对硝基酚在超高交联吸附树脂NDA-701上的脱附行为研究

通过碱当量选择、脱附动力学以及固定床吸附-脱附实验,研究了对硝基酚在自制的超高交联吸附树脂NDA-701上的脱附行为,考察了2个温度下不同碱当量比(MNaOH/4-NP)对树脂脱附率的影响;研究了3个脱附温度和3种MNaOH/4-NP值情况下NDA-701的脱附动力学性能;考察了NDA-701的固定床吸附性能和不同脱附...     

吸附硝基苯酚的超高交联树脂微波辅助再生研究

以NDA-150超高交联树脂为吸附剂,邻硝基苯酚为吸附质,氢氧化钠稀溶液为脱附剂,采用微波间歇辐照脱附的方法,对吸附了邻硝基苯酚树脂的再生过程进行了研究。实验结果表明,采用多次、短时间微波辐照时,脱附体系温升速率随初始温度的不断升高而降低;利用这一特点对脱附体系进行辐照,可有效避免体系内“热点”现象的出现。邻硝基苯酚的脱附率随微波辐照时间的增加平缓上升,却随脱附剂浓度的增加而迅速上升,再生过程受脱附剂在树脂孔道内的扩散控制。树脂经多批次微波辐照,吸附性能和化学结构保持稳定。     

新型树脂NDA-66处理DBP生产废水及影响因素

采用新型超高交联树脂NDA-66处理增塑剂DBP生产废水,对比不同吸附剂对DBP生产废水中的邻苯二甲酸的吸附效果,考察了吸附时间、p H、温度、流速和不同初始溶液浓度对NDA-66静态吸附效果的影响。结果表明,NDA-66对邻苯二甲酸的最佳吸附条件为p H 2.0,温度30℃,最佳静态吸附时间为12 h。经过8批次连续吸附-脱附后,NDA-66树脂对邻苯二甲酸的去除率在94%以上,脱附率在90%以上,回收邻苯二甲酸晶体纯度高达95%,实现了废水有用物质的资源化。     

酚类化合物在矿化垃圾中的吸附性能与结构相关性研究

采用静态吸附方法,对8种酚类化合物在矿化垃圾中的吸附行为进行了研究,并用Langmuir和Fieundlish等温吸附方程对其进行了拟合.研究结果表明,8种代酚的吸附能力大小顺序为3-甲基酚＞4-甲氧基酚＞4-氯酚＞2,4-二氯酚＞3-硝基酚＞4-硝基酚＞2-氯酚＞苯酚.对8种酚类化合物Langmuir和Frendlich等温吸附方程常数和18个量子化学参数采用PLS进行逐步回归分析,得到了以Frendlich方程参数lnκ为因变量的数学模型.该模型表明,有机酚在矿化垃圾中的吸附性能主要与有机酚分子的疏水性和极性有关.而且该模型得到的预测值与实测值接近,说明利用PLS进行回归处理得到的模型较为合理、能有效地预测有机酚类化合物在矿化垃圾中的吸附行为.     

磁性高交联纳米吸附树脂的合成及其对酚类的吸附

采用油酸双层包覆Fe₃O₄纳米粒子,然后进行共聚和交联反应,制备出耐酸性的磁性高交联纳米吸附树脂YQ-3.YQ-3树脂的比表面积为653.5 m²·g^-1,平均孔径为4.12 nm,磁化强度为1.72 emμ·g^-1,具有超顺磁性.苯酚（PN）、对苯二酚（HN）、对硝基苯酚（PNP）在YQ-3上的吸附等温线符合Freundlich方程,主要通过疏水和 π-π作用进行吸附.3种酚的饱和吸附量顺序为PNP>PN>HN,与其疏水性顺序一致.准一级动力学和颗粒内模型适合拟合YQ-3对酚的吸附,由于YQ-3磁性树脂具有较小的粒径和丰富的中-大孔隙,其动力学速率比传统超高交联树脂更快.     

