Integrated coupled systems as biodegradability enhancement of textile wastewater by photo-fenton process

Photo-Fenton process was explored as photochemicalpre-treatment to enhance and improve the biodegradabilityand complete mineralization of a wastewater coming from a textile industry located in the east of Germany containing reactive dyes which was characterized as biorecalcitrant,non-biodegradable and refractory organic compounds.Wastewater treatment was carried out including a series of bench scale experiments, to identify optimum operating conditions for the treatment of textile wastewater at the end of the pipe effluent. The effect of operating parameters as: pH, irradiation time and initial concentrations of both H2O2 and Fe2+ on the photomineralization processes as a pretreatment step have been studied and the optimal conditions were found. Chemical oxygen demand (COD), total organic carbon (TOC) and colour removal are the parameters used to trace the experiments course.The color removal of the textile wastewater reached to above 100% within 30 min of photocatalytic treatment. The wastewater was completely degraded by a photo-Fenton treatment after 60 min irradiation time by using a 50 mg/L of Fe2+ catalyst concentration and the H2O2 concentration was 1000 mg/L and pH=3 at 25°C. At these optimum operating conditions % removal of TOC, COD and colour removal were 89, 95 and 100 respectively of photo-mineralization. The experimental results show that the ratio of BOD5/COD of the wastewater increased from original 0.09 up to 0.7 after 60 min. The result implies that photocatalytic oxidation enhanced the biodegradability of the dye-containing wastewater and therefore relationship between decolorization and biodegradability exists.When the color disappeared completely, the wastewaterbiodegraded normally and could be discharged for furthertreatment. The biodegradability tests also demonstratedthat photo-treated effluents within a short time of startingthe photo-Fenton process were biodegradable with a BOD5/COD ratio of 0.4 after 30 min of irradiation time.The experimental results demonstrate that it is possible tocombine photocatalysis with conventional biological treatmentfor the remedy of wastewater containing generally non-biodegradable azo dyes. The results of the present study revealed that the treated effluent by photo-Fenton process is complying with the environmental regulations for discharge of textile wastewater in Germany

Sevoflurane Anesthesia Improves Cognitive Performance in Mice, but Does Not Influence In Vitro Long-Term Potentation in Hippocampus CA1 Stratum Radiatum

BACKGROUND: Whether the occurrence of postoperative cognitive dysfunction is a result of the effects of surgery or anesthesia is under debate. In this study, we investigated the impact of sevoflurane anesthesia on cognitive performance and cellular mechanisms involved in learning and memory. METHODS: Male C57Bl6/J mice (4–5 months) were exposed to one minimum alveolar concentration sevoflurane for two hours. After 24 h, cognitive performance of mice was assessed using the modified hole board test. Additionally, we evaluated hippocampal long-term potentiation and expression levels of different receptor subunits by recording excitatory postsynaptic field potentials and using the western blot technique, respectively. Non-anesthetized mice served as controls. RESULTS: In anesthetized mice, neither cognitive performance nor long-term potentiation was impaired 24 h after anesthesia. Interestingly, sevoflurane anesthesia induced even an improvement of cognitive performance and an elevation of the expression levels of N-methyl-D-aspartate (NMDA) receptor type 1 and 2B subunits in the hippocampus. CONCLUSIONS: Since NMDA receptor type 1 and 2B subunits play a crucial role in processes related to learning and memory, we hypothesize that sevoflurane-induced changes in NMDA receptor subunit composition might cause hippocampus-dependent cognitive improvement. The data of the present study are in favor of a minor role of anesthesia in mediating postoperative cognitive dysfunction

Synthesis, characterization of cesium and cobalt substituted wells–Dawson heteropolyoxotungstates salts and their photocatalytic applications

Heteropoly compounds in the solid state are ionic crystals (sometimes amorphous) consisting of large polyanions, cations, water of crystallization, and other molecules. Heteropolyacids (HPAs) have several advantages as catalysts. On the one hand, they have a very strong Brønsted acidity, especially the cobalt and cesium salts; on the other hand they are exhibiting fast reversible multielectron redox transformations under mild conditions. The cobalt and cesium salts of wells–Dawson HPAs were synthesized and characterized using elemental analysis and spectroscopic techniques (31P-NMR, FT-IR). The wells–Dawson anions possess the ability to accept or release electrons through an external potential or upon exposure to UV radiation (photochemical reactions). The catalytic tests of these salts were investigated on phenol degradation where the UV photodegradation of acidified aqueous solutions (pH = 2) were studied in a batch photoreactor under ambient temperature and continuous circulation of phenol solution. The results reveal high catalytic activity for two HPAs, the best catalyst is the salt of cesium; where the presence of cesium improves significantly both the photcatalytic activity and the selectivity to oxalic acid

Cloned human and murine serotonin(3A) receptors expressed in human embryonic kidney 293 cells display different single- channel kinetics

In the present study, well-resolved single-channel events of cloned human and murine homomeric 5-hydroxytryptamine type 3 (h5-HT3A and m5-HT3A) receptors, expressed in human embryonic kidney 293 cells, are reported for the first time. 5-HT (1 muM) applied in Ca2+- and Mg2+-free external solution to excised outside-out membrane patches induced non-rectifying single- channel inward currents. These currents were not observed in untransfected cells or in the presence of the antagonist ondansetron (1 muM). The mean single-channel conductance of the h5-HT3A and m5-HT3A receptors was 48 +/- 8 pS and 46 +/- 7 pS, the mean reversal potential was 10.3 +/- 1.8 mV and 4.7 +/- 5.3 mV, respectively. The analysis of single-channel open-times revealed for both h5-HT3A and m5-HT3A receptors only one type of open state, but different mean open-times (7.1 +/- 2.9 ms vs. 4.1 +/- 0.8 ms) indicating species-dependent gating mechanisms of 5-HT3 receptors. (C) 2002 Elsevier Science Ireland Ltd. All rights reserv

Neurosci. Lett.

In the present study, well-resolved single-channel events of cloned human and murine homomeric 5-hydroxytryptamine type 3 (h5-HT3A and m5-HT3A) receptors, expressed in human embryonic kidney 293 cells, are reported for the first time. 5-HT (1 muM) applied in Ca2+- and Mg2+-free external solution to excised outside-out membrane patches induced non-rectifying single- channel inward currents. These currents were not observed in untransfected cells or in the presence of the antagonist ondansetron (1 muM). The mean single-channel conductance of the h5-HT3A and m5-HT3A receptors was 48 +/- 8 pS and 46 +/- 7 pS, the mean reversal potential was 10.3 +/- 1.8 mV and 4.7 +/- 5.3 mV, respectively. The analysis of single-channel open-times revealed for both h5-HT3A and m5-HT3A receptors only one type of open state, but different mean open-times (7.1 +/- 2.9 ms vs. 4.1 +/- 0.8 ms) indicating species-dependent gating mechanisms of 5-HT3 receptors. (C) 2002 Elsevier Science Ireland Ltd. All rights reserv