Treatment of tequila distillation volatile residues by electrochemical oxidation using titanium electrodes.

Tequila production occurs in Mexico's designated area of origin, principally in the Jalisco State. Its residues are a challenge in treatment and tracking due to a lack of technology, non-economic treatments available, low environmental consciousness and incipient control from authorities. In 2021, average production was close to 1.5 million tequila litres per day with an estimated residue yield of 10-12 litres of stillage (tequila vinasses) per tequila litre produced, including volatile fractions. This research aims to reduce organic matter by electrooxidation (EO) from 5 distillation volatile residual effluents (two-stage still distillation) from three tequila distilleries, first and second-stage heads and heads and tails and second-stage non-evaporated fraction. Round 3 mm titanium (grade-1) electrodes (one anode and one cathode) were used, with fixed voltage to a value of 30 VDC at 0, 3, 6, 9 and 12 h with 75 experiments. Gas chromatography was used to analyse methanol, ethanol, acetaldehyde, ethyl acetate, n-propanol, sec-butanol, iso-butanol, n-butanol, iso-amyl, n-amyl, and ethyl lactate content. Treatment shows positive results, reducing organic matter content in all effluents in a Chemical Oxygen Demand COD range of 580-1880 mg/L.h, particularly useful in the second-stage non-evaporated fraction for water recovery.HIGHLIGHTSResidual effluent treatment is beneficial to environmental and resource sustainability.Process without adding materials achieving cleaner treated effluents.Process aimed as the final step to recover water.This process could help the Tequila industry to reach a higher sustainability level by reducing water usage and untreated residues.

Quantitative microbial risk assessment of Cryptosporidium and Giardia in well water from a native community of Mexico.

Cryptosporidium and Giardia are gastrointestinal disease-causing organisms transmitted by the fecal-oral route, zoonotic and prevalent in all socioeconomic segments with greater emphasis in rural communities. The goal of this study was to assess the risk of cryptosporidiosis and giardiasis of Potam dwellers consuming drinking water from communal well water. To achieve the goal, quantitative microbial risk assessment (QMRA) was carried out as follows: (a) identification of Cryptosporidium oocysts and Giardia cysts in well water samples by information collection rule method, (b) assessment of exposure to healthy Potam residents, (c) dose-response modelling, and (d) risk characterization using an exponential model. All well water samples tested were positive for Cryptosporidium and Giardia. The QMRA results indicate a mean of annual risks of 99:100 (0.99) for cryptosporidiosis and 1:1 (1.0) for giardiasis. The outcome of the present study may drive decision-makers to establish an educational and treatment program to reduce the incidence of parasite-borne intestinal infection in the Potam community, and to conduct risk analysis programs in other similar rural communities in Mexico.

Occurrence and quantitative microbial risk assessment of Cryptosporidium and Giardia in soil and air samples.

BACKGROUND: Cryptosporidium oocysts and Giardia cysts can be transmitted by the fecal-oral route and may cause gastrointestinal parasitic zoonoses. These zoonoses are common in rural zones due to the parasites being harbored in fecally contaminated soil. This study assessed the risk of illness (giardiasis and cryptosporidiosis) from inhaling and/or ingesting soil and/or airborne dust in Potam, Mexico. METHODS: To assess the risk of infection, Quantitative Microbial Risk Assessment (QMRA) was employed, with the following steps: (1) hazard identification, (2) hazard exposure, (3) dose-response, and (4) risk characterization. RESULTS: Cryptosporidium oocysts and Giardia cysts were observed in 52% and 57%, respectively, of total soil samples (n=21), and in 60% and 80%, respectively, of air samples (n=12). The calculated annual risks were higher than 9.9 × 10(-1) for both parasites in both types of sample. CONCLUSIONS: Soil and air inhalation and/or ingestion are important vehicles for these parasites. To our knowledge, the results obtained in the present study represent the first QMRAs for cryptosporidiosis and giardiasis due to soil and air inhalation/ingestion in Mexico. In addition, this is the first evidence of the microbial air quality around these parasites in rural zones.