自养硝化颗粒污泥吸附铜离子性能及吸附等温线

以自养硝化颗粒污泥作为吸附剂，研究了其对铜离子的吸附效果及最佳吸附工艺条件，并探索了其吸附等温线。通过单因素实验研究铜离子浓度、吸附时间、污泥浓度、搅拌速度和温度对吸附效果的影响，最终得出搅拌速度、吸附时间以及污泥浓度对吸附效果有明显影响。在此基础上，通过响应曲面法耦合出吸附的最佳工况点：时间（A）=2.50h，转速（B）=125r/min，污泥量（C）=5250mg/L。在此条件下研究了颗粒污泥的吸附特性及稳定性。结果表明，硝化颗粒污泥在重金属废水中表现出极强的耐受性与稳定性，不同浓度下颗粒化率均维持在93%以上。Langmuir与Freundlich方程动力学拟合结果显示：Langmuir等温方程的拟合度R²_Cu=0.999，表明硝化颗粒污泥对于Cu²⁺属于典型的单分子层吸附，且能描述最大吸附量为Q_max=15.02mg/g。Freundlich等温方程的拟合过程中，相关系数R²_Cu=0.969，1/n=0.1305，表明硝化颗粒污泥对Cu²⁺吸附能力较强；较高的拟合度也在一定程度上表明硝化颗粒污泥对Cu²⁺的吸附是一个复杂的物理化学过程。     

胶原纤维对Cr3 的吸附性能研究

以铬粉溶液为处理对象,研究了胶原纤维对Cr3+的吸附性能;通过单因素实验分别考察了pH、温度、时间、铬液初始浓度、吸附剂用量以及盐离子浓度（Na+、Ca2+）对吸附过程的影响,结果表明：胶原纤维对Cr3+具有较强的吸附能力,吸附的最佳pH为4.5,最适温度40℃,在最佳吸附条件下,胶原纤维对Cr3+的吸附容量高达90mg/g,对于一定量的铬粉溶液,吸附容量随着Cr3+初始浓度的增大而增加,随着吸附剂用量的增加而减小,随着时间的延长先增加后趋于平缓。溶液中Na+、Ca2+离子的存在会抑制吸附过程的进行,并且随着离子浓度的增加,抑制作用增强;对Cr3+在胶原纤维上的吸附热力学和吸附动力学进行了研究,结果表明：Freundlich等温方程和二级速率方程能够更好的描述Cr3+在胶原纤维上的吸附行为。     

磷酰基乙酸改性粉煤灰基SBA-15及选择性吸附稀土性能

以粉煤灰为硅源合成了介孔二氧化硅SBA-15，对其进行磷酰基乙酸（PAA）功能化改性制备了PAA-SBA-15吸附剂，对改性前后的吸附剂进行了XRD，N2-吸脱附、红外光谱表征。结果显示，改性后SBA-15的孔道保持高度有序。将PAA-SBA-15用于模拟溶液中稀土离子吸附，发现PAA-SBA-15对Eu3+、Gd3+、Tb3+、Nd3+和Sm3+的吸附容量分别可达18.6、23.2、21.9、22.6和20.2 mg/g。考察了竞争离子Ca2+、Mg2+、Al3+和Fe3+对稀土离子吸附的影响。结果显示，Fe3+的存在对PAA-SBA-15吸附稀土离子干扰性最强。吸附动力学和热力学结果显示，PAA-SBA-15对稀土离子的吸附符合准二级动力学和Langmuir等温吸附模型，吸附过程中化学吸附占主导作用。     

柚皮粉复合高吸水树脂吸附溶液中Cu2

研究了柚皮粉接枝聚丙烯酸-聚丙烯酰胺复合高吸水树脂（PP-SA）对Cu2 的吸附行为及机理。考察了吸附时间及硫酸铜初始质量浓度对PP-SA铜离子吸附容量的影响，并对其吸附Cu2 过程进行了热力学等温线及动力学方程拟合，应用X射线光电子能谱（XPS）及热重分析（TG）技术对吸附Cu2 溶液饱和的PP-SA做了表征，探讨了其吸附Cu2 机理。结果表明硫酸铜初始质量浓度为2000 mg/L时PP-SA铜离子吸附容量最大，可达199.3 mg/g，吸附约4 h即达饱和；PP-SA对Cu2 的吸附等温线符合Langmuir吸附等温式，吸附动力学符合准二级动力学方程；PP-SA对Cu2 的吸附主要通过离子交换、螯合作用及静电吸引实现，被吸附的铜物种以Cu2 形式存在，其中有小部分CuSO4。     

