Novel Nanostructural Hybride Materials for Photodynamic Theraphy

Photodynamic theraphy (PDT) is a clinically approved method for treatment of cancer and some other diseases. It employs the combination of a drug (photosensitizer) and light to induce photoxicity towards the cancerous cells. The efficiency of currently used photosensitizers is limited due to their aggregation in aqueous media and low chemical purity; usually a mixture of various isomers is used. This paper presents the results of our studies on the development of nanostructural materials for PDT. They are constructed from porphyrin (Po) which is covalently attached to the chain of hydrophylic polymer such as poly(methacrylic acid) (PMA) or poly(ethylene glycol) (PEG) and solubilized in lipid bilayer of liposome vesicles. The attachment of Po to the polymer chain improves its solubility in water while the solubilization in liposome carriers helps the dye to penetrate the cell membranes. Physicochemical and photophysical properties of those systems were determined. The in vitro studies on cancer cell lines demonstrated that the photosensitizers are efficiently accumulated in the cells. Their dark toxicity is negligible, while phototoxicity is very high.     

Experimental design approach for petrochemical waste water treatment using solar assisted photo Fenton process

In this study, the effect of photo-Fenton process on the treatment of petrochemical waste water treatment was investigated. The influence of process conditions were determined by factorial design. Optimization of the process conditions were performed by central composite design. Under, optimized conditions lab scale and solar assisted pilot scale of petrochemical waste water treatment was performed. Three factors namely initial pH, H₂O₂ concentration (mM) and Fe²⁺ concentration (mM) executed the essential role in petrochemical waste water treatment. Central composite design resulted in the prediction of optimized value as 6.5 initial pH, 15.65 mM of H₂O₂ concentration and 2.09 mM of Fe²⁺ concentration. Under these conditions, the reduction in chemical oxygen demand (COD) percentage reached about 68.67 ± 2.8% after 280 min in pilot scale of solar assisted photo Fenton process of petrochemical waste water treatment. Thus, experimental design combined with advanced Fenton process can become a feasible unconventional method for petrochemical waste water treatment.     

无机-有机复合聚合物:材料研究的一个新领域

无机-有机复合聚合物特别是类分子筛聚合物、类多层钙钛矿和仿生物材料的合成及其应用研究成为近几年来一个热门的研究领域。我们瞄准了这一前沿领域并合成和表征了以下四个系列具有纳米孔洞的分子笼和一维、二维或三维的新型无机聚合物:(1)带有纳米尺寸空腔和孔状结构的新型过渡金属和稀土金属聚合物;(2)含有螺旋链的一维链状聚合物;(3)具有石墨形态层状结构和优异导电性能的聚合物;(4)以强金属-金属相互作用为核心、有机分子为稳定外壳的纳米线聚合物。本文总结这四个系列化合物的合成结构和特性。     

Nanofiltration and electrodialysis: alternatives in heavy metal containing high salinity process water treatment

Desalination is priority in process water treatment and several different technologies can be applied to minimize the total salinity of water. Our aim was to study desalination and simultaneous elimination of heavy metal residues from process waters. Nanofiltration (NF) and electrodialysis (ED) treatment technologies were applied for high salinity model solutions and high salinity, heavy metal containing real process waters originating from electroplating industry. Efficiencies of two technologies were compared in respect to salt and heavy metal removal both for model solutions (NaCl and Na₂SO₄) and three real process water samples. Initial concentrations of model solutions chosen accordingly the most common process water salt composition. Both technologies showed similar efficiency of heavy metal (Ni²⁺ and Cu²⁺) removal; however, they provide different demineralization rates, rejection, and extraction percentage for sodium and chloride ions. ED experiments of model solutions showed complete desalination after 1 h operating time at 6 V applied voltage; on the other hand, the increasing conductivities of NF permeates verified the selectivity of NF membrane, therefore, representing partial desalination. These phenomena were confirmed by demineralisation rate values as well (NF: for NaCl: 41.5–66.6%, for Na₂SO₄: > 96.6%; ED: both for NaCl and Na₂SO₄ > 98%). Significantly. higher demineralisation rates were achieved by ED (37.3–99.2%) than NF (20.2–62.3%) during the treatment of real process waters. We successfully demonstrated that ED is more efficient for simultaneous salt and heavy metal removal for process waters originating of electroplating industry.     

