活性染料对壳聚糖改性腈纶的染色与动力学研究

以活性艳红X-3B上染壳聚糖改性腈纶,测定上染百分率、固色率、K/S值、耐水洗牢度等;并测定了活性艳红X-3B上染壳聚糖改性腈纶的上染速率曲线,分析不同温度对半染时间、扩散系数、染色速率常数等染色动力学参数的影响。结果表明,活性艳红X-3B对壳聚糖改性腈纶具有良好的染色性能,上染百分率31.28%,固色率28.60%,K/S值3.931,耐水洗牢度在3级以上。活性艳红X-3B上染壳聚糖改性腈纶,初染率较好,染色60 min达到上染平衡;半染时间较短,且随着温度的升高而降低;扩散系数和染色速率常数随温度升高增大。     

活性炭载羟基铁协同H2O2类芬顿降解活性艳红X-3B

以活性炭为媒介,采用浸渍法制备了活性炭载羟基铁催化材料(FeOOH@AC),并协同双氧水类芬顿降解活性艳红X-3B染料。在pH=7、FeOOH@AC质量浓度1 g/L、H₂O₂浓度10 mmol/L的反应条件下,FeOOH@AC+H₂O₂体系对活性艳红X-3B的降解率达98.2%,相较AC和FeOOH@AC体系提高了17.2和3.7倍。初始pH试验表明,对活性艳红X-3B,FeOOH@AC+H₂O₂体系不仅在酸性条件下具有很好的降解能力,在碱性条件下(pH=9)的降解率可达83.6%,表现出较宽的pH适用范围。另外,4次循环试验后,FeOOH@AC对活性艳红X-3B的降解率仍大于60%。对其用盐酸洗脱并重新负载FeOOH,可再生。     

AgCl-Bi6O26N5H9可见光催化降解活性艳红X-3B的研究

采用水解法制备AgCI/Bi6O26N5H9复合催化剂,并用XRD、SEM进行表征;光催化性能以碱性染料活性艳红X-3B为目标污染物,金属卤化物灯为可见光光源进行研究;实验结果表明,在摩尔比(Bi3+/Ag+)为1:1时,光照30分钟后,浓度为80mg/L的活性艳红X-3B脱色率达到96%;用光度法测定出光催化过程中有自由基产生,表明染料被彻底降解.     

AgCI-Bi_6O_(26)N_5H_9可见光催化降解活性艳红X-3B的研究

采用水解法制备AgCI/Bi6O26N5H9复合催化剂,并用XRD、SEM进行表征;光催化性能以碱性染料活性艳红X-3B为目标污染物,金属卤化物灯为可见光光源进行研究;实验结果表明,在摩尔比(Bi3+/Ag+)为1:1时,光照30分钟后,浓度为80mg/L的活性艳红X-3B脱色率达到96%;用光度法测定出光催化过程中有自由基产生,表明染料被彻底降解。     

烧碱代替纯碱作为活性艳红X-3B染色的固着剂

几年来,我厂一直选用纯碱作为活性艳红X-3B染色的固着剂,但存在着染料的固着率较低以及浮色多而造成皂洗牢度不够理想等问题。因此,我们进行了反复的试验,试成了用烧碱代替纯碱作为活性艳红X-3B染色的固着剂的工艺。 一、理论依据 活性艳红X-3B在正常染色条件下会造成染料固着率较低和色布皂洗牢度不够理想,这与染料的水解率较高有关;染料的水解率提高,必然会导致染料的固着率降低。     

