嗪草酮农药生产环合废水物化处理工艺研究

采用絮凝-树脂吸附组合工艺对嗪草酮农药生产环合废水进行物化预处理.实验确定的最佳工艺条件为:(1)絮凝-絮凝剂为10%硫酸铝溶液(W/W),投加量为8%(V/V),废水pH为6～9,快速搅拌1 min(150～180 r/min),慢速搅拌15 min(80～100 r/min);(2)树脂吸附-双柱串联吸附:上柱液p...     

嗪草酮农药生产废水的预处理工艺研究

采用树脂吸附法处理嗪草酮农药生产环合工段废水,XF-03树脂静态吸附环合工段生产废水时,COD去除率为55.9%.动态吸附随着吸附流速增大,吸附出水的COD增加,适宜的吸附流速为25 BV/g.在连续4批的吸附-脱附实验中,各批次吸附出水的ρ(COD)约为3000～4400mg/L.甲基化工段废水按1%(体积比)分3次加入质量分数为30%的H2O2,pH值调节至3.0,氧化温度为80℃时,废水ρ(COD)由110000～113000mg/L降至53000～55000mg/L.     

大孔弱碱性树脂对2,4-二硝基苯酚吸附性能的研究

研究了2,4-二硝基苯酚在D301大孔弱碱树脂上的吸附性能。结果表明:在283～313K和研究的浓度范围内,吸附行为符合Freundlich和Langmuir等温式,D301树脂对2,4-二硝基苯酚的平衡吸附容量为235.9mg/g,动态吸附容量为121.3mg/g。用质量分数为10%的氢氧化钠溶液作脱附剂,温度333K,体积为6BV(床体积)时,脱附率为89.2%,树脂脱附再生后可反复使用,并回收2,4-二硝基苯酚。     

聚丙烯酸-聚偏氟乙烯树脂对Cu(Ⅱ)的吸附性能

采用溶液热诱导聚合和相转移共混新技术,制备了聚丙烯酸-聚偏氟乙烯(PAA-PVDF)微球树脂,研究了该树脂对水溶液中Cu₂₊的吸附性能,吸附热力学及吸附动力学.模型拟合结果表明,PAA-PVDF树脂对Cu₂₊具有优良的吸附性能,吸附量随温度升高而增大.热力学参数△G0<0、△H0>0、△S0>0,证实了该树脂对Cu₂₊的吸附为自发的吸热过程.PAA-PVDF树脂对Cu2+的等温吸附较好地符合Freundlich等温吸附模型,D-R等温吸附表明该吸附过程为离子交换反应.该吸附过程的动力学符合准二级动力学方程.PAA-PVDF树脂的吸附/脱附性能优良,经吸附/脱附4次循环后,其吸附量>5mg/g,脱附率仍超过95%.     

巯基树脂的合成及对Hg2+的吸附特征

使用聚苯乙烯交联微球为前驱体,经一系列反应合成了一种苯环上含巯基的离子交换树脂(巯基树脂),研究了其对水中Hg2+的吸附特征. 巯基树脂的红外与元素分析结果表明,巯基官能团成功地嫁接到树脂表面,树脂中b(巯基)为2.89 mmol/g. pH对吸附的影响较大,当pH为1时,巯基树脂对Hg2+的吸附量很低,因此,可以用酸洗树脂使其再生. 当pH为2～7时,巯基树脂对Hg2+的吸附量相差不大. 巯基树脂对水中Hg2+的吸附等温线结果表明,温度的升高有利于吸附,吸附量高达14.500 mg/g,且符合Langmuir模型. Hg2+在巯基树脂上的吸附符合准二级动力学方程,对于初始ρ(Hg2+)为1 mg/L的溶液,吸附后最终ρ(Hg2+)可降到0.003 mg/L.      

