HDX-8树脂对2,4-二氯苯酚吸附的研究

研究了HDX-8树脂对2,4-二氯苯酚的吸附性能。结果表明,静态条件下在pH2~6范围内,对2,4-二氯苯酚具有良好的吸附性能,最大静态吸附量为9.725 mg 2,4-二氯苯酚/g树脂。等温吸附符合Freundlich和Langmuir方程式,相关系数均在0.99以上;柱长8 cm,内径1.0 cm,内装2.5 g HDX-8树脂的吸附柱对流速为5 mL/min,浓度为20μg/mL的2,4-二氯苯酚溶液的吸附率达到99%;负载柱可用1 mol/mL的NaOH洗脱。     

乙酰苯胺修饰的吸附树脂对2,4-二氯苯酚的吸附研究

通过后交联反应,用乙酰苯胺修饰氯甲基化的低交联大孔聚苯乙烯-二乙烯(氯球),合成了一种超高交联吸附树脂ZH-05。用活性炭GAC和Amberlite XAD-4树脂作为参照,测试了ZH-05吸附树脂对2,4-二氯苯酚的吸附性能。讨论了静态平衡吸附行为和化学吸附特征的证实。结果表明:吸附等温线都能用Langmu ir方程很好的拟合,且2,4-二氯苯酚在ZH-05吸附树脂上的吸附是一个吸热过程,吸附量随吸附温度的升高而增加,和活性炭一样,ZH-05树脂对水溶液中2,4-二氯苯酚的吸附过程中同时存在着物理吸附和化学吸附。     

胺基化壳聚糖树脂吸附2,4-二氯苯酚

改性制得的胺基化壳聚糖用于对2,4-二氯苯酚吸附的研究中,最佳吸附条件为在30℃、pH为4、吸附时间为1 h,胺化剂用量为0.1 g以及二氯苯酚浓度为0.09 mol/L。通过对Langmuir等温吸附方程及Freundlich等温吸附方程的分析得出吸附更加符合Langmuir等温吸附方程。     

双官能基修饰的超高交联吸附树脂对2,4-二氯苯酚的吸附性能研究

合成了用2-氨基酚修饰的新型双官能基聚苯乙烯-二乙烯苯吸附树脂MOAPR-1和MOAPR-2,研究了其在288~318 K下对水溶液中2,4-二氯苯酚的静态吸附和静态脱附特征。结果表明,2,4-二氯苯酚在两种树脂上存在化学吸附现象,符合Freundlich等温吸附方程。利用半经验分子轨道法计算了几种吸附剂的近似结构和2,4-二氯苯酚的前线轨道能级,并对吸附过程进行了合理的解释。     

氯化铁改性椰壳活性炭去除2,4-二氯苯酚的吸附性能研究

以椰壳活性炭为原料,进行氯化铁改性,探究其对2,4-二氯苯酚吸附性能影响的研究。通过静态吸附实验得到了最佳改性条件,使得对2,4-二氯苯酚吸附性能进一步得到提升,并结合实际水体酸碱性探究,对模拟废水实验进行了pH探究,进一步优化了材料对实际水体的适用性。研究表明,氯化铁浓度为0.8 mol/L、改性时间为24 h条件下改性得到的炭材料(BC-F)吸附性能最佳,吸附剂的最佳使用量应为0.04 g,吸附过程应在弱酸或碱性环境中进行,在实际水体中实用性较好;且该吸附过程符合准一级动力学和Freundlich等温吸附方程,以化学吸附为主。     

2,4-二氯-5-硝基苯酚的合成

研究了以磷酸三(2，4-二氯)苯酯为原料，经硝化、水解合成2，4-二氯-5-硝基苯酚的工艺，讨论了反应条件对反应的影响，获得了较好的工艺条件。在优化条件二步反应总收率为97％(以磷酸三(2，4-二氯)苯酯计)。产物经IR及元素分析表征了结构。产品是合成多种高效除草剂如“稻思达”的关键中间体。     

2,4--二氯苯酚尾气的处理方法

介绍了国内2，4-二氯苯酚尾气的处理方法，并对其进行了技术评估。     

阳离子木屑纤维素的制备及其对水中2,4-二氯苯酚的吸附性能

以3-氯-2-羟丙基三甲基氯化铵(CTA)为醚化剂,对木屑纤维素(MC)进行了改性,并对产物进行了表征. 探讨了阳离子木屑纤维素用量、pH值、吸附温度、吸附时间等因素对水溶液中2,4-二氯苯酚(2,4-DCP)静态吸附效果的影响. 结果表明,阳离子木屑纤维素的制备条件为：CTA/MC质量比2.0,反应时间2.0 h,反应温度30℃,NaOH溶液浓度30%(w). 阳离子木屑纤维素对水溶液中2,4-DCP的最佳吸附条件为：pH 8.0,吸附时间90 min,吸附温度25℃. 此条件下,处理100 mL 2,4-DCP溶液(50 mg/L)的吸附率可达88.92%,吸附容量为1.482 mg/g. 木屑纤维素经改性后,对水中2,4-二氯苯酚存在化学吸附.     

