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Liquid digestate can be used to provide nutrients for microalgae cultivation but the medium needs to be clear and colorless. The aim of this work was to use liquid digestate from coffee waste biomass to produce a light-permeable medium for microalgae cultivation. A boron-doped diamond anode was applied for electrochemical decolorization of the digestate. The electrochemical oxidation process reduced the platinum-cobalt color value by up to 97% and the chemical oxygen demand by 84.1%. After electrochemical oxidation, 87.4% of the ammonium nitrogen (NH4-N) was retained. Decolorization of the spent coffee grounds liquid digestate was compared with that of dairy cow manure liquid digestate. It took 90 min longer to fully decolorize the spent coffee grounds liquid digestate compared with the dairy cow manure liquid digestate. The boron-doped diamond anode performed better in the decolorization than Ti/IrO2 and Ti/Pt anodes. The effects of the initial Fe2+ concentration and current on the electrochemical oxidation process were also evaluated. Increasing the initial Fe2+ concentration enhanced the Fenton reaction and chemical oxygen demand removal. A higher current enhanced the electrochemical decolorization process and side reactions. Electrochemical oxidation using a boron-doped diamond anode is a promising method for producing an appropriate medium for microalgae cultivation because it promotes decolorization of liquid digestate and retains most of the NH4-N. [ABSTRACT FROM AUTHOR]

Bioconversion of organic waste requires the development and application of rather simple, yet robust technologies capable of transferring biomass into energy and sustainable materials for the future. Food waste plays a significant role in this process as its valorisation reduces waste and at the same time avoids additional exploitation of primary resources. Nonetheless, to literally become “litterate”. extensive research into such robust large-scale methods is required. Here, we highlight some promising avenues and materials which fulfill these “waste to value” requirements, from various types of food waste as sustainable sources for biogas, bioethanol and biodiesel to fertilizers and antioxidants from grape pomace, from old-fashioned fermentation to the magic of anaerobic digestion.

Objectives: The study of hormone modulation may offer important insight into the responses of individuals to environmental challenges. Here we studied C‐peptide, thyroid hormone (T3), glucocorticoid (GC), and testosterone (T) metabolites of mantled howler males to assess: 1) correlations among hormones; 2) individual and temporal variation in hormone concentrations; and 3) the influence of ecological, climatic, behavioral, social, and reproductive factors on hormone variation. Methods: We studied 10 adult males at La Flor de Catemaco (Mexico) from January 2012 to December 2016. We collected information on food availability; ambient temperature; time budgets; male involvement in mating, agonistic interactions, and interactions with extragroup males. We analyzed C‐peptide concentrations in urine samples and T3, GC, and T in fecal samples. Results: C‐peptide was negatively correlated with other hormones, whereas T3, GC, and T were positively related. Hormonal variation was unrelated to individual or yearly differences. Food availability was positively related to C‐peptide and T3, and negatively related to GC. Involvement in mating was positively related to T3 and T, whereas the rate agonistic interactions was positively related to GC and T. The rate of interactions with extragroup males was positively related to T. When males mated, the increase in C‐peptide and the decrease in GC with increasing food availability were less notable. Conclusions: Hormonal variation in mantled howler monkey males is generally stable, but it is influenced by several factors. Our results offer a broad picture of the hormonal modulation of mantled howler monkey males in response to diverse challenges. [ABSTRACT FROM AUTHOR]

Bioconversion of organic waste requires the development and application of rather simple, yet robust technologies capable of transferring biomass into energy and sustainable materials for the future. Food waste plays a significant role in this process as its valorisation reduces waste and at the same time avoids additional exploitation of primary resources. Nonetheless, to literally become "litterate". extensive research into such robust large-scale methods is required. Here, we highlight some promising avenues and materials which fulfill these "waste to value" requirements, from various types of food waste as sustainable sources for biogas, bioethanol and biodiesel to fertilizers and antioxidants from grape pomace, from old-fashioned fermentation to the magic of anaerobic digestion., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Razouk, Tiganescu, von Glahn, Abdin, Nasim and Jacob.)