Multiscale Simulation Starting at the Molecular Level for Adsorption Process Development

This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of methanol on an activated carbon at the molecular level. The adsorption isotherms obtained in the linear region （or adsorption constant） are exploited as a model parameter required for the adsorption process simulation. The adsorption process model described by a set of partial differential equations （PDEs） is solved by using the conservation element and solution element method, which produces a fast and an accurate numerical solution to PDEs. The simulation results obtained from the adsorption constant estimated at the molecular level are in good agreement with the experimental results of the pulse response. The systematical multiscale simulation approach addressed in this study may be useful to accelerate the adsorption process development by reducing the number of experiments.

STUDY ON THE DECOLORIZATION OF D-RIBOSE ZYMOTIC FLUID BY RESIN ADSORPTION

In this paper, effects on of six type of resins the decolorization of D-ribosezymotic fluid have been studied for the fist time. The results show that resinNKA-II has the best effect. the decolorization rate of D-ribose zymotic fluid is91% at velocity of 1.0BV/hr and 25℃, the adsorption capacity can reach up to5.7BV. The effects of adsorption conditions as well as conditions of resinregeneration on the resin decolorization capability were also studied.

Preparation and decolorization of sapindus mukurossi extract and its application in sebum-control shampoos

Background:Sapindus mukurossi extract(SME)is a kind of natural surface active ingredient with potential applications in cleansing products.However,the polyphenols and pigments contained in the extract may cause color browning of the products during storage especially at elevated temperatures,affecting its high level addition in the products.Objective:To explore a decolorization process suitable for industrialization realize the high level addition of SME and explore the potential of SME in the field of controlling sebum esters.Materials and Methods:SME was prepared by adsorbing polyphenols on the D301 resin and oxidation decoloring oxidation.Investigated its sebum-control efficacy by SZ95 model and clinical study.Results:The results demonstrate that the D301 resin displays the best adsorption selectivity for polyphenols in SME,and the polyphenol adsorption ratio of D301 resin(5 wt%)can reach 83.6%;The optimal decolorization conditions are pH=7.8,temperature 73℃and decolorization time 5.7 h when H2O2 content is 6%,The prepared SME shows no obvious changes in color and retain stable during the high temperature(50℃)test period of 28 days.4μg/mL of SME decreases the lipid synthesis of SZ95 cells by 24.8%.The clinic efficacy of the shampoo containing 10%SME(by dry extract weigh)is further evaluated.No significant changes in the skin moisture content and transepidermal water loss(TEWL)are observed within four weeks after using the product,while the scalp sebum level is significantly reduced.Conclusion:In this study,we prepared a light-colored,highly stable SME,enabled its high-level addition in cleansing and care products and found its sebum-control efficacy.

Influence of particle size and salinity on adsorption of basic dyes by agricultural waste: dried Seagrape (Caulerpa lentillifera)

Green macroalga Caulerpa lentillifera was found to have reasonable adsorption capacity for basic dyes, Astrazon Blue FGRL （AB）, Astrazon Red GTLN （AR）, and Astrazon Golden Yellow GL-E （AY）. The initial dye concentration was in the range of 100-1,800 mg/L. The dried algal sorbent was ground and sieved into 3 sizes： S （0.1-0.84 mm）, M （0.84-2.0 mm）, and L sizes （larger than 2.0 mm）. For all conditions examined in this work （at 25℃ in batch systems）, the adsorption reached equilibrium within the first hour. The kinetic data corresponded well with the pseudo second order kinetic model where the rate constant, k2, decreased as the sorbent size increased for all dyes. The adsorption isotherms followed both Langmuir and Freundlich models. Among three sorbent sizes, S size gave the highest adsorption capacity followed by M and L sizes. A reduction of sorbent size increased the specific surface area for mass transfer, and also increased the total pore volume, thus providing more active sites for adsorption. The adsorption of AB was adversely influenced by the protonation of algal surface at low pH. On the other hand, the adsorption of AR and AY could be due to weak electrostatic interaction, which was not significantly affected by pH. Increasing salinity of the system caused a decrease in adsorption capacity possibly due to the competition between Na^＋ and the dye cations for the binding sites on algal surface. Moreover, an increase in salinity generated a compressed electrical double layer on the algal surface which exerted repulsive force, retarding the adsorption of positive charged molecules such as the basic dyes.

