生物炭/凹凸棒土的制备及对磺胺嘧啶的吸附

利用凹凸棒土（ATP）和碱性木质素（AL）慢速限氧热解制备生物炭/凹凸棒土（BC/ATP）吸附水中的磺胺嘧啶（SDZ）,研究原料比例和热解温度对产品组分含量和吸附效果的影响,并探讨初始pH、BC/ATP投加量、吸附时间和SDZ初始浓度等因素对去除率的影响。分别采用拟一级、拟二级和颗粒内扩散方程拟合吸附过程动力学,用Langmuir和Freundlich方程拟合等温吸附线。通过扫描电镜、傅里叶红外光谱、X射线衍射、拉曼光谱和比表面积测定分析BC/ATP的表面形貌、孔结构和官能团。结果表明ATP能有效促进热解过程中挥发性中间产物二次热解,提高BC得率,改善BC/ATP吸附性能,并通过ATP的金属离子作用扩宽BC/ATP的pH敏感度。吸附动力学均符合拟二级动力学模型,且由颗粒内扩散模型拟合说明该扩散行为不是限制吸附速率的唯一因素,等温吸附线更符合Langmuir等温吸附模型,0＜R_L＜1,为优惠吸附,说明吸附过程易于进行,最大吸附量为109.53mg/g。不同pH条件下吸附机理可分为两部分：①在酸性和中性条件下,主要依靠BC/ATP的上BC表面负电荷与SDZ静电作用;②碱性条件下主要依靠ATP表面金属离子与SDZ氢键的金属阳离子桥接作用。     

榴莲壳基多级孔炭材料的制备及其对染料吸附行为研究

以农林废弃物榴莲壳为原料,用KOH化学活化法制备榴莲壳基活性炭(DSAC),通过单因素分析法和正交试验得出最佳工艺条件,对有机染料亚甲基蓝和甲基橙进行吸附研究。结果表明:在炭化温度500℃,活化温度800℃,活化时间90 min,碱炭比4∶1的条件下得到多级孔炭材料,比表面积达到了2 975 m~2/g,其微孔率为94%,介孔率为6%。DSAC对亚甲基蓝吸附值高达315 mg/g。同时研究了DSAC对有机染料的吸附行为,实验表明其吸附等温模型更接近Langmuir吸附等温模型,吸附动力学更符合准二级动力学模型,吸附过程由液膜扩散和颗粒内扩散共同控制。     

改性石墨烯-生物炭复合材料对磺胺类抗生素的吸附

本文研究海藻酸钠和磁性改性的石墨烯-生物炭复合材料对磺胺嘧啶的吸附动力学,以及p H值对吸附的影响。结果表明,吸附平衡时间是48 h,在p H值=6.0时,磺胺嘧啶的吸附量最高。本研究为选择吸附效果较好的生物炭复合材料作吸附剂去除水体中磺胺类抗生素提供理论依据。     

热解温度和生物质类型对生物炭吸附U(Ⅵ)性能的影响

以稻壳、竹子和杉木屑为原料，分别在不同热解温度下热解制备生物炭（DBC、ZBC和MBC）。采用傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）、X射线能谱（EDS）和X射线衍射（XRD）表征其理化性质，并通过批量吸附实验研究生物炭对U（VI）的吸附特性与机理。结果表明：随着热解温度升高，3种生物炭pH值和灰分增加，产率下降，且ZBC与DBC表面更加粗糙，孔状形貌更加明显，芳香结构趋于完善，含氧官能团减少，无机元素占比增加，碳纤维结晶度降低；准二级吸附动力学模型能更好地拟合3种生物炭吸附U（VI）的过程（R₂²>0.96），在25℃、pH值4、固液比为1：1（g：L）的条件下3 h可达到吸附平衡；3种生物炭的吸附等温线拟合更符合Langmuir模型，以化学吸附为主，ZBC700对U（VI）的理论最大吸附量为18.55 mg/g；随着热解温度的升高，ZBC和DBC吸附U（VI）的能力增强，阳离子-π和离子交换作用贡献增加。MBC吸附U（VI）的能力与热解温度关系不明显，相同热解温度，ZBC和DBC的吸附量高于MBC。     

