405 nm的己内酰胺污泥氧化液的2种特征荧光峰,反应温度升高使荧光峰向短发射波长移动,DOM中主要成分为类色氨酸、类富里酸和可溶性微生物的代谢产物。UV-Vis结合3D-EEMs分析,波长254 nm处UV吸收系数(α_(254))、波长355 nm处UV吸收系数(α_(355))、单位DOC浓度在波长254 nm处的吸收系数(SUVA_(254))和腐殖化指数(HIX)呈下降趋势,254 nm处吸光度与365 nm处吸光度的比率(E_(2)/E_(3))和300 nm处吸光度与400 nm处吸光度的比率(E_(3)/E_(4))呈上升趋势。【结论】WO对己内酰胺污泥的处理效果显著,处理前无需事先脱水,处理后随温度升高氧化液中DOM浓度及相对分子质量均下降,腐殖化程度降低,芳香性减弱。温度对于乙酸生成的促进作用明显,乙酸可作为前序污水处理反硝化�[Objective]During the treatment of wastewater from caprolactam production,complex sludge is generated.This study investigates the detoxification and reduction efficiency of wet oxidation(WO)under various conditions,as well as the compositional changes of volatile fatty acids(VFAs)and dissolved organic matter(DOM)in the oxidation solution with increasing temperature.[Methods]The removal efficiency of detoxification and reduction was evaluated by measuring the total chemical oxygen demand(TCOD_(Cr))and volatile suspended solids(VSS)of caprolactam sludge before and after the WO process.Gas chromatography(GC)equipped with a chromatographic column and flame ionization detector(FID)was used to identify and quantify VFAs,while ultravioletvisible absorption spectroscopy(UV-Vis)combined with three-dimensional excitation-emission matrix(3D-EEMs)and fluorescence regional integration(FRI)was employed to analyze the composition and changes of DOM at different reaction temperatures.[Results]The result showed that,compared to sludge with a moisture content of 86.8%,the TCOD_(Cr) and VSS removal rates of sludge with a moisture content of 97.8% increased by 23.3% and 19.7%,respectively.Under the conditions of 97.8% moisture content,a reaction temperature of 260℃,a reaction time of 1 hour,and an initial oxygen pressure of 1 MPa,the maximum removal rates of TCOD_(Cr) and VSS reached over 70% and 95%,respectively.Acetic acid accumulated with increasing reaction temperature,and the acetic acid/volatile fatty acids ratio reached a maximum of 89.6%.The 3D fluorescence spectrum-regional integral revealed two characteristic fluorescence peaks of caprolactam sludge oxidation solution located at excitation wavelength(E_(x))/emission wavelength(E_(m))=220~235 nm/375~410 nm and E_(x)/E_(m)=290~315 nm/375~405 nm.As the reaction temperature increased,the fluorescence peaks shifted to shorter emission wavelengths,and the main components of DOM were identified as tryptophan-like substances,fulvic acid-like substances,and soluble microbial meta

关 键 词：湿式氧化(WO) 己内酰胺污泥 溶解性有机质(DOM) 紫外-可见吸收光谱(UV-Vis) 三维激发发射矩阵-荧光 区域积分(3D-EEMs-FRI) 

分 类 号：X703[环境科学与工程—环境工程]