榴莲壳生物炭对磺胺嘧啶的吸附性能

以榴莲壳为原材料，制备了榴莲壳生物炭（biochar，BC），以磷酸为活化剂，在碳化温度为350℃、浸渍比为2.5∶1（磷酸∶生物质，质量比）的条件下，制备了活化榴莲壳生物炭（activated durian shell biochar，DBC），并探究二者对磺胺嘧啶（sulfadiazine，SDZ）的吸附作用。通过单因素实验探究了DBC投加量、溶液pH、初始浓度、吸附温度对水中SDZ的去除影响，并用正交实验确定了DBC对SDZ吸附的最优条件。在生物炭的投加量为1.2g/L、SDZ初始浓度为10mg/L、溶液pH为4时，SDZ最大去除率最高。利用吸附等温模型（Langmuir、Freundlich）和吸附动力学模型（准一级动力学、准二级动力学），探究DBC对SDZ的吸附特性，并进行了比表面积及孔径分析、扫描电镜（SEM）、傅里叶红外光谱（FTIR）的表征分析。结果表明，与BC相比，DBC有丰富的微孔结构，比表面积达1224.635m²/g，含氧官能团数量增加，为SDZ的吸附提供了更多的吸附位点，同时Langmuir吸附等温模型可以较好地描述DBC对SDZ的吸附等温过程，吸附动力学过程更符合准二级动力学方程。因此，磷酸活化榴莲壳生物炭可以作为一种高效的吸附剂去除水中的磺胺嘧啶。     

磷基生物炭对含Pb2+废水的吸附特性研究

以污泥与含磷试剂(磷酸二氢钾、磷酸二氢钙)为原料制备磷基生物炭(BC600、BC650)并用于废水中Pb2+的去除.通过单因素静态吸附实验分别研究了吸附剂添加量、含Pb2+废水初始pH、浓度和吸附时间等对BC600和BC650吸附水中Pb2+的影响.结果表明,含Pb2+废水初始pH显著影响BC600和BC650的吸附效率,在pH=5时,BC600和BC650的吸附量分别为37 mg/g和10 mg/g.吸附动力学和吸附等温模型拟合结果表明BC600符合二级动力学模型和Langmuir吸附等温模型,BC650符合一级动力学模型和Freundlich吸附等温模型.结合XRD与SEM分析,BC600和BC650对Pb2+的吸附过程包含物理-化学吸附协同作用,其中BC600以化学吸附为主,BC650以物理吸附为主.     

硫脲改性磁性壳聚糖微球对Hg2+,Cu2+和Ni2+的吸附

利用反相分散-化学交联的方法制备磁性壳聚糖微球（MCS）,并利用硫脲改性,得到改性磁性壳聚糖微球（TMCS）。考察接触时间、pH值、温度以及金属离子初始浓度对TMCS吸附Hg^2＋,Cu^2＋和Ni^2＋的影响。发现相同条件下,Hg^2＋,Cu^2＋和Ni^2＋达到吸附平衡的时间依次增加,饱和吸附容量随pH值和金属离子初始浓度的增高而增加,随温度升高而下降。利用拟一级反应动力学模型和拟二级反应动力学模型对实验数据进行拟合,并分别采用Freundlich模型、Langmuir模型和Tempkin模型对吸附等温线进行拟合。结果表明,吸附动力学符合拟二级反应动力学模型,化学吸附为控制步骤,且吸附等温线用Langmuir模型拟合结果最好。在TMCS1．5g／L,金属离子初始浓度100mg／L,pH值5．0和吸附6h条件下,TMCS对Hg^2＋,Cu^2＋和Ni^2＋饱和吸附容量分别为625．2,66．7和15．3mg／g。吸附金属离子的TMCS利用0．01mol／L的乙二胺四乙酸（EDTA）再生,金属离子脱附率高于85％。     

膨润土-活性炭复合吸附剂对锰离子的吸附

以膨润土和活性炭为原料制备了复合吸附剂并将之应用于含锰离子废水的吸附。考察了不同条件下该吸附剂对水体中Mn（Ⅱ）的去除效果,并研究了吸附动力学特征和等温吸附过程。结果表明膨润土和活性炭复合吸附剂对Mn（Ⅱ）具有优良的吸附能力,在25 ℃下,当投加量为4 g/L、Mn（Ⅱ）初始质量浓度为50 mg/L、溶液pH为6时,吸附180 min,吸附率为93.2%。准一级、准二级动力学和内扩散模型用来拟合吸附过程,结果表明准二级动力学符合该吸附过程,吸附速率常数为0.003 6 g/（mg·min）,内扩散过程不是吸附的限速步骤,还存在吸附机制的制约。用Langmuir和Freundlich模型描述吸附等温过程,结果得出该吸附过程服从Langmuir吸附,饱和吸附容量为27.781 mg/g。     

