The purpose of this research is to produce and characterize bacterial cellulose (BC) films coated with chitosan (BC-CH). BC films were produced in a fermentation medium based on Camellia sinensis tea and dextrose (12 days at 25 °C) and subsequently treated with coating-forming solutions (CFSs) based on chitosan (BC-CH 0.5%, BC-CH 1.0%, and BC-CH 1.5%). As a result, the FTIR spectra of BC and BC-CH 1.5% showed the main characteristic bands of cellulose and chitosan. In the physicochemical characterization of the films, it was found that the incorporation of the chitosan coatings did not affect the thickness; however, it decreased the luminosity (L*) and increased redness (a*), yellowness (b*), and opacity (75.24%). Additionally, the light absorption properties in the UV-Vis range were improved. Furthermore, the application of the CFSs increased: the solubility (64.91%), the antimicrobial activity against S. aureus (6.55 mm) and E. coli (8.25 mm), as well as the antioxidant activity (57.71% and 24.57% free radical scavenging activity), and the content of total phenols (2.45 mg GAE/g). Finally, our results suggest that the BC-CH films developed in the present study show a potential application as active packaging material for food.

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.

Scale-up of a lead dioxide (PbO2) anode system is significant to the practical application of electrochemical oxidation (EO) in biorefractory wastewater treatment. In this study, response surface methodology (RSM) was employed to investigate the effects of different operating conditions on phenol removal by electro-oxidation with a Ti/PbO2 anode. A central composite design (CCD) was used to optimize the electro-oxidation process and to evaluate the individual and interactions effects of current intensity, electrolysis time, and recirculation flow rate on phenol removal. Synthetic wastewater (or distillate water) with phenol concentration of 10 mg/L−1 was used in this study. Optimal conditions for phenol removal were established at 1.12 A current intensity, 40 min electrolysis time, and 188 mL·min−1 recirculation flow rate, in which a removal of 78.97±1.72% was achieved. The decay kinetics of phenol removal was fitted a first-order reaction.

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 wastewaters of nejayote and food waste leachate are polluting effluents with a high load of organic matter that cause great problems when discharged to water receptors. In this work, we investigated the treatment of nejayote wastewaters and food waste leachate for the production of microalgae Scenedesmus acutus and Haematococcus pluvialis. For Scenedesmus acutus, treatment with 10% food waste leachate and 90% growth medium resulted in a concentration of 5.34 g/L in 20 days (μmax = 0.16/day). Meanwhile, 10% nejayote and 90% medium growth produced 4.45 g/L at 20 days (μmax = 0.13/d). A significant reduction of up to 82.6% ammonium, 84.1% orthophosphate, and 87.25% COD was also observed between the different treatments. For Haematococcus pluvialis, the treatment of 90% food waste leachate and 10% growth medium produced a concentration of 4.73 g/L at 6 days (μmax = 0.71/day), while the mixture of 25% najayote, 25% food waste leachate, and 50% growth medium produced a concentration of 5.5 g/L at 20 days (μmax = 0.25/dat). A reduction of up to 97.8% ammonia, 97.4% orthophosphate, and 73.19% COD was also recorded. These findings demonstrated the potential to cultivate microalgae and extract biomolecules for commercial purposes.

The application and design of treatment systems in wastewater are necessary due to antibiotics' potential toxicity and resistant genes on residual effluent. This work evaluated a coupled bio-electrochemical system to reduce chloramphenicol (CAP) and chemical oxygen demand (COD) on swine wastewater (SWW). SWW characterization found CAP of 99.99%, respectively. This coupled system can be applied to eliminate antibiotics and other organic pollutants in agricultural, industrial, municipal, and other wastewaters.