Efficient decolorization of dye-containing wastewater using mycelial pellets formed of marine-derived Aspergillus niger

In order to improve the efficient decolorization of dye-containing water by biosorbent and understand the biosorption mechanism, the self-immobilization mycelial pellets were prepared using a marine-derived fungus Aspergillus niger ZJUBE-1, and an azo dye, Congo red was chosen as a model dye to investigate batch decolorization efficiency by pellets. The pellets as biosorbent showed strong salt and acid tolerance in biosorption process. The results for dye adsorption showed that the biosorption process fitted well with models of pseudo-second-order kinetic and Langmuir isotherm, with a maximum adsorption capacity of 263.2 mg·g^(-1) mycelium. During 6 batches of continuous decolorization operation, the mycelial pellets could possess efficient decolorization abilities(>98.5%).The appearance of new peak in the UV–Vis spectral result indicated that the decolorization process may also contain biodegradation. The mechanism studies showed that efficient biosorption ability of pellets only relies on the active zone on the surface of the pellet, which can be enhanced by nutrition supplement or be shifted outward by a reculture process.

Development of a charge transfer space loop to improve adsorption performance in aerial electrostatic spray

In order to solve the problem of insufficient adsorption rate of droplets on the target back via aerial electrostatic spray,this study proposed a high-voltage electrostatic generator to charge the liquids in two isolated water tanks with positive and negative charges respectively.A charge transfer loop was developed in space between the aerial electrostatic spray system and the ground.This method greatly enhanced the adsorption performance under outdoor conditions that 16.7%droplets density increased on the target front,a nearly fourfold destiny increased on the target back compared with the conventional UAV spray system.The target back-to-front ratio of droplet density was improved from 6.1%to 25.7%,which validated the satisfactory performance of the developed system.

Synergy of adsorption and visible light photocatalysis to decolor methyl orange by activated carbon/nanosized CdS/chitosan composite

Activated carbon/nanosized CdS/chitosan(AC/n-CdS/CS) composites as adsorbent and photoactive catalyst were prepared under low temperature(≤60 ℃) and ambient pressure.Methyl orange(MO) was chosen as a model pollutant to evaluate synergistic effect of adsorption and photocatalytic decolorization by this innovative photocatalyst under visible light irradiation.Effects of various parameters such as catalyst amount,initial MO concentration,solution pH and reuse of catalyst on the decolorization of MO were investigated to optimize operational conditions.The decolorization of MO catalyzed by AC/n-CdS/CS fits the Langmuir-Hinshelwood kinetics model,and a surface reaction,where the dyes are absorbed,is the controlling step of the process.Decolorization efficiency of MO is improved with the increase in catalyst amount within a certain range.The photodecolorization of MO is more efficient in acidic media than alkaline media.The decolorization efficiency of MO is still higher than 84% after five cycles and 60 min under visible light irradiation,which confirms the reusability of AC/n-CdS/CS composite catalyst.

Adsorption of Anthraquinone Dyes from Aqueous Solutions by Penicillium Terrestre

Penicillium terrestre was used for removing four anthraquinone dyes from aqueous solution. The experiments were performed in Erlenmeyer flasks and spore suspension was used for inoculation. The results show that the mechanism of dye removal by penicillium terrestre is biosorption and the growing pellets exhibit higher adsorptive capacity than the resting or dead ones. The maximum removals of disperse blue 2BLN, reactive brilliant blue KN-R, acid anthraquinone blue and bromamine acid at the concentration of 120 mg/L by biosorptionof growing pellets are 10096, 100%, 96% and 91%, respectively. The 100.0% and 91.4% KN-R removals are achieved respectively at the much higher concentration of 250 and 400 mg/L. 2.5 g/L glucose is sufficient for 100% KN-R removal by growing pellets. Salinity （NaCl） increase from 0 to 2% （W/ V） moderately accelerates both mycelium growth and KN-R removal.