交联壳聚糖微球的制备及吸附性能研究

采用反相悬浮戊二醛交联、NaBH4还原制备了壳聚糖微球树脂,红外光谱和光学显微镜对微球进行表征。研究了微球树脂对2,4-二氯苯酚的吸附性能,试验了吸附时间、pH值、酚的浓度和树脂用量等因素对吸附的影响。结果表明,在pH=7,吸附时间2h,对酚的去除率达80%。     

复合功能树脂吸附对苯二酚的热力学研究

研究了复合功能超高交联树脂对水溶液中对苯二酚的静态吸附热力学特征,结果表明:超高交联树脂上引入适量的胺基,可明显地提高树脂的吸附容量。该类树脂对对苯二酚的吸附为自发的放热过程,属于物理吸附过程。     

悬浮泥沙对酚类化合物的吸附特性研究

研究了4种分别取自长江口和杭州湾的悬浮泥沙样品对苯酚、邻氯酚和2,4-二氯酚的吸附特性.结果表明,在12 h内可以达到对酚类化合物的吸附平衡,对苯酚的吸附量小,且不同样品间无显著差别,样品对酚类化合物吸附量随着酚类化合物氯化程度的提高而增大,与样品粒径分布、比表面积、有机物含量有关.在酚类化合物初始浓度＜2.0 mg/L时,样品对酚类化合物的等温吸附可以用Freundlich吸附等温式来表征,计算得到吸附常数Koc分别为622～1 410、3 287～3 707、6 444～8 787.挥发酚国家二级排放标准限定浓度为0.5 mg/L以下,此浓度下水体中悬浮泥沙能够有效吸附挥发酚,但高盐度不利于酚类化合物的吸附.     

我国24个典型饮用水源地中14种酚类化合物浓度分布特征

研究了14种酚类化合物在我国五大流域(黄河、海河、辽河、长江、淮河)24个典型饮用水源地水源水中的浓度水平.结果显示:14种酚类化合物在我国饮用水源地中的浓度在nd～213 ng·L-1范围内,浓度均值在2.44～31.2 ng·L-1范围内,浓度中位数在nd～40.0 ng·L-1范围内.14种酚类化合物中,硝基苯酚类化合物浓度最高,浓度中位数为37.9 ng·L-1,浓度平均值为27.4 ng·L-1.其次为苯酚、五氯酚、二氯苯酚(2,4-二氯苯酚和2,6-二氯苯酚)和三氯苯酚(2,4,6-三氯苯酚和2,4,5-三氯苯酚);四氯苯酚(2,3,5,6-四氯苯酚、2,3,4,6-四氯苯酚、2,3,4,5-四氯苯酚)和烷基苯酚(邻甲基苯酚、间甲基苯酚和对甲基苯酚)浓度较低.通过商值法对14种酚类化合物进行生态风险评价后发现,14种酚类化合物的风险商均远小于1,表明其对我国饮用水源地的生态风险较低.对8种已报道健康参考剂量或致癌斜率因子的酚类化合物进行健康风险评价,结果显示,7种酚类化合物的最大非致癌风险在10-6到10-4范围内,2,4,6-三氯酚和五氯酚的致癌风险在10-6量级以下,表明其健康危害较弱.     

苯酚及其衍生物对氨氮生物硝化的抑制研究

利用富集培养的硝化污泥研究了苯酚及其衍生物2,4-二氯苯酚、对氨基酚、邻甲基酚和对硝基酚对氨氮生物硝化过程的抑制特性。结果表明,上述5种酚类化合物对硝化细菌的抑制类型均为非竞争性抑制,抑制常数KI和EC50值相等,分别为2.61、1.92、8.50、1.18和6.65 mg/L。上述5种酚类化合物对硝化细菌的抑制程度由大到小的顺序为：邻甲基酚〉2,4-二氯苯酚〉苯酚〉对硝基酚〉对氨基酚。酚类化合物对硝化细菌的抑制是可逆的,通过简单的抑制剂稀释或洗涤可以使硝化细菌恢复活性。在保证出水水质的前提下,抑制剂存在时硝化工艺的泥龄被迫延长,且抑制程度越大,泥龄延长的程度越大。当系统受到有毒物质冲击时,和调控泥龄相比,调节工艺的进水流量或改变容积负荷是缓冲冲击的更简捷、快速和有效的途径。     

Adsorption selectivity of salicylic acid and 5-sulfosalicylic acid onto hypercrosslinked polymeric adsorbents

