6-氨基青霉烷酸在弱碱性阴离子树脂IRA67上的吸附研究

用静态法研究了6-氨基青霉烷酸在弱碱性阴离子交换树脂IRA67上的吸附行为．在溶液pH为8．0，6-APA起始浓度介子3.00mg／m1-20．00mg／ml条件下，测定了25℃时IRA67树脂的静态交换动力学曲线、吸附等温线，并求得了IRA67树脂的平衡速率常数及吸附等温线方程．分别用Langmuir型和Frendlich型方程对IRA67树脂吸附等温线进行线性回归拟合，结果表明，6-APA在IRA67树脂上的吸附更符合Langmuir型吸附．     

Salen–Mg-doped NH2–MIL-101(Cr) for effective CO2 adsorption under ambient conditions

A novel metal-doped metal–organic framework (MOF) was developed by incorporating salen–Mg into NH₂–MIL-101(Cr) structure under ambient conditions. The Schiff base complex was successfully prepared by condensing salicylaldehyde with a free amino group and then coordinating metal ions. Such a structure can endow the sample with higher CO₂ adsorption performance. At 0°C and 1 bar, the salen–Mg-modified sample achieves the maximum adsorption capacity of 2.18 mmol g⁻¹ for CO₂, which was 5.8% higher than the pristine salen–MOF under the same conditions. Notably, the Freundlich model indicates that the CO₂ adsorption process of all samples conforms to reversible adsorption. However, the correlation coefficients (R²) of the Mg-doped sample are lower than that of the pristine sample. Besides, the CO₂/N₂ adsorption selectivity and isosteric heat also show a similar trend. These results indicate that the salen–Mg can enhance the interaction between the material and CO₂ molecules.     

Application of Natural Clinoptilolite for Ammonium Removal from Sludge Water

Sludge water (SW) arising from the dewatering of anaerobic digested sludge causes high back loads of ammonium, leading to high stress (inhibition of the activity of microorganisms by an oversupply of nitrogen compounds (substrate inhibition)) for wastewater treatment plants (WWTP). On the other hand, ammonium is a valuable resource to substitute ammonia from the energy intensive Haber-Bosch process for fertilizer production. Within this work, it was investigated to what extent and under which conditions Carpathian clinoptilolite powder (CCP 20) can be used to remove ammonium from SW and to recover it. Two different SW, originating from municipal WWTPs were investigated (SW1: c₀ = 967 mg/L NH₄-N, municipal wastewater; SW2: c₀ = 718–927 mg/L NH₄-N, large industrial wastewater share). The highest loading was achieved at 307 K with 16.1 mg/g (SW1) and 15.3 mg/g (SW2) at 295 K. Kinetic studies with different specific dosages (0.05 g_CLI/mg_NH4-N), temperatures (283–307 K) and pre-loaded CCP 20 (0–11.4 mg/g) were conducted. At a higher temperature a higher load was achieved. Already after 30 min contact time, regardless of the sludge water, a high load up to 7.15 mg/g at 307 K was reached, achieving equilibrium after 120 min. Pre-loaded sorbent could be further loaded with ammonium when it was recontacted with the SW.     

Anionic groups on cellulosic fiber surfaces investigated by XPS, FTIR-ATR, and different sorption methods

Anionic groups (AGs) on different cellulosic fiber surfaces were investigated by methylene blue (MB) and polyelectrolyte (PE) sorption, X-ray photoelectron spectroscopy (XPS), and total attenuated reflectance infrared spectrometry (FTIR-ATR). The MB sorption isotherms fitted well the Langmuir equation that gave consistent estimations of sorption capacities. FTIR-ATR showed that MB molecules had extensive accessibility to the fiber wall pores. Estimation of surface AGs by PE sorption gave much higher values than a new method combining MB sorption and XPS measurements (MB-XPS). The surface AGs in different cellulosic fibers accounted for 1-3% of the total AG content as revealed by MB-XPS. It was suggested that PE molecules can penetrate the fiber wall and form loops or unattached segments at external fiber surfaces that disrupt the PE sorption stoichiometry. The competition of MB and PE for the anionic sites in papermaking was assessed and it was shown that MB ions have a much stronger affinity to AGs than PE molecules.     