细菌纤维素对重金属离子的吸附机理研究

以细菌纤维素(BC)为吸附剂,对重金属离子Cu2+,Pb2+和Cd2+的吸附等温线和吸附动力学特性进行了研究,并采用红外光谱分析法探讨了吸附作用机理。结果表明:BC对Cu2+,Pb2+和Cd2+吸附更好地符合Langmuir吸附等温方程和准二级反应动力学模型,说明吸附过程为单分子层吸附,化学吸附作用为主。粒子内扩散拟合曲线均不经过原点,证明粒子内扩散并不是唯一速率控制步骤。FT-IR分析表明吸附金属离子后的BC中—OH最大吸收位发生不同程度的蓝移,说明BC中部分—OH参与吸附,即与重金属离子之间发生反应,从而使—OH的数量减少。     

污泥生物炭/凹凸棒土的制备及其吸附性能研究

利用凹凸棒土(ATP)和污水污泥(SS)慢速共热解制备污泥生物炭/凹凸棒土(SBC/ATP)，并开展其对亚甲基蓝(MB)吸附性能的研究。通过扫描电镜、X射线衍射光谱、红外光谱、X射线光电子能谱等表征对污泥生物炭及其复合材料的微观形貌和理化性质进行了分析。探究了热解温度和原料配比对污泥生物炭/凹凸棒土吸附性能的影响，同时考察了吸附剂投加量、pH、MB溶液初始质量浓度及吸附时间等因素对MB去除率的影响。实验结果表明，500℃下制备的SBC/ATP₍(50%))在吸附剂投加量为1.2 g/L、pH=11、MB溶液初始质量浓度为100 mg/L、吸附时间为180 min时，吸附容量最大为53.74 mg/g。SBC/ATP₍(50%))对MB的吸附更符合Langmuir等温线模型和准二级动力学模型，说明该吸附过程主要为化学吸附控制的单分子层吸附。     

Fe浸渍污泥生物炭对含Cd(Ⅱ)废水的吸附性能研究

通过城市污泥热解制备污泥生物炭(BC),采用FeCl_3溶液浸渍污泥生物炭后制备出磁性污泥生物炭(MBC),对比了BC与MBC去除水溶液中Cd(Ⅱ)的能力。考察溶液初始pH、吸附时间、吸附温度以及Cd(Ⅱ)初始浓度对BC和MBC去除Cd(Ⅱ)效果的影响。结果表明,BC和MBC均符合拟二级动力学吸附模型;Langmuir吸附等温模型能够更好地描述BC和MBC去除Cd(Ⅱ)的过程。在溶液初始pH为6.0,生物炭投加量为10 mg,Cd(Ⅱ)质量浓度为10～150 mg/L的溶液25 mL,吸附时间为360 min,温度为25℃的最佳条件下,BC和MBC对Cd(Ⅱ)最大的吸附量分别为76.93 mg/g和167.42 mg/g。经过5次吸附解吸试验,MBC的Cd(Ⅱ)去除率保持在90%以上,BC的Cd(Ⅱ)去除率在55%左右,说明MBC具有更好应用于去除含Cd(Ⅱ)废水的能力。     

原花青素在HZ818树脂上的吸附热力学和动力学

通过在不同温度下的静态吸附实验,研究了葡萄籽原花青素在大孔树脂HZ818上的吸附热力学及动力学特性。分别采用Langmuir、Freundlich等温式对不同温度下的等温吸附数据进行拟合,采用Largergren拟一级动力学模型、拟二级动力学模型和颗粒内扩散动力学模型对吸附动力学数据进行分析。结果表明:原花青素在HZ818树脂上的吸附量随着温度的升高而增大,等温吸附数据更符合Langmuir等温吸附方程,吸附焓变大于0,吉布斯自由能变小于0,HZ818树脂对原花青素的吸附过程为自发进行的吸热过程;吸附动力学更符合拟二级动力学模型,过程受主要包括颗粒内扩散在内的多因素共同影响。     

高岭土吸附结晶紫性能研究

研究了高岭土对结晶紫的吸附性能,并进一步探讨了等温吸附模型和吸附动力学。分别考察了吸附时间、pH值、高岭土投加量、结晶紫初始浓度和温度等因素对高岭土吸附结晶紫效果的影响。结果表明,吸附时间90 min,高岭土投加量10 g/L,碱性条件下能达到较好的结晶紫吸附效果。高岭土对结晶紫吸附动力学符合准二级动力学模型,吸附等温方程符合Langmuir和Freundlich吸附模型。     

