Polyphenolrückgewinnung aus Olivenölabwasser durch Einsatz von Membrantechnologie

Olive mill wastewater (OMW) is obtained as byproduct of oil production in large quantities after the olive harvest, mainly in the Mediterranean region. One problem is the high load of organic matter, such as phytotoxic polyphenols, which causes significant environmental problems. However, due to their antioxidant properties the use of these polyphenols is also popular in several industry branches, e.g. production of plastics, cosmetics and drugs. A combined wastewater treatment permits besides water purification also recovery of the polyphenolic compounds for industrial use. One possibility is membrane technology. An overview of research studies concerning polyphenol recovery from OMW using membrane technologies is given.     

Influence of Membrane Intrusion on Permeate‐Sided Pressure Drop During High‐Pressure Reverse Osmosis

By replacing thermal concentration processes, high‐pressure reverse osmosis has the potential to contribute to cost and energy savings regarding concepts for industrial water reuse. To provide a better understanding of the spiral‐wound element behavior during high‐pressure operation, this study focusses on the investigation of their performance by scrutinizing the crucial effect of the permeate‐sided pressure drop induced by membrane‐spacer interactions. The experiments show a considerable influence of membrane intrusion on the element performance with a strong dependence on the feed pressure.     

An in situ method for measuring acid loss from polymer films

This article reports an in situ approach to studying acid loss from polymer (films of the type used in microlithiography. We developed a method which makes use of the dye coumarin 6 (C6) which has absorption characteristics which change dramatically as a result of acid‐induced changes in its prototropic forms. Acid loss from polymer films containing C6 is accompanied by its deprotonation, which is signaled by a change in the absorption of the film. This technique provides kinetic data describing acid loss from polymer films. Acid loss is a function of both acid volatilization from sites at the surface of the film as well as diffusional processes within the film. Under controlled conditions, acid loss obeys first‐order kinetics, and the half‐lives, τ_1/2, of acids in phenolic and acrylate polymer films were determined. We studied the effects of temperature, acid structure, polymer structure, and T_g on the τ_1/2 values obtained. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1897–1905, 2000     

Nonglycosidic Agonists of Invariant NKT Cells for Use as Vaccine Adjuvants

Based on the crystal structures of human α‐GalCer–CD1d and iNKT–α‐GalCer–CD1d complexes, nonglycosidic analogues of α‐GalCer were synthesized. They activate iNKT cells resulting in dendritic cell maturation and the priming of antigen‐specific T and B cells. Therefore, they are attractive adjuvants in vaccination strategies for cancer and infectious diseases.

     

Spatial distributions of O2, CO2 and SO2 in a pilot-scale fluidized bed combustor operated with different coals

Axial concentration profiles of O₂, CO₂ and SO₂ have been measured at different radial positions in a coal-fired fluidized bed combustor. The profiles show some spatial inhomogeneity in the bed, the degree of which depends on fluidizing velocity and amount of excess air. Comparison of SO₂- with CO₂-concentration profiles reveals that SO₂ is formed in proportion to CO₂ only with anthracite as fuel. With bituminous coals, SO₂ is preferentially formed near the coal feed point. These results are discussed with regard to characteristic times of mixing and chemical reaction in fluidized beds, and SO₂-formation characteristics of the employed coals obtained in a thermobalance.     

Simultaneous measurement of weight loss by DTG combustion and SO2-formation for different coals

Burning profiles and SO₂-formation profiles were measured simultaneously for four different coals by slowly heating coal samples in a flow of air in a thermobalance. The profiles of weight loss and SO₂ formation have the same shape with anthracite combustion. The SO₂-formation profiles of bituminous coals usually display two peaks that approximately correspond to the release of volatile matter and combustion of char in the burning profiles. No correlations could be found between either the types of sulphur present in the raw coals or the ratio of volatile matter to fixed carbon and the shape of the SO₂-formation profiles for the bituminous coals.     