胶原纤维对Cr~(3+)的吸附性能

以铬粉溶液为处理对象,研究了胶原纤维对Cr3+的吸附性能;通过单因素实验,考察了pH、温度、时间、铬液初始质量浓度、吸附剂用量以及盐离子浓度(Na+、Ca2+)对吸附过程的影响,结果表明,胶原纤维对Cr3+具有较强的吸附能力,吸附的最佳pH=4.5,最适温度40℃,在最佳吸附条件下,胶原纤维对Cr3+的吸附容量高达90mg/g,对于一定量的铬粉溶液,吸附容量随着Cr3+初始质量浓度的增大而增加,随着吸附剂用量的增加而减小,随着时间的延长先增加后趋于平缓。溶液中Na+、Ca2+离子的存在会抑制吸附过程的进行,并且随着离子浓度的增加,抑制作用增强;对Cr3+在胶原纤维上的吸附热力学和吸附动力学进行了研究,结果表明,Freundlich等温方程和二级速率方程能够更好地描述Cr3+在胶原纤维上的吸附行为。     

活性炭对实验室废水中金属铬的动态和静态吸附研究

采用活性炭吸附法处理含铬水样,在动态和静态吸附试验条件下,讨论了溶液p H、活性炭颗粒大小以及Na+、NH4+、Ca2+离子对铬去除率的影响。实验结果表明,动态吸附比静态吸附效果明显;水中Na+、NH4+、Ca2+离子对活性炭吸附铬的去除率没有明显影响;在溶液p H分别为1、3、5的情况下,p H=1时活性炭对铬的去除率最高,p H=5时活性炭对铬的去除率最低;在p H=1时,200目的活性炭动态吸附140 min时,铬的去除率可达99%。     

含咪唑啉基偕胺肟化共聚物对Cu(Ⅱ)吸附性能

本文以丙烯酰胺（AM）、丙烯腈（AN）、1-(2-N-烯丙基氨乙基)-2-油酸基咪唑啉（NIPA）为原料,制备了咪唑啉基偕胺肟化聚合物AM/AO/NIPA。对其进行了FTIR、SEM和TG表征,通过静态吸附实验考察了pH、吸附时间、溶液初始浓度对聚合物AM/AO/NIPA和吸附剂聚丙烯酰胺（PAM ）吸附低浓度Cu2+过程的影响,并拟合吸附动力学和等温吸附曲线探讨了吸附机理。结果表明：聚合物AM/AO/NIPA的铜吸附容量受溶液pH影响不大;当聚合物AM/AO/NIPA加入量为0.05 g时,在30 ℃,pH=5,吸附3 h后,对铜离子质量浓度为100 mg/L的溶液吸附达到平衡 ,此时吸附容量为37.32 mg/g;整个吸附过程服从准二级动力学模型,以化学吸附为主;对Langmuir和Freundlich等温吸附模型均能较好的拟合。通过Langmuir模型拟合计算得到,偕胺肟化聚合物AM/AO/NIPA的Cu2+饱和吸附量为267.38 mg/g,超过相同条件下吸附剂PAM的饱和吸附量3倍以上。AM/AO/NIPA循环使用5次后,其吸附量保留率可高达92.99%。     

混凝强化型好氧颗粒污泥对Ni2+吸附性能及机理研究

为强化好氧颗粒污泥(AGS)对重金属Ni²⁺的吸附效能，利用聚合氯化铝(PAC)和天然混凝剂(SNC)的特性培养形成混凝强化型AGS，并探究AGS对Ni²⁺的吸附性能及机理。结果表明：PAC型和SNC型AGS对Ni²⁺均具有良好的吸附性能且存在特异性，Ni²⁺质量浓度为0～25 mg/L时，PAC型AGS吸附效能较优；Ni²⁺质量浓度为100～150 mg/L时，SNC型AGS吸附性能较优。模型拟合结果表明：混凝强化型AGS对Ni²⁺的吸附以物理-化学吸附为主，对于吸附量及吸附速率，SNC型AGS均大于PAC型AGS。傅里叶红外变换光谱(FT-IR)结果表明，吸附过程中混凝强化型AGS存在大量羟基、羧基和氨基等基团与Ni²⁺吸附结合，实现了Ni²⁺的有效去除；同时，SNC能强化AGS中的官能团，提高吸附性能。     