Both bottle-point and column-feeding experiments involving different solutes and sorbents were carried out to investigate the adsorption selectivity and separation performance of salicylic acid and 5-sulfosalicylic acid. Their adsorption isotherms onto such hypercrosslinked polymeric adsorbents as NDA-100 and NDA-99 could be well described by the Freundlich equations whose characteristics describe extrathermic and favorable adsorption processes. The adsorption towards NDA-100 mainly depended on the π-π interaction, while that towards NDA-99 was extremely influenced by the static-electric interaction. Additionally, the adsorptive capacity of salicylic acid on NDA-99 decreased while it increased on NDA-100 with the presence of 5-sulfosalicylic acid in the adsorptive environment as the competitive component. Comparatively, the adsorption capacity of 5-sulfosalicylic acid decreased on both resins with salicylic acid as the competitive component. In fact, the difference in the interaction between adsorbent and adsorbate resulted in the straight antagonism on the effective adsorption sites on the adsorbent. In conclusion, the adsorption selectivity of salicylic acid onto NDA-100 was obviously larger than that onto NDA-99 with the existence of 5-sulfosalicylic acid in the adsorptive environment. A satisfactory separation and recovery of tested solutes in aqueous phase could be foreseeably achieved by the sequencing adsorption technique involving NDA-100 as well as NDA-99. Translated from Environmental Pollution & Control, 2005, 27(8): 570–574 [译自: 环境污染与防治]     

A novel aminated polymeric adsorbent for removing refractory dissolved organic matter from landfill leachate treatment plant

Refractory dissolved organic matter (DOM) from landfill leachate treatment plant was with high dissolved organic carbon (DOC) content. An aminated polymeric adsorbent NDA-8 with tertiary amino groups and sufficient mesopore was synthesized, which exhibited high adsorption capacity to the DOM (raw water after coagulation). Resin NDA-8 performed better in the uptake of the DOM than resin DAX-8 and A100. Electrostatic attraction was considered as the decisive interaction between the adsorbent and adsorbate. Special attention was paid to the correlation between porous structure and adsorption capacity. The mesopore of NDA-8 played a crucial role during uptake of the DOM. In general, resin in chloride form performed a higher removal rate of DOC. According to the column adsorption test, total adsorption capacity of NDA-8 was calculated to 52.28 mg DOC/mL wet resin. 0.2 mol/L sodium hydroxide solution could regenerate the adsorbent efficiently.     

选择性生物强化处理二元互抑体系中苯胺和硝基苯

采用树脂吸附与生物强化相组合的方法处理含有苯胺和硝基苯的混合废水,对苯胺和硝基苯的降解抑制类型、吸附分离条件、生物强化降解过程与树脂性能变化等进行了研究.结果表明,硝基苯与苯胺均对对方的生物降解产生抑制;当进水中苯胺与硝基苯浓度分别为330与44mg/L时,在pH为4且流速为110mL/h条件下,通过装填有10mL吸附树脂NDA-150(7.2g)的吸附柱,吸附出水中硝基苯浓度低于4mg/L;吸附出水中苯胺的浓度保持不变,可通过生物强化而得到降解;吸附过程中约有597mg的硝基苯被树脂所吸附,其中约有224mg可通过生物强化方法得到脱附降解,系统降解硝基苯的容积负荷为315mg/(L·d);在此过程中树脂吸附能力获得部分恢复,其再生程度受到微生物对硝基苯降解能力的限制;70d的重复性实验证明,树脂性能保持稳定.     

复合功能树脂吸附处理2-氨基吡啶生产废水的研究

采用中和法对2-氨基吡啶生产废水进行预处理,然后采用NDA-88复合功能吸附树脂固定床工艺对预处理过的废水进行动态吸附和脱附.实验结果表明,NDA-88树脂对2-氨基吡啶的吸附量为150.1 mg/g.每个周期处理废水30 BV(床体积),前12 BV出水COD由2 800mg/L降至100mg/L以下,后18BV出水...     

