Wastewater chemical contaminants: remediation by advanced oxidation processes

• Published in: Photochemical & photobiological sciences 2018-11, Vol.17 (11), p.1573-1598
• Main Authors: Bartolomeu, M, Neves, M. G. P. M. S, Faustino, M. A. F, Almeida, A
• Format: Article
• Language: English
• Subjects: Agricultural wastes; Agrochemicals; Antibiotics; Biochemistry; Biological activity; Biomaterials; Chemical pollutants; Chemical pollution; Chemistry; Contaminants; Endocrine disruptors; Eutrophication; Grease; Halogenated compounds; Halogenated hydrocarbons; Heavy metals; Microorganisms; Organic chemistry; Oxidation; Pesticides; Phthalates; Physical Chemistry; Plant Sciences; Pollutants; Pollution control; Polyaromatic hydrocarbons; Polycyclic aromatic hydrocarbons; Receiving waters; Remediation; Scum; Sediments; Terrestrial environments; Urban agriculture; Wastewater pollution; Wastewater treatment; Water resources; Water reuse; Water scarcity; Water stress; Water treatment
• ISSN: 1474-905X; 1474-9092
• DOI: 10.1039/c8pp00249e

Approximately 70% of the terrestrial area is covered with water, but only a small water fraction is compatible with