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).

Hospital Wastewater-Source of Specific Micropollutants, Antibiotic-Resistant Microorganisms, Viruses, and Their Elimination.

Municipal wastewaters can generally provide real-time information on drug consumption, the incidence of specific diseases, or establish exposure to certain agents and determine some lifestyle consequences. From this point of view, wastewater-based epidemiology represents a modern diagnostic tool for describing the health status of a certain part of the population in a specific region. Hospital wastewater is a complex mixture of pharmaceuticals, illegal drugs, and their metabolites as well as different susceptible and antibiotic-resistant microorganisms, including viruses. Many studies pointed out that wastewater from healthcare facilities (including hospital wastewater), significantly contributes to higher loads of micropollutants, including bacteria and viruses, in municipal wastewater. In addition, such a mixture can increase the selective pressure on bacteria, thus contributing to the development and dissemination of antimicrobial resistance. Because many pharmaceuticals, drugs, and microorganisms can pass through wastewater treatment plants without any significant change in their structure and toxicity and enter surface waters, treatment technologies need to be improved. This short review summarizes the recent knowledge from studies on micropollutants, pathogens, antibiotic-resistant bacteria, and viruses (including SARS-CoV-2) in wastewater from healthcare facilities. It also proposes several possibilities for improving the wastewater treatment process in terms of efficiency as well as economy.

Wastewater-Based Epidemiology as an Early Warning System for the Spreading of SARS-CoV-2 and Its Mutations in the Population.

New methodologies based on the principle of "sewage epidemiology" have been successfully applied before in the detection of illegal drugs. The study describes the idea of early detection of a virus, e.g., SARS-CoV-2, in wastewater in order to focus on the area of virus occurrence and supplement the results obtained from clinical examination. By monitoring temporal variation in viral loads in wastewater in combination with other analysis, a virus outbreak can be detected and its spread can be suppressed early. The use of biosensors for virus detection also seems to be an interesting application. Biosensors are highly sensitive, selective, and portable and offer a way for fast analysis. This manuscript provides an overview of the current situation in the area of wastewater analysis, including genetic sequencing regarding viral detection and the technological solution of an early warning system for wastewater monitoring based on biosensors.

Effervescent ferrate(VI)-based tablets as an effective means for removal SARS-CoV-2 RNA, pharmaceuticals and resistant bacteria from wastewater.

Waterborne pathogens including viruses, bacteria and micropollutants secreted from population can spread through the sewerage system. In this study, the efficiency of unique effervescent ferrate-based tablets was evaluated for total RNA and DNA removal, disinfection and degradation of micropollutants in hospital wastewater. For the purpose of testing, proposed tablets (based on citric acid or sodium dihydrogen phosphate) were used for various types of hospital wastewater with specific biological and chemical contamination. Total RNA destruction efficiency using tablets was 70-100% depending on the type of acidic component. DNA destruction efficiency was lower on the level 51-94% depending on the type of acidic component. In addition, our study confirms that effervescent ferrate-based tablets are able to efficiently remove of SARS-CoV-2 RNA from wastewater. Degradation of often detected micropollutants (antiepileptic, antidepressant, antihistamine, hypertensive and their metabolites) was dependent on the type of detected pharmaceuticals and on the acidic component used. Sodium dihydrogen phosphate based tablet appeared to be more effective than citric acid based tablet and removed some pharmaceuticals with efficiency higher than 97%. Last but not least, the disinfection ability was also verified. Tableted ferrates were confirmed to be an effective disinfectant and no resistant microorganisms were observed after treatment. Total and antibiotic resistant bacteria (coliforms and enterococci) were determined by cultivation on diagnostic selective agar growth media.

Wastewater-based epidemiology to assess the occurrence of new psychoactive substances and alcohol consumption in Slovakia.

Consumption of alcohol and new psychoactive substances (NPS) in a population or during special events (music festivals) is usually monitored through individual questionnaires, forensic and toxicological data, and drug seizures. However, consumption estimates have some biases due mostly to the unknown composition of drug pills for NPS and stockpiling for alcohol. The aim of this study was to evaluate for the first time the real use of alcohol and the occurrence of NPS in Slovakia by wastewater-based epidemiology (WBE). Urban wastewater samples were collected from nine Slovak cities over two years (2017-2018) and during three music festivals. The study included about 20% of the Slovak population and 50 000 festival attendees. The urinary alcohol biomarker ethyl sulfate (EtS) and thirty NPS were analyzed by liquid chromatography tandem mass spectrometry (LC - MS/MS). EtS concentrations were used for estimating the per capita alcohol consumption in each city. The average alcohol consumption in the selected cities and festivals in 2017-2018 ranged between 7 and 126 L/day/1000 inhabitants and increased during the weekends and music festivals. Five NPS belonging to the classes of synthetic cathinones (mephedrone, methcathinone, buphedrone and pentedrone) and phenethylamines (25-iP-NBoMe) were found in the low ng/L range. Methcathinone was the most frequently detected NPS, while the highest normalized mass load corresponded to mephedrone (3.1 mg/day/1000 inhabitants). Wastewater-based epidemiology can provide timely information on alcohol consumption and NPS occurrence at the community level that is complementary to epidemiology-based monitoring techniques (e.g. population surveys, police seizures, sales statistics).