超临界二氧化碳短时作用煤体裂隙演化CT/XRD实验研究

ECBM可以在提高煤层气开采效率的同时实现CO_(2)封存,推动“双碳”目标实现,在深部煤层气的开发中具有广泛的应用前景。煤层裂隙结构和分布规律决定了超临界二氧化碳(SC-CO_(2))的压裂效果,是提高煤层气开采效率的关键。长时作用下SC-CO_(2)与煤体接触产生的吸附膨胀和溶解萃取作用能够改变煤体裂隙形态,但压裂过程中SC-CO_(2)与煤体接触时间较短,短时作用下SC-CO_(2)的吸附膨胀及溶解萃取作用对煤体裂隙的影响尚未明确。因此开展了SC-CO_(2)短时作用下煤体的裂隙演化研究,通过CT扫描研究不同变质煤体裂隙随累计浸泡时间的变化规律;建立CT二维扫描图像的灰度分布函数并构建浸泡时间与裂隙演化规律的关系,定量表征煤体裂隙的变化。结合XRD实验研究浸泡时间对煤体物质成分变化的影响,明确SC-CO_(2)短时作用煤体裂隙演化规律的主要原因。结果表明:SC-CO_(2)短时作用下吸附膨胀作用会导致煤体裂隙收缩,溶解萃取作用使裂隙发生扩展;浸泡煤体过程中吸附膨胀和溶解萃取作用同时发生且强度随时间发生变化,在不同时间段内分别交替占据对煤体裂隙的主导作用;不同变质煤会影响吸附膨胀和溶解萃取作用的强度和主导时间。褐煤浸泡30 min时吸附膨胀占据主导作用,浸泡90~240 min溶解萃取作用增强并占据主导。烟煤浸泡30~90 min时吸附膨胀作用较强,浸泡90~240 min时溶解萃取占据主导。无烟煤浸泡30~150 min时吸附膨胀作用占据主导,浸泡150~240 min时溶解萃取占据主导。

生物质基吸附剂在糖汁脱色中的应用研究进展

近年来,生物质材料在糖汁脱色中的应用引起了广泛的关注。生物质具有成本效益高、环境友好和去除效率高等特性,这使其成为一种很有前途的吸附剂。糖汁中含有的大分子还原糖碱性降解色素(HISADPs)、类黑素(ME)、酚类物质严重影响了食糖的品质。文章综述了改性的生物质吸附剂(包括纤维素、壳聚糖、淀粉)在糖汁脱色中的最新研究进展,并提出未来生物质基吸附剂如何扩大在糖厂中的应用性。

微囊藻毒素去除技术研究现状及进展

蓝藻水华造成的最主要危害之一是产生和释放微囊藻毒素(MCs),其会直接危害到水环境和人类健康,因此选用切实可行的MCs去除新技术对于富营养化水体的治理至关重要。文章从物理方法、化学方法、生物方法以及组合方法综述了目前国内外MCs的去除方法的研究现状及进展,主要包括吸附、膜滤、氧化剂氧化、光化学氧化、光催化、生物降解、吸附和光催化、吸附和生物降解组合等工艺。并在此基础上从4个方面提出未来MCs去除技术的发展方向:对蓝藻水华暴发机制进行详细研究,研究MCs更加详细的去除机理,对MCs的降解产物进行进一步毒性研究,以及开发天然可生物降解且易于从水中分离和回收的吸附材料。希望能为今后蓝藻水华污染修复,特别是消除MCs对水环境以及人类的影响提供参考。