污泥热解半焦对罗丹明B吸附行为研究

以污泥热解半焦为吸附剂,研究其对模拟罗丹明B(RhB)染料废水的吸附行为。考察了吸附剂投加量、RhB溶液初始浓度、温度、pH对半焦吸附RhB结果的影响。结果表明,半焦投加量、温度及pH的升高均可提高RhB的去除率,SiO_2的骨架作用、较大的比表面积及良好的孔隙结构为吸附RhB提供了更多的吸附点位。随着RhB初始浓度的增加,更高的浓度差推动RhB分子由吸附剂表面向其内部迁移,提高了RhB的吸附量。准二级动力学模型和颗粒内扩散模型能较准确地描述吸附动力学过程。吸附平衡研究表明,Langmuir模型比Freundlich模型能更好地拟合吸附过程,最大饱和吸附量为46.51 mg/g。热力学计算结果显示,污泥热解半焦吸附水中RhB为自发的吸热过程。     

聚丙烯酸改性凹土对Pb2+、Ni2+和Cr3+的选择性吸附

通过凹土的表面功能化开发高性能低成本的吸附材料,采用溶液聚合法在其表面接枝聚丙烯酸,制备出聚丙烯酸/凹土吸附材料(PAA/ATP),系统考察了PAA/ATP对Pb²⁺、Ni²⁺和Cr³⁺三元混合体系的吸附性能。结果表明:PAA/ATP复合吸附材料的有机物接枝率为14.1%,其结构中出现聚丙烯酸的特征官能团;PAA/ATP吸附Pb²⁺的动力学符合拟二级动力学,即化学吸附是速率控制步骤,说明PAA/ATP对Pb²⁺的吸附是一个有化学作用的过程,吸附过程与Pb²⁺和吸附剂PAA/ATP表面官能团之间的电子转移或电子共用有关;PAA/ATP对Pb²⁺的吸附符合Langmuir吸附等温模型;PAA/ATP对Pb²⁺、Ni²⁺和Cr³⁺的竞争吸附能力依次为Pb²⁺ > Cr³⁺ > Ni²⁺,即对Pb²⁺具有较好的选择性吸附。     

REMOVAL OF METAL IONS FROM AQUEOUS SOLUTIONS USING PYROLYZED RICE HUSKS: ADSORPTION KINETICS AND EQUILIBRIA

Four carbon/silica-containing materials obtained by pyrolysis of rice husks were characterized and their adsorption properties towards some metal ions were evaluated. GC/MS analysis and FT-IR spectroscopy were applied for identification of functional groups finely dispersed on the surface. Their amounts were gravimetrically determined after extraction with acetone. The specific surface area and porosity of the materials were characterized by the Brunauer-Emmett-Teller (BET) method and by mercury porosimetry, respectively. The adsorption properties of the carbonized rice husks towards Fe(III), Pb(II), Cr(III), and Cu(II) ions in single- and multicomponent aqueous solutions also containing Ni(II), Co(II), Mn(II), and Cd(II) were studied in a batch system. The effects of contact time, acidity of initial solutions, and metal ion concentrations were followed. Pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were used to analyze kinetic data. Equilibrium experimental data were fitted to linear Langmuir and Freundlich models. The maximum adsorption capacities for single- and multicomponent adsorption were calculated and compared with literature data. A correlation between the adsorption properties of pyrolyzed rice husks and their textural and surface parameters was established. Possibilities for desorption of the investigated ions were estimated.     

Adsorption of Pb(II) from aqueous solution to Ni-doped bamboo charcoal

Bamboo charcoal (BC) obtained by pyrolysis of Makino bamboo in the absence of oxygen was used as support for the preparation of Ni-doped adsorbent (Ni-BC). The low-cost composite was characterized and used as an adsorbent for Pb(II) removal from water. The results showed that both BET surface area and total pore volume of Ni-BC increased. The adsorption of Pb(II) strongly depended on solution pH, temperature and ionic strength. The adsorption isotherms followed Langmuir isotherm model well, and the maximum adsorption capacities of Pb(II) at 298 K were 25.0 and 142.7 mg/g for BC and Ni-BC, respectively. The adsorption processes were well fitted by pseudo-second-order kinetic model. Thermodynamic parameters showed that the adsorptions of Pb(II) onto both adsorbents were feasible, spontaneous, and exothermic under the studied conditions. The spent Ni-BC could be readily regenerated for reuse.     