Hospital wastewaters treatment: Fenton reaction vs. BDDE vs. ferrate(VI).

Various types of micropollutants, e.g., pharmaceuticals and their metabolites and resistant strains of pathogenic microorganisms, are usually found in hospital wastewaters. The aim of this paper was to study the presence of 74 frequently used pharmaceuticals, legal and illegal drugs, and antibiotic-resistant bacteria in 5 hospital wastewaters in Slovakia and Czechia and to compare the efficiency of several advanced oxidations processes (AOPs) for sanitation and treatment of such highly polluted wastewaters. The occurrence of micropollutants and antibiotic-resistant bacteria was investigated by in-line SPE-LC-MS/MS technique and cultivation on antibiotic and antibiotic-free selective diagnostic media, respectively. The highest maximum concentrations were found for cotinine (6700 ng/L), bisoprolol (5200 ng/L), metoprolol (2600 ng/L), tramadol (2400 ng/L), sulfamethoxazole (1500 ng/L), and ranitidine (1400 ng/L). In the second part of the study, different advanced oxidation processes, modified Fenton reaction, ferrate(VI), and oxidation by boron-doped diamond electrode were tested in order to eliminate the abovementioned pollutants. Obtained results indicate that the modified Fenton reaction and application of boron-doped diamond electrode were able to eliminate almost the whole spectrum of selected micropollutants with efficiency higher than 90%. All studied methods achieved complete removal of the antibiotic-resistant bacteria present in hospital wastewaters.

Music festivals and drugs: Wastewater analysis.

Drug consumption in individual cities, regions, and at various music events and festivals across the EU has generally been monitored via questionnaires, patients' medical data, and police reports. However, an overview of drug consumption obtained from these methods can be negatively affected by various subjective factors. We aimed to investigate an association between levels of target drugs in wastewater, music genres, and festival courses. The occurrence of illicit drugs, their metabolites, and psychoactive compounds was investigated in the influent of six wastewater treatment plants in the Czech and Slovak Republic during seven large-scale music festivals from different music genres: metal, rock, pop, country and folk, ethnic, multi-genre, dance, and trance. The total number of participants included >130,000 active festival attendees. The association between music genre and illicit drug and/or psychoactive pharmaceutical consumptions is discussed on the basis of the results obtained through wastewater analyses. The observed trend was similar to worldwide published data with a specific local phenomenon of methamphetamine prevalence that did not significantly change between music events. Increased specific loads of cocaine (measured as its metabolite benzoylecgonine) and Ecstasy, along with some cannabis, were mainly observed during pop/rock and dance music festivals. However, there was no significant increase observed in the specific loads of all monitored psychoactive pharmaceuticals. This study demonstrates that the abuse of some illicit drugs is closely associated with specific music preferences.

National study of illicit drug use in Slovakia based on wastewater analysis.

The aim of this study was to analyze illicit drugs and their metabolites in wastewater from eight selected wastewater treatment plants (WWTPs) in Slovakia. The effect of two of the biggest music festivals in Slovakia on illicit drugs in wastewater was also investigated. Urinary bio-markers of amphetamine, methamphetamine, cocaine, cannabis and ecstasy use were analyzed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). We then compared our results with data obtained in other parts of Europe and the world. This study demonstrates that Slovakia has one of highest methamphetamine consumption rates in Europe. Within Slovakia, the highest level of methamphetamine consumption was found in Petrzalka, where the mean specific load of this drug in sewage was 169 mg/day/1000 inhabitants; the next highest loads were detected in Piestany (128 mg/day/1000 inhabitants) and Bratislava (124 mg/day/1000 inhabitants). Amphetamine, ecstasy and cannabis consumption in our study were comparable to that found in other European cities, whereas cocaine consumption was lower. We also analyzed the pattern of drug consumption over the course of a week. The load of the cocaine metabolite benzoylecgonine in wastewater increased during the weekend. The use of this drug was most common in the capital of Slovakia. Increased consumption was also found during a folk festival in Piestany. The ecstasy load in wastewater from larger cities also significantly increased over the weekend. An increase of drug consumption was also detected during a music festival in Trencín, especially for ecstasy. The specific load of ecstasy during this festival increased from 3mg/day/1000 inhabitants to 29 mg/day/1000 inhabitants. The possible influence of music styles on the consumption of certain drugs was also observed. During a folk festival, methamphetamine and cocaine were more commonly used.

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.