Book Review: Advances in Biodegradation and Bioremediation of Industrial Waste

After the treatment of wastewater coming from textile industry from and an industrial estate by different Advanced Oxidation Technologies (AOTs), was possible to determine that the most effective treatment processes were Photo-Fenton 2 (𝐹𝑒0/𝐻2𝑂2) for the textile industry effluents and the combination of TiO2/H2O2/UV-Vis for industrial estate wastewater. Photo-Fenton 2 (𝐹𝑒0/𝐻2𝑂2) exhibited superior performance in the mineralization of organic compounds, leading to remove azo dyes, ions such as 𝐶𝑙−,𝑁𝑂3−,𝑆𝑂42−, and heavy metals, which is due to the synergistic effects of both, homogeneous and heterogeneous photocatalysis. On the other hand, 𝑖𝑂2/𝐻2𝑂2/𝑈𝑉 −𝑉𝑖𝑠 was more efficient for heavy metals removal and the ions previously mentioned, as well as, for the mineralization of organic compounds present in the effluents of the industrial estate. Subsequently, in order to determine the intermediaries produced after the treatment 𝐹𝑒0/𝐻2𝑂2 applied to textile wastewater, HPLC analysis were carried out; and was possible to identify the formation of short-chain organic acids, the amount of those compounds were not more toxic than the original compounds, thus indicaticating the suitability of these treated waters to be recycled in agricultural activities. During the Photo-Fenton 2 treatment was observed the formation of a sludge, this remaining material was analyzed by XRD which indicated the transitioning of the sludge from a cubic structure to an amorphous phase and hematite, which was confirmed by Raman spectroscopy. By XPS analysis, was identified the presence of N, Cl, Na, Si, O, C, and Fe in the sludge, thus indicating the precipitation of pollutants and the oxidation of some elements like Fe, which is determinant for the cycle of Fenton reaction. Besides by UV-Vis DRS analysis was demonstrated that the recovered sludge has a band gap of 1.75 eV, which indicates that probably, this residual material could have photocatalytic activity for further applications. During the analysis of the potential residual pollution in soil and Lolium Perenne crop irrigated with treated textile, industrial, and river water, no significant differences of heavy metals residuality were noticed compared with the results observed when the irrigation was carried out with tap water. However, the crop irrigated with treated wastewater from the industrial estate xi showed necrosis, which is associated to high concentrations of 𝐻2𝑂2 during the treatment. In addition, the plants exhibited yellow coloration after irrigation with the Photo-Fenton 2 treated water, then the vegetable specie recovered its original color due to the iron excess in the aqueous phase being absorbed by the plants. In contrast, after the irrigation with treated river water did not result in necrosis or coloration changes in the plants. Nonetheless, although the wastewater treated not fully compliant with Colombian regulations of the Ministerio de Ambiente y Desarrollo Sostenible Resolution 1207 of 2014, which indicated the use for treated wastewaters, this proved to be suitable for irrigating Lolium Perenne, except those of the industrial estate treated by 𝑖𝑂2/𝐻2𝑂2/𝑈𝑉 −𝑉𝑖𝑠. To achieve a better comprehension of the behavior observed in the application of Photo-Fenton 2 treatment, a kinetic study was also developed. In this stage of the work, AO7 dye was selected as target molecule, and the effectiveness of different concentration of 𝐻2𝑂2 in the process was also studied. Thus, it was determined that a concentration of 0.05M peroxide led to achieve 95% of AO7 dye mineralization in simulated water sample. Besides, to know the reaction mechanism, an analysis with scavengers was also performed highlighted the essential roles played by holes, hydroxyl radicals, an electron within the reaction process due to without them, the reaction is avoided the AO7 removal efficiency about a 40%, 15% and 10%, respectively. Furthermore, the influence of ions presents previously mentioned in the wastewater was also analyzed, indicating that these are primarily responsible for developing the reaction; in its absence, the reaction proceeds at only 10% of its efficiency. As additional contributions of this research, it is possible to enlist: a short research stay at University of Salerno in Italy, as a contribution of scientific agreement between UPTC and UNISA; a scientific article submitted to a scientific journal, and two presentations in national and international scientific events focused on water treatment.