天然活化沸石负载壳聚糖对高氟水的处理

为提高天然沸石对氟的吸附能力,采用活化天然沸石负载壳聚糖改性处理,研究了除氟剂的性能,确定了除氟剂的最佳改性条件:2.0%冰醋酸溶液,壳聚糖浓度为0.05 g/mL,壳聚糖:沸石(质量比)=0.07,室温下改性5 min。最适除氟条件:pH=6.0,粒径1~2 mm,100 r/min的速度搅拌反应50 min,静置0 min。吸附剂对F-的吸附过程符合Langmuir吸附等温线,对氟离子的饱和吸附容量为10.63 mg/g。     

改性人造沸石处理含黄玉铬洁(Ⅵ张焕)祯地下水的实验研究

为了提高人造沸石对地下水中铬(Ⅵ)的去除能力,采用氯化铝对人造沸石进行改性。确定最佳改性条件:20%氯化铝溶液,液固比12 mL/g,室温下以180 r/min振荡改性8 h;最佳除Cr(Ⅵ)条件:pH值为4～8,液固比为33.3 mL/g,室温下水浴恒温振荡2 h。改性沸石对铬(Ⅵ)的吸附符合Langmuir及Freundlich等温线方程,由Langmuir吸附等温线可得其吸附容量为5.624 mg/g。在最佳反应条件下,水样中铬(Ⅵ)浓度可由5 mg/L下降到0.026 mg/L,低于0.05 mg/L,满足GB/T 14848—93《地下水环境质量标准》Ⅲ类标准。     

负载镧镁活性氧化铝的制备及除氟性能研究

采用浸渍法制备负载镧镁活性氧化铝改性除氟剂,用于去除溶液中氟离子。通过正交实验考察镧镁摩尔比、焙烧温度和焙烧时间对改性活性氧化铝吸附性能的影响,得出最佳合成条件为镧、镁物质的量比1∶2,焙烧温度300℃,焙烧时间2.0 h。研究吸附时间、投加量、p H值和共存阴离子对氟离子吸附效果的影响。结果表明:吸附时间为3.0 h、投加量为3.6 mg/L,p H值在6~9,除氟效果最好,氟离子去除率为94.5%;对比不同阴离子对除氟性能的影响,除氟性能受阴离子影响力大小为:CO2-3>SO2-4>Cl->NO-3;吸附剂对氟离子的吸附过程符合伪二级动力学模型,吸附等温线满足Langmuir吸附等温式,其饱和吸附量为7.663 mg/g;不同温度下的热力学结果表明该反应为自发吸热反应。     

CTMAB/CPAM/膨润土复合材料的制备与应用

以钠基膨润土为原料,CTMAB、CPAM为改性剂制备复合改性膨润土。探讨了最佳制备条件为:CTMAB投加量2 mmol,CPAM投加量0.03 g,原土投加量6 g,搅拌速度200 r/min,改性时间大于1.5 h。FTIR和XRD对复合改性膨润土进行表征,表明CTMAB、CPAM进入膨润土层间,扩大了膨润土的层间距从而提高了吸附性能。在原水浓度191 600 mg/L,改性土投加量2 g,搅拌时间1~3 h,pH值6~8,搅拌速度200~300 r/min,离心速度1 400 r/min,离心时间2 min的工艺条件下,制药废水COD去除率可达70%。吸附动力学研究结果表明准二级动力学模型能很好地描述膨润土复合材料对制药废水的吸附过程。     

载铝改性人造沸石对含氟水除氟效果的研究

采用盐酸浸泡活化和硫酸铝溶液浸泡改性的方法对人造沸石进行改性,用模拟高氟水样进行静态及动态除氟实验。动力学研究结果表明:吸附剂吸附速度快,30 min接近吸附平衡,吸附速率可用拟二级动力学方程描述。吸附等温线符合Langmuir方程,饱和吸附量为5.07 mg/g,吸附平衡常数为0.060 2 L/mg。静态实验对浓度...     