Operation of an Oxygen Gas Diffusion Electrode in a Hybride Fuel Cell

The paper is devoted to the operation of a hybride fuel cell (i.e. in the course of simultaneous electrosynthesis of a chemical product), in particular, the polarization characteristic of an oxygen electrode and the ratio of the produced electric energy to the amount of the produced target product. An equation for the dependence of the polarization of an oxygen gas diffusion hydrophobized electrode of a hydrogen-oxygen fuel cell on the concentration of the produced electroactive soluble product H₂O₂ in an inner-kinetic regime is suggested. It is established that the polarization variation does not depend on its initial magnitude but does depend on the concentration of the target product and the ratio between currents of the side and target reactions. The ratio of the produced electric energy to the amount of the produced target product is found to depend on the concentration of the produced target product, the electrode polarization, and the ratio between exchange currents of the side and target reactions.     

A polysaccharide composite for water treatment to remove nitrates: Synthesis,properties, and utilization

A sorbent for water treatment to remove nitrates was prepared from readily available vegetable boipolymers: cellulose and starch. The adsorption characteristics of the polysaccharide composite were determined. Biodegradation of the spent composite in the course of its utilization was studied.     

Photooxidative treatment of sulfurous water for its potabilization

The feasibility of potabilization of sulfurous water was investigated by photochemical oxidation processes using a batch photoreactor and a continuous-flow photoreactor, equipped with UV lamps of 1000 W and 1500 W, respectively. Additionally, two advanced processes of oxidation were applied i.e. with a use of a UV light/H2O2/air and UV light/H2O2/O3/air. These two processes were compared for their efficiency to the direct oxidation process where ozone is used in the absence of UV light. Results obtained for both advanced processes showed better oxidation than takes place by ozone in the absence of UV light. After the photooxidation processes, different processes for the absorption or precipitation of sulfates were investigated to comply with the World Health Organization (WHO) norm that demands a limit of < or =250 mg L(-1) of SO4(2-) in drinking water. Additionally, reverse osmosis was simulated using Osmonics Inc. software to predict the feasibility of lowering the salt concentration below WHO limits.     

Membrane technologies for water treatment and agroindustrial sectors

Although water is essential for human survival and progress, it is distributed very unevenly and with a different purity over the surface of the earth. A variety of contaminants can be present in raw water, depending on its origin. The size of these contaminants ranges from the micrometer (e.g. bacteria) to the tenths of a nanometer order (ions). Membrane processes like microfiltration, ultrafiltration, nanofiltration and reverse osmosis could be a solution for an advanced physical treatment of water for drinking purposes as well as for agroindustrial sectors. Many applications are well assessed and are expanding very quickly; however, to obtain an ever-growing performance, it is necessary to prepare membranes with tailored structure and transport properties. Characterisation methods play also a role of paramount importance for the selection of the more appropriate membrane for the above-mentioned applications. In this work the main membrane preparation techniques and characterisation methods will be reviewed and discussed.     

Electron treatment of wood pulp for the viscose process

Electron processing is currently being evaluated by several viscose producers for integration into their process. The viscose industry converts dissolving wood pulp into products such as staple fibre, filament, cord, film, packaging, and non-edible sausage casings. These materials are used in the clothing, drapery, hygiene, automobile, food, and packaging industries. Viscose producers are facing increasingly high production costs and stringent environmental regulations that have forced some plants to close. Electron treatment of wood pulp can significantly reduce the amounts of chemicals used for producing viscose and the production of hazardous pollutants. Acsion Industries has worked with companies worldwide to demonstrate the benefits of using electron treated pulp for producing viscose (rayon). This paper describes the viscose process, the benefits of using electron treatment in the viscose process, and Acsion’s efforts in developing this technology.     