改性树脂吸附硼的动力学和热力学研究

通过接枝法成功制备了酚羟基型改性树脂,选用典型的动力学方程、热力学方程以及非线性两参数的4种等温吸附模式对改性树脂吸附硼的试验数据进行拟合,从动力学和热力学角度分析并揭示改性树脂对硼的吸附特征和吸附机理。结果表明:伪二级动力学吸附模式可较好地描述改性树脂对硼的动力学吸附过程;在3种不同温度下的自由能变(ΔG)分别为-5.44 kJ/mol、-6.32 kJ/mol、-4.01 kJ/mol,焓变(ΔH)为-6.43kJ/mol,均小于零,活化能(E)为11.06 kJ/mol,说明该吸附过程为可自发进行的放热反应,是基于树脂表面试钛灵的邻羟基与硼酸分子发生配位反应的、以化学吸附为主的物理化学吸附过程;非线性两参数的4种等温吸附模式对改性树脂吸附硼的吸附试验数据拟合结果显示该吸附过程最符合Langmuir等温吸附模式,且在25℃条件下改性树脂对硼的吸附量最高达20.87 mg/g。     

丁二酰亚胺基修饰的吸附树脂对苯胺的吸附热力学性能

有效去除废水中苯胺及其衍生物是重要的环境问题. 由氯甲基聚苯乙烯树脂与丁二酰亚胺反应,合成大孔交联聚(对乙烯基苄基丁二酰亚胺)树脂(简称丁二酰亚胺树脂),测定了丁二酰亚胺树脂对正庚烷溶液中苯胺的吸附性能. 结果表明:丁二酰亚胺树脂对正庚烷溶液中苯胺的吸附量大于原料树脂. 吸附等温线符合Freundlich等温吸附方程,相关系数大于0.99. 利用热力学函数计算了等量吸附焓变、吸附自由能变和吸附熵变. 树脂对正庚烷中苯胺的等量吸附焓变在20～30 kJ/mol,推测吸附过程为氢键吸附;同时,通过比较树脂对正庚烷溶液中苯胺和N,N-二甲基苯胺的吸附性能的差别,进一步论证了丁二酰亚胺树脂对正庚烷中苯胺的吸附是基于氢键作用的机理.      

树脂吸附法处理采矿塌陷区废水的研究

文章采用ND-90型超高交联吸附树脂吸附处理采矿塌陷区废水.原废水COD质量浓度为200～230mg·L-1,经沉淀-树脂吸附法处理,处理量20BV,吸附流出液COD质量浓度为40～50 mg·L-1,COD去除率≥80.23%,树脂经过碱液脱附后可重复利用且运行稳定.该处理工艺投资少、操作简便,为解决采矿塌陷区水体修复问题提供了一种新的方法.     

硫脲修饰超高交联聚苯乙烯树脂吸附Cr（Ⅵ）

以氯甲基聚苯乙烯树脂（CMPS）为前体,经后交联反应合成超高交联树脂（J-2）,再经硫脲胺基改性得到硫脲修饰超高交联聚苯乙烯树脂（TU-PS）.通过BET、FTIR等对树脂结构进行表征,并考察了pH、吸附温度、接触时间等因素对TU-PS改性树脂吸附Cr（Ⅵ）性能的影响.结果表明,改性树脂（TU-PS）对Cr（Ⅵ）吸附的最佳条件为：Cr（Ⅵ）初始浓度为500 mg·L^-1、初始pH值为2、树脂用量为2.5 g·L^-1、吸附温度为45 ℃、吸附时间为6 h.在此最佳条件下,TU-PS树脂对Cr（Ⅵ）的最大吸附量为140.00 mg·g^-1,去除率为70.18%.吸附过程符合Langmuir等温吸附模型和 准二级动力学模型,吸附过程以单分子层化学吸附为主.TU-PS树脂对Cr（Ⅵ）的吸附是静电吸附和化学吸附共同作用的结果.     

富集甲基汞的树脂膜筛选及条件优化

树脂膜作为DGT技术的核心部分,是影响 DGT测定的关键因素。为确保树脂吸附和洗脱实验的准确性,筛选出醋酸-盐酸混合溶液作为甲基汞溶液的保存试剂。以标液中甲基汞的吸附率为指标,比较了4种吸附树脂的基本特征及在室内标液浓度为1μg/L的条件下对甲基汞的吸附效果,筛选出吸附效果最佳的树脂TCH-95,并对TCH-95树脂胶的不同洗脱试剂进行了研究。结果表明：24h TCH-95对甲基汞的吸附率高达98.9%。且在洗脱实验中,对硫脲-盐酸混合溶液添加冰醋酸有助于提高树脂胶中甲基汞的洗脱率,其2%硫脲-0.2mol/L HCl-4%HAc混合溶液的甲基汞洗脱率为84.5%,是目前TCH-95树脂的最佳洗脱剂。     

