竹炭对铬(Ⅵ)离子吸附性能的研究

研究了竹炭的粒径与用量,以及溶液的pH值与初始浓度、吸附时间、温度等因素对Cr(Ⅵ)离子吸附性能的影响.结果表明,竹炭对Cr(Ⅵ)离子的吸附能力随其粒径的增大而降低;在酸性条件下,尤其是当pH值＜3时,竹炭能够很好地适应Cr(Ⅵ)离子初始浓度的变化,120min内达到吸附平衡,对其有较好的去除率;按Cr(Ⅵ)/竹炭质量比为1∶1200投加竹炭,Cr(Ⅵ)离子的去除率可达到87.8%以上;竹炭对Cr(Ⅵ)离子等温吸附服从Freundlich方程式,在低于20℃的较低温度下容易进行,吸附效果更好.竹炭可作为理想的除铬吸附材料.     

MgAl-LDH吸附甲基橙性能研究

在水热反应温度为180℃,反应溶液pH值=9～10,反应时间为4h,反应总物质浓度为0.1mol/L的实验条件下,探索Mg/Al的摩尔比对MgAl-LDH吸附甲基橙性能的影响,并考察了材料再生后的吸附性能。研究结果表明,Mg/Al摩尔比为2.5∶1时的MgAl-LDH吸附甲基橙性能最优;在最佳吸附条件下,MgAl-LDH对甲基橙吸附量高达83.33mg/g;并对吸附材料循环利用焙烧温度进行探讨,可再生循环焙烧温度在400℃达到最佳,循环使用3次吸附性能保持良好。此外,对Mg/Al-LDH及其各个温度焙烧产物进行TG-DTA和SEM表征,显示其片状构型及对甲基橙进行的离子交换吸附和表面静电吸附作用。     

酸化花生壳对甲基橙的生物吸附研究

主要研究了酸化花生壳对甲基橙的吸附作用,结果表明花生壳能有效结合甲基橙,吸附60min达到平衡,随着甲基橙初始浓度的增加,吸附量逐渐增大,随着吸附剂投加量的增加,吸附量逐渐减小,在pH值为5左右,吸附效果最好。随着Na+和K+浓度的增大,吸附量逐渐减小,随着Ca2+和Mg2+浓度的增大,吸附量逐渐增大,温度升高,对吸附有利。吸附符合Langmuir等温吸附方程,293.3K时,最大吸附量为2.67mg.g-1,吸附平衡常数为0.059L.mol-1。     

质子化交联壳聚糖对甲基橙的吸附研究

研究了吸附剂投加量、甲基橙初始浓度、pH值、吸附时间等条件对甲基橙脱色效果的影响。结果表明,在质子化壳聚糖用量为3.6g/L条件下,对质量浓度低于200mg/L甲基橙溶液的吸附率不低于90%。拟二级动力学模型能很好地描述其吸附过程;吸附等温线符合Langmuir模型。质子化壳聚糖在较宽的pH值范围内对甲基橙具有较好的脱色效果,可提高壳聚糖的利用价值。     

TiO2纳米棒光催化降解甲基橙的研究

本文以甲基橙为目标降解物考察了催化剂的添加量、甲基橙溶液的pH值、晶化时间、热处理温度等因素对用"软模板"制备的TiO2纳米棒光催化活性的影响.研究表明:当催化剂添加量为0.08g、甲基橙溶液的pH=4、晶化时间为24h、热处理温度为500℃时,TiO2光催化剂的催化效果最佳,达到了85.96%.     

