Tequila vinasses: generation and full scale treatment processes

Abstract

The production of Tequila (55% Alc. Vol.) in Mexico for the year 2008 was 227 million liters, and consequently around 2,270 million liters of Tequila vinasses (TVs) were generated, which without proper treatment is equivalent to the pollution produced by 6.2 million people. The lack of both finances and technology availability are reasons for the absence of wastewater treatment plants (WTP) in the Tequila factories, with the exception of some big and medium size factories. There are WTPs based on both biological and physicochemical processes and also combinations of them that have been implemented to treat TVs; however, in most of the cases the implementation has not been effective. The WTPs that utilize a biological anaerobic process seem to be the most suitable for the treatment of TVs; however, there are some technical factors that have to be considered before the implementation of a technological solution for this environmental issue. This mini-review presents the state of the art of wastewater treatments performance in the Tequila industry, discussing the efficacy of the systems together with other technologies that could be considered to fulfill the requirements for the environmental regulation in Mexico.

Influence of alkalinity and VFAs on the performance of an UASB reactor with recirculation for the treatment of Tequila vinasses

“…Therefore, a post-treatment of aerobic type needs to be considered to remove the residual COD, which could be an extended aeration process with operating parameters that allow not only to remove the organic matter but also the nutrients; in order to meet the standards for discharge and/or agricultural reuse [2]. Table 2 shows the overall COD balances for different OLRs, since biomass-COD was not determined, the proportion of influent COD converted to biomass was assumed to be 10% [21,24]; therefore, it was possible to calculate the overall COD recovery.…”

“…Tequila vinasse is a dark brown liquid; it presents a pH of 3.5 and a high chemical oxygen demand (COD), which ranges from 60 to 100 g l -1 ; generating potential risks to the environment if it is discharged without treatment to water bodies [1][2][3][4]. Between the different treatments of vinasses, the anaerobic process stands out as the most viable; it has been used for the treatment of Tequila vinasse [2,[5][6][7] and for other distilled spirits [3,[8][9][10]. Anaerobic processes are considered energy, environmental and economically viable for the treatment of vinasses; biogas rich in methane generated during the anaerobic process could be used for electric energy generation.…”

Performance of a Microbial Fuel Cell Operated With Vinasses Using Different Cod Concentrations

“…Due to their acidic composition, high concentration of mineral salts, and high recalcitrant organic matter, vinasses can contaminate the environment and their discharge into soils and water and can have a negative impact on the ecosystem. When used on fertile soils, vinasses may affect the soil structure, nutrient uptake and crop yield (López-López et al 2010, Robles-González et al 2012, Moraes et al 2014. For this reason, in Mexico, biological and physicochemical treatments of vinasses have been researched recently.…”

Effect of the organic loading rate on the performance and microbial populations during the anaerobic treatment of tequila vinasses in a pilot‐scale packed bed reactor

“…Nonetheless, such increase has also impacted the generation of the main residues produced by this industry: bagasse and vinasses. Due to the physicochemical characteristics and high production rate of tequila vinasses, approximately 10–12 L per litre of tequila, much attention has been paid to investigate suitable technologies for the treatment and valorization of this residue . According to López‐López et al, only 20% of the vinasses generated by the tequila industry are adequately treated.…”

“…without receiving adequate treatment, and are negatively impacting the environment. The main characteristics of tequila vinasses that cause environmental damage are their low pH (3.5–4.5), high temperature (above 90 °C), high organic matter content (60–100 g COD L ‐1 or 35–60 g BOD L ‐1 ), TSS (2–8 g L ‐1 ) and the brown color due to the content of phenolics, melanoids and products of the Maillard reaction, which increase the recalcitrance of these effluents …”