活性和酸性染料废水的改性腈纶脱色

采用三乙烯四胺(TETA)对腈纶纤维进行改性,探究了吸附温度、pH值和氯化钠对改性腈纶吸附活性红B-3BF和酸性红B吸附速率的影响,分析了改性腈纶对活性红B-3BF和酸性红B的吸附热力学,并对吸附热力学曲线进行拟合。研究结果表明,三乙烯四胺改性腈纶纤维在常温条件下可较快地吸附阴离子染料,酸性越强吸附速率越快、吸附量越高;三乙烯四胺改性腈纶对阴离子染料的吸附符合Langmuir+Nernst模型,说明三乙烯四胺改性腈纶与阴离子染料之间存在离子键、氢键和范德华力等多种结合方式;三乙烯四胺改性腈纶连续6次吸附1 g/L的活性红B-3BF后,1 kg纤维上染料吸附量达到700 g以上,说明改性腈纶对阴离子染料有较强的吸附能力。     

酚醛基活性炭纤维的制备及其对亚甲基蓝染料溶液的吸附性能研究

以酚醛纤维为原料,采用水蒸气活化法进行物理活化,制备具有丰富微孔结构的酚醛基活性炭纤维,并以亚甲基蓝染料溶液作为吸附质,探讨吸附时间、吸附温度、染料溶液初始浓度对其吸附性能的影响,同时对其吸附平衡、吸附动力学进行研究。结果表明:酚醛基活性炭纤维对亚甲基蓝染料分子的吸附性较好,吸附时间、吸附温度及染料溶液初始浓度均对吸附性能有较大影响;吸附过程符合Langmuir吸附等温线模型和准二级动力学模型,表明酚醛基活性炭纤维对亚甲基蓝染料分子的吸附属于单分子层吸附,且吸附过程以化学吸附为主导。     

活性炭吸附活性黄3RS染料的研究

针对活性炭对活性黄3RS染料模拟废水吸附的影响因素,比较了不同活性炭目数、初始质量浓度、pH值和温度条件下活性炭吸附活性黄3RS染料模拟废水的去除率。结果表明:静态吸附中活性炭质量0.1 g,粒径425μm(35目),活性黄3RS染料模拟废水pH值为4.0,初始质量浓度为20 mg/L,温度为50℃吸附300 min,模拟废水染料的去除率达99.9%。用准二级动力学方程模拟活性炭对活性黄3RS染料的吸附,其相关系数R~2=0.999,表明活性黄3RS染料在活性炭上的吸附遵循准二级动力学方程。     

活性染料水解对棉织物染色性能的影响

用水解和未水解活性艳红X-3B染料染色棉织物,通过测试水解和未水解染料溶液的吸收光谱及其染色织物的颜色指标值(L﹡、a﹡、b﹡、c﹡值)及K/S值,研究了活性染料和水解活性染料对改性和未改性棉织物的染色性能。结果表明:水解和未水解染料的紫外可见吸收光谱相差较大,染料水解后产生了明显的浅色效应;染料水解影响染料的上染率和固色率及染色织物的颜色和K/S值;棉织物经阳离子非反应性和反应性改性,均会改善染料和水解染料的染色性能,反应性改性剂会显著提高染料和水解染料的上染率和固色率,特别是非常明显地提高了固色率。     

具有表面活性的含氟染料在锦纶上的应用研究

将全氟长碳链引入活性染料母体中，改变染料的性质，使染料具有表面活性，有利于染料在纤维上扩散、渗透、吸附。以全氟辛基磺酰氟和活性艳红X-3B为原料，经磺酰化、缩合，合成了含氟长碳链的染料．将此染料应用于锦纶染色中，结果表明，该染料在锦纶上具有较高色牢度、高的得色量，尤其是湿处理牢度更为优异。     

Removal of Pb(II) from aqueous solutions by carbons prepared from Sal wood (Shorea robusta)

In the present work, physically and chemically activated carbons are prepared using Sal wood (Shorea robusta) sawdust by thermal process and using sulfuric acid as the activation agent to remove Pb(II) from aqueous solutions. Adsorption equilibrium studies have been done at a pH of 4 and a room temperature of 30 °C. It was found that the adsorption isotherms are favorable and chemically activated carbons are better than physically activated carbon in terms of adsorption capacity. Various two-parameter adsorption isotherm models, viz. Freundlich, Langmuir, Temkin and Dubinin-Radushkevich, were used to fit the equilibrium data and it was found that the Freundlich adsorption model provided best-fit. The first-order irreversible unimolecular reaction model and the pseudo-second-order kinetic models were used to fit the kinetic data and it was found that both the models provided good fit. Kinetic and film diffusion studies show that the adsorption of lead(II) on the activated carbons tested in this work are both intra-particle and film diffusion controlled.     

