
硅藻土对废水中活性黑K-BR和活性金黄X-G吸附性能研究.docx
117页目ﻩ录摘要 .ﻩIIIAbstract. . ............... .............................IV第1章绪论ﻩ11.1染料与印染废水 .11.2染料废水的处理方法 31.3硅藻土在废水处理中的应用 111.4本课题研究的提出及意义 .161.5本课题研究的内容 .17第2章硅藻土吸附剂制备ﻩ192.1天然硅藻土的制备ﻩ192.2有机改性硅藻土制备ﻩ19第3章硅藻土对染料吸附影响因素分析研究 22 3.1实验部分 .223.2实验结果和分析 .2333小结 .28第4章硅藻土吸附剂吸附动力学研究ﻩ304.1吸附动力学理论 304.2实验部分ﻩ.3243硅藻土吸附剂吸附废水中染料的动力学实验结果 ..3344小结 .51第5章硅藻土吸附染料热力学研究ﻩ53 / 5.1热力学基本理论 ..5352实验部分ﻩ.555.3实验结果与分析 565.4小结 70第6章吸附机理与规律初探 716.1硅藻土矿物表面物理化学理论ﻩ.716.2硅藻土早期吸附机理理论ﻩ716.3硅藻土吸附机理初探ﻩ726.4小结 76第7章结论与建议ﻩ777.1结论ﻩ7772应用建议ﻩ。
787.3展望ﻩ80附录:动力学模型拟合曲线 .8 l参考文献 ..97论文发表情况ﻩ.1 08致 谢 1 09n硅藻土对废水中活性黑K.BR和活性金黄X.G吸附性能研究摘要通过实验研究了天然硅藻土NADT和聚乙烯亚胺改性硅藻土PEMD对活性 染料活性黑K-BR和活性金黄X.G的吸附性能,探讨了外部因素对吸附效果的影响,研究了两种吸附剂的吸附动力学、吸附等温式和吸附热力学,总结了吸附 机理,研究结果表明:硅藻土对染料有较强的吸附能力,用聚乙烯亚胺PEI对硅藻土改性,提高其 吸附能力.通过对吸附剂用量、染料初始浓度、初始pH和温度对吸附的影响研 究发现,增加吸附剂用量、降低染料初始浓度和pH、提高温度都能提高对染料 的去除率两种吸附剂对两种染料吸附速率都较快,前5min时吸附量上升最快,90min 时吸附基本达到平衡;准一级动力学模型和准二级动力学模型都比颗粒内扩散模 型更好的描述NADT和PEMD对活性黑K-BR和活性金黄X.G吸附过程,但准 二级动力学模型能更好的描述吸附的过程;颗粒内扩散不是控制吸附过程的唯一 步骤,控制吸附的过程还应该有膜扩散NADT对活性黑K-BR和活性金黄X-G两种染料的吸附等温线最符合 Frcundlich吸附等温方程;PEMD对活性黑K—BR和活性金黄X.G两种染料的吸 附等温线最符合Langmuir吸附等温方程。
热力学分析表明,NADT吸附染料活 性黑K—BR和活性金黄X.G吸附活化能邑分别为12.373KJ/tool、25913ICl/mol; PEMD吸附染料活性黑K—BR和活性金黄X-G吸附活化能昂分别为9.4498ICl/moi、88612Ⅺ/mol;吸附活化能易值在42 kJ/mol以下,说明它们对 染料的吸附作用中物理吸附占主导作用;在实验条件下,AG<0,表明在常温下, 吸附过程能自发进行:/LE>0,表明吸附反应都吸热,升高温度有利于吸附的进 行,同时表明吸附过程以物理吸附为主;AS>0,说明此吸附反应熵值都增大硅藻土吸附剂对染料的吸附机理:通过静电引力、氢键生加石作用及范德华 力吸附染料分子,其中,静电引力和氢键吸附起主要作用 关键词:硅藻土、吸附、染料、改性、动力学模型、热力学mStudy on Adsorption Properties of Reactive Black K-BR and Reactive Golden Yellow X—G in Wastewater by DiatomiteAbs仃actThe adsorption performance oftwo dyes,reactive black K—BR(RB)and reactive golden yellowX—G(ROY)on natural diatomit哈(NADT)and PEI-modified diatomit(PEIVlD)we∞studied by research。
The effects of external factors on theadsorption were discussedFurthermore,adsorption kinetics and isothermal adsorption equation of two kinds of absorbents were studied,and Adsorption mechanism was summarized.The research conclusions indicated:Diatomite had strong adsorption performance Modification by polyethyleneimine could improve adsorption capacity of diatomite.It was found that increasing the dosage of adsorbent and temperature and decreasing the pH valve and initial concentration of dye all Can increase the removal rate through research On effect of the dosage of adsorbent,initial concentration of dye,initial pH value andtemperature on the adsorption.The adsorption rates of two dyes on the two sorbents were rapid。