壳聚糖/Ni-TiO2复合絮凝剂对印染废水的处理研究

利用溶胶-凝胶法制备壳聚糖/Ni-TiO2复合絮凝剂,去处理模拟印染废水。用可见分光光度测定法对甲基橙的含量进行了测定,考察了壳聚糖/Ni-TiO2复合絮凝剂投加量、反应时间、反应温度、pH值对废水处理效果的影响。结果表明:在超声波频率为50kHz时,甲基橙溶液初始浓度为25mg/L,溶液pH=6,壳聚糖/Ni-TiO2复合絮凝剂的加入量为0.1g,时间60min,温度为40℃,甲基橙溶液脱色率到达到95.0%以上。同时,壳聚糖/Ni-TiO2复合絮凝剂处理甲基橙溶液时,不仅有吸附作用的存在,同时还有光催化降解的作用。     

黄原酸化膨润土对甲基橙的吸附性能研究

研究了黄原酸化膨润土(XB)对甲基橙的吸附性能,考察了甲基橙初始浓度、吸附时间、温度、pH值、吸附剂用量对其吸附性能的影响。结果表明:在15～25℃,[甲基橙]起始=300mg/L,pH=5～6,XB用量0.5g,吸附时间80min时,XB对甲基橙的去除率最高达98.5%,处理后染料废水可达标排放。吸附动力学研究表明,吸附过程符合准二级动力学吸附模型,以化学吸附为主。     

宁夏无烟煤基活性炭的制备及吸附性能研究

优化制备工艺,改善吸附性能,一直是活性炭研究的热点问题之一。研究了宁夏无烟煤基活性炭的制备及其吸附性能。分别通过混合、氯化锌化学活化、酸洗、中和和烘干等步骤,得到活性炭并测定了碘值。另外,通过活性炭对甲基橙溶液的吸附性能,运用正交试验法,分析了温度、甲基橙溶液浓度、活性炭用量和吸附时间等4个因素对吸附效果的影响。最佳吸附条件为:活性炭用量1.5g、吸附时间20min、甲基橙溶液的浓度30mg/L、温度50℃,此时脱除率达96.23%。     

超声波降解水中甲基橙的实验研究

为开发利用超声降解染料废水技术,建立了以甲基橙为模型化合物的超声降解模拟实验。考察了pH值、甲基橙初始浓度、氧化剂过氧化氢的投加浓度以及超声设备声能密度等实验条件对超声氧化降解甲基橙效果的影响。当甲基橙溶液初始浓度为2 mg.L-1、pH值为2时,按0.01 mL/100 mL浓度投加过氧化氢,在300 W声能密度条件下仅需20 min,甲基橙的降解率可达到91.79%。实验结果表明,超声降解染料废水技术操作简单、高效快速,具有广阔的应用前景。     

响应面法优化ZnCl2/AlCl3改性生物炭吸附甲基紫工艺

利用高温热解法制备ZnCl₂/AlCl₃改性生物炭,将其用于吸附甲基紫染料。探究ZnCl₂/AlCl₃-AC投加量、溶液pH、甲基紫浓度、反应时间和吸附温度这5个因素对甲基紫吸附率的影响。利用Plackett-Burman设计联合响应面分析法,筛选优化出对甲基紫吸附率影响较为显著的因素,并探究各因素间的交互影响作用,确定ZnCl₂/AlCl₃-AC吸附甲基紫的最佳工艺条件。结果表明:在选取的五个因素中,对甲基紫吸附率影响显著的因素为ZnCl₂/AlCl₃-AC投加量>甲基紫浓度>吸附温度;其中ZnCl₂/AlCl₃-AC投加量和吸附温度对甲基紫吸附率影响最明显,甲基紫浓度和吸附温度影响最不显著;ZnCl₂/AlCl₃-AC吸附甲基紫最佳工艺条件为:活性炭投加量为47.00 mg、甲基紫溶液浓度为82.00 mg/L、吸附温度为22.90℃,pH为7、反应时间为120 min,其甲基紫吸附率可达到93.04%,与模型预测值的误差仅为3.51%。     

Adsorption of dimethyl sulfide from aqueous solution by a cost-effective bamboo charcoal