Agave sisalana,a biosorbent for the adsorption of Reactive Red 120 from aqueous solution

The textile industry is one of the largest producers of dye effluent. Treatment of these effluents has to be cost effective hence a number of precursors have been studied as a viable alternative adsorbent. Sisal fibre was converted to activated carbon by chemical methods. Sisal fibre was activated with different activating agents such as H₃PO₄, HCl, HNO₃, NaOH and KOH. The adsorption of Reactive Red 120 (RR 120) dye onto sisal fibre activated carbon (SFAC) from aqueous solution was investigated. Adsorption experiments were carried out at different dye concentrations, initial solution pH and carbon dosage. Batch adsorption studies were carried out using activated carbon produced using phosphoric acid yielded better carbon as it good results in terms of Methylene Blue number and Iodine number. These carbons were used to study the batch adsorption studies. Methylene Blue number and Iodine number of SFAC were found to be 240 mg/g and 855 mg/g, respectively. The BET surface area of the carbon was 885 m²/g. The batch experiments adsorption isotherm studies fitted well to Langmuir isotherm and the adsorption capacity was found to be 110 mg/g. Adsorption kinetics data were tested using pseudo-first-order and pseudo-second-order models. Kinetic studies showed that the adsorption data followed a pseudo-second-order reaction.     

Adsorption of carotenes and phosphorus from palm oil onto acid activated bleaching earth: Equilibrium,kinetics and thermodynamics

In this work, the adsorption of carotenes and phosphorus from crude palm oil onto acid activated bleaching earth was investigated under bleaching conditions, i.e. high temperature (90, 105 and 115 °C) and low pressure (less than 50 mbar). Bleaching earth was added to palm oil in a range of 0.5–3.0 wt%. Results presented in this work suggest that adsorption of β-carotene increases with temperature, while phosphorus adsorption was less affected. Both the pseudo-first-order and the pseudo-second-order kinetic model describe efficiently the β-carotene experimental data. Intra-particle diffusion is involved in β-carotene adsorption mechanism, although it is not the sole rate limiting step in the adsorption onto acid activated bleaching earth. Phosphorus adsorption was too fast resulting in a lack of kinetic data. The equilibrium data were described better by Langmuir and Freundlich models, for β-carotene and phosphorus, respectively. A multi-component Freundlich type isotherm was tested. Its competition coefficients were too low, and it assumed the same form as the monocomponent Freundlich. A thermodynamic study demonstrated that β-carotene and phosphorus adsorption is spontaneous, endothermic and an entropy-driven process. Isosteric heat values suggest that the interactions between adsorbate and adsorbent are heterogeneous.     

Effect of strongly competing background compounds on the kinetics of trace organic contaminant desorption from activated carbon

Strongly competing (SC) compounds, naturally found in any drinking water source, are known to decrease the adsorption capacity of activated carbon for trace contaminants. While the effect of these substances on the capacity and adsorption kinetics of trace contaminants is fairly well studied, relatively little is known about their impact on desorption kinetics. The purpose of this study was to investigate the relationship between SC matter and trace compound desorption kinetics. A surrogate SC compound, 1,4-dichlorobenzene (p-DCB), was used to displace the preadsorbed target trace contaminant, atrazine, from powdered activated carbon (PAC). The initial concentrations of p-DCB and atrazine were varied to achieve different degrees of competition to atrazine. Atrazine's desorption diffusion coefficient was found to increase with increasing adsorbed concentration of the SC matter, expressed as an equivalent background compound (EBC).The EBC was modeled with atrazine-like adsorption properties, thus representing the portion of p-DCB that competed to occupy atrazine adsorption sites. The increase in atrazine diffusion rate can be explained by a shift from surface diffusion to diffusion through the carbon's pores as the availability of surface sites decreased due to the EBC's competition. The observed desorption kinetic relationship was consistent with the effect of SC competition on adsorption kinetics; further, the effect was consistent for three different types of SC matter. These findings highlight that the impact of SC matter on activated carbon applications could be either detrimental (displacing adsorbed trace contaminants and enhancing their rate of release) or beneficial (offsetting pore constriction effects by enhancing their rate of uptake).     