The adsorptioncapacity of dyes rose rapidly at the beginning of 5 rains and then the adsorptionequilibrium was nearly reached at 90minThe pcsudo-first-order model and pesudo—second—order model a陀all better than intraparticle diffusion model On describing the adsorption process of reactive black K-BR and reactive golden yellow X—G on NADT and PEMD,and the pesudo—second-ordcr model is the best oneThe intraparticle diffusion is not the unique process controlling the adsorption andfilm diffusion also can control the adsorptiom r。
3The dye adsorption of reactive black K—BR and reactive golden yellow X·Gonto NADT fit well to Freundlieh isotherm and The dye adsorption onto PEMD fitk well to Langmuir isotherm.Activation energy of RB K-RB and RGY X—G adsorptiononto NADT 12.373 IO/mol and 25.913 IU/mol,respectively;Activation energy ofRB ⅣK-RB and ROY X·G adsorption onto NADT iS 9.4498K.1/mol and 8.8612KJ/mol, respectively.Lower activation energy values(<42K.1/m01)indicate physical adsorption control process of dyes adsorption。
The thermodynamic analysis indicated that AG〈0,adsorption is a spontaneous process at normal temperature;△日>0, indicates the exothermic reaction,and it is favorable for the adsorption to increase the temperature;AS>0,indicates entropy of reaction increased.Adsorption mechanisms of dyes were proposed as—adsorption by an electrostatic force,hydrogen bond,,l-石interaction and Van der Waals force,of which the electrostatic force and hydrogen bond、)l,ere the main effects.Key words:diatomite,adsorption,dye,modification,kinetic models,thermodynamiesGu Zhipan(Municipal Engineering)Directed by Pro£He ShaohuaV第1章绪论1.1染料与印染废水1.1.1染料有色物质,采用适当的方法,使其它物质具有坚固的颜色,这种有色物质成为着色剂或称染料。
11.2印染废水的来源印染废水按来源来分,主要包括印染工业废水和染料生产废水染料工业的 废水排放量很大,平均生产1吨染料排放的废水量约为30-,.,100吨【l,21染料生产 从原料、中间体到产品往往经过多个单元操作,生产工艺复杂,工艺流程长,副 反应多,转化率和产品收率低,同时染料工业具有品种多、产量小,产品更新快 等特点,因此在印染工业生产和染料生产中产生大量废水,为染料废水的主要来 源3印染废水的特点(1)色度大、有机物含量高 印染废水总体上属于有机废水,其中所含的颜色及污染物主要有天然有机物质(天然纤维所含的蜡质、胶质、半纤维、油脂等)及人工合成有机物质(染料 和颜料)所构成由于在印染加工大量试用了各种染化料,这些染化料不可能全 部转移到织物上,在水中有部分残料,使得废水的颜色深2)水质变化大 印染废水是印染企业生产过程中排放的各种废水混合后的总称.有些企业排放的全部为生产废水(包括生产废水和辅助生产废水),而有些企业排放的废水 中则还有部分生活废水,致使其废水水质处于经常变化之中.因此印染废水排放 由于企业生产的织物品种、数量及染化料等多种因素有关,水质变化大,在所排放的废水中,化学需氧量(COD)高时可达2000—-—3000mg/L,且生化需氧量(BOD) 与COD之比小于0。
2,可生化性差‘(3)pH值变化大由于不同纤维。
