钠基膨润土、粉煤灰吸附预处理煤气化废水效果及机理  

Adsorption effect and mechanism of sodium bentonite and pulveized fuel ash on pretreatment of coal gasification wastewater

作　　者：张娟 黑生强 张会琴 李仁威 卢可馨 马超 田小方 ZHANG Juan;HEI Shengqiang;ZHANG Huiqin;LI Renwei;LU Kexin;MA Chao;TIAN Xiaofang(Innovation Demonstration Base of Ecological Environment Geotechnical and Ecological Restoration of Rivers and Lakes,School of Civil Engineering,Architecture and Environment,Hubei University of Technology,Wuhan 430068,China;State Key Joint Laboratory of Environment Simulation and Pollution Control,School of Environment,Tsinghua University,Beijing 100084,China)

机构地区：[1]湖北工业大学土木建筑与环境学院,生态环境岩土与河湖生态修复学科引智创新示范基地,武汉430068 [2]清华大学环境模拟与污染控制国家重点联合实验室,北京100084

出　　处：《环境工程学报》2023年第11期3593-3602,共10页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(51808202)。

摘　　要：煤气化废水具有可生化性差,酚类物质含量高、毒性强的特点,导致生物处理效果不理想。以煤气化废水厌氧段进水为研究对象,分别以钠基膨润土(Na-BBT)与粉煤灰(PFA)作为吸附剂,探究其对煤气化废水中主要特征污染物的去除效果和吸附机理。结果表明:Na-BBT、PFA对煤气化废水中的化学需氧量(COD)、氨氮(NH_(3)-N)与总酚(total phenols,Tph)有一定的去除效果,其可生化性得到提升,经过Na-BBT和PFA处理后,BOD5/COD由0.29分别提高至0.37和0.32;废水中的NH_(3)-N由221.3 mg·L^(-1)分别降至128.6 mg·L^(-1)和180.8 mg·L^(-1),总酚由554.8 mg·L^(-1)分别降至360.6 mg·L^(-1)和386.7 mg·L^(-1)。气相色谱质谱(GC-MS)分析结果表明,去除的主要物质为苯酚、4-甲基苯酚、邻苯二酚、(R)-(+)-3-甲基环戊酮和对羟基苯乙酮等毒性物质,废水毒性得到降低,毒性单元(toxic unit,TU)值由22.3分别降至15.2和18.4。通过吸附等温和吸附动力学分析可知,Na-BBT和PFA对煤气化废水的吸附符合Langmuir模型和准一级动力学模型;三维荧光光谱、孔径比表面积(BET)、扫描电镜(SEM)、红外光谱(FT-IR)、X射线衍射(XRD)、X射线荧光光谱(XRF)和X射线电子能谱(XPS)等分析结果表明,Na-BBT和PFA对煤气化废水中污染物的吸附去除过程和机理主要受物理扩散控制,为表面和孔道的物理吸附,同时也存在离子交换吸附。以上结果表明Na-BBT和PFA作为吸附剂,可以有效提高煤气化废水的可生化性,降低毒性,将其用于煤气化废水的预处理,具有潜在和广泛的应用前景。Coal gasification wastewater is characterized by poor biodegradability,high phenolic content and strong toxicity,which leads to its unsatisfactory biological treatment effect.In this study,the anaerobic section influent of coal gasification wastewater was taken as the research object,the removal effect and adsorption mechanism on the main characteristic pollutants were absorbed by Na-bentonite(Na-BBT)and pulveized fuel ash(PFA).The result showed that Na-BBT and PFA could remove COD,NH_3-N and The total phenol(Tph)from coal gasification wastewater to a certain extent,and the biodegradability of wastewater could be improved because BOD5/COD increased from 0.29 to 0.37 and 0.32,respectively,NH_3-N in wastewater decreased from221.3 mg·L^(-1)to 128.6 mg·L^(-1)and 180.8 mg·L^(-1),and Tph decreased from 554.8 mg·L^(-1)to 360.6 mg·L^(-1)and386.7 mg·L^(-1),respectively.Gas chromatography mass spectrometry(GC-MS)results indicated that the main toxic substances such as phenol,4-methylphenol,catechol,(R)-(+)-3-methylcyclopentanone and phydroxyacetophenone were removed,and the toxicity of coal gasification wastewater was reduced because the toxic unit TU value decreased from 22.3 to 15.2 and 18.4,respectively.When Na-BBT and PFA removed the pollutants from coal gasification wastewater,the adsorption process was consistent with Langmuir model and quasi-first-order kinetic model through analysis of adsorption isotherms and adsorption kinetics.It was found that the adsorption process and mechanism of Na-BBT and PFA removed pollutants from coal gasification wastewater were mainly controlled by physical diffusion due to their surfaces and pores,also including ion exchange adsorption based on the analysis of three-dimensional fluorescence spectrum,pore specific surface area(BET),scanning electron microscope(SEM),infrared spectroscopy(FT-IR),X-ray diffraction(XRD),Xray fluorescence spectrum(XRF)and X-ray electron spectroscopy(XPS).The results showed that Na-BBT and PFA,as adsorbents,could effectively improve the biodegradabili

关 键 词：钠基膨润土 粉煤灰 煤气化废水 吸附 机理 

分 类 号：X703.1[环境科学与工程—环境工程]