碳纳米管溶胶对水中微量污染物的吸附去除性能研究

吸附法是目前最经济有效去除水中微量污染物的方法之一。经强酸表面氧化法制备的碳纳米管溶胶具有稳定的高效吸附性能。采用静态吸附法,对水中微量有机物和重金属进行同步吸附去除实验研究。结果表明,碳纳米管溶胶对水中的微量有机物和重金属具有很好的去除效能。这对微污染水的深度处理具有良好的应用前景。     

竹炭对微污染水中有机污染物的吸附

测定了竹炭对微污染水源水中CODMn,UV254,UV410的去除效果,研究了竹炭粒径、竹炭用量、吸附时间、溶液pH值对竹炭吸附特性的影响,并由正交试验确定出竹炭去除水中CODMn,UV254,UV410的最佳吸附条件。研究表明,粒径越小,竹炭的吸附效果越好;竹炭用量为100mg、吸附时间为1h时,竹炭对各指标去除率最高;弱酸条件对竹炭对各指标的吸附最有利,当pH值=4时竹炭对各指标的去除率最大;正交试验确定出动态吸附最佳操作条件为：竹炭粒径为100～200目,质量为100mg,振荡吸附1h,原水pH值为4。     

介孔复合吸附材料对微污染水源水中有机污染物的吸附试验

研究介孔复合吸附材料对微污染水源水中有机污染物和总磷的去除效果。"静态吸附"试验结果表明,介孔复合吸附材料对微污染水源水的TOC和总P去除率分别为76.7%和68.9%;TOC饱和吸附量为5.27mg/(g·L),总P饱和吸附量为0.486mg/(g·L);"动态吸附"试验结果表明,介孔复合吸附材料的最佳处理量为35mL/g,最佳吸附流速为5mL/min,在此条件下对TOC和总P的去除效果分别为68.7%和20.3%。综上所述,介孔复合吸附材料的整体吸附效果与活性炭相当,具有一定的应用价值。     

羧化CTS微球对共存有机污染物的吸附研究

采用反相悬浮法制备交联羧甲基化壳聚糖微球,并用高效液相色谱法-紫外检测研究了改性壳聚糖微球对共存有机污染物的吸附。试验了吸附时间、溶液pH值、有机物的浓度等因素对水中共存有机污染物吸附的影响。结果表明,在有机物浓度相近的情况下,羧化改性壳聚糖微球对水中2,4-二硝基酚的去除量最大。     

活性污泥对有机污染物的吸附研究

通过中试试验,分析了活性污泥对污染物吸附的影响因素,并考察了活性污泥对城市污水中污染物的吸附效果.试验研究表明,污泥浓度(MLSS)、水力停留时间(HPT)和污泥龄(SRT)对活性污泥吸附污染物的效果有一定的影响,但污泥龄影响较小.在污泥质量浓度为3～5 g/L,HRT为36 min和SRT为2 d的运行参数下,活性污泥时COD,SS,TN和TP吸附效果分别为70.7%,87.7%,30.2%和72.2%.     

有机改性膨润土吸附水中有机污染物的性能研究

以浙江临安钙基膨润土为原料,以溴化十六烷基三甲胺为改性剂,研究了改性剂用量以及钠化、热活化和酸活化对有机膨润土吸附苯酚、苯胺、苯、甲苯、二甲苯的影响.试验结果表明,改性剂用量增加,有机膨润土的层间距d001也增大,对有机物的吸附能力增大.在改性剂用量相同时,钠化土的吸附效果明显优于直接改性的有机膨润土.     

介孔炭干凝胶对孔雀石绿的吸附性能研究

以间苯二酚和甲醛为原料,采用溶胶-凝胶法,通过调整碱性催化剂碳酸钠用量,制备了一系列介孔丰富的炭干凝胶吸附剂.主要考察了介孔炭干凝胶对染料孔雀石绿的吸附性能,并进行了孔结构、表面形貌和官能团的分析.结果表明,催化剂用量不同的介孔炭干凝胶具有不同的粒径和孔径,当间苯二酚与碳酸钠的物质的量比为1000∶1时,制得的吸附剂比表面积和介孔最丰富,且其对孔雀石绿的吸附量最大.同时,介孔炭干凝胶的用量、吸附时间和温度对吸附容量均有一定的影响,吸附过程符合伪二阶动力学模型和Langmuir等温模型,最大吸附量为208.33 mg·g~(-1);吸附过程是自发的吸热反应.介孔炭干凝胶对孔雀石绿的主要吸附机理是染料分子与羟基和羧基等官能团之间存在静电作用、氢键作用及范德华力作用.     