The adsorption of dimethyl sulfide from an aqueous solution by a cost-effective bamboo charcoal from Dendrocalamus was studied in comparison with other carbon adsorbents. The bamboo charcoal exhibited superior adsorption on dimethyl sulfide compared with powdered activated carbons at different adsorbent dosages. The adsorption characteristics of dimethyl sulfide onto bamboo charcoal were investigated under varying experimental conditions such as particle size, contact time, initial concentration and adsorbent dosage. The dimethyl sulfide removal was enhanced from 31 to 63% as the particle size was decreased from 24-40 to >300 mesh for the bamboo charcoal. The removal efficiency increased with increasing the adsorbent dosage from 0.5 to 10mg, and reached 70% removal efficiency at 10mg adsorbed. The adsorption capacity (μg/g) increased with increasing concentration of dimethyl sulfide while the removal efficiency decreased. The adsorption process conforms well to a pseudo-second-order kinetics model. The adsorption of dimethyl sulfide is more appropriately described by the Freundlich isotherm (R(2), 0.9926) than by the Langmuir isotherm (R(2), 0.8685). Bamboo charcoal was characterized by various analytical methods to understand the adsorption mechanism. Bamboo charcoal is abundant in acidic and alcohol functional groups normally not observed in PAC. A distinct difference is that the superior mineral composition of Fe (0.4 wt%) and Mn (0.6 wt%) was detected in bamboo charcoal-elements not found in PAC. Acidic functional group and specific adsorption sites would be responsible for the strong adsorption of dimethyl sulfide onto bamboo charcoal of Dendrocalamus origin.     

炭布的研制及其应用

采用特殊烧制工艺制得的优质竹炭,比表面积高达700m2/g .将竹炭制成0.5～100μm的超细微粉,与多种高分子材料结合,可制成许多种高分子复合材料,如各种具有不同性能、不同用途和不同类型的包装材料-炭布,这些炭布具有极好的催化活化、吸附分解、吸湿干燥和除臭抗菌等性能.     

Use of cellulose-based wastes for adsorption of dyes from aqueous solutions

Low-cost banana and orange peels were prepared as adsorbents for the adsorption of dyes from aqueous solutions. Dye concentration and pH were varied. The adsorption capacities for both peels decreased in the order methyl orange (MO) > methylene blue (MB) > Rhodamine B (RB) > Congo red (CR) > methyl violet (MV) > amido black 10B (AB). The isotherm data could be well described by the Freundlich and Langmuir equations in the concentration range of 10-120 mg/l. An alkaline pH was favorable for the adsorption of dyes. Based on the adsorption capacity, it was shown that banana peel was more effective than orange peel. Kinetic parameters of adsorption such as the Langergren rate constant and the intraparticle diffusion rate constant were determined. For the present adsorption process intraparticle diffusion of dyes within the particle was identified to be rate limiting. Both peel wastes were shown to be promising materials for adsorption removal of dyes from aqueous solutions.     

Isotherm, thermodynamic, kinetics and adsorption mechanism studies of methyl orange by surfactant modified silkworm exuviae

This paper reports on the development of organo-modified silkworm exuviae (MSE) adsorbent prepared by using hexadecyltrimethylammonium bromide (HDTMAB) for removing methyl orange (MO), a model anionic dye, from aqueous solution. The natural and modified samples were characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and Fourier transform infrared spectroscopy (FT-IR). Batch adsorption experiments were carried out to remove MO from its aqueous solutions using SE and MSE. It was observed that the adsorption capacity of MSE is 5-6 times of SE. The different parameters effecting on the adsorption capacity such as pH of the solution, initial dye concentration, temperature and contact time have been investigated. Analysis of adsorption results obtained at different temperatures showed that the adsorption pattern on the MSE can be described perfectly with Langmuir isotherm model compared with Freundlich and Dubinin-Radushkevich (D-R) isotherm models, and the characteristic parameters for each adsorption isotherm were also determined. The adsorption process has been found exothermic in nature and thermodynamic parameters have been calculated. The adsorption kinetic followed the pseudo-second order kinetic model. The results of FT-IR, EDS and desorption studies all suggest that methyl orange adsorption onto the MSE should be mainly controlled by the hydrophobic interaction mechanism, along with a considerable contribution of the anionic exchange mechanism. The results indicate that HDTMAB-modified silkworm exuviae could be employed as low-cost material for the removal of methyl orange anionic dye from wastewater.     