新型改性壳聚糖的制备及其对2,4-二氯苯酚的吸附

采用水杨醛与壳聚糖反应生成Schiff’s碱,再用NaBH4还原,环氧氯丙烷交联制备壳聚糖衍生物,用FTIR对改性壳聚糖进行表征,并用于2,4-二氯苯酚的吸附研究。测试了改性产物的溶解性能,考察了吸附时间、溶液pH值、酚的浓度以及改性剂用量等因素对氯酚吸附的影响。结果表明,水杨醛改性环氧氯丙烷交联壳聚糖不溶于水、酸和碱;在pH=7、吸附时间为2 h时,对2,4-二氯酚的吸附量为128.2 mg/g。     

2，4-二氯苯酚在超高交联树脂上的吸附性能的研究

比较了超高交联聚苯乙烯吸附树脂与大孔吸附树脂Amberlite对2,4-二氯苯酚的静态和动态吸附行为。结果表明：在288-318K和研究的浓度范围陡,JP-1和XAD-4对2,4--二氯苯酚的吸附平衡数据符合Freundlieh吸附等温方程。吸附为吸热过程,适当降低温度有利于吸附,并计算了2,4-二氯苯酚在JP-1、XAD．4树脂上的吸附焓变、自由能变、吸附熵变,对吸附行为进行了合理豹解释。     

Photocatalyzed Degradation of Phenol, 2,4-Dichlorophenol,Phenoxyacetic Acid and 2,4-Dichlorophenoxyacetic Acid over SupportedTiO2 in a Flow System

The photodegradation of phenol, 2,4-dichlorophenol, phenoxyacetic acid and 2,4-dichlorophenoxyacetic acid using TiO₂ as photocatalyst is investigated. The photodegradations of these compounds have been conducted in a continuous mode by means of a flow system, in which TiO₂ remains fixed onto glass pearls. The use of this system gives high yields of degradation for the chemicals tested, except for 2,4-dichlorophenol for which a slow dechlorination process is observed. The rate of photodegradation depends on the pH of the solution, the point of zero charge of TiO₂ and the pK_a of the chemicals being the key parameters. The main aromatic intermediates detected have been hydroquinone,paraquinone and hydrohydroquinone during phenol degradation; phenol and hydroquinone during phenoxyacetic acid degradation; chlorohydroquinone and chlorophenol during 2,4-dichlorophenol degradation; and dichlorophenol during 2,4-dichlorophenoxyacetic acid degradation. Finally, some long term irradiations with phenol as model compound have been performed, showing high degrees of photodegradation. It has been observed that only a periodic evacuation of the effluent out of the reactor is needed to sustain high percentages of photodegradation.     

炭化芝麻秆对苯酚废水的吸附性能

采用KH2PO4活化原材料芝麻秆,分别在300和600℃对活化后芝麻秆进行炭化,制得炭化芝麻秆吸附剂(CSS1和CSS2),通过静态吸附实验研究了其对苯酚的吸附性能,考察了pH值、吸附时间和温度对苯酚吸附的影响,分析了炭化芝麻秆对苯酚的吸附机理. 结果表明,CSS2吸附苯酚能力比CSS1强,其吸附较好地满足Langmuir和Freundlich等温方程,在20, 30和40℃下CSS2对苯酚的最大吸附容量分别高达13.53, 18.42和21.32 mg/g;动力学研究表明其吸附速率快,在150 min内能达到吸附平衡,准二级动力学模型较好地描述了该吸附行为,相关系数高达0.999;计算了热力学参数DGq, DHq和DSq的值,该吸附过程为自发过程.     

Co3O4对2,4-二氯苯酚的吸附性能影响

以硝酸钴(Co(NO₃)₂·6H₂O)为钴源,考察了不同沉淀剂(6 mol/L氨水、1 mol/L NaOH溶液、饱和碳酸铵溶液)对Co₃O₄吸附2,4-二氯苯酚(2,4-DCP)性能的影响。考察了焙烧温度、pH值、沉淀剂种类、吸附剂用量、2,4-DCP初始质量浓度对Co₃O₄吸附性能的影响,并进行了离子干扰实验。结果表明,焙烧温度为300℃、pH=9.0、沉淀剂为1 mol/L NaOH时,Co₃O₄对20 mg/L 2,4-DCP吸附性能最佳。Co₃O₄对2, 4-DCP的动力学吸附过程符合准二级动力学方程,等温吸附方程符合Langmuir方程,吸附过程以单分子层化学吸附为主。     

超声波协同铁粉降解水中2,4-二氯酚的研究

采用超声波/铁粉协同降解水中2,4-二氯酚。考察了初始浓度、超声功率、铁粉投加量以及pH对降解效率的影响,并初步探讨了超声波/铁粉协同降解2,4-二氯酚的动力学规律。结果表明,超声波与铁粉对2,4-二氯酚的降解具有明显的协同效应。降解效率随超声功率和铁粉投加量的增大而增大,随初始浓度的增大而减小。pH对2,4-二氯酚的降解有显著影响,在pH为4时,降解效率最高。超声波/铁对2,4-二氯酚的协同降解符合一级反应动力学规律,降解速率常数为1.52×10-2min-1,与铁粉单独作用和超声单独作用相比,分别提高了约5倍和13倍。     