零价铁、铜改性生物炭及其对Cr(Ⅵ)吸附性能的影响

针对纳米零价铁（nanoscale zero valent iron，nZVI）易团聚的特性，本文用鸡骨生物炭（BC）作载体，制备出生物炭-零价铁（Fe-BC）去除Cr(Ⅵ)，并与铜改性的生物炭-零价铁（Fe-Cu-BC）和BC对Cr(Ⅵ)的吸附性能进行了对比。通过扫描电镜（SEM）和能谱仪（EDS）、X射线衍射（XRD）、N₂吸脱附等温线和傅里叶红外光谱（FTIR）对材料表面形貌及结构性质进行分析，同时考察了溶液pH、接触时间等条件对吸附剂吸附容量的影响，通过吸附动力学和吸附等温线分析了吸附特性。结果表明，在pH=2的条件下去除Cr(Ⅵ)效果较好；吸附平衡遵从Langmuir吸附等温式；吸附动力学符合准二级动力学方程。Fe-BC材料吸附水体污染物后可用磁分离技术加以回收。Fe-Cu-BC缩短了对Cr(Ⅵ)的吸附平衡时间。制备出的吸附剂对Cr(Ⅵ)的理论最大吸附量顺序为 Fe-BC>Fe-Cu-BC>BC；同时， Fe-BC吸附量为153.60mg/g，对比于先前报道的nZVI对Cr(Ⅵ)的吸附容量85mg/g左右，有了很大的提升，说明BC作载体成功解决了nZVI易团聚的缺点，拓展了实际应用。     

废白土榴莲壳粘土生物炭的制备及对Cr(VI)的吸附

以废白土与榴莲壳为原料制备了粘土生物炭吸附剂(spent bleaching earth biochar,SBEC)、以废白土为原料制备了粘土炭基吸附剂(spent bleaching earth,SBE)吸附废水中的Cr（VI）。用比表面积分析、SEM、XRD、FTIR对吸附剂进行了表征。考察了溶液初始pH、Cr(VI)溶液浓度、吸附剂投加量、吸附时间和吸附温度分别对吸附Cr(VI)的影响。25℃下pH为3时、SBEC 投加量为0.5g/L、Cr(VI)初始浓度为100mg/L、吸附时间120min,SBEC对Cr(VI)去除效率最高为86.1%,SBE则在pH为2去除效率最高为52.5%。SBEC、SBE对Cr(VI)的吸附过程符合准二级动力学模型，SBEC吸附过程符合Freundlich模型，SBE则与Langmuir吸附等温线模型较符合；吸附行为是自发吸热过程。经过5次吸附-脱附后,SBEC对Cr(VI)的去除率达58.8%。     

镁浸渍生物炭吸附氨氮和磷：制备优化和吸附机理

利用废弃的木薯杆制备了载镁的生物炭吸附剂。以氨氮、磷为目标污染物，采用控制变量法研究了不同镁盐改性、MgCl₂浓度、碳化温度、固液比和碳化时间对氨氮、磷吸附性能的影响，制备最具吸附性能的载镁木薯秆基生物炭（Mg-BC），进行批量吸附氨氮和磷实验。利用等温模型（Langmuir和Freundlich模型）和动力学模型（准一级动力学、准二级动力学和颗粒内扩散模型）探究其吸附特性，在其吸附特性研究的基础上，运用FTIR、XRD、SEM-EDS、XPS等表征手段对其吸附机理进行探讨。结果表明，Mg-BC对氨氮和磷的吸附过程均符合Freundlich模型和准二级动力学模型，为多分子层的化学吸附，理论饱和吸附量分别为43.48 mg·g^-1和96.00 mg·g^-1。结合表征结果推测，Mg-BC吸附氨氮、磷主要通过官能团作用、络合沉淀和离子交换等多过程协同完成。     

废白土榴莲壳粘土生物炭的制备及对Cr(VI)的吸附

以废白土与榴莲壳为原料制备了粘土生物炭吸附剂(spent bleaching earth biochar,SBEC)、以废白土为原料制备了粘土炭基吸附剂(spent bleaching earth,SBE)吸附废水中的Cr（VI）。用比表面积分析、SEM、XRD、FTIR对吸附剂进行了表征。考察了溶液初始pH、Cr(VI)溶液浓度、吸附剂投加量、吸附时间和吸附温度分别对吸附Cr(VI)的影响。25℃下pH为3时、SBEC 投加量为0.5g/L、Cr(VI)初始浓度为100mg/L、吸附时间120min,SBEC对Cr(VI)去除效率最高为86.1%,SBE则在pH为2去除效率最高为52.5%。SBEC、SBE对Cr(VI)的吸附过程符合准二级动力学模型,SBEC吸附过程符合Freundlich模型,SBE则与Langmuir吸附等温线模型较符合;吸附行为是自发吸热过程。经过5次吸附-脱附后,SBEC对Cr(VI)的去除率达58.8%。     

