阳离子淀粉在水处理上的絮凝研究

以玉米淀粉为原料、3-氯-2-羟丙基三甲基氯化铵(CTA)为阳离子化试剂,采用半干法工艺制备了不同取代度阳离子淀粉,并将其用于实验室配制的高岭土水样的絮凝实验,探讨了阳离子淀粉取代度及用量、pH值、絮凝时间、絮凝温度对絮凝效果的影响,并分析了絮凝机理。结果表明,阳离子淀粉对高岭土类水样具有很好的絮凝效果,可显著降低水样的浊度。     

高岭土吸附结晶紫性能研究

研究了高岭土对结晶紫的吸附性能,并进一步探讨了等温吸附模型和吸附动力学。分别考察了吸附时间、pH值、高岭土投加量、结晶紫初始浓度和温度等因素对高岭土吸附结晶紫效果的影响。结果表明,吸附时间90 min,高岭土投加量10 g/L,碱性条件下能达到较好的结晶紫吸附效果。高岭土对结晶紫吸附动力学符合准二级动力学模型,吸附等温方程符合Langmuir和Freundlich吸附模型。     

高岭土尾矿对亚甲基蓝的吸附行为的研究

文章探索了高岭土尾矿对亚甲基蓝溶液的吸附性行为,测定了高岭土尾矿的粒度与用量、亚甲基蓝溶液的pH与浓度、吸附时间及吸附温度等因素对亚甲基蓝吸附性能的影响。结果表明：在碱性条件下,高岭土尾矿对亚甲基蓝溶液有较好的吸附能力,亚甲基蓝浓度增加,高岭土尾矿对其脱色率减小,而随着高岭土尾矿用量的增加,则脱色率不断提高。高岭土尾矿对亚甲基蓝的等温吸附服从Freundlich方程式。高岭土尾矿对亚甲基蓝吸附的随时间的增加、温度的升高而增加。通过对这些参数的探索和测定,高岭土尾矿的吸附能力可以达到98%以上,高岭土尾矿能有效除去溶液中的亚甲基蓝。     

酸改性高岭土处理含锌废水的研究

采用酸处理对高岭土进行改性,并将其用于含锌废水的处理。研究了反应时间、废水pH值及反应温度对吸附过程的影响,同时研究了吸附过程的等温线及热力学。结果表明:高岭土经酸改性后吸附性能显著提高。前10min内吸附反应速率较快,并且吸附反应受废水pH值及反应温度的影响明显。Langmuir吸附等温方程和Freundlich吸附等温方程均能很好地描述未改性高岭土及酸改性高岭土吸附Zn~(2+)的过程。热力学研究发现,酸改性高岭土吸附Zn~(2+)是一个自发的放热过程。     

固体吸附剂对油页岩半焦燃烧过程中重金属元素的影响

通过对桦甸油页岩半焦进行燃烧实验,研究了不同终温下部分重金属元素的挥发特性及吸附剂的吸附效果,研究表明：随着温度的增加,各元素的挥发率均呈现出增大的趋势,且当温度为650℃时,元素Cd、Te、Co、Sn、Pb、Sb的挥发率呈现出明显的增大趋势;相对而言,各温度段下元素Cd、Te的挥发率较大,元素Mn、Y、W的挥发率较低。添加吸附剂CaO和高岭土后,大部分元素在页岩灰中的含量均明显增加,表明吸附剂对大部分重金属元素具有良好的吸附效果;通过吸附率可以看出,吸附剂CaO除元素W、Te未发现吸附效果外,对其他所研究的重金属元素均有较强的吸附效果,尤其是元素Co、Mn、Cu、Y、Sn、Cd;而高岭土除对元素Pb、Te未发现吸附效果外,对其他元素均具有一定的吸附效果,尤其是元素Co、Mn。相比而言,CaO对重金属元素的吸附效果要比高岭土强。     