新型除氟剂竹炭的优选和改性方法实验研究

采用不同产地的竹炭进行除氟研究,分别进行了直接除氟和改性后除氟的效果比较。在水浴恒温振荡箱,振荡速度100 r/min,温度30件下,保持固液比0.03,反应1.5 h,处理初始氟浓度10 mg/L的溶液,浙江丽水的机械竹炭的直接除氟效果比其它地方的竹炭都好,其对氟去除率为47.8%。通过该竹炭的直接除氟工艺参数优化结果可知,pH是影响竹炭除氟的关键因素,最佳值为4;随着竹炭量的增大,氟离子的去除率明显上升;氟离子的初始浓度增大,竹炭的单位吸附量也逐渐上升;反应时间为90 min时,反应逐渐趋于平衡。选用Al2（SO4）3对竹炭进行改性后,浙江丽水的机械竹炭的除氟率有很大的上升;采用MgSO4改性后各类竹炭除氟效果均有所下降。采用Fe2（SO4）3改性后,氟离子的去除率达到91.8%,剩余浓度为0.82 mg/L,达到国家饮用水的标准。     

沸石的载铁改性及饮用水除氟试验研究

为避免使用含铝材料,采用新方法制得载铁改性斜发沸石,并通过一系列静态及动态试验对其除氟性能及影响因素进行了研究.结果表明:经过改性活化的斜发沸石滤料的除氟容量(DC)得到显著提高,静态达0.665 mg/g,动态达0.2 mg/g,分别约为原沸石除氟容量(0.03 mg/g)的20和7倍.载铁改性斜发沸石对F的吸附符合Langmuir吸附等温模式,其最适pH为6～7,氟吸附速率快,再生稳定;同时其也能高效去除饮用水中的锰离子,除锰容量(MRC)达2.442 mg/g.对高氟地下水的处理效果证明,该滤料不仅降氟达到国家饮用水标准,而且具有再生简易、使用寿命长等特点.     

铬、砷离子吸附剂的制备及其吸附性能的研究

通过对沸石的改性,在沸石表面形成了一层纳米态的二氧化锰,而纳米态的二氧化锰及沸石都对水中重金属有强烈的吸附性能,从而达到对铬、砷离子的吸附作用。通过沸石与二氧化锰的配比、吸附溶液的pH值、吸附时间、改性沸石的用量对其去除效果的影响,探讨了吸附作用机理。通过吸附测定,改性沸石的最佳配比沸石：MnO2为2：1;改性沸石对As（III）的最佳吸附pH和时间为5.0和30 min;对Cr（VI）的最佳吸附pH和时间为7.0和30 min的条件下吸附效果最佳。     

铝改性粉煤灰漂珠材料吸附水中氟的性能研究

采用湿法+干法制备铝改性漂珠材料,借助静态吸附实验研究吸附剂用量、pH值、共存离子、反应时间和反应温度对去除水溶液中氟离子性能的影响,并对实验数据进行吸附等温线和动力学拟合。结果表明:铝改性漂珠材料吸附水中氟离子的最佳pH值为3;最佳吸附剂用量2.5 g/L;共存离子影响由强到弱的顺序为H2PO4-,SO42-和NO3-的混合物﹥H2PO4-﹥SO42-﹥NO3-;在温度298 K、吸附剂用量2.5 g/L、pH值为3和反应时间24 h的条件下,最大吸附容量约10.2 mg/g;吸附等温线符合Langmuir单层吸附模型;动力学过程符合准二级动力学模型。     

钛改性锰矿的除砷效果及机理研究

天然锰矿是一种廉价、易得的除砷矿物材料,为了进一步提高天然锰矿的除砷效果和吸附容量,采用TiCl4对广西桂林天然锰矿进行改性,并对其改性的条件进行优化。实验结果表明最佳的改性条件为:TiCl4浓度为10 mg/L,浸泡时间为18 h,pH=3.05,振荡吸附时间为1 h。与天然锰矿的去除效率(82.95%和77.93%)相比,改性锰矿对As(Ⅲ)和As(Ⅴ)去除率分别可达94.87%和99.31%,相应的饱和吸附量分别为3.48 mg/g和3.27 mg/g,较天然锰矿各自提高了1.25 mg/g和1.21 mg/g。改性锰矿对As(Ⅲ)的吸附符合Freundlich等温吸附模型,对As(Ⅴ)的吸附更符合Langmuir等温吸附模型。     