Adsorption of catechol from aqueous solution by aminated hypercrosslinked polymers

Adsorption of catechol from aqueous solution with the hypercrosslinked polymeric adsorbent NDA-100 and its derivatives AH-1,AH-2 and AH-3 aminated by dimethylamine, the commercial resin Amberlite XAD-4 and weakly basic anion exchanger resin D301 was compared. It was found that the aminated hypercrosslinked resins had the highest adsorption capacities among the tested polymers. The empirical Freundlich equation was successfully employed to describe the adsorption process. Specific surface area and micropore structure of the adsorbent, in company with tertiary amino groups on matrix affected the adsorption performance towards catechol. In addition, thermodynamic study was carried out to interpret the adsorption mechanism. Kinetic study testified that the tertiary amino groups on the polymer matrix could decrease the adsorption rate and increase the adsorption apparent activation energy.     

胺基树脂吸附去除水中的壬基酚聚氧乙烯醚

使用氯球作为前驱体与二乙烯三胺在回流条件下反应合成一种胺基树脂,对胺基树脂的特征进行了表征,并研究了胺基树脂对水中的壬基酚聚氧乙烯醚(NP₁₀EO)的吸附行为.树脂的红外、元素分析及比表面积与平均孔径分析结果表明,胺基官能团成功地嫁接到树脂表面,胺基浓度为5.6 mmol/g,且胺基树脂的比表面积较氯球有较大增加.胺基树脂对NP₁₀EO的吸附等温线表明,温度的升高有利于吸附,在35 ℃下胺基树脂对NP₁₀EO的最高平衡吸附量达58.36 mg/g.采用Langmuir方程和Freundlich方程用于吸附等温线的解释,结果表明,吸附等温线更加符合Langmuir模型,相关系数(R2)均大于0.98. NP₁₀EO在胺基树脂上的吸附符合准二级动力学方程,初始ρ(NP_10EO)越低达到吸附平衡所需时间越短,初始ρ(NP_10EO)为9.41 mg/L的溶液能在2 h内达到吸附平衡.      

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。     

Effect of dissolved organic matter on nitrate-nitrogen removal by anion exchange resin and kinetics studies

The effects of dissolved organic matter (DOM) on the removal of nitrate-nitrogen from the model contaminated water have been investigated utilizing the strong base anion exchange resins. With the increase of gallic acid concentration from 0 to 400 mg/L, the adsorption amount of nitrate-nitrogen on the commercial resins, including D201, Purolite A 300 (A300) and Purolite A 520E (A520E), would significantly decrease. However, the presence of tannin acid has little impact on nitrate-nitrogen adsorption on them. Compared to D201 and A300 resins, A520E resin exhibited more preferable adsorption ability toward nitrate-nitrogen in the presence of competing organic molecules, such as gallic acid and tannin acid at greater levels in aqueous solution. Attractively, the equilibrium data showed that the adsorption isotherm of nitrate-nitrogen on A520E resin was in good agreement with Langmuir and Freundlich equations. The rate parameters for the intra particle diffusion have been estimated for the different initial concentrations. In batch adsorption processes, nitrate-nitrogen diffuse in porous adsorbent and rate process usually depends on t 1/2 rather than the contact time. The pseudo first- and the second-order kinetic models fit better for nitrate-nitrogen adsorption onto A520E resin. The observations reported herein illustrated that A520E resin will be an excellent adsorbent for enhanced removal of nitrate-nitrogen from contaminated groundwater.     

对乙酰氨基酚修饰的后交联树脂对双酚A的吸附性能

用二氯乙烷为溶剂,用FeCl3为催化剂,使氯球和对乙酰氨基酚发生Friedel-Crafts反应制得了对乙酰氨基酚修饰的后交联树脂,对其结构进行了表征,研究乙酰氨基和酚羟基二类氢键作用位点修饰的后交联树脂对双酚A的吸附性能.结果表明,红外光谱显示对乙酰氨基酚已被成功地修饰在后交联树脂上.对乙酰氨基酚修饰的后交联树脂与氯球相比,BET比表面积、孔容明显增大,孔径明显变小.对乙酰氨基酚修饰的后交联树脂对双酚A的吸附量明显高于75%活性炭的聚砜微球对双酚A的吸附量.对乙酰氨基酚修饰的后交联树脂对双酚A的吸附为放热、自发的过程;树脂可以用100%酒精解吸,解吸率为99.92%;吸附动力学数据符合一级吸附速率方程,颗粒内扩散是吸附速率的主要控制步骤,吸附速率同时还受液膜扩散的影响.