高岭土尾矿对铬(Ⅵ)离子的吸附行为研究

研究了高岭土尾矿对Cr(Ⅵ)的吸附性行为,探索了Cr(Ⅵ)离子初始浓度、pH值、高岭土尾矿的综合用量、吸附综合时间及溶液吸附综合温度等多种因素对Cr(Ⅵ)溶液吸附综合性能的影响。研究分析结果表明,随初始Cr(Ⅵ)浓度不断增大,高岭土矿岩尾矿对Cr(Ⅵ)浓度吸附的比率逐渐减小;高岭土矿岩尾矿对Cr(Ⅵ)浓度吸附的比率随着高岭土矿石尾矿用量的不断增加而逐渐增大;高岭土尾矿对Cr(Ⅵ)的吸附可在40 min达到平衡;高岭土尾矿的最佳吸附温度为30℃;高岭土尾矿在酸性环境下对Cr(Ⅵ)表现出良好的吸附性能。高岭土尾矿对六价铬的等温吸附符合Freundlich吸附等温方程。结果表明,高岭土尾矿是较为理想的铬离子吸附材料。     

改性高岭土对扎布耶盐湖卤水中锂的吸附性能研究

以高岭土为原料,采用煅烧-酸浸法制备改性高岭土,研究高岭土于不同煅烧温度、盐酸质量浓度、酸浸温度和酸浸时间下制备的改性高岭土对卤水中Li+的吸附性能。最佳工艺条件为:高岭土700℃煅烧1 h,20 wt%HCl 90℃酸浸2.5 h;此时改性高岭土对卤水中锂的吸附量为2.3 mg/g,说明用煅烧-酸浸法制备改性高岭土可以有效的富集卤水中的锂离子。     

水泥和黏土矿物对不同减水剂的吸附特性

采用有机碳测定仪和紫外分光光度计,分别研究了聚羧酸减水剂、萘系减水剂和木质素磺酸钠在水泥、高岭土和蒙脱石颗粒表面的吸附特性,并对掺高岭土和蒙脱石的水泥净浆的流动度和黏度进行了测试,用三维视频显微镜观察了三种颗粒的形貌特征。结果表明:水泥、高岭土和蒙脱石对不同减水剂的吸附量不同;水泥比高岭土和蒙脱石对萘系减水剂的吸附量大,高岭土和蒙脱石比水泥对聚羧酸和木质素磺酸钠减水剂的吸附量大;水泥和高岭土颗粒表面较平滑,蒙脱石表面较粗糙;在掺入不同减水剂的水泥浆体中,蒙脱石和高岭土的掺入都会降低浆体流动度,提高浆体黏度,并且蒙脱石的影响更大。     

煤系高岭土吸附城市生活污水中磷的影响

为了拓宽煤系高岭土的应用前景,利用正交实验考察了反应条件对煤系高岭土吸附城市生活污水中磷的影响,确定了各因素对煤系高岭土吸附城市生活污水中磷的影响顺序依次为:煤系高岭土的用量、搅拌速度、反应时间、反应温度、pH值和生活污水的相对浓度,得到了最佳的反应条件为煤系高岭土的用量为6 g,搅拌速度为45 r/min,反应时间120 min,反应温度35℃,生活污水pH为4,生活污水相对浓度为0.50.在此条件下煤系高岭土吸附城市生活污水中的磷含量达96.80%.     

金属阳离子的化学键合特性对捕收剂吸附的影响

本文根据矿物表面金属阳离子电子外层结构的不同对其进行了分类。并通过各类金属阳离子的化学键合特性的不同 ,分析了各类金属阳离子与捕收剂吸附的作用关系及金属阳离子的化学键合特性对捕收吸附作用产生的影响     

EFFECT OF EXCHANGEABLE CATIONS ON HYDROPHILIC NATURE OF KAOLIN AND BENTONITE*

The affinity for water of a kaolinite-type clay (kaolin) and a montmorillonite-type clay (bentonite), saturated with hydrogen, calcium, sodium, and potassium, was studied by three methods, namely, heat of wetting as determined by calorimetric measurements, sorption of water from the vapor phase by weighing, and desorption or removal of water by differential-thermal analysis. It was shown that hydrogen and calcium clays had a greater affinity for water than sodium and potassium clays. Although the bentonite evolved more heat and sorbed more water per gram of clay, it evolved less heat and sorbed less water per milliequivalent of exchangeable cation than did the kaolin; the differences in the effects of various cations were more pronounced in bentonite than in kaolin. The results may be explained as follows from considerations of the mineral structures: (1) A greater amount of water hydrates the surface of kaolinite in proportion to that hydrating the exchangeable cations than is the case in montmorillonite and (2) the exchangeable cations may be hydrated to a greater degree (i.e., less strongly held) on kaolinite than on montmorillonite.     