果胶-PDA微球的功能化制备及对Th4 的吸附性能的研究

利用溶胶-凝胶法，以Ca2+为交联剂制备出果胶-Ca微球，再用多巴胺修饰果胶微球生成功能化的果胶-PDA微球吸附剂，探讨了该吸附剂去除Th4+的吸附性能，并利用SEM、FTIR和XPS分析了其功能化制备和吸附机理。结果表明：果胶-PDA微球在pH=3.5时效果最好，在25 ℃、pH=3.5、初始Th4+质量浓度为20 mg/L、吸附剂质量为0.03 g的条件下，接触时间为1200 min，吸附容量可达到37.172 mg/g；共存离子Cs+、Sr2+、Mn2+和Mg2+对Th4+的吸附影响较小，说明该吸附剂对Th4+的吸附选择性较好；热力学和动力学研究结果表明：此吸附过程符合线性Langmuir等温吸附模型和准二级动力学模型，拟合的最大吸附量为99.010 mg/g；热力学数据表明果胶-PDA吸附Th4+是一个自发吸热的过程；通过TG分析知果胶-PDA的热稳定性较改性前有所提高；果胶-PDA上的N、O与溶液中Th4+的发生螯合作用是果胶-PDA微球吸附Th4+的主要吸附机理。     

粘质沙雷氏菌HB-4吸附重金属镉的机制

从重金属污染土壤中筛选出1株对Cd²⁺具有高耐受能力和高吸附容量的菌株HB-4,经16S rDNA序列分析鉴定为粘质沙雷氏菌（Serratia marcescens）。该菌株能在Cd²⁺浓度为300 mg·L^-1的条件下正常生长;对Cd²⁺的最大吸附量为（154.7±0.9（ mg·g^-1。考察了Cd²⁺初始浓度、pH、盐浓度以及共存离子对HB-4吸附Cd²⁺的影响,结果表明：pH=3.0~8.0时,对吸附效果无影响;NaCl含量为8.0%时,菌株对Cd²⁺的去除率仍可达到49.9%±0.1%;Pb²⁺、Zn²⁺、Cu²⁺与Cd²⁺共存时,几种重金属离子的去除率分别为98.7%±0.2%（Pb²⁺）、44.6%±0.6%（Zn²⁺）、52.7%±0.1%（Cu²⁺）和64.2%±0.3%（Cd²⁺）。解吸实验证明了HB-4对Cd²⁺极强的吸附能力,洗脱液pH=7.0时,解吸率小于2%。检测了细胞内外镉的分布情况,并利用SEM、XPS和FTIR对吸附机理进行了研究,推断HB-4对Cd²⁺的吸附机理为胞外吸附和胞内摄取。     

Rare Earth Ions Adsorption onto Graphene Oxide Nanosheets

Graphene oxide (GO) was synthesized and used as a coagulant of rare earth elements (REEs) from aqueous solution. Stability and adsorption capacities were exhibited for target REEs such as La(III), Nd(III), Gd(III), and Y(III). The parameters influencing the adsorption capacity of the target species including contact time, pH, initial concentration, and temperature were optimized. The adsorption kinetics and thermodynamics were studied. The method showed quantitative recovery (99%) upon desorption using HNO₃ acid (0.1 M) after a short contact time (15 min).     

Ion exchange characteristics of rhodium and ruthenium from a simulated radioactive liquid waste

Radioactive high-level liquid wastes contain significant quantities of platinum group metals (PGM) such as palladium [Pd(II)], rhodium [Rh(III)] and ruthenium [Ru(III)]. The PGM are produced as fission products in a nuclear reactor. In this study, batch and column experiments were carried out to investigate the ion exchange characteristics of Rh(III) and Ru(III) including the effects of the ionic group of ion exchangers, solution temperature, and the concentration of nitric acid by various ion exchangers such as IRN 78 and Dowex 1x 8; the elution characteristics of Rh(III) and Ru(III) by various eluents were also investigated. Anion exchangers such as Dowex 1x 8 with the ionic group of quaternary methyl ammonium had a higher capacity than anion exchanger such as IRN 78 with amine group for the adsorption of Rh(III) and Ru(III) from a simulated liquid waste. The optimal nitric acid concentration for the adsorption of Rh(III) and Ru(III) by anion exchangers was shown to be about 3 M and 2–3 M, respectively.     