Removal efficiency of fluoride by novel Mg-Cr-Cl layered double hydroxide by batch process from water

The fluoride ion removal from aqueous solution using synthesized Mg-Cr-Cl layered double hydroxide has been reported.Mg-Cr-Cl was characterized by X-ray powder diffraction,Fourier-transform infrared,thermo-gravimetric analysis,differential thermal analysis,and scanning electron microscope.Adsorption experiments were carried out in batch mode as a function of adsorption dosages,contact time,pH,and initial fluoride concentration to get optimum adsorption capacity.The adsorption kinetic study showed that the adsorption process followed first order kinetics.The fluoride removal was 88.5% and 77.4% at pH 7 with an adsorbent dose of 0.6 g/100 mL solution and initial fluoride concentration of 10 mg/L and 100 mg/L,respectively.The equilibrium was established at 40 min.Adsorption experiment data were fitted well with Langmuir isotherm with R 2 = 0.9924.Thermodynamic constants were also measured and concluded that the adsorption process was spontaneous and endothermic in nature.The removal percentage decreased slowly with increasing pH.This process is suitable for industrial effluents.The regeneration of the material is not possible.     

Acid Blue 25 adsorption on base treated Shorea dasyphylla sawdust: Kinetic, isotherm, thermodynamic and spectroscopic analysis

The potential of base treated Shorea dasyphylla (BTSD) sawdust for Acid Blue 25 (AB 25) adsorption was investigated in a batch adsorption process. Various physiochemical parameters such as pH, stirring rate, dosage, concentration, contact time and temperature were studied. The adsorbent was characterized with Fourier transform infrared spectrophotometer, scanning electron microscope and Brunauer, Emmett and Teller analysis. The optimum conditions for AB 25 adsorption were pH 2, stirring rate 500 r/min, adsorbent dosage 0.10 g and contact time 60 min. The pseudo second-order model showed the best conformity to the kinetic data. The equilibrium adsorption of AB 25 was described by Freundlich and Langmuir, with the latter found to agree well with the isotherm model. The maximum monolayer adsorption capacity of BTSD was 24.39 mg/g at 300 K, estimated from the Langmuir model. Thermodynamic parameters such as Gibbs free energy, enthalpy and entropy were determined. It was found that AB 25 adsorption was spontaneous and exothermic.     

A laboratory scale study on arsenic（Ⅴ） removal from aqueous medium using calcined bauxite ore

The present work deals with the As（Ⅴ） removal from an aqueous medium by calcined refractory grade bauxite （CRB） as a function of solution pH, time, As（Ⅴ） concentration and temperature. The residual As（Ⅴ） was lowered from 2 mg/L to below 0.01 mg/L in the optimum pH range 4.0-7.0 using a 5 g/L CRB within 3 h contact time. The adsorption data fits well with Langmuir isotherm and yielded Langmuir monolayer capacity of 1.78 mg As（Ⅴ）/g of CRB at pH 7.0. Presence of anions such as silicate and phosphate decreased As（Ⅴ） adsorption efficiency. An increase temperature resulted a decrease in the amount of As（Ⅴ） adsorbed by 6%. The continuous fixed bed column study showed that at the adsorbent bed depth of 30 cm and residence time of 168 min, the CRB was capable of treating 340 bed volumes of As（V） spiked water （C0 = 2 mg/L） before breakthrough （Ce = 0.01 mg/L）. This solid adsorbent, although not reusable, can be considered for design of adsorption columns as an efficiency arsenic adsorption media.     