改性黄曲霉A5P1对染料酸性蓝25的吸附效果与机理研究

以黄曲霉A5P1为原料,利用盐酸改性法制成生物吸附剂A5P1_(acid),用于吸附酸性蓝25(AB25)染料。对A5P1_(acid)吸附的影响因素进行分析,结果表明:染料吸附的最佳吸附剂用量为0.5 g/L,最适pH为2,60 min达到吸附平衡。吸附剂经盐酸改性后,吸附量从137 mg/g提高到182 mg/g,染料去除率提高了32%。通过分析A5P1_(acid)吸附去除AB25的机理,发现吸附过程符合准二级动力学模型,是由化学吸附控制吸附速率;符合Freundlich吸附等温线,吸附属于多层非均相吸附。热力学结果表明吸附过程是一个吸热自发的过程。Zeta电位和FTIR结果表明,吸附是由多种官能团的静电吸附和氢键作用的。吸附剂经过循环吸附-解吸7次仍保留初始吸附量的50.6%。实验研究证明,A5P1_(acid)是一种绿色有效可用于去除阴离子染料的生物吸附质材料。

金属基吸附剂除氟技术及吸附机理研究进展

氟化物是水污染评价的重要指标之一,高浓度氟化物对饮用水安全构成了威胁,因此开发高效、低成本、高选择性的除氟技术是当前研究的重点。在沉淀、膜分离、离子交换、电絮凝和吸附等除氟技术中,吸附除氟是目前最有前景的技术之一。众多吸附材料中,金属基吸附剂因独特的结构和形貌、优异的吸附性能,被广泛应用于水体除氟研究。综述了铝、铁、稀土基等典型金属吸附剂的开发和改性,阐述了金属基吸附剂制备工艺的强化方法,对比分析了各类金属基吸附剂性能的影响因素,总结了金属基吸附剂的吸附机理和再生技术,提出了金属基吸附剂在除氟领域存在困难和未来发展趋势,为后续金属基吸附剂的开发改性、工艺强化提供理论参考。

高、低阶煤孔隙结构差异性及其对甲烷吸附特性的影响研究

采集沁水盆地高阶煤、二连盆地低阶煤,采用氮气、二氧化碳吸附法对煤基质纳米级吸附孔隙进行测试,分析高低阶煤的储气特征,从而确定影响高、低阶煤煤层气开发的关键因素。研究结果发现,高、低阶煤的比表面积相似,高阶煤的比表面积均值为215.33 m~2/g,可吸附甲烷49.53 cm~3/g;低阶煤的比表面积均值为212.17 m~2/g,可吸附甲烷48.96 cm~3/g。高、低阶煤储气主要为吸附气,占总储气量的99%以上,高阶煤储气主要是微孔吸附气,占总储气量的99.71%;低阶煤不同孔隙均有贡献,微孔最多,占比47.33%,其次是中孔,占比32.644%,大孔最少,占比19.69%。地层水侵入对低阶煤储气量影响大于高阶煤,平衡水条件下,高阶煤可储气量43.46 cm~3/g,低阶煤可储气量33.89 cm~3/g;受微孔特性影响,高阶煤储层储气量较高,但易储难逸,因此煤层气开采的关键问题是疏导微孔吸附气;受中、大孔及亲水性强影响,低阶煤储气量较低,且易储易散,勘察储气聚集区是低阶煤煤层气开发的首要工作。

聚醚废浓缩液絮凝上清液脱色工艺研究

本文研究了双氧水氧化、活性炭吸附和二者组合对絮凝上清液脱色的影响。结果表明,双氧水氧化脱色率可以达到88.74%但脱色液随时间延长会有沉淀析出。凹凸棒土、白土、活性炭三种吸附剂脱色效果不理想,活性炭的脱色率可以达到30.69%,脱色上清液没有沉淀析出。双氧水氧化和活性炭吸附组合效果更好,脱色率可以达到94.52%且脱色上清液没有沉淀析出。脱色后的上清液可以作为水基切削液的原料使用。