New nitrogen-and-phosphorus-containing fibrous ion exchangers for water treatment

New nitrogen-and-phosphorus-containing fibrous ion exchangers were produced by two-stage synthesis from Nitron fiber. The ion exchangers are efficient sorbents of heavy and nonferrous metals from aqueous solutions under dynamic conditions.     

Magnetic water treatment for a less tenacious scale

This paper discusses the mechanism for magnetic water treatment, which has been used practically for over a century but is still not completely understood. Modified crystallization and agglomeration, which produce a less tenacious scale, retain this property for hours following treatment. It is considered to be a result of magnetically modified hydration and Lorentz force effects of magnetic devices. In treated water, as a complex solution/dispersion system, they affect the kinetics of processes at solution/solid interfaces. Which effect prevails depends on the treatment regime and water composition.     

Optical biosensor for pharmaceuticals, antibiotics, hormones, endocrine disrupting chemicals and pesticides in water: Assay optimization process for estrone as example

Certain contaminants at trace concentrations in surface waters can have dramatic effects on the hormonal system of organisms in the aquatic environment. Therefore, immunoanalytical methods at a very low limit of detection (LOD) and a low limit of quantification (LOQ) are becoming more and more important for environmental analysis and especially for monitoring drinking water quality. Environmental monitoring of antibiotics, hormones, endocrine disrupting chemicals, and pesticides in real water samples (e.g. surface, ground or drinking water) with difficult matrices places high demands on chemical analysis. Biosensors have suitable characteristics such as efficiency in allowing very fast, sensitive, and cost-effective detection. Here we describe an assay optimization process with a fully automated immunoassay for estrone which resulted in a LOD below 0.20 ng L⁻¹ and a LOQ below 1.40 ng L⁻¹. In contrast to common analytical methods such as GC-MS or HPLC-MS, the biosensor used requires no sample pre-treatment and pre-concentration. The very low validation parameters for estrone are the result of the continuous optimization of the immunoassay. The basis of our sensitive assay is the antibody with a high affinity constant towards estrone. During the optimization process, we reduced the amount of antibody per sample and improved the chip surface modification. Finally, this proceeding led to a calibration routine with an amount of antibody of only 3.0 ng per sample (sample volume: 1.0 mL). The reduction of the amount of antibody per sample results in better validation parameters (LOD, LOQ, and IC₅₀), but this reduction leads to the current device-related limitation of the River Analyser (RIANA).For some endocrine disrupting compounds, no effect levels (NOELs) in the lower nanogram per liter range are reported. This defines the challenge, which analytical methods have to compete with and our RIANA instrument with its improved sensitivity for the detection of a single hormone in the lower nanogram per liter range is a powerful tool in aquatic analytics in addition to the common analytical methods.     

Preparation and application of alumina- and titania- nanocrystals-dispersed thin films via sol-gel process with hot water treatment

A process to prepare nanocrystals-dispersed thin films at low temperatures using a hot water treatment of the gel films, and application of these nanocomposite thin films were demonstrated. When amorphous Al₂O₃ gel films were immersed in a hot water, we found that boehmite nanocrystals were formed on the surface of the films. In the hot water treatment of Al₂O₃-ZnO amorphous films, Zn-Al layered double hydroxide (LDH) was found to be formed on the films. When the SiO₂-TiO₂ gel films containing poly(ethylene glycol) were treated in a hot water, anatase nanocrystals were formed on the surface and inside of the films, and for the gel films without an organic polymer, the anatase nanocrystals were formed only on the surface of the films. In the hot water treatment of SiO₂-TiO₂ gel films under a vibration, titania nanosheets were found to be precipitated, instead of anatase nanocrysltals. Since formation of nanocrystals on the substrates using a hot water treatment is very mild conditions as the precipitation of crystals, we believe this process will open new application fields of nanocystals-dispersed thin films.