Statistical optimization of adsorption processes for removal of 2,4-dichlorophenol by activated carbon derived from oil palm empty fruit bunches

The adsorption capacity of activated carbon produced from oil palm empty fruit bunches through removal of 2,4-dichlorophenol from aqueous solution was carried out in the laboratory. The activated carbon was produced by thermal activation of activation time with 30 min at 800℃. The adsorption process conditions were determined with the statistical optimization followed by central composite design. A developed polynomial model for operating conditions of adsorption process indicated that the optimum conditions for maximum adsorption of phenolic compound were： agitation rate of 100 r/min, contact time of 8 h, initial adsorbate concentration of 250 mg/L and pH 4. Adsorption isotherms were conducted to evaluate biosorption process. Langmuir isotherm was more favorable （R^2=0.93） for removal of 2,4-dichlorophenol by the activated carbon rather than Freundlich isotherm （R^2=0.88）.     

污泥活性炭理化性质表征及吸附抗生素效果研究

文章以北京方庄污水处理厂的浓缩和脱水污泥为原料,采用ZnCl2活化法分别制备污泥活性炭。对制得的污泥活性炭进行表征,并将其应用于加替沙星废水的处理。研究2种污泥活性炭吸附反应的吸附时间、吸附剂投加量、pH值、初始浓度4个因子对吸附量的影响,设计正交实验。正交实验结果表明:2种污泥活性炭受到4个因子影响程度相当,表现出明显的相似性,但短期吸附时,脱水污泥表现出更好的吸附性能。初始浓度对吸附量的影响最大,获得最大吸附量的条件组合为:初始浓度200 mg/L,投加量0.05 g,pH=9,t=2 h。浓缩和脱水污泥活性炭的最大吸附量分别可达34.541 mg/g和34.925 mg/g,表明2种污泥活性炭对加替沙星均有良好的吸附效果。污泥活性炭作为一种废水吸附剂,是废水处理的一种新途径。     

活性炭对含铜制药废水的吸附特性

以粉末活性炭为吸附剂,采用批式试验,研究静态吸附对黄连素脱铜废水中Cu2+的去除效果,分析了吸附剂投加量(5～50 g/L),pH(1.0～5.0)和接触时间(20～600 min)对吸附效果的影响. 当pH为2.4,吸附剂投加量为30 g/L时,反应300 min即可达到吸附平衡状态. 通过对吸附动力学和吸附等温线的模型分析发现,二级吸附动力学模型能够更好地描述试验结果,对吸附平衡数据的拟合采用Langmuir吸附等温线优于采用Freundlich吸附等温线.      

氧化铁改性沸石对Se(Ⅳ)的吸附性能及试验废物再利用研究

为解决天然沸石去除废水中Se（Ⅳ）能力低的问题,采用氯化铁对天然沸石进行改性,制备表面负载氧化铁的改性沸石,即氧化铁改性沸石,并将其应用于去除水体中Se（Ⅳ）.首先对比天然沸石和氧化铁改性沸石的结构特征,研究二者对Se（Ⅳ）溶液的吸附特性,并通过X射线荧光光谱（XRF）、X射线衍射图谱（XRD）、扫描电镜（SEM）和氮气吸附孔径分布测试（BET）对二者进行表征;其次进行吸附试验,考虑接触时间、pH、吸附剂投加量、初始溶液反应浓度的影响,并通过天然沸石和氧化铁改性沸石的吸附动力学及吸附等温线对吸附的机理进行阐述.结果表明:①氧化铁改性沸石表面形成细碎的球状颗粒,分布在沸石的表面.②氧化铁改性沸石能够高效地吸附水体中的Se（Ⅳ）,且在pH为3时吸附效率最高,其对Se（Ⅳ）溶液的去除率最高达97.7%,其理论最大吸附量为46.901 mg/g.③氧化铁改性沸石对Se（Ⅳ）的吸附过程符合准二级动力学模型和Langmuir等温吸附模型.④添加负载Se（Ⅳ）后的氧化铁改性沸石土壤均达到富硒土壤标准（>0.4 mg/kg）.研究显示,氧化铁改性沸石吸附Se（Ⅳ）的效果较好,显著优于天然沸石的吸附效果,且吸附Se（Ⅳ）废水后的废弃氧化铁改性沸石还可应用于土壤改良方向.