Tequila vinasses: generation and full scale treatment processes

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.