Textile wastewater is widely produced and its discharge without treatment contributes to environmental pollution. The adsorption process is a suitable and eco-friendly process due to its low initial cost, no formation of degradation products, operation simplicity, insensitivity to toxic compounds, and the possibility of removal from greatly diluted solutions. Orange seed (OS) powder, from which lipids were removed by hexane extraction, was evaluated as a bio-adsorbent to remove dyes from real textile wastewater. In the screening step, pH was a more significant variable (p-value < 0.05) than bio-adsorbent dosage, temperature, stirring speed, and process time. Moreover, under optimized conditions (pH = 2.6, 0.58 g/L from OS powder and 26 °C), more than 95% of the dye was removed from real textile wastewater. Additionally, the dye removal percentage was reduced by only 4% when the volume of textile wastewater was increased from 0.05 L to 10 L. Then, 96% turbidity was removed using a 3 µm tubular ceramic membrane at a pH of 11. Furthermore, the permeate flux through the membrane was kept constant for longer than was observed at low pH (<11). Therefore, the proposed process is an interesting option, due to the fact that orange seeds are currently not valorized and, combined with the membrane process, this could prove a suitable option for the treatment of real textile wastewater.

Rubber is a natural product, the main car tire component. Due to the characteristics acquired by this material after its vulcanization process, its degradation under natural conditions requires very long times, causing several environmental problems. In the present work, the existence of a bacterial consortium isolated from a discarded tire found within the Socabaya River with the ability to degrade shredded tire rubber without any chemical pretreatment is explored. Taking into consideration the complex chemical composition of a rubber tire and the described benefits of the use of pretreatments, the study is developed as a preliminary analysis. The augmentative growth technique was used, and the level of degradation was quantified as a percentage through the analysis of microbial respiration. Schiff’s test and the use of comparative photographs of scanning electron microscopy (SEM) were also used. The consortium using next generation genetic sequencing was analyzed. A 4.94% degradation point was obtained after 20 days of experimentation, and it was found that the consortium was mostly made up with Delftia tsuruhatensis with 69.12% of the total genetic readings of the consortium and the existence of 15% of unidentified microbial strains at the genre level. The role played by the organisms in the degradation process is unknown. However, the positive results in the tests carried out show that the consortium had action on the shredded tire, showing a mineralization process.

Water is a finite resource. Its safety and cleanliness are highly important to meet current and future human needs. Compared to other resources, water represents a main factor to achieve development in several areas and leads to reach economic progress of a nation. However, in recent years, the excessive demographic and industrial growth has exacerbated water contamination. In this study, biodepuration process of domestic sewage (DS), textile effluents (TE) and acid mine drainage (AMD) is conducted using starch-based xerogel (XG) from potato (Solanum tuberosum) peels. Results showed that the treatment is effective to achieve the reduction of 5-day biochemical oxygen demand (BOD₅). The most important result was the achievement of heavy metals removal for the three components. Firstly, there was a reduction of barium, zinc, and cadmium (91, 60 and 46%, respectively) for raw AMD. Secondly, there was a reduction in the levels of zinc, aluminum, and barium (89, 86 and 64%, respectively) for TE biodepuration. Finally, results showed a reduction in zinc, iron and cadmium levels (81, 78 and 57%, respectively) for DS biodepuration.

Cattle slaughtering produce large amounts of wastewater containing high concentrations of organic matter and nutrients and requires significant treatment before disposal or reutilization. However, the nutrients contained can be valued as a medium for microalgal biomass generation. In this work, hydrodynamic cavitation (HC) followed by membrane filtration or biological (microalgae cultivation) treatment in continuous mode were performed. From cattle slaughterhouse wastewater (CSW), by the effect of HC treatment with air injection in batch mode, more than 20% of the chemical oxygen demand (COD) was removed. In a continuous HC process, the COD content in output was 324 mg O₂/L, which is 68% lower than the supplied CSW. After that, 76% of residual COD was removed by filtration through a tubular alumina membrane (600 nm). Finally, 85% of residual COD after HC treatment in 24 h in a batch mode was removed by microalgae. On the other hand, the COD concentration in the output was around 59 mg O₂/L in continuous mode, which represents 85–93% COD removal. The process involving HC and microalgae growing looks promising since in addition to water treatment, the microalgae produced could be valued in a biorefinery concept.

El arsénico es un elemento natural presente en el medio ambiente tanto en formas orgánicas como inorgánicas, siendo el arsénico inorgánico el más tóxico. El objetivo de la presente investigación fue cuantificar el arsénico presente en aguas subterráneas y muestras de suelo e identificar el impacto en los suelos agrícolas de la cuenca del río Callacame. En el caso de las aguas subterráneas se tomaron en cuenta 32 puntos de muestreo y en el caso de suelo 4 puntos de muestreo. Se colectaron y prepararon las muestras para su posterior análisis con la metodología EPA 6020 utilizando un ICP-MS, adicionalmente se tomaron parámetros fisicoquímicos de pH, CE, STD y ORP, Fe, Mg, Na y K. Los resultados mostraron concentraciones de arsénico en aguas subterráneas del orden de 3 a 446 ug/L, en suelos de 10 a 42,7 mg/Kg. En el caso de agua subterránea existieron 4 puntos que sobrepasaron los estándares de calidad ambiental para el país de origen de las muestras (Perú), en el caso de suelo no hubo concentraciones que sobrepasen los estándares de calidad ambiental por lo que se determinó que actualmente no representan un impacto ni riesgo ambiental o hacia la salud. Sin embargo, se concluyó que en un futuro si no se cuenta con la vigilancia adecuada pueden darse pie a procesos de bioacumulación y biomagnificación producto del riego de suelos con aguas subterráneas contaminadas con arsénico.