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The aim of the study was to determine the impact of the constant magnetic field (CMF) application on the effectiveness of anaerobic digestion of algal biomass. The highest yield of biogas in the range of 448.9 L/kg volatile solids (VS) to 456.6 L/kg VS was observed in the variants, in which the retention time in the CMF-exposed area ranged from 144 to 216 min/d. Under these conditions, the concentration of methane in the biogas was nearly 65.0%. The increase in the contact time of the fermentation medium with the CMF-exposed area had a significant impact of reducing the effectiveness of anaerobic digestion. The lowest biodegradation was observed when the retention time was 432 min/d. Under such condition, 281.1 L of biogas/kg VS with methane content of 41.8% was obtained. A correlation between the time of exposure to CMF and the values of parameters characterizing the methane production was found.

We experimentally and theoretically investigate the size effect of gelation using Resorcinol-Formaldehyde aerogels. We find a clear dependence of gelation time on the sample size under mild shear conditions. We developed a theoretical model based on Smoluchowski’s aggregation model adding, however, a growth term which accounts for the continuous growth of the colloidal particles while clustering happens. The model is solved analytically and agrees with our experimental observations for base catalyzed RF-gels.

The class of triarylamine-based dyes has proven great potential as efficient light absorbers in inverse (p-type) dye sensitized solar cells (DSSCs). However, detailed investigation and further improvement of p-type DSSCs is strongly hindered by the fact that available synthesis routes of triarylamine-based dyes are inefficient and particularly demanding with regard to time and costs. Here, we report on an efficient synthesis strategy for triarylamine-based dyes for p-type DSSCs. A protocol for the synthesis of the dye-precursor (4-(bis(4-bromophenyl)amino)benzoic acid) is presented along with its X-ray crystal structure. The dye precursor is obtained from the commercially available 4(diphenylamino)benzaldehyde in a yield of 87% and serves as a starting point for the synthesis of various triarylamine-based dyes. Starting from the precursor we further describe a synthesis protocol for the dye 4-{bis[4′-(2,2-dicyanovinyl)-[1,1′-biphenyl]-4-yl]amino}benzoic acid (also known as dye P4) in a yield of 74%. All synthesis steps are characterized by high yields and high purities without the need for laborious purification steps and thus fulfill essential requirements for scale-up.

The objective of this study was to determine the possibility of using microalgae biomass from natural water bodies as a substrate for methane fermentation and to verify the effect of taxonomic structure and other physicochemical traits of the biomass on the technological effectiveness of the process. Harvested algae was characterized by a diversified taxonomic structure and on the content of nitrogen compounds and concentration of organic compounds in biomass, that was subject to seasonal dynamics of changes. The highest technological effects of the methane fermentation process were achieved with microalgae biomass harvested in July. In this period, the predominating taxonomic group were the Cyanoprokaryota, with a significant contribution of Chlorophyta. The mean yield of biogas production reached 441.15 ± 19.03 cm3/g o.d.m., at the mean production rate of r = 98.99 cm3/day and a reaction constant of k = 0.224 1/day. The mean content of methane in biogas accounted for 68.68 ± 1.67%. The lowest technological effects linked with biogas production were determined in November. These were the periods of the vegetative season with Bacillariophyceae constituting the predominating taxonomic group. The total production of biogas accounted for 333.65 ± 18.85 cm3/g o.d.m. The methane content were at mean levels of 54.19 ± 2.31%. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 858–865, 2015