Tequila vinasses is a mixture made from up to six still distillation two-stage process residual effluents. First stage fractions: residual must (60%), heads (0.9%) and tails (20.0%); second stage fractions: non-evaporated (8.0%), heads (0.1%) and tails (1.0%); the result is a more complex effluent for its treatment or biorefining. The objectives of this study were to: (a) characterize the five still distillation volatile streams in the Tequila 100% Agave processing; compounds: methanol, ethanol, acetaldehyde, ethyl acetate, sec-butanol, n-propanol, iso-butanol, n-butanol, iso-amyl, n-amyl, and ethyl lactate were detected by gas chromatography; calculated chemical oxygen demand from chemical composition had very high values (53,760–1,239,220 mg/L); measurement of pH (3.24–4.80), color (38.6 UC Pt-Co max), turbidity (46.1 max), electrical conductivity (3.30–172.20 μS/cm), and solid content (0 mg/L) was also made; (b) report an energy analysis (2.02 × 10⁹ KWh) and CO₂ production (429 × 10⁶ kg) in the Tequila industry during 2019; (c) up to date residues (365.2 × 10⁶ kg agave bagasse, 1146.1 × 10⁶ kg agave leaves and 3300.0 × 10⁶ L agave vinasse) in 2019; (d) economic analysis, current tequila vinasses treatment price is 16.00 USD/m³ but could reach a considerable fraction value if is bio-refined, a break down component analysis reach for five volatile streams $51.23–$140.00 USD/m³.

Phenolic compounds are toxic and dangerous to the environment and human health. Although the removal of phenols and their derivatives is very difficult, it has been achieved by applying some biological processes. The capacity of microalga to remove phenolic compounds has been demonstrated; however, few reports of the removal of these compounds in a mixture have been published. The removal of phenol, p-cresol and o-cresol was performed by batch kinetics at 50 and 100 mg L⁻¹, and the simultaneous degradation of phenol, p-cresol and o-cresol was carried out in a mixture at 40 mg L⁻¹ using the marine microalga Tetraselmis suecica. The kinetic study was carried out for 192 h. For concentrations of 50 mg L⁻¹ and 100 mg L⁻¹, phenolic compound consumption efficiencies greater than 100% and 85%, respectively, were obtained, and up to 73.6% removal in the mixture. The results obtained indicate that the marine microalga carries out a process of the oxidation of organic matter and phenolic compounds, mineralizing up to 31.4% to CO2 in the mixture. Biological treatments using the marine microalga T. suecica can be considered feasible to treat effluents with concentrations similar to those of the present study.

In Mexico, atrazine is widely used in agriculture to control broadleaf weeds. The objective of this research was to compare atrazine removal in water and energy consumption between an up-flow cylinder electro-oxidation reactor (UCER) and an up-flow rectangular electro-oxidation reactor (URER) using the response surface methodology. In each reactor, two titanium (Ti) mesh electrodes (cathodes) and one Titanium-Lead Dioxide (Ti-PbO2) mesh electrode (anode). Current intensity effects, electrolysis treatment time, and recirculation flow were evaluated. Synthetic water with 5 mg/L atrazine content was used. Optimum atrazine removal values were obtained at 2 A electric current, 180 min of treatment time, and 200 mL/min recirculation rate for both reactors: in these conditions an atrazine removal of 77.45% and 76.89% for URER and UCER respectively. However, energy consumption showed a significant difference of 137.45 kWh/m3 for URER and 73.63 kWh/m3 for UCER. Regarding energy efficiency, a 60% atrazine removal was reached in both reactors using less energy for UCER at (1.5 A–135 min–150 mL/min–25.8 kWh/m3) and for URER at (0.66 A–135 min–150 mL/min–20.12 kWh/m3).

The catalytic effects of different quinoid redox mediators (RM) on the simultaneous removal of sulphide and p-cresol in a denitrifying process were evaluated in batch studies. 2-Hydroxy-1,4-naphthoquinone (LAW) and anthraquinone-2,6-disulphonate (AQDS) did not significantly affect the sulphide oxidation rate, which, in contrast, was increased 14% in the presence of 1,2-naphthoquinone-4-sulphonate (NQS). The input of NQS on the oxidation of sulphide was also favourably reflected in a 13% higher sulphate production. All RM promoted a higher (up to 34% compared to the control lacking RM) degree of mineralization of p-cresol. LAW also supported a 47% higher denitrifying yield (YN2), compared to the control lacking quinones. Nevertheless, AQDS and NQS decreased the YN2 by 12–13%. Our results suggest that a proper scrutiny should be conducted before deciding the sort of quinone to be applied in denitrifying processes. The heterogeneous effects observed also advise to consider both the respiratory rates and the yields as important parameters for deciphering the impact of RM on denitrifying processes.