Electrochemical degradation of amoxicillin in acidic aqueous medium using TiO2-based electrodes modified by oxides of transition metals

Environmental Science and Pollution Research - One of the most widely used antibiotics is amoxicillin (AMX), which is the most widely used in humans and animals, but it is discharged metabolically...     

Persistence of gemfibrozil, naproxen and mefenamic acid in natural waters

The occurrence of pharmaceuticals in natural waters is a potential threat to human nutrition and ecosystem quality. The persistence of the acidic pharmaceuticals gemfibrozil, naproxen and mefenamic acid was studied in surface waters of Maracaibo Lake and Tule reservoir (Venezuela) under laboratory conditions. A quick and easy analytical method was developed for the determination of the acidic drugs at microgram per liter levels using aqueous derivatization, liquid–liquid extraction and gas chromatography–mass spectrometry. Pharmaceuticals degradation followed a pseudo first-order kinetic and their half-lives were calculated for every experimental condition. Under sunlight, naproxen and mefenamic acid were degraded at moderate rates with half-lives from 9.6 ± 0.5 to 27.0 ± 6.6 days, while gemfibrozil had a higher persistence (t _1/2 = 119.5 ± 15.6 − 288.8 ± 61.3 days).     

Rose Bengal‐sensitized photooxygenation of chlorohydroxyaromatic contaminants in water: A kinetic study

A kinetic study of the RB‐sensitized photooxygenation of a series of chlorohydroxyaromatic (ClArOH) water contaminants (phenolic and dihydroxybenzene derivatives) has been carried out. In addition, an exhaustive study on the possible interactions of RB electronically excited triplet and singlet states with ClArOH was also developed. The determination of relative rates of oxygen uptake upon sensitized irradiation, employing auxiliar selective quenchers of oxygen active species, indicate the contribution of both singlet molecular oxygen (ca. 71%) and Superoxide ion (ca. 26%) as the reactive pathways for ClArOH degradation. The substitution by chlorine atoms in position meta greatly decrease the photooxygenation rate of the phenolic derivatives. For the dihydroxybenzene series, increase in nuclear chlorination parallels a decrease in the photodegradation rate.

Outdoors sensitized solar irradiation experiments on different ClArOH mixtures leads to measurable levels of oxygen after a few minutes exposure. From the environmental point of view, and ruling out the possibility of direct‐irradiation photoreactions, sensitized photooxygenation appears as an alternative pathway for ClArOH degradation, in competence with other naturally‐occurring photoprocesses involving reactive transient species.     

Bioconversion of marine crustacean shell waste

This paper appraises the potential of marine crustacean shell waste from the world's fishing industry for bioconversion to industrial products and envisages almost total low-waste utilisation of such materials. Techniques for the processing of waste shells are considered and compared. We additionally investigate what is considered a vital early stage in shell processing - the viability of a lactic acid fermentation on demineralised shell for deproteinisation under both aerobic and anaerobic conditions. An integrated bioconversion scheme is proposed whereby protein, pigment (astaxanthin) and the main biopolymer constituent, chitin, can be isolated for industrial or commercial use. The scheme also suggests further conversion of the chitin to its monomer, N-acetylglucosamine, for use as a sugar or as a medium source for production of microbial biomass protein.     

Nighttime lights and population changes in Europe 1992–2012

Nighttime satellite photographs of Earth reveal the location of lighting and provide a unique view of the extent of human settlement. Nighttime lights have been shown to correlate with economic development and population but little research has been done on the link between nighttime lights and population change over time. We explore whether population decline is coupled with decline in lighted area and how the age structure of the population and GDP are reflected in nighttime lights. We examine Europe between the period of 1992 and 2012 using a Geographic Information System and regression analysis. The results suggest that population decline is not coupled with decline in lighted area. Instead, human settlement extent is more closely related to the age structure of the population and to GDP. We conclude that declining populations will not necessarily lead to reductions in the extent of land development.     

Algal cultures with effluents from biological treatment of urban wastewaters by anaerobiosis

Experiments have been carried out on cultures of native algae of Andalucía (Spain) with effluents from the biological treatment of urban wastewaters by anaerobiosis, using continuous and discontinuous systems.The influence of different hydraulic retention times of the wastewater on the algal cultures has been determined: on the level of algal biomass reached, and on the degree of purification achieved, measured from the evolution of various quality parameters.