2,4-二硝基酚在离子交换树脂上吸附与微波脱附

研究了717强碱阴离子交换树脂对水中2,4-二硝基苯酚(2,4-DNP)的吸附解吸性能,探讨了吸附的热力学和动力学特性及其微波脱附性能。结果表明:在pH=4～11时,该树脂对2,4-DNP有较强的吸附能力。Freundlich吸附等温方程能很好地描述吸附平衡数据,吸附过程为放热、熵减的自发过程。吸附动力学符合Lagergren二级速率方程,颗粒内扩散是吸附速率的主要控制步骤,可采用HSDM模型描述。以1mol/L HNO3+C2H5OH溶液作为脱附剂,采用微波辅助脱附再生,微波辐照累计5min时,酚脱附率可达90%以上。     

Adsorption mechanism of phenolic compounds from aqueous solution on hypercrosslinked polymeric adsorbent

The adsorption of two phenols, namely, phenol and salicylic acid(SA) onto a water-compatible hypercrosslinked polymeric resin (NJ-8) were studied in terms of pseudo-second-order and first order mechanisms for chemical sorption as well as an intraparticle diffusion mechanism process. Kinetic analysis showed that the intraparticle diffusion process was the essential rate-controlling step. The activation energies of sorption have also been evaluated with the pseudo-second-order and intraparticle diffusion constants, respectively. Adsorption equilibrium data were well fitted by the Langmuir, Freundlich and Redlich-Peterson isotherms. Adsorption was exothermic and basically of a type of transition between physical and chemical character. The sorption capacity was higher for SA due to its more hydrophobic. Phenol has a higher adsorption enthalpy since it could form stronger hydrogen bonding on NJ-8.     

NDA-100大孔树脂对水溶液中水杨酸的吸附行为研究

通过静态吸附试验，研究了NDA－100大孔树脂对水溶液中水杨酸的吸附动力学及热力学特性，结果表明吸附符合一级动力吸附方程，颗粒内扩散过程是影响吸附速率的主要控制步骤，吸附符合Langmuir和Freundlich等温吸附方程，吸附为放热的物理吸附过程。     

DVB-MMA共聚物树脂吸附水相苯酚的研究

以二乙烯基苯(DVB)和甲基丙烯酸甲酯(MMA)的混合液为单体,分别采用悬浮聚合法和溶剂热法合成高分子树脂PDMA和PDVB.通过BET、IR、SEM对样品的结构和形貌进行表征,对比2种方法合成吸附树脂的性能差异,并考察各高分子树脂对水中苯酚的吸附效果.结果表明,采用悬浮聚合法制备的DVB-MMA共聚物树脂在2~4nm和5~30nm范围内均有明显孔径分布,具有较大的比表面积566m2/g. DVB-MMA共聚物树脂(PDMA-XF)对4500mg/L苯酚溶液的饱和吸附量为170.4mg/g,其酯羰基中的氧原子与酚羟基当中的氢原子产生氢键作用,这些分子间的氢键作用有助于吸附水中苯酚.     

Adsorption thermodynamics and kinetic investigation of aromatic amphoteric compounds onto different polymeric adsorbents

The adsorption behavior of p-aminobenzoic acid and o-aminobenzoic acid onto the different polymeric adsorbents was systematically investigated as a function of the solution concentration and temperature.Experimental results indicated that the equilibrium adsorption data of the four polymeric adsorbents fitted well in the Freundlich isotherm.The adsorption capacity of multi-functional polymeric adsorbent NJ-99 was the highest,which might be attributed to the strong hydrogen-bonding interaction between the amino groups on the resin and the carboxyl group of aminobenzoic acid.The adsorption capacity of o-aminobenzoic acid onto any adsorbent was higher than p-aminobenzoic acid.Thermodynamic studies suggested the exothermic,spontaneous physical adsorption process.Adsorption kinetics results showed that the adsorption followed the pseudo-second-order kinetics model and the intraparticle mass transfer process was the rate-controlling step.     