铜抗性菌株的筛选及其对Cu2+的吸附性能

利用选择性培养基分离出铜抗性细菌BX,经鉴定该菌为产碱普罗威登斯菌(Providencia alcalifaciens)。考察了细菌BX对环境的适应性,讨论了pH、初始Cu²⁺浓度等对其吸附铜离子的影响,分析了吸附过程的动力学及等温吸附特性,并以多孔陶瓷为载体对其进行固定化。结果表明,该菌对Cu²⁺和NaCl的抗性浓度分别为7 mmol·L^-1和7.5%,可生长于pH4.0～11.0、15～50℃的环境中;其最佳吸附条件为pH5.5、温度30℃、起始Cu²⁺浓度100 mg·L^-1,在该条件下,Cu²⁺吸附率达85.84%,吸附量为128.74 mg·g^-1;其对Cu²⁺的吸附符合准二级动力学方程和Freundlich等温吸附模型;采用曝气挂膜法将细菌固定于多孔陶瓷上,形成的菌膜对50 mg·L^-1铜离子的吸附率达92.53%。表明细菌BX对Cu²⁺有较强的吸附能力,对含Cu²⁺废水的处理具有良好的应用前景。     

Aqueous Phase Adsorption of Cephalexin onto Bentonite and Activated Carbon

The adsorption of cephalexin in aqueous solution has been investigated using bentonite and activated carbon as the adsorbents. Batch kinetics and isotherm studies were carried out to evaluate the effect of contact time, adsorbent dosage, pH, particle size, and temperature. Adsorption equilibrium data were well represented by the Langmuir and Freundlich isotherm models. The adsorption intensity was found to be increased as the aqueous phase pH increased, and had a maximum at pH = 6.1. The pseudo-first order, pseudo-second order, and intraparticle diffusion kinetic models were used to describe the kinetic data. The experimental data fitted very well with the pseudo-second-order kinetic model and also followed the simple external and intraparticle model.     

改性蜂窝煤残渣对刚果红的吸附

以改性蜂窝煤渣为吸附剂,用扫描电镜对改性前后蜂窝煤残渣的形貌进行了表征,研究了其吸附水中刚果红染料的动力学和热力学,分别用Langmuir, Freundlich和Tempkin吸附等温线模型进行拟合. 结果表明,改性蜂窝煤残渣对刚果红的吸附能力良好. Langmuir方程的拟合效果最好(RC2≥0.9979),25, 35, 45℃下的饱和吸附量分别为80.64, 92.59和108.7 mg/g. 吸附过程符合拟二级动力学模型(RC2≥0.9961),吸附活化能为22.87 kJ/mol,为物理吸附过程. 吸附为表面扩散和颗粒内扩散联合控制过程. 改性蜂窝煤渣对刚果红的吸附是自发的吸热过程.     

The removal of sodium dodecyl benzene sulfonate by activated carbon modified with quaternary ammonium from aqueous solution

Activated carbon (AC) was modified via grafting quaternary ammonium for the selective adsorption of sodium dodecyl benzene sulfonate (SDBS) from aqueous solution. The surface modification of AC was confirmed by FT-IR, XPS and Raman spectroscopy. The results showed that the modified AC selectively adsorbed the anionic SDBS. Adsorption kinetics could be well described by pseudo-second-order kinetic equation (or three-stage intraparticle diffusion mode), adsorption isotherms fitted well with Langmuir model. Quaternary ammonium on AC enhanced electropositivity and led to the selective adsorption of SDBS.     

Fast Removal of Sr(II) From Water by Graphene Oxide and Chitosan Modified Graphene Oxide

Graphene oxide is a unique material that can be used for adsorption of radioactive waste because it contains various function groups such as epoxide, carbonyl, carboxyl and hydroxyl in addition to its high specific surface area. The as-prepared GO and the modified one (GO-chitosan composite) have been prepared then characterized and used as adsorbent for radioactive metal ions [Strontium, Sr(II)]. The results showed that the prepared materials are efficient adsorbents for removal of Sr(II) from water. The effect of contact time, pH and temperature on adsorption have been studied. The results indicated that the maximum adsorption capacity was about 140 and 179.6 mg/g for GO and GO-chitosan composite respectively. It was found that pH?~?6 and temperature?~?40 °C are the best condition for removal of Sr(II) from water. Two isotherm models (Langmuir and Freundlich) and three kinetic models (Pseudo-first-order, pseudo-second-order, and intra-particle particle diffusion model) have been applied. Based on the calculated isotherm parameters (R²), it can be concluded that Langmuir model fits the adsorption equilibrium data better than Freundlich model, the results also indicated that the second order kinetic model is the best representative for adsorption of Sr(II) on GO, Chitosan and GO-Chitosan. Based on the regressions of intraparticle diffusion model, experimental data showed that the adsorption process involved intraparticle diffusion, which was not the only rate-controlling step.