Adsorption of dyes from aqueous solutions on activated charcoal

Adsorption of industrially important dyes namely bromophenol blue, alizarine red-S, methyl blue, methylene blue, eriochrome black-T, malachite green, phenol red and methyl violet from aqueous media on activated charcoal has been investigated. The effect of shaking time, pH and temperature on the adsorption behaviour of these dyes has been studied. It was noted that adsorption of all the dyes on activated charcoal decreases with an increase in the pH and the temperature. The adsorption isotherms at different temperatures were found to be of L-type. Adsorption data was fitted to Freundlich, BET and Langmuir isotherms and various adsorption parameters have been calculated. The thermodynamic parameters such as DeltaG, DeltaH and DeltaS were calculated from the slopes and intercepts of the linear variation of lnK against 1/T, where K is the adsorption coefficient obtained from Langmuir equation, was used. The calculated values for the heat of adsorption and the free energy indicate that adsorption of dyes is favored at low temperatures and the dyes are chemisorbed on activated charcoal.     

竹碳的结构及电化学性能研究

用XRD、SEM和EDS对由天然竹子烧制而成的竹碳进行了组织结构表征。表明竹碳主要呈无定形碳结构 ,并含有钾等金属元素。对竹碳的电化学嵌脱锂性能进行了初步的研究 ,竹碳的首次嵌锂容量约 2 0 0mAh g ,但不可逆容量较大。除去竹碳中的钾等金属离子并进行球磨处理 ,竹碳的首次嵌锂容量超过 4 0 0mAh g ,经过几次充放电循环以后 ,处理后的竹碳显示出良好的充放电效率。     

壳聚糖-CdS复合纳米粒子对甲基橙的光催化降解作用

用反相微乳液法制备了壳聚糖-CdS复合纳米粒子,并考察了复合纳米粒子用量、光照条件和溶液pH值等因素对光催化降解甲基橙的影响.结果表明:在100 mL质量浓度为20 mg/L的甲基橙溶液中加入0.30 g复合纳米粒子,可以达到较好的光催化降解效果;甲基橙在光催化降解过程中最大吸收波长464 nm处的吸收峰迅速减弱,并最终消失,且在258 nm和455 nm处出现了新的吸收峰,说明甲基橙发生了降解;溶液pH值对光催化降解甲基橙有一定的影响,在弱酸性条件下降解效率较高;复合纳米粒子比普通CdS降解效率高,2 min时高出50%,400 min时高出21.3%.初步提出了复合纳米粒子光催化降解机理,复合纳米粒子的吸附作用是光催化降解作用的前置步骤.     

Degradation of methyl orange through synergistic effect of zirconia nanotubes and ultrasonic wave

Zirconia nanotubes with a length of 25 μm, inner diameter of 80 nm, and wall thickness of 35 nm were prepared by anodization method in mixture of formamide and glycerol (volume ratio = 1:1) containing 1 wt% NH(4)F and 1 wt% H(2)O. Experiments showed that zirconia nanotubes and ultrasonic wave had synergistic degradation effect for methyl orange and the efficiency of ultrasonic wave increased by more than 7 times. The decolorization percentage was influenced by pH value of the solution. Methyl orange was easy to be degraded in acidic solution. The decolorization percentage of methyl orange reached 97.6% when degraded for 8h in 20mg/L methyl orange solution with optimal pH value 2. The reason of synergistic degradation effect for methyl orange might be that adsorption of methyl orange onto zirconia nanotubes resulted in the easy degradation of the methyl orange through ultrasonic wave.