A High Legume Low Glycemic Index Diet Improves Serum Lipid Profiles in Men

Clinical studies have shown that fiber consumption facilitates weight loss and improves lipid profiles; however, the beneficial effects of high fermentable fiber low glycemic index (GI) diets under conditions of weight maintenance are unclear. In the Legume Inflammation Feeding Experiment, a randomized controlled cross-over feeding study, 64 middle-aged men who had undergone colonoscopies within the previous 2 years received both a healthy American (HA) diet (no legume consumption, fiber consumption = 9 g/1,000 kcal, and GI = 69) and a legume enriched (1.5 servings/1,000 kcal), high fiber (21 g/1,000 kcal), low GI (GI = 38) diet (LG) in random order. Diets were isocaloric and controlled for macronutrients including saturated fat; they were consumed each for 4 weeks with a 2–4 week break separating dietary treatments. Compared to the HA diet, the LG diet led to greater declines in both fasting serum total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) (P < 0.001 and P < 0.01, respectively). Insulin-resistant (IR) subjects had greater reductions in high density lipoprotein cholesterol (HDL-C; P < 0.01), and triglycerides (TAG)/HDL-C (P = 0.02) after the LG diet, compared to the HA diet. Insulin-sensitive (IS) subjects had greater reductions in TC (P < 0.001), LDL-C (P < 0.01), TC/HDL-C (P < 0.01), and LDL-C/HDL-C (P = 0.02) after the LG diet, compared to the HA diet. In conclusion, a high legume, high fiber, low GI diet improves serum lipid profiles in men, compared to a healthy American diet. However, IR individuals do not achieve the full benefits of the same diet on cardiovascular disease (CVD) lipid risk factors.     

Solid State and Gas Phase NMR Studies of Immobilized Catalysts and Catalytic Active Nanoparticles

In the current study two new classes of stabile, catalytic active nanomaterials are investigated. The first class of nanoparticles consists of an inner metal core. To stabilize their structure the metal core is surrounded by organic ligands or embedded in a polymer. The second class consists of catalysts immobilized on mesoporous silica supports of SBA-3 type silica. Employing a combination of ¹H, ²H, ¹³C and ²⁹Si-solid state NMR spectroscopy the structure of the catalysts is analyzed. As a simple model for the catalytic properties of the particles, the activation of ²H₂ gas on the surface of the particles is studied. Employing ¹H and ²H gas phase NMR the kinetics of simple catalytic model reactions is studied. Employing ²H-NMR solid state NMR spectroscopy, the interaction of the metal surface with the substrate is characterized and kinetic data, which characterize the mobility of the deuterium on the surface, are extracted. For the interpretation of these data, parallel NMR studies of model η²-bound transition metal complexes are employed, which allow, owing to their simpler geometry and higher sensitivity, a quantitative modeling of the spin dynamics in the NMR experiment.     

Investigations of silica scaling on reverse osmosis membranes

In reverse osmosis systems with high silica water severe and irreversible membrane scaling can be observed. But suitable test methods to find an appropriate antiscalant agent and the optimal dosage are missing. Usually only the silicate concentration in the feed water is regarded.In this paper the results of laboratory experiments about the influence of Ca²⁺- and Mg²⁺-ions on the behaviour of supersaturated solutions of silica in different test waters are discussed first. After that the new developed membrane-based test method to determine the effectiveness of antiscalants is presented.The applied different methods of analysis enabled the differentiation of three groups of silicates: ‘monomeric’, ‘polymeric’ and ‘filterable’.With the test method the strong impact of silicate scaling was proven, even if only small amounts of scale had been formed. It could be shown, that the ‘polymeric silica’ is mainly responsible for the membrane scaling. The kinetic of the formation of ‘polymeric silica’ is strongly influenced by the cations and the pH-value. It could be demonstrated that the use of a suitable antiscalant makes it possible to operate the plant at significantly higher recovery rates.