磁性菠萝蜜壳生物炭对水中重金属铅的吸附性能研究

以废弃果皮菠萝蜜壳为原料,以磷酸活化后的菠萝蜜壳生物炭（AJSB）为基体,采用共沉淀法负载MnFe2O4纳米磁性颗粒制备出磁性菠萝蜜壳生物炭（MAJSB）,并将MAJSB用于去除水中铅离子。采用SEM、Zeta电位、XRD、FTIR和VSM手段对MAJSB进行表征,探究MAJSB的结构特性,考察了MAJSB投加量、吸附时间、初始pH等因素对废水中铅离子吸附效率的影响。从表征结果分析可知,MnFe2O4纳米磁性颗粒成功负载到了AJSB上使其携带磁性的同时,也增加了表面官能团种类和吸附点位;实验结果表明,MAJSB用于处理pH为5,浓度为100 mg/L的铅离子废水时,在MAJSB投加量为0.75 g/L、温度为25℃、吸附时间为60 min的条件下,对铅的吸附效率达98.17%;吸附过程符合准二级动力学模型和Langmuir等温吸附模型。     

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.     

Study of adsorption isotherms and kinetic models for Methylene Blue adsorption on activated carbon developed from Egyptian rice hull (Part II)

Adsorption of Methylene Blue (MB) from aqueous solutions on activated carbon prepared from Egyptian rice hulls (ERHA) is studied experimentally. Results obtained indicate that the removal efficiency of Methylene Blue at 25 °C exceeds 99% and that the adsorption process is highly pH-dependent. Results showed that the optimum pH lies between 5 and 9. The amount of Methylene Blue adsorbed form aqueous solution increases with the increase of the initial Methylene Blue concentration and temperature. Smaller adsorbent particle adds to increase the percentage removal of Methylene Blue.The results fit the BET model for adsorption of MB on ERHA, corroborating the assumption of that the adsorbate molecules could be adsorbed in more than one layer thick on the surface of the adsorbent.A comparison of kinetic models at different conditions (pH, Temperature, adsorbent particle size, adsorbent dose and adsorbate concentration) applied to the adsorption of Methylene Blue on the adsorbent was evaluated for the pseudo first-order, the pseudo second-order, Elovich and intraparticle diffusion kinetic models, respectively. Results showed that the pseudo second-order kinetic model correlate the experimental data well.     

镧改性核桃壳生物炭制备及吸附水体磷酸盐性能

为研发低成本的磷酸盐吸附剂,以核桃壳为原料,LaCl₃为改性试剂热解制备核桃壳生物炭。通过SEM-EDS、ICP-OES、FTIR和XRD对生物炭进行表征,采用吸附等温模型和动力学模型拟合生物炭的吸磷特征,并研究热解温度、La改性浓度、添加量、初始溶液pH和共存离子对生物炭吸附磷的影响。结果表明：La改性后,生物炭表面由于负载了La₂O₃和LaOCl,其吸附能力明显提高。热解温度为400℃、La浸渍浓度为0.1mol/L时获得的生物炭（BC-La400）,其Langmuir最大磷吸附容量为12.18mg/g,吸附过程主要受化学吸附和颗粒内扩散控制。热解温度和La改性浓度过高均不利于磷的吸附。磷初始浓度为50mg/L时,BC-La400添加量为2.7g/L可获得较理想的吸附能力,但当添加量超过4.0g/L时,磷脱除率可超过98%。BC-La400吸磷时最佳初始pH为3,CO{}_{\mathrm{3}}^{\mathrm{2}-}共存会明显削弱BC-La400对磷的吸附能力。     

酸改性猪粪生物炭的制备及其对直接红23染料的吸附性能

以直接红23染料（DR23）溶液模拟印染废水,对比分析了酸改性前后猪粪生物炭对DR23的吸附特性与机理。通过静态吸附实验考察了DR23溶液的pH、初始浓度、吸附时间、吸附温度、吸附剂添加量等条件对吸附效果的影响,并确定了该吸附过程的吸附动力学和吸附等温线。研究发现,相比于未改性生物炭（PMB）,酸改性后生物炭（PMB_acid）结构变得疏松多孔,表面官能团丰富,表现出更优的脱色性能,对DR23的吸附去除率最高可达96.10%,最大饱和吸附量为111.51mg/g,且在经过3次循环再生后,PMB_acid对DR23的去除率仍可达到88.31%;此外,pH对PMB_acid的脱色吸附性能影响较小。PMB_acid对DR23的吸附是一个受反应速率和扩散控制的复杂过程,符合于伪二级动力学模型和Langmuir等温吸附模型;PMB_acid对DR23的吸附机理取决于吸附剂的物理化学性质,其孔结构及各官能团通过不同的机制参与了生物炭对DR23的吸附过程。     

Removal of cadmium(II) cations from an aqueous solution with aminothiourea chitosan strengthened magnetic biochar