Removal of alpha-picoline, beta-picoline, and gamma-picoline from synthetic wastewater using low cost activated carbons derived from coconut shell fibers

In the present study the ability of activated carbons developed from coconut shell fibers to remove alpha-picoline, beta-picoline, and gamma-picoline from aqueous solution in the broad range of concentrations (1-100 mg/L) is investigated. The derived carbons are designated as FAC (activated carbon derived from coconut shell fibers without any treatment) and ATFAC (activated carbon derived from acid treated coconut shell fibers). Systematic equilibrium and kinetic adsorption studies at different pH, temperatures, particle size, and solid-to-liquid ratio were carried out to determine various parameters necessary to establish the fixed bed reactors. The Langmuir and Freundlich models were applied and the data are not fitted well by the Freundlich and Langmuir equations, but the Langmuir model has an edge over Freundlich model. The monolayer adsorption capacity (Q0) as calculated using Langmuir adsorption isotherm of the activated carbons viz., FAC and ATFAC is found to increase with an increase in temperature confirming the endothermic process. The ATFAC has a higher sorption capacity than FAC. Overall the adsorption of alpha-picoline, beta-picoline, and y-picoline on FAC and ATFAC follow the order FACalpha-picoline < ATFACalpha-picoline < FAC gamma-picoline < ATFACbeta-picoline < FACbeta picoline < ATFAC gamma-picoline. The adsorption of alpha-,beta-, and gamma-picoline followed the pseudosecond-order rate kinetics. On the basis of these studies, various parameters such as effective diffusion coefficients, activation energy, and entropy of activation were evaluated to establish the mechanisms. It was concluded that the adsorption occurred through particle diffusion at low temperatures viz., 10 degrees C and 25 degrees C (except alpha-picoline where it was film diffusion), while at 40 degrees C it occurred through film diffusion. Similarly at concentrations of 25 and 50 mg/L the adsorption was particle diffusion controlled (except for alpha-picoline where it was film diffusion), while at > 50 mg/L it was film diffusion controlled.     

颗粒活性炭对模拟活性染料废水的吸附脱色效果

本文借助SEM观察了颗粒活性炭的表面形态结构,利用紫外-可见分光光度计测试分析了模拟染料废水吸附前后的吸光度变化,以考察颗粒活性炭种类、目数、染料废水浓度、pH值、吸附温度及时间对染液吸附脱色效果的影响。实验结果表明：椰壳活性炭的吸附脱色效果较煤质、果壳活性炭好;活性炭目数越大,其吸附脱色效果越好;活性炭对染料废水的吸附脱色效果随染料浓度的增大而呈线性函数下降;酸性环境下活性炭的吸附脱色效果好于碱性环境,pH值为5.5时,吸附脱色效果最好;吸附温度越高,脱色率越高,但升至一定温度后对吸附脱色效果增加不再显著;达平衡吸附前,增加吸附时间对活性炭的吸附脱色效果增加较为显著。     