The adsorption of fatty acids from vegetable oils with zeolites and bleaching clay/zeolite blends

The adsorption of model fatty acids (hepatnoic, oleic), using spiked vegetable oils, was studied using different kinds of zeolites (A-zeolite, X, Y-zeolites, mordenite), Y-zeolite exchanged with different cations (alkali, alkaline earth, transition metal ions), and with bleaching clay/zeolite blends. The adsorption process was shown to be governed by the molecular sieving properties of the zeolites involved as well as the electrostatic field strengths of the exchange cations. Facile interparticle diffusion of cations between clay and zeolite particles in the blends was verified by electron microprobe analysis and shown to cause unexpected results with respect to bleaching and fatty acid removal.     

Surface Area and Exchange Capacity Relation in a Florida Kaolinite

In connection with the study of certain properties of clay-water systems, an investigation was made of the exchange behavior-surface area relations of a series of controlled particle-size (monodisperse) fractions of a domestic kaolin. Surface areas were estimated by application of the Brunauer-Emmett-Teller theory to low-temperature nitrogen adsorption isotherms. Similar estimates were made based on room-temperature water adsorption isotherms. Exchange behavior was studied using direct quantitative techniques involving the exchange of divalent manganese. Good correlation was found to exist between the computed Brunauer-Emmett-Teller areas and the exchange capacities over the particle-size range 10 to 0.05 μ, equivalent spherical diameter. These results suggest that the exchange behavior in kaolinites is primarily a surface phenomenon and does not depend on isomorphous substitutions.     

H_2SO_4改性焙烧高岭土的性能研究

以内蒙古鄂尔多斯高岭土为原料,经过不同温度焙烧,将焙烧高岭土样品进行不同浓度H_2SO_4改性后,得到酸改性焙烧高岭土样品。通过扫描电镜(SEM)结合能谱(EDS)、X射线衍射(XRD)、傅里叶红外线光谱(FT-IR)、热重-差热(TG-DTA)、比表面积(BET)对样品进行表征分析。高岭土结构水的脱离高于525.9℃;当焙烧温度高于600℃后,高岭土的特征峰消失,转化为偏高岭土;焙烧高岭土,有明显的堆积孔道且表面更加粗糙;改性焙烧高岭土由片状结构变成块状结构,堆积孔道大量消失,其比表面积增大。     

The conditions of cationic exchange with the use of recycling polystyrene derivative,the product of sulfonation by silica sulfuric acid

Growing amount of waste plastics has become an environmental problem on a global scale. This study presents an investigation of the conditions of cleaning water from heavy metal ions using chemically recycled polystyrene. To get effective ion exchangers, the sulfonation of virgin polystyrene and expanded polystyrene wastes were obtained using silica sulfuric acid. As it turned out, the use of this solid sulfonating agent simplifies the separation of the polymeric product from the acid and the solvent in comparison to conventional sulfonation methods. The ion exchange behavior of copper and zinc cations in the yielded sulfonated derivatives of polystyrene was studied. Batch shaking adsorption experiments depending on contact time, pH, temperature, and dosage of adsorbate were carried out. The stability of resin to cyclical adsorption and regeneration (column experiment) was also investigated. We report that resins have a high adsorption efficiency with total ion exchange capacity (IEC) about 2.6 meq g^?1, which drops with decreasing pH owing to competition between protons H⁺ and metal cations, whereas with the increasing resin doses the removal of cations rises for a constant initial metal concentration. The speed of cation exchange for yielded adsorbents was even better than for commercial resins. After 360 cyclical adsorption and regeneration in column, resin had working IEC of about 2.3 meq g^?1. The study shows that cation exchange resin from polystyrene wastes can be used as an efficient adsorbent for the removal of heavy metal ions from water. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