LX-92树脂对硫酸体系低浓度镓离子的动态吸附

研究了粉煤灰模拟硫酸浸出液中的镓在聚苯乙烯树脂(LX-92)上吸附分离的可能性,采用固定床吸附装置考察了树脂动态吸附?脱附镓的行为,利用Thomas, Yoon-Nelson和Adam-Bohart经验模型对动态吸附过程进行了分析和预测。结果表明,降低流速(F)、增加床层高度(Z)、减小镓(Ш)初始浓度(C0)有助于提高固定床吸附效率和平衡吸附容量;在C0为260 mg/L, Fad为5.0 mL/min、吸附温度为55℃的条件下,树脂的最大动态平衡吸附容量为56.65 mg/g;用3.0 mol/L H2SO4在1.0 mL/min流速的最佳洗脱条件下,洗脱率达到94.40%;树脂在硫酸体系中对低浓度镓离子的吸附?脱附具有良好的循环使用性,经过吸附?脱附镓离子可富集10倍以上;树脂吸附镓的动态行为满足Yoon-Nelson动态吸附模型,建立了动态吸附速率常数KYN和半穿透时间τ值常数与初始离子浓度、流速、床层高度的对应方程,为低浓度镓离子的吸附法提取工程化提供了理论基础。     

大孔螯合树脂对Pb2+的吸附行为及机理

通过静态和动态吸附实验,研究了Pb2+在D418树脂上的吸附行为,从热力学和动力学方面对吸附过程进行了分析,并通过红外光谱探讨了吸附机理. 结果表明,在所研究的条件范围内,Pb2+在D418树脂上的吸附是吸热过程,同时符合Freundlich和Langmuir等温吸附方程;液膜扩散为Pb2+在D418树脂上吸附速率的主要控制步骤,随着溶液初始浓度的增大,吸附速率逐渐减小;313 K温度下树脂的静态饱和吸附容量为375 mg/g,在298 K下用3 mol/L的硝酸作为解吸剂,解吸率可达97%;最佳的解吸剂用量为5倍床层体积. 该树脂吸附操作简单,易再生,不产生二次污染,有望用于含铅废水的治理及铅的富集.     

Kinetics and Thermodynamics of Lead (II) Adsorption on Vermiculite

Abstract

The kinetics and thermodynamics of Pb(II) adsorption on vermiculite have been studied by the sets of experiments at various conditions (temperature, initial lead concentration and adsorption time). The structures of the vermiculite before and after Pb(II) adsorption were measured using X‐ray diffraction (XRD), thermogravimetric analysis (TA), and X‐ray photoelectron spectroscopy (XPS). Adsorption of Pb(II) was strongly affected by pH. First order kinetics model best described the reaction rate, and the adsorption capacity calculated by the model was consistent with that actual measurement. Isotherms for the adsorption of Pb(II) on vermiculite were developed and the equilibrium data fitted well to the Langmuir and Freundlich models. Thermodynamic parameters such as enthalpy, entropy, and free energy were calculated using the Van't Hoff equations. The thermodynamics of Pb(II) on vermiculite indicates the spontaneous and endothermic nature of adsorption. Quantitative desorption of Pb(II) from vermiculite was found to be more than 40% which facilitates the sorption of metal by ion exchange     

Dehydration of Ethanol-Water Mixture Using Activated Carbons from Sawdust and Palm Kernel Shells

This work was carried out to determine the optimum conditions for preparing activated carbons from sawdust and palm kernel shells (PKS); the maximum initial water concentration in feed solution to produce anhydrous ethanol using the adsorbents; and the effects of initial water concentration on water removal efficiency, selectivity, and adsorption capacity. The sawdust was chemically activated with ammonium chloride as catalyst while the PKS was carbonized and steam activated. Different particle sizes of the activated carbons were used in the study. The optimum conditions for preparing the activated carbons were established. It was found that only the activated sawdust particle sizes could break the ethanol-water azeotropic composition in feed solutions containing 5–9% (v/v) water to produce anhydrous ethanol. Powdered activated sawdust particles had the highest adsorption capacity compared to all the other particle sizes. The water removal efficiency, selectivity of water-to-ethanol adsorption, and adsorption capacity were higher at low initial water concentrations.     