D113大孔树脂吸附Ni~(2+)的动力学与热力学研究

研究了D113大孔树脂吸附Ni2+的动力学与热力学的特性。动力学研究表明,在298K温度下,D113大孔树脂对Ni2+的吸附符合拟一级动力学方程和拟二级动力学方程,颗粒扩散过程为吸附的控速步骤。热力学研究表明,在实验温度下,D113大孔树脂对Ni2+的吸附符合Langmuir等温方程,吸附焓变ΔHθ=15.1306kJ/mol,熵变ΔSθ=0.1002kJ/mol.K,反应吉布斯自由能ΔGθ随温度升高向负方向增加。热力学参数表明吸附过程为吸热和自发的。     

D301树脂对水中氟虫腈的吸附去除研究

文章研究D301树脂对水溶液中氟虫腈的吸附行为,考察了吸附剂投加量和溶液pH值对吸附效果的影响,对吸附等温线和吸附动力学进行了探讨,并选择不同模型对吸附曲线进行拟合。结果表明,当氟虫腈溶液初始浓度为2 mg/L,吸附剂投加量为0.5 g/L时,氟虫腈的去除率达到100%;溶液pH值在3⁹范围内变化时,对吸附的影响较小,相对而言pH=7的吸附效果最好;D301树脂对氟虫腈的吸附等温线满足Langmuir吸附等温式和Freundlich吸附等温式,相关系数R2分别为0.994和0.991;吸附动力学符合Lagergren一级反应方程。总体来说,D301树脂对氟虫腈的吸附效果较好。     

改性羧甲基纤维素对铀吸附机理的试验研究

对羧甲基纤维素(CMC)进行改性,并将其用于吸附废水中的铀.研究结果表明:在温度为70℃~80℃、单体质量浓度为30%~35%、羧甲基纤维素:丙烯酸(质量比)为10:2.5、反应时间为3.5~4h条件下,CMC改性效果最好;在改性CMC质量浓度为0.10g/L,温度为25℃, pH值为5.0,反应时间60min的条件下,对废水中铀去除率达到了97.1%;改性CMC对溶液中U(VI)的吸附过程符合Freundlich方程,其吸附动力学数据符合准一级方程(R2=0.9618),表明改性CMC的吸附主要是表面吸附;热力学研究表明,改性CMC对铀的吸附吉布斯自由能(ΔG0)0,吸附过程是自发的吸热反应、以物理吸附为主的过程.     

Preparation and utilization of wheat straw anionic sorbent for the removal of nitrate from aqueous solution

In order to reduce the impact of eutrophication caused by agricultural residues(i.e.,excess nitrate)in aqueous solution,economic and effective anionic sorbents are required.In this article,we prepared anionic sorbent using wheat straw.Its structural characteristics and adsorption properties for nitrate removal from aqueous solution were investigated.The results indicate that the yield of the prepared anionic sorbent,the total exchange capacity,and the maximum adsorption capacity were 350%,2.57 mEq/g,and 2.08 mmol/g, respectively.The Freundlich isotherm mode is more suitable than the Langmuir mode and the adsorption process accords with the first order reaction kinetic rate equation.When multiple anions(SO_4~(2-),H_2PO_4~-,NO_3~-,and NO_2~-)were present,the isotherm mode of prepared anionic sorbent for nitrate was consistent with Freundlich mode;however,the capacity of nitrate adsorption was reduced by 50%.In alkaline solutions,about 90% of adsorbed nitrate ions could be desorbed from prepared anionic sorbent.The results of this study confirmed that the wheat straw anionic sorbent can be used as an excellent nitrate sorbent that removes nitrate from aqueous solutions.     

Adsorption of β-naphthalenesulfonic acid/sulfuric acid from their solution by weakly basic resin: equilibrium

Experiments for single and bisolute competitive adsorption were carried out to investigate the adsorption behavior of β-naphthalenesulfonic acid(NSA) and sulfuric acid (H2SO4) from their solution at 25℃ onto weakly basic resin D301R. Adsorption affinity of sulfuric acid on D301R was found to be much higher than that of NSA. The data of single-solute adsorption were fitted to the Langmuir model and the Freundlich adsorption model. The ideal adsorbed solution theory(lAST) coupled with the single-solute adsorption models were used to predict the bisolute competitive adsorption equilibria. The lAST coupled with the Langmuir and the Freundlich model for sulfuric acid and NSA, respectively, yields the favorable representation of the bisolute competitive adsorption behavior.