Utilization of Biodiesel By-Products for Biogas Production

This contribution reviews the possibility of using the by-products from biodiesel production as substrates for anaerobic digestion and production of biogas. The process of biodiesel production is predominantly carried out by catalyzed transesterification. Besides desired methylesters, this reaction provides also few other products, including crude glycerol, oil-pressed cakes, and washing water. Crude glycerol or g-phase is heavier separate liquid phase, composed mainly by glycerol. A couple of studies have demonstrated the possibility of biogas production, using g-phase as a single substrate, and it has also shown a great potential as a cosubstrate by anaerobic treatment of different types of organic waste or energy crops. Oil cakes or oil meals are solid residues obtained after oil extraction from the seeds. Another possible by-product is the washing water from raw biodiesel purification, which is an oily and soapy liquid. All of these materials have been suggested as feasible substrates for anaerobic degradation, although some issues and inhibitory factors have to be considered

Histological changes in Poecilia reticulata after interaction of ionizing radiation and zinc sulfid

In our experiment we have studied interaction of ionizing radiation and zinc at Poecilia reticulata. Fish were irradiated with a 20 Gy of gamma-rays. Zinc sulphate in concentration 25 mg.l-1 was added to water in aquarium. Food intake, clinicl symptoms and histological changes were followed after gamma-irradiation and zinc sulfid in guppy Poecilia reticulata. In the first days timidity and lethargy were observed. The most prominent clinical symptoms observed were emaciation, hampered breathing and haemorrhages. Histological findings corresponded with these symptoms

Monitoring Alcohol Consumption in Slovak Cities during the COVID-19 Lockdown by Wastewater-Based Epidemiology.

The consumption of alcohol in a population is usually monitored through individual questionnaires, forensics, and toxicological data. However, consumption estimates have some biases, mainly due to the accumulation of alcohol stocks. This study's objective was to assess alcohol consumption in Slovakia during the COVID-19 pandemic-related lockdown using wastewater-based epidemiology (WBE). Samples of municipal wastewater were collected from three Slovak cities during the lockdown and during a successive period with lifted restrictions in 2020. The study included about 14% of the Slovak population. The urinary alcohol biomarker, ethyl sulfate (EtS), was analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). EtS concentrations were used to estimate the per capita alcohol consumption in each city. The average alcohol consumption in the selected cities in 2020 ranged between 2.1 and 327 L/day/1000 inhabitants and increased during days with weaker restrictions. WBE can provide timely information on alcohol consumption at the community level, complementing epidemiology-based monitoring techniques (e.g., population surveys and sales statistics)

Biochar – An efficient sorption material for the removal of pharmaceutically active compounds, DNA and RNA fragments from wastewater

Wastewaters are considered a remarkable source of micropollutants capable of influencing the environment both directly and indirectly. Here we tested porous ecological carbon (Biochar), an effective sorbent material for removing pharmaceuticals, drugs, and their metabolites found in wastewaters. The tested Biochar type was first characterised and used for adsorption experiments of selected micropollutants from a municipal WWTP (wastewater treatment plant) effluent sample. The sorption efficiency was studied on selected pharmaceuticals due to their common presence in aquatic ecosystems. The results show that the studied Biochar type removed the pharmaceuticals with high efficiency (above 90%), so this material can potentially be applied in wastewater treatment. We achieved greater than 99% efficiency in total RNA removal from wastewater. Wastewater might contain infectious RNA fragments of the SARS-CoV-2 virus. However, Biochar can be used as a sorbent in wastewater treatment to remove antibiotic resistance genes. We have also observed a total DNA removal ability of Biochar. On the other hand, the total number and antibiotic-resistant coliform bacteria and enterococci were not changed after Biochar wastewater treatment.Web of Science94art. no. 10574