改性高岭土捕集CdCl2、PbCl2蒸气

针对两种重金属氯化物PbCl₂、CdCl₂,探究高岭土表面羟基对吸附重金属的作用。对高岭土进行煅烧及水热改性,并在两段式管式炉上进行高岭土捕集重金属氯化物蒸气实验,并使用原子吸收分光光度计（AAS）测量吸附剂中的重金属氯化物含量。吸附数据表明对于PbCl₂及600～700℃的CdCl₂吸附,高岭土经过煅烧吸附效率大幅降低,水热重新赋予羟基后吸附效率有所提升,但仍低于原高岭土。结合热重（DTG）及红外谱图（FTIR）分析可知,高岭土经800℃煅烧脱除全部羟基,经水热重新获得部分羟基,且所获数量随水热程度的加深而增多,结合XRD谱图可知羟基促进了高岭土与重金属氯化物的吸附反应;800℃以上高温下原高岭土吸附效率逐渐低于煅烧高岭土和水热高岭土,结合核磁共振谱图（NMR）分析可知其原因在于,高岭土经煅烧改性及水热改性,Al原子配位数降低,活性增强,更易与重金属氯化物蒸气结合。     

A COMPREHENSIVE APPROACH FOR MODELING SORPTION OF LEAD AND COBALT IONS THROUGH FISH SCALES AS AN ADSORBENT

Removal of lead and cobalt cations from both industrial and municipal water is of extreme importance for waste water disposal standards. Using fish scales as an adsorbent, 95% of the lead cations and 70% of the cobalt ions can be removed. The processes related to the removal of the cations include adsorption and precipitation. The effect of precipitation of the cations in a neutral medium (pH 7) is studied and is found to be insignificant. Although the effect of precipitation is negligible in the studied experimental runs, it may assume significance in a highly nonporous medium. As sorption dictates the interactions between the bulk and adsorbed phases, it is the most important factor influencing the transport of the chemical species through the medium. Mobility of the cations has extreme importance to overall sorption characteristics because of high adsorption coefficients of the fish scales. It can be further concluded that even at cation concentration levels of 1000 ppm, sorption behavior is insensitive to change. To investigate the nature of the sorption mechanism, a series of experimental runs was conducted using fish scales of the Gadus Morhua (Atlantic cod) and Lethrinus nebulosus (spangled emperor or shouairi) species as substrates. A simulation model based on the theory of surface excess with mechanical entrapment is developed in this study. Numerical simulation results demonstrate reasonable agreements with the experimental results. This study illustrates that variations of flow rates of the cations did have a considerable effect on breakthrough time intervals. An increase in flow rate led to earlier contaminant breakthrough. However, variance of the cation concentrations did not have a dominant effect on the corresponding breakthrough values. The effect of porosity of the adsorbents is observed, and it is determined it has a profound impact on adsorption phenomena. The dispersion parameter is found to be a function of porosity, and its effect was studied in relation to the flow rate of the bulk phase. A decrease in porosity of the adsorbent results in an increase of the retardation factor of the contaminant in bulk phase and an equivalent delay in the breakthrough interval. In order to study the adsorption characteristics by surface excess model, the pH parameter was maintained at a constant pH value of 7 for all the experimental runs. The adsorption coefficient (K) was coupled into the numerical model as a parameter independent of the pH values. The numerical simulations did fit reasonably well with the experimental data.

The surface excess theory has been tested in the past only for anionic solutions. The significance of this research is that this model has been applied for the first time with respect to a bio-adsorbent in relation to heavy metal cations. It is found to be suitable for describing adsorption behavior of metallic contaminants at neutral pH. For studying adsorption with respect to the pH variable, a different adsorption model based on, the Langmuir isotherm is proposed.     

Asphaltene adsorption on clay

Asphaltene adsorption measurements with a well crystallized kaolin, a poorly crystallized kaolin, and a montmorillonite under anhydrous conditions and in the presence of water showed that the adsorption varied depending on the properties of the clay and the amount of water. The presence of presorbed water on the clays reduced asphaltene adsorption. Adsorption experiments made at elevated temperatures did not substantially alter adsorption data.     