高分子多孔小球GDX-102对水中有机氯农药的富集作用

测定了国产高分子小球GDX-102对水中微量有机氯农药(β-666、p,p’-DDE和p,p’-DDT)的吸附容量和富集效率,选取了动态富集最佳水样流速.结果表明,GDX-102对上述三种有机氯农药均有较大的吸附容量,其数值分别为14.2mg/g(β-666)、22.3mg/g(p,p’-DDE)和31.4mg/g(p,p’-DDT).在实验条件下,水样流速在0—60ml/min范围内变化时,对GDX-102的富集效率影响甚小,富集效率接近100％,因此,GDX-102可应用于环境水样中微量有机氯农药的现场采样富集.     

大孔树脂对邻苯二甲酸的吸附研究

研究了XDA-200大孔树脂对水溶液中邻苯二甲酸的吸附。结果表明XDA-200树脂对水溶液中的邻苯二甲酸吸附速度很快，30min内基本达到平衡，其后达到完全平衡的吸附进程非常缓慢。树脂对邻苯二甲酸的吸附量随质量浓度增加而增加。pH值降低，有利于邻苯二甲酸在溶液中以分子态存在，易于树脂吸附。邻苯二甲酸的吸附均满足Freundlich和Langmiur等温吸附方程。泄漏点与进水浓度和流速均有很大关系。     

改性壳聚糖对酚类污染物的竞争吸附研究

采用庚醛与壳聚糖反应生成schiff’s碱,NaBH4还原制备N-烷基化壳聚糖衍生物,并用反相HPLC-紫外检测研究了改性壳聚糖对酚类化合物的竞争吸附。试验了吸附时间、溶液pH值、酚的浓度等因素对水中共存酚类污染物竞争吸附的影响。结果表明,庚醛改性壳聚糖优先去除水中2,4-二氯酚。     

Highly efficient and selective removal of low-concentration antibiotics from aqueous solution by regenerable Mg(OH)2

The prevalent presence of fluoroquinolone antibiotics in aquatic environments has attracted considerable attention because of their harmful effects on humans and the ecological environment.Magnesium hydroxide nanocrystals were found to act as a simple and effective adsorbent to remove low-concentration ciprofloxacin(CIP) in aqueous solution.The as-prepared Mg(OH)₂ nanocrystals exhibited excellent CIP adsorption performance and high selectivity toward CIP molecules compared with other ...     

Adsorption removal of thiocyanate from aqueous solution by calcined hydrotalcite

A hydrotalcite with Mg/AI molar ratio 2 was prepared by co-precipitation method and was characterized by XRD, TG/DTA, Zeta potential and BET surface area. The hydrotalcite was calcined at 500℃, with the dehydration from interlayer, the dehydroxilation from the brucite-like layer and the decomposition of carbonate successively, transformed into the mixed oxide type. The removal of thiocyanate from aqueous solution by using the original hydrotalcite and calcined hydrotalcite （HTC-500） was investigated. The results showed that the thiocyanate adsorption capacity of calcined hydrotalcite was much higher than that of the original form. Calcined hydrotalcite was particularly effective at removing thiocyanate, and that the effective range of pH for the thiocyanate removal are between 5.5-10.0. The experimental data of thiocyanate removal fit nicely with Langmuir isotherm, and the saturated adsorption uptake was 96.2 mg SCN-/g HTC-500. The adsorption of thiocyanate by calcined hydrotalcite follows first-order kinetics. And the intercalation to the structure recovery for calcined hydrotalcite. But the presence of additional anions could affect the adsorption behavior of thiocyanate.     