不同脱色剂对油脂中叶绿素脱除的影响

为筛选高效脱除叶绿素的脱色剂,为油脂工业生产中脱色剂的精准使用提供参考,以大豆油和菜籽油为例,采用不同种类脱色剂进行脱色,分析脱色剂参数(比表面积、介孔面积、孔道结构)对叶绿素脱除效果的影响。结果表明:3种主要的矿物类脱色剂对叶绿素的脱除能力强弱为活性白土>凹凸棒土>膨润土,活性白土对叶绿素的脱除效果与其比表面积或介孔面积呈正相关关系;活性炭对叶绿素的脱除效果与其比表面积没有明确的相关性,但与其介孔面积呈正相关关系,当活性炭介孔面积从3.8 m^(2)/g提升至275.4 m^(2)/g时,叶绿素脱除率提升了140.8%;单以介孔面积无法明确判定不同种类脱色剂如活性炭与活性白土对叶绿素的脱除效果,应结合脱色剂的大孔孔容进行判定。综上,对于相同的脱色剂,可以用介孔面积判定脱色剂对叶绿素脱除能力的强弱,而对于不同种类的脱色剂,介孔面积和大孔孔容是影响脱色剂对叶绿素脱除效果的关键因素。

辣椒油树脂脱色工艺的研究

为了改善辣椒油树脂产品品质和扩大其使用范围,采用磁性活性炭为吸附剂,对工业生产辣椒红的副产物辣椒油树脂进行脱色研究。采用共沉淀法制备了磁性活性炭,并采用XRD、SEM和比表面积及孔径分析仪等手段对其结构与性能进行了表征与测试。考察了磁性活性炭用量、脱色温度、脱色时间对辣椒油树脂脱色效果的影响。试验结果表明,以10 g/L辣椒油树脂的乙醇溶液为原料,当磁性活性炭的添加量为0.08 g,吸附温度为40℃,吸附时间为90 min时,辣椒油树脂的脱色率达75%,吸附脱色后辣椒油树脂中辣椒素含量保留95%左右。磁性活性炭制备简单,固液分离效率高,为辣椒油树脂的脱色工艺研究提供新思路。

Isolation and characterization of Pseudomonas otitidis WL-13 and its capacity to decolorize triphenylmethane dyes

Pseudomonas otitidis WL-13, which has a high capacity to decolorize triphenylmethane dyes, was isolated from activated sludge obtained from a wastewater treatment plant of a dyeing industry. This strain exhibited a remarkable color-removal capability when tested against several triphenylmethane dyes under both shaking and static conditions at high concentrations of dyes. More than 95% of Malachite Green and Brilliant Green was removed within 12 h at 500 μmol/L dye concentration under shaking conditions. Crystal Violet lost about 13% of its color under the same conditions tested. The rate of decolorization increased when the M9 medium was supplemented with yeast extract. The optimum pH and temperature for color removal were 7-9 and 35-40℃, respectively. The observed changes in the visible spectra and the inspection of bacterial growth indicated the color-removal by the adsorption of dye to the cells during incubation with strains.

生物基高分子两性清水剂的合成与应用

以壳聚糖和木棉纤维为基础原料,依次经过羧甲基、缩聚、亲核取代及接枝改性等反应步骤,合成了生物基高分子两性清水剂,并试验了其清水性能。结果显示:处理油田采出水时,清水剂投加量30 mg/L,反应时间20 min,反应温度65℃,除油率达89.3%;处理重金属离子废水时,pH=6.0,清水剂投加量为40 mg,Cu^(2+)、Pb^(2+)的去除率达92%以上;处理染料废水时,清水剂对阴阳离子染料废水的脱色率均可达90%以上。该清水剂具有更好的除油、吸附、脱色等性能。

碳基复合材料去除水中PPCPs研究进展

近几年来,药品和个人护理产品(PPCPs)的广泛和不当使用导致了严重的水体污染,对生态系统造成了严重影响。碳基复合材料吸附技术是解决水体PPCPs污染问题的重要技术之一,多孔碳材料孔隙结构发达、比表面积大、表面官能团丰富,同时高度芳香族结构使其具有优异的吸附性能。本文总结了用于去除水中PPCPs的碳基吸附剂种类、制备方法和相关的吸附机制。