Adsorption of Phenol on Different Activated Carbons Prepared from Date Pits

The potential use of different activated carbons (ACs) prepared from dates pits and phosphoric acid for the removal of phenol from aqueous solutions was investigated. Date pits were converted into five different types of activated carbons by air and phosphoric acid activation. The specific surface area (BET) of the prepared ACs varied from 794 m²/g, for the phosphoric acid:date pit ratio of 5:1, to 1707 m²/g for a ratio of 2:1. Batch adsorption experiments revealed that the adsorption of phenol varied among all of the prepared ACs, where the 2:1 AC showed the highest uptake. Equilibrium pH studies showed that the phenol removal was pH dependent and the maximum phenol uptake occurred at an equilibrium pH of 3.0. Dynamics studies indicated that the initial uptake of phenol on 2:1 AC at pH 4 was rapid, where 80% of the maximum uptake was achieved during the first 30 minutes; both surface adsorption and intraparticle diffusion were involved in the adsorption process and the data followed the pseudo second-order reaction. The equilibrium adsorption data of phenol on 2:1 AC at solution pH 3 was best described by the Redlich-Peterson, Sips, and Langmuir models.     

新型超高交联树脂对2-甲基-4-氯苯氧乙酸的吸附机理研究

在静态条件下,研究了水溶液中超高交联树脂ZZ和大孔吸附树脂Am berlite XAD-4吸附2-甲基-4-氯苯氧乙酸的热力学特性,测定了283K和323K温度下的吸附等温线。对两个温度下的吸附等温线的比较和热力学数据的计算,结果表明,在稀溶液中两种吸附剂对2-甲基-4-氯苯氧乙酸的吸附同时符合Langm u ir和F reund lich模型,并且两种吸附剂对2-甲基-4-氯苯氧乙酸的吸附都是放热过程。     

螯合树脂对铜离子的吸附动力学和热力学

针对以谷氨酰胺-铜(II)配合物为供体酶法制备茶氨酸体系,研究了D401螯合树脂对Cu2+的吸附,探讨了吸附过程的热力学和动力学,通过红外光谱鉴定了树脂的配位结构. 结果表明,树脂吸附量随离子浓度和温度升高而增加,当pH为5.6时吸附量最大,达1.887 mmol/g. 不同温度下Langmuir方程均呈现很好的拟合度. 热力学平衡方程计算得DG<0, DH=21.5 kJ/mol, DS>0,表明该吸附过程是自发的、吸热、熵增加的过程. 动力学研究表明,该过程符合准二级动力学模型,吸附反应速率由颗粒扩散和液膜扩散共同控制. 该树脂在较宽的pH范围内对Cu2+具有很好的选择吸附性,可用于酶转化茶氨酸体系中Cu2+的去除.     

纤维对苯酚的吸附性能研究

研究了自制的纤维对苯酚的吸附热力学特性,测定了不同温度下的吸附等温线,结果显示,纤维对水溶液中的苯酚有较高的吸附能力,吸附过程符合Langmuir和Freundlich方程,吸附焓变为正值,表现为吸热的吸附过程。     

Isotherm,Thermodynamics, and Kinetics of Methyl Orange Adsorption onto Magnetic Resin of Chitosan Microspheres

Severe environmental pollution problems arising from toxic dyestuffs (e.g., methyl orange) are receiving increasing attention. Therefore, dyes’ safe removal has become a research hotspot. Among the many physical–chemical removal techniques, adsorption using renewable biological resources has proved to be more advantageous over others due to its effectiveness and economy. Chitosan is a natural, renewable biopolymer obtained by deactivated chitin. Thus, the magnetic resin of chitosan microspheres (MRCM), prepared by reversed-phase suspension cross-linking polymerization, was used to remove methyl orange from a solution in a batch adsorption system. The main results are as follows: (1) The results of physical and swelling properties of MRCM indicated that MRCM was a type of black spherical, porous, water-absorbing, and weak alkali exchange resin, and it had the ability to adsorb methyl orange when it was applied in solutions above pH 2.0. (2) In batch adsorption studies, the maximum adsorption capacity was obtained at pH 5; the adsorption equilibrium time was 140 min; and the maximum adsorption was reached at 450 mg/L initial concentration. (3) Among the three isotherm adsorption models, Langmuir achieved the best fit for the adsorption of methyl orange onto MRCM. (4) The adsorption thermodynamics indicated that the adsorption was spontaneous, with increasing enthalpy, and was driven by the entropy. (5) The pseudo-second-order kinetics equation was most suitable to describe the adsorption kinetics, and the adsorption kinetics was also controlled by the liquid–film diffusion dynamics. Consequently, MRCM with relatively higher methyl orange adsorption exhibited the great efficiency for methyl orange removal as an environment-friendly sorbent. Thus, the findings are useful for methyl orange pollution control in real-life wastewater treatment applications.