纳米零价铁对水中芴的去除研究

研究了实验室自制的纳米零价铁在不同投加量、初始浓度、pH及温度条件下,对芴溶液的吸附效果、吸附等温线及吸附动力学.结果表明,随着纳米铁投加量的增加,芴的去除率升高;增加芴的初始浓度,去除率则相应下降,同时平衡吸附量增加.另一方面,纳米铁对芴的吸附能力随pH的升高而下降;温度为15~35℃时,芴的平衡吸附量随温度的升高而增加,但变化不大.纳米铁对芴的吸附等温线符合Langmuir和Freundlich方程;纳米铁对芴的吸附过程很好地符合准二级速率方程,吸附速率随芴初始浓度的增大而减小,平衡吸附量随芴初始浓度的增大而增大.除上述结果以外,本文还对此反应体系的吸附机理进行了初步探讨.     

巯基乙胺改性蛭石对水体中Ag(I)的吸附性能研究

用巯基乙胺(MEA)来改性天然蛭石,并利用FTIR、BET、TG-DSC等手段对蛭石和改性蛭石进行表征,分析结果显示MEA成功负载到蛭石上.同时,研究改性蛭石对Ag+的吸附性能,结果表明,经过巯基乙胺改性后蛭石的吸附能力得到较大提升Ag+的去除率从20%提升到79%,吸附大约在200min达到平衡,吸附剂最佳投加量为2g/L左右,pH值在6~12范围内都有较好的吸附效果.Langmuir等温吸附模型和准二级动力学模型能够很好的解释VER和MEA-VER对Ag+的吸附过程.VER和MEA-VER对Ag+的吸附机理主要有电荷吸附和配位吸附.     

一种新型水处理剂合成及其对阴离子污染物的选择性去除

通过键合法合成了一种新型水处理剂—氯甲基聚苯乙烯树脂固载的功能化离子液体〔PS-CH₂-(CH₂)₁₆Im〕,选取Cr(Ⅵ)和甲基橙(MO)为模型阴离子污染物,采用静态与动态柱试验对其选择性去除水中阴离子污染物的性能进行系统研究。结果表明,PS-CH₂-(CH₂)₁₆Im对阴离子污染物选择性吸附性能良好,30 min可达吸附平衡,对Cr(Ⅵ)与MO的静态最大吸附量分别为90.9和62.8 mg/g,可有效去除低至0.004 mg/L的Cr(Ⅵ)。PS-CH₂-(CH₂)₁₆Im易于再生,5次重复使用后吸附性能无显著降低。通过测定缔合常数,明确PS-CH₂-(CH₂)₁₆Im对阴离子污染物的吸附机理为离子缔合作用。

     

One-step preparation of polyimide-inlaid amine-rich porous organic block copolymer for efficient removal of chlorophenols from aqueous solution

A novel polyimide-inlaid amine-rich porous organic block copolymer (PI-b-ARPOP) was prepared via one-step polymerization by using different molar ratios of melamine (MA)/terephthalaldehyde (TA)/pyromellitic dianhydride (PMDA), at molar ratios of 4/3/1, 4/2/2 and 4/1/3. The copolymer contained both aminal groups belonging to ARPOP and imide groups belonging to PI, and the bonding styles of the monomers and growth orientations of the polymeric chains were diversiform, forming an excellent porous structure. Notably, MA/TA/PMDA (4/2/2) had a surface area and pore volume of 487.27?m²/g and 1.169?cm³/g, respectively. The adsorption performance of the materials towards 2,4-dichlorophenol (2,4-DCP) in ultra-pure water was systematically studied. The pH value of 7 was optimal in aqueous solution. Na⁺ and Cl^? ions did not negatively affect the adsorption process, while humic acid (HA) slightly decreased the capacity. The equilibrium time was 40 sec, and the maximum adsorption capacity reached 282.49?mg/g at 298?K. The removal process was endothermic and spontaneous, and the copolymer could maintain its porous structure and consistent performance after regeneration by treatment with alkali. Moreover, to further assess the practical applicability of the material, the adsorption performance towards 2,4-DCP in river water was also investigated. This paper demonstrated that the PI-b-ARPOP can be an efficient and practical adsorbent to remove chlorophenols from aqueous solution.     

