Heterogeneous alternative catalysts: A bibliometric and systematic evaluation of their application in solar photocatalytic processes

The present study sought to objectively demonstrate how a researcher can, in a structured way, select relevant articles about alternative heterogeneous catalysts in photocatalytic processes. Therefore, the ProKnow-C (Knowledge Development Process – Constructivist) method was used to systematize the results found, with the application bibliometric and systematic analysis techniques for the evaluation of the results. The search string adopted as criteria was: solar photocatalysis AND heterogeneous catalysts OR alternative catalysts AND effluents. The databases were Web of Science, Science Direct and Scopus. The final bibliographic portfolio obtained for the research theme was made up of 19 articles. It was possible to verify advances in the number of publications on the theme over the evaluated period, with the Journal of Photochemistry and Photobiology A: Chemistry standing out in the final portfolio. Evaluating each article in the portfolio individually, it was possible to verify that most studies use combinations of catalysts already reported to create an alternative material to those already investigated in the literature. Those that use waste as catalysts chose to source this material from treatment plants and the steel industry. Around 58% of the papers used hydrogen peroxide in their processes, while 42% chose not to use it. Finally, approximately 63% of the papers in the portfolio used synthetic effluent in their processes, while the rest (37% of the research) chose to use real effluent. The results obtained in this research by applying the method can contribute to studies related to heterogeneous photocatalysis by alternative means over the years.     

Influence of a flooding event discharge on accretion in wetlands

Flooding events in wetlands transport sediment particles landwards and can increase accretion in some areas of the wetland or resuspend the sediment in other areas. In this study a flooding event with different water discharges was analyzed in a laboratory simulated wetland to determine the effect stem density has on particle trapping. The discharge that entered the simulated wetland was a particle laden barotropic current that initially produced a pulse that traveled through the wetland. After the first pulse, a baroclinic current, with a different timescale to the initial pulse, developed. Three stem densities, along with the ‘without plant case’, were considered. A semi-empirical model was formulated to explain the propagation of the water pulse. The model predicted the velocity of the pulse dampening in the presence of the simulated vegetation, by using the roughness parameter that had been found to increase with stem density. The baroclinic current propagated at a lower velocity than the pulse did, and its velocity decreased with stem density. As less sediment was found in the wetland with denser canopies, this indicates that the presence of a canopy acts as a barrier to sediment transportation. Furthermore, a greater amount of sediment was deposited in regions at the foot of the denser vegetated wetland zone and the sediment deposition also increased with the water discharge.     

Enhanced reduction of phenol content and toxicity in olive mill wastewaters by a newly isolated strain of Coriolopsis gallica

The search for novel microorganisms able to degrade olive mill wastewaters (OMW) and withstand the toxic effects of the initially high phenolic concentrations is of great scientific and industrial interest. In this work, the possibility of reducing the phenolic content of OMW using new isolates of fungal strains (Coriolopsis gallica, Bjerkandera adusta, Trametes versicolor, Trichoderma citrinoviride, Phanerochaete chrysosporium, Gloeophyllum trabeum, Trametes trogii, and Fusarium solani) was investigated. In vitro, all fungal isolates tested caused an outstanding decolorization of OMW. However, C. gallica gave the highest decolorization and dephenolization rates at 30 % v/v OMW dilution in water. Fungal growth in OMW medium was affected by several parameters including phenolic compound concentration, nitrogen source, and inoculum size. The optimal OMW medium for the removal of phenolics and color was with the OMW concentration (in percent)/[(NH₄)₂SO₄]/inoculum ratio of 30:6:3. Under these conditions, 90 and 85 % of the initial phenolic compounds and color were removed, respectively. High-pressure liquid chromatography analysis of extracts from treated and untreated OMW showed a clear and substantial reduction in phenolic compound concentrations. Phytotoxicity, assessed using radish (Raphanus sativus) seeds, indicated an increase in germination index of 23–92 % when a 30 % OMW concentration was treated with C. gallica in different dilutions (1/2, 1/4, and 1/8).

Reassessing the role of the honeybee (Apis mellifera) Dufour's gland in egg marking

Dufour's gland secretion may allow worker honeybees to discriminate between queen-laid and worker-laid eggs. To investigate this, we combined the chemical analysis of individually treated eggs with an egg removal bioassay. We partitioned queen Dufour's gland into hydrocarbon and ester fractions. The bioassay showed that worker-laid eggs treated with either whole gland extract, ester fraction or synthetic gland esters were removed more slowly than untreated worker-laid eggs. However, the effect only lasted up to 20 h. Worker-laid eggs treated with the hydrocarbon fraction were removed at the same rate as untreated eggs. The amount of ester which reduced the egg removal rate was far higher than that naturally found on queen-laid or worker-laid eggs, and at natural ester levels no effect was found. Our results indicate that esters or hydrocarbons probably do not function as the signal by which eggs can be discriminated.     

Foraminiferal proxies for pollution monitoring in moderately polluted harbors

Benthic foraminifera are increasingly used as environmental bio-indicators, especially in polluted environments where their sensitivity to pollutants may be expressed by a modification of the assemblages. Eighteen sediment samples were collected in September 2000 in five harbors located in moderately polluted estuaries on the coast of Vendée (France) for the study of foraminiferal assemblages. Ten heavy metals and 13 PAH have been analyzed from the sediments. The marine to continental estuarine gradient has a prevalent influence on the foraminiferal distribution. However, the results show that foraminiferal density and species richness of the assemblages decrease with an increase in heavy metal and PAH concentration, and therefore may be used as pollution indicators. Moreover, the more polluted areas are dominated by the tolerant pioneer species Haynesina germanica that may be used as bio-indicator of pollution, mainly in the uppermost areas.     

Fuzzy clustering analysis of the first 10 MEIC chemicals

In this paper, we discuss the classification results of the toxicological responses of 32 in vivo and in vitro test systems to the first 10 MEIC chemicals. In this order we have used different fuzzy clustering algorithms, namely hierarchical fuzzy clustering, hierarchical and horizontal fuzzy characteristics clustering and a new clustering technique, namely fuzzy hierarchical cross-classification. The characteristics clustering technique produces fuzzy partitions of the characteristics (chemicals) involved and thus it is a useful tool for studying the (dis)similarities between different chemicals and for essential chemicals selection. The cross-classification algorithm produces not only a fuzzy partition of the test systems analyzed, but also a fuzzy partition of the considered 10 MEIC (multicentre evaluation of in vitro cytotoxicity) chemicals. In this way it is possible to identify which chemicals are responsible for the similarities or differences observed between different groups of test systems. In another way, there is a specific sensitivity of a chemical for one or more toxicological tests.     

Optimization of fuel briquette production from cassava peels,plantain peels and corn cobs

Journal of Material Cycles and Waste Management - Mechanical properties enable to handle storage and transport of fuel briquette. Binder is key element of these mechanical properties. Biobinder is...     

Performance of mortars with PET

Journal of Material Cycles and Waste Management - The massive amount of plastic production inevitably leads to huge levels of pollution and, consequently, is threatening the environment and...