Effect of metal ion loaded in a resin towards fluoride retention

Indion FR 10 is a commercially available ion exchange resin with sulphonic acid functionality named as H⁺ form, has appreciable defluoridation capacity (DC). It has been chemically modified to La³⁺, Fe³⁺, Ce³⁺ and Zr⁴⁺ forms by incorporating respective metal ions into the resin in order to know their fluoride selectivity by measuring the DC of the respective resin. The maximum DC of these chemically modified ion exchange resins namely La³⁺, Fe³⁺, Ce³⁺ and Zr⁴⁺ forms were found to be 469.7, 467.5, 456.3 and 470.9 mg F⁻/kg respectively suggests their higher selectivity towards fluoride than H⁺ form which has the DC of only 275 mg F⁻/kg at 11 mg/L initial fluoride concentration. The higher DC of the modified resins was explained by electrostatic adsorption and complexation whereas H⁺ form retains fluoride by hydrogen bond. The functional groups present in the sorbents were identified by FTIR and the existence of fluoride onto the resins was confirmed by EDAX analysis. The experimental data was fitted with both Freundlich and Langmuir isotherms. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° indicate that the nature of sorption is spontaneous and endothermic. The applicability of reaction-based and diffusion-based kinetic models was investigated. A field trial was carried out with fluoride water collected from a nearby fluoride-endemic village to test the suitability of these sorbents at field conditions.     

Study on the Binding Characteristic of Methamidophos‐Specific Molecularly Imprinted Polymer and the Interactions between Template and Monomers

A new molecularly imprinted polymer (MIP) was prepared using methamidophos (MAP) as the template molecule based on non‐covalent interaction. The complexes formed between template and monomers before polymerization were characterized by ¹H NMR titration test, FT‐IR and UV spectrometry study. These studies indicated that a 1:2 molecular complex formed dominantly between MAP and functional monomers. A model mainly involving cooperative hydrogen interaction was proposed by exact placement of functional groups. Association constant was estimated to be 2.894 × 10⁶ L²/mol². When the initial concentration of MAP was 1.0 mmol L^?1, the affinity capacity of MIP was 4.23 times that of NIP. The binding performance of MIP was modeled with the Freundlich isotherm (FI) and the total number of binding sites was calculated to be 33.97 μmol/g. The MIP showed great homogeneity with a heterogeneity index of m = 0.7356. The specificity of MIP was investigated by single‐analyte binding and molecularly imprinted solid‐phase extraction (MISPE) assays using MAP and other structurally related organophorous pesticides (OPPs). The results indicated that the MIP had a marked preference for MAP.     

Removal of phenol from aqueous phase by using neutralized red mud

The objective of this study is to remove the phenol from aqueous solution by using the neutralized red mud in batch adsorption technique. The study was carried out as functions of contact time, pH, initial phenol concentration, red mud dosage and effect of salt addition. The experiments demonstrated that maximum phenol removal was obtained in a wide pH range of 1-9 and it takes 10 h to attain equilibrium. The adsorption data was analyzed using the Langmuir and the Freundlich isotherm models and it was found that the Freundlich isotherm model represented the measured sorption data well. The influence of addition of salt on phenol removal depends on the relative affinity of the anions for the red mud surface and the relative concentrations of the anions.     

In Vitro Investigation on Interaction of Ranitidine Hydrochloride in the Presence of Cross-Linked Carboxymethyl Cellulose Sodium.

Summary: The adsorbance of ranitidine hydrochloride – drug selective H₂ histamine receptor inhibitor used In the treatment of gastric and duodenal ulcer was investigated in the presence of croscarmellose, a cross- linked polymer of polysaccharide character used as a swelling additive in oral pharmaceutical formulations – capsules, tablets and granules. The evaluation of adsorbance capability was carried out by means of a statistical method in in vitro conditions, taking into account environmental pH, concentration of the investigated drug as well as the properties of the polymer. Obtained results prove that the analyzed active agent is adsorbed on polymer at all the investigated pH ranges and the capability of polymer binding depends on environmental pH. The highest binding capability was revealed in samples with pH of 7.6, (adsorbance capacity k = 0.6958) while the lowest binding capability was observed at pH 1.5 (adsorbance capacity k = 0.0005) in the presence of croscarmellose sodium. Level of adsorption depends on the analyzed drug concentration and adsorption on polymer in increasing concentration and pH environment.     

白蛋白在以染料为配基的醋酸纤维滤棒上的等温吸附行为(英文)

 以醋酸纤维滤棒为基质 ,染料CibacronBlueF3GA为配基 ,合成了一种新的染料亲和介质 ;分别以牛血清白蛋白 (BSA)和人血清白蛋白 (HSA)为对象 ,用静态法进行了吸附实验 ,得到了相应的亲和等温吸附曲线 ;对曲线按Langmuir模型和Freundlich模型分别进行拟合 ;结果表明 ,醋酸纤维滤棒染料亲和介质对BSA和HSA的等温吸附遵循Freundlich模型。采用该亲和介质装柱并分离实际样品人血浆 ,可得到纯化的人血清白蛋白。