Ion exchange characteristics of palladium from nitric acid solution by anion exchangers

Radioactive high-level liquid wastes contain significant quantities of platinum group metals (PGM) such as Pd(II), Rh(III) and Ru(III). The PGM are produced as fission products in nuclear reactors. In this study, batch and column experiments were carried out to investigate the ion exchange characteristics of Pd(II), including the effects of the ionic group of ion exchangers, solution temperature, and the concentration of nitric acid by various anion exchangers such as IRN 78 and Dowex 1×8 and also the elution characteristics of Pd(II) by various eluents for the determination of optimal separation conditions. Anion exchangers such as Dowex 1x8 with the ionic group of quaternary methyl ammonium showed a higher capacity than anion exchangers such as IRN 78 with amine group for the adsorption of Pd(II) from nitric acid solution. The optimal nitric acid concentration was shown to be in 2–3 M. The adsorbed Pd(II) was effectively eluted out by 0.5 M thiourea and 0.1 M nitric acid mixed solution.     

改性Zr-Na/Zeolite双功能沸石脱除水溶液中氨氮和磷性能研究

采用氯化钠离子交换和氯氧化锆沉积沉淀两步法改性天然沸石,得到具有脱除水中氨氮和磷的双功能锆钠改性天然沸石（Zr-Na/Zeolite）,考察了不同pH、溶液初始质量浓度和温度下Zr-Na/Zeolite对氨氮溶液、含磷溶液及氮磷共存溶液的吸附情况。结果表明,Zr-Na/Zeolite能够在保持Na改性沸石（Na/Zeolite）优良的吸附氨氮性能的基础上,极大地提高吸附磷的能力。在不同pH下,Zr-Na/Zeolite 吸附氨氮和磷的效果呈现不同的规律。对于氨氮,水溶液pH在4~8时具有最佳吸附性能,最高吸附量达到4.5 mg/g。对于含磷阴离子,脱磷能力随pH的升高而降低,吸附容量从pH=2时的4.71 mg/g降到pH=10时的2.20 mg/g。溶液初始质量浓度从10 mg/L提高到200 mg/L时,氨氮和磷的单位吸附容量分别从1.42和2.46 mg/g提高到11.6和11.8 mg/g,去除率分别从57.0%和98.2%降低到23.2%和23.6%。溶液温度从25 ℃升高到45 ℃,氨氮的吸附容量提高了10%,磷的吸附容量提高了11%。磷和氨氮的吸附过程符合准二级动力学模型。0.1 mol/L NaOH和1.0 mol/L NaCl混合溶液可以再生Zr-Na/Zeolite,循环吸附14次,吸附效率几乎保持不变。     

活性炭吸附法分离纯化ADN

采用静态吸附试验,研究了3种活性炭(AC、BC、CC)的静态吸附与解吸,筛选出一种较好的活性炭AC;通过动态吸附和解吸实验,对二硝酰胺铵(ADN)的吸附、解吸工艺条件进行了优化。结果表明,AC的吸附能力与解吸能力均优于活性炭BC与CC,是分离纯化ADN的理想吸附剂;当上样溶液质量浓度为30 155.32mg/L、流速为5mL/min时,活性炭AC对ADN的吸附量较大。以80℃热水为洗脱溶剂,洗脱至第10个柱体积时,总洗脱率达95.64%。     

SQD201树脂对钒的吸附-解吸行为及机理

通过静态吸附-解吸实验研究了SQD201树脂吸附-解吸钒的交换平衡和动力学特性,考察了pH值、温度和溶液浓度对离子交换过程的影响. 结果表明,在298 K、pH=2.0、溶液浓度为0.040 mol/L条件下,SQD201树脂的静态饱和吸附量为573.80 mg/g;钒在SQD201树脂上的吸附是吸热过程,符合Langmuir等温吸附方程. 吸附和解吸过程主要受颗粒扩散控制,吸附过程的表观活化能为20.41 kJ/mol,解吸表观活化能为22.21 J/mol. 吸附机理分析表明,SQD201树脂主要吸附的钒阴离子为H2V10O284-,H2V10O284-与树脂的理论摩尔比为1:4.