Cr(VI) removal from aqueous solution with bamboo charcoal chemically modified by iron and cobalt with the assistance of microwave

Bamboo charcoal (BC) was used as starting material to prepare Co-Fe binary oxideloaded adsorbent (Co-Fe-MBC) through its impregnation in Co(NO3)2 , FeCl3 and HNO3 solutions simultaneously, followed by microwave heating. The low-cost composite was characterized and used as an adsorbent for Cr(VI) removal from water. The results showed that a cobalt and iron binary oxide (CoFe2O4 ) was uniformly formed on the BC through redox reactions. The composite exhibited higher surface area (331 m2/g) than that of BC or BC loaded with Fe alone (Fe-MBC). The adsorption of Cr(VI) strongly depended on solution pH, temperature and ionic strength. The adsorption isotherms followed the Langmuir isotherm model well, and the maximum adsorption capacities for Cr(VI) at 288 K and pH 5.0 were 35.7 and 51.7 mg/g for Fe-MBC and Co-Fe-MBC, respectively. The adsorption processes were well fitted by the pseudo second-order kinetic model. Thermodynamic parameters showed that the adsorption of Cr(VI) onto both adsorbents was feasible, spontaneous, and exothermic under the studied conditions. The spent Co-Fe-MBC could be readily regenerated for reuse.     

Adsorption removal of phosphate from aqueous solution by active red mud

Red mud is the waste of alumina industry and has high TiO_2 and Fe_2O_3 content which are active components for the adsorption of anion pollutants.In this study,the uptake of phosphate by red mud activated by heat treatment and acid-heat treatment was investigated. The factors influencing the adsorption were also investigated.The result showed that the red mud sample treated using acid-heat method at 80℃with 0.25 mol/L HC1 for 2 h achieved the highest phosphate removal.For the heat-activated red mud,the sample heated at 700℃for 2 h preformed better than the other heat treatment.Phosphate removal by the activated red mud was significantly pH dependent,and pH 7 was the optimal pH for phosphate removal.The adsorption fits Langmuir isotherm model well and the maximum adsorption capacities of the acid-heat activated red mud and the heat activated samples were 202.9 mgP/g and 155.2 mgP/g,respectively.     

聚合氯化铝污泥吸附除磷的改性研究

研究了聚合氯化铝污泥(PACS)的酸和热改性及吸附动力学理论模型.结果表明,在酸处理过程中,经0.075mol/L盐酸在20℃下改性12h后所得酸改性PACS对磷的去除率最高,可达97.0%;在热处理过程中,经300℃煅烧温度下改性1h后所得热改性PACS对磷的去除能最高可达97.8%;相同静态吸附条件下,两种改性后PACS比原PACS对磷的去除率分别提高了21.4%及22.2%;吸附动力学拟合数据显示,PACS及酸、热改性PACS对磷的吸附行为可以用Simple Elovich模型较好的进行描述(R2≥0.97).     

磁性氧化石墨烯制备及去除水中刚果红的研究

采用Hummer方法制备了氧化石墨烯(GO),采用化学共沉淀法把铁氧化物纳米粒子覆盖在GO上制成磁性氧化石墨烯(MGO),并把MGO用作吸附剂去除水中阴离子染料刚果红.采用扫描电镜(SEM)、透射电镜(TEM)、Zeta电位仪和磁强计对MGO进行了表征.研究了吸附动力学,吸附等温线及初始pH值,离子强度对吸附的影响.考察了MGO对自来水中刚果红的去除效果.结果表明,GO具有片状的二维纳米结构,表面有许多的褶皱;当pH3.5,吸附剂表面带负电荷,等电点为3.5;MGO的饱和磁化强度为31.2emu/g,足够从水溶液中分离出来.刚果红的吸附符合准二级动力学模型,且在吸附时间为7h内基本达到吸附平衡.在超纯水中最大吸附容量高达140.6mg/g,且吸附量随pH值升高先增加再降低,当pH4~5达到最大值.MGO对自来水中刚果红的最大吸附容量为287.6 mg/g,为在超纯水中的2倍,表明MGO对刚果红具有很好的去除效果.