An aminothiourea chitosan modified magnetic biochar composite (TMBC) was prepared for the efficient removal of Cd(II) from wastewater. The synthesized materials were characterized, and the detailed adsorption mechanisms and thermodynamics were studied. The adsorption experiments revealed that TMBC had a higher affinity for Cd(II) than the magnetic biochar composite, raw biochar, and other carbon‐based adsorbents did. The Cd(II) adsorption process fit the pseudo‐second‐order kinetic model, and the maximum adsorption capacities on the basis of the Langmuir model were 93.72, 121.9, and 137.3 mg/g at 298, 308, and 318 K, respectively. The practical efficacy of the adsorbent was also tested with a real mine water. The metal‐ion‐loaded TMBC could be conveniently collected by a magnet and could be easily regenerated with adsorption efficiencies up to 84% after five adsorption–desorption cycles. The as‐prepared TMBC might be a promising adsorbent for the treatment of heavy‐metal‐ion‐contaminated water or highly mineralized mine water. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46239.     

PBMA/GMA-SiO2吸附剂的制备及其高效去除铅离子

以甲基丙烯酸丁酯(BMA)和甲基丙烯酸缩水甘油酯(GMA)功能化的纳米SiO2为单体,通过可逆加成-断裂链转移自由基聚合(RAFT)法制备了PBMA/GMA-SiO2有机/无机复合吸附材料,并将其用于吸附含Pb2+的水溶液。考察了吸附时间、温度、pH以及Pb2+初始质量浓度对吸附效果的影响,并对其吸附动力学和热力学特性进行了探讨。结果表明,PBMA/GMA-SiO2对Pb2+具有良好的吸附性能,其对Pb2+的饱和吸附量为423.84mg/g,吸附最佳pH=5~6,平衡时间为1 h,去除率随Pb2+初始质量浓度的减小而增加。优化实验条件下,50 mg吸附剂在298 K时,对pH=6的50 mL 0.02 g/L含Pb2+溶液的去除率高达100%。热力学和动力学过程模拟结果表明,吸附的动力学过程比较符合准二级动力学速率方程,Langmuir等温方程比Freundlich等温方程更适合于描述此吸附行为。颗粒内扩散过程是吸附速率的控制步骤,但不是唯一的速率控制步骤。吸附剂经过5次脱附、吸附后,依然具有较强吸附Pb2+的能力。     

用椰壳制活性炭吸附去除三价铋离子(英文)

In present study,we report the preparation of coconut shell activated carbon as adsorbent and its appli-cation for Bi(Ⅲ) removal from aqueous solutions.The developed adsorbent was characterized with scanning elec-tron microscope(SEM),Fourier Transform Infrared(FTIR),C,H,N,S analyzer,and BET surface area analyzer.The parameters examined include agitation time,initial concentration of Bi(Ⅲ),adsorbent dose and temperature.The maximum adsorption of Bi(Ⅲ)(98.72%) was observed at 250 mg·L-1 of Bi(Ⅲ) and adsorbent dose of 0.7 g when agitation was at 160 r·min-1 for 240 min at(299±2) K.The thermodynamic parameters such as Gibb’s free energy(△Gθ),enthalpy(△Hθ) and entropy(△Sθ) were evaluated.For the isotherm models applied to adsorption study,the Langmuir isotherm model fits better than the Freundlich isotherm.The maximum adsorption capacity from the Langmuir isotherm was 54.35 mg?g?1 of Bi(Ⅲ).The kinetic study of the adsorption shows that the pseudo second order model is more appropriate than the pseudo first order model.The result shows that,coconut shell ac-tivated carbon is an effective adsorbent to remove Bi(Ⅲ) from aqueous solutions with good adsorption capacity.     

Thermodynamic,kinetic, and equilibrium studies on phenol removal by use of cashew nut shell

Adsorption of phenol from aqueous solution onto cashew nut shell (CNS) was investigated to assess the possible use of this adsorbent. The influence of various parameters such as contact time, phenol concentration, adsorbent dose, pH, and temperature has been studied. Studies showed that the pH of aqueous solutions affected phenol removal as a result of decrease in removal efficiency with increasing solution pH. The experimental data were analysed by the Langmuir equation. Equilibrium data fitted well with the Langmuir model with maximum monolayer adsorption capacity of 5.405 mg/g. Thermodynamic parameters such as ΔG°, ΔH°, and ΔS° have also been evaluated and it has been found that the sorption process was feasible, spontaneous, and exothermic in nature. The pseudo‐first‐order and pseudo‐second‐order kinetic models were selected to follow the adsorption process. Kinetic parameters, rate constants, equilibrium sorption capacities and related correlation coefficients, for each kinetic model were calculated and discussed. It was shown that the adsorption of phenol could be described by the pseudo‐second‐order equation, suggesting that the adsorption process is presumable a chemisorption. The CNS investigated in this study showed good application potential for the removal of phenol from aqueous solution.