A COMPREHENSIVE APPROACH FOR MODELING SORPTION OF LEAD AND COBALT IONS THROUGH FISH SCALES AS AN ADSORBENT

Removal of lead and cobalt cations from both industrial and municipal water is of extreme importance for waste water disposal standards. Using fish scales as an adsorbent, 95% of the lead cations and 70% of the cobalt ions can be removed. The processes related to the removal of the cations include adsorption and precipitation. The effect of precipitation of the cations in a neutral medium (pH 7) is studied and is found to be insignificant. Although the effect of precipitation is negligible in the studied experimental runs, it may assume significance in a highly nonporous medium. As sorption dictates the interactions between the bulk and adsorbed phases, it is the most important factor influencing the transport of the chemical species through the medium. Mobility of the cations has extreme importance to overall sorption characteristics because of high adsorption coefficients of the fish scales. It can be further concluded that even at cation concentration levels of 1000 ppm, sorption behavior is insensitive to change. To investigate the nature of the sorption mechanism, a series of experimental runs was conducted using fish scales of the Gadus Morhua (Atlantic cod) and Lethrinus nebulosus (spangled emperor or shouairi) species as substrates. A simulation model based on the theory of surface excess with mechanical entrapment is developed in this study. Numerical simulation results demonstrate reasonable agreements with the experimental results. This study illustrates that variations of flow rates of the cations did have a considerable effect on breakthrough time intervals. An increase in flow rate led to earlier contaminant breakthrough. However, variance of the cation concentrations did not have a dominant effect on the corresponding breakthrough values. The effect of porosity of the adsorbents is observed, and it is determined it has a profound impact on adsorption phenomena. The dispersion parameter is found to be a function of porosity, and its effect was studied in relation to the flow rate of the bulk phase. A decrease in porosity of the adsorbent results in an increase of the retardation factor of the contaminant in bulk phase and an equivalent delay in the breakthrough interval. In order to study the adsorption characteristics by surface excess model, the pH parameter was maintained at a constant pH value of 7 for all the experimental runs. The adsorption coefficient (K) was coupled into the numerical model as a parameter independent of the pH values. The numerical simulations did fit reasonably well with the experimental data.

The surface excess theory has been tested in the past only for anionic solutions. The significance of this research is that this model has been applied for the first time with respect to a bio-adsorbent in relation to heavy metal cations. It is found to be suitable for describing adsorption behavior of metallic contaminants at neutral pH. For studying adsorption with respect to the pH variable, a different adsorption model based on, the Langmuir isotherm is proposed.     

Adsorption of Hydroxypropyl Methyl Cellulose in an Aqueous System Containing Multicomponent Oxide Particles

The adsorption behavior of a hydroxypropyl methyl cellulose (HPMC) polymer in aqueous suspensions of alumina, silica, kaolin, and talc powders, two-component combinations, and one three-component combination was determined. Powders were well characterized by chemical analysis, XRD, DRIFT, SEM, particle size, surface area, and density analyses. The zeta-potential of each powder in aqueous suspension was determined over a range of pH to determine particle charging and the isoelectric point for each material. Alumina and silica powders having heavily hydroxylated surfaces were observed not to adsorb the HPMC polymer over a range of pH. The layer-type minerals talc, which was noticeably hydrophobic, and kaolin, which had differently hydrated basal planes, adsorbed the HPMC polymer but in different amounts per unit of surface area. In the two-component systems, HPMC polymer adsorption for systems of dispersed particles of like electrical charge (kaolin + silica, talc + silica or alumina, and kaolin + talc) was proportionate to the sum of the fraction x specific surface area x adsorption capacity for each particle type. In systems where particles had an opposite electrical charge (kaolin + alumina, kaolin + talc + alumina), the HPMC polymer adsorption was significantly lower than that calculated for a dispersed system. SEM analysis showed very fine, nonadsorbing alumina particles predominantly on the faces of the adsorbing kaolin particles that apparently masked polymer adsorption. Results suggested a hydrophobic mechanism for the HPMC polymer adsorption and adsorption on only one face of the kaolin particles.