柳絮纤维生物质炭的制备及其对染料废液中Cr(Ⅵ)的吸附性能

针对目前酸性媒染染料废水中的六价铬Cr(VI)对水体环境污染严重的问题,以柳絮纤维为原料,通过限氧裂解法制备了KOH活化生物质炭(CBK)、NaOH活化生物质炭(CBN),采用吸附批实验法研究模拟染料废液pH值、吸附剂投放量、温度效应等对柳絮纤维生物质炭吸附处理Cr(VI)的影响,利用动力学和热力学相关模型对吸附过程进行拟合,探究柳絮纤维生物质炭对Cr(VI)的吸附机制。结果表明:CBK较CBN比表面积显著增大,表面吸附位点增多;在模拟废液pH值为2时,CBK、CBN对Cr(VI)的理论最大吸附量分别为82.68、47.16 mg/g,且吸附过程符合Freundlich热力学模型和准二级动力学模型,吸附过程主要为多分子层吸附,同时还伴随着化学吸附,该吸附反应是自发进行且为吸热反应,温度升高可显著提高柳絮纤维生物质炭对Cr(VI)的吸附量。     

Removal of methylene blue from aqueous media using activated carbon web

Activated carbon web is prepared by controlled pyrolysis of acrylic fibrous waste under the layer of charcoal using physical activation in high-temperature furnace. The carbonization was carried out at 1200 °C under different heating rate (i.e. 150 to 450 °C h^?1) with different holding time (i.e. 0 to 60 min) to decide optimum pyrolysis parameters. The heating rate of 300 °C h^?1 with no holding time revealed higher specific surface area of 280 m² g^?1. The prepared activated carbon web was later employed as adsorbent for removal of methylene blue from aqueous media. The effect of initial dye concentration, adsorbent dosage, stirring speed, and pH of solution was studied. The obtained results were later compared with adsorption isotherms (i.e. Langmuir and Freundlich). The Freundlich model was found to fit closely with results due to heterogeneous adsorption of dye molecules. Finally, virgin activated carbon and dye adsorbed activated carbon were tested for desorption behavior using differential scanning calorimetry and thermo gravimetric analysis. The significant reduction in desorption enthalpy from 172.46 to 52.43 J g^?1 is attributed to less adsorption energies of dye molecules on the surface of activated carbon due to nonhomogeneous distribution of active sites.     

废弃棉/亚麻混纺织物制备活性炭的性能

为实现废弃织物的综合利用,以废弃的棉／ 亚麻（50／50）混纺织物为原料,以氮气为载体,将水蒸气送入高温管式炉中进行活化制备活性炭。研究了活化温度、活化时间和水蒸气的载体流速对活性炭的比表面积、孔径分布的影响;利用废弃棉／ 亚麻活性炭的碘吸附量来表征其吸附能力,分析结构性能与吸附性能之间的关系。试验结果表明：随着活化温度、活化时间、水蒸气载体流速的增加,活性炭碘吸附量先增大后减小,而孔直径不断增大;当活化温度为800 ℃、活化时间为50min、水蒸气载体流速为240L／h时,活性炭比表面积及孔容达到最大,分别为1047.34ｍ２／g和1.25ｃｍ３／g,孔直径在18nm左右,碘吸附量为805.16mg／g;当活化温度为750 ℃,活化时间为50min,水蒸气载体流速为240L／h 时,活性炭比表面积为648.25m2／g,孔直径为4nm左右,此时碘吸附量达到最大值,为1079.39mg／g。     

黄麻纤维活性炭对亚甲基蓝和甲基橙溶液的吸附性能研究

以黄麻纤维为原料,采用磷酸活化法制得黄麻纤维活性炭作为吸附剂,以纺织印染加工中较为常用的亚甲基蓝(MB)和甲基橙(MO)染料溶液为吸附质,研究染料溶液初始浓度、活性炭投加量、吸附时间等因素对黄麻纤维活性炭吸附性能的影响。结果表明:随着染料溶液初始浓度的增加,两种染料的去除率逐渐降低,吸附量逐渐增大;随着活性炭投加量的增加和吸附时间的延长,两种染料的去除率和吸附量均呈现逐渐增大的变化规律;水浴温度对两种染料的去除率和吸附量影响都较小;染料溶液pH值对两种染料吸附性能的影响存在较大差异,MB的去除率和吸附量随染料溶液pH值增加而增大,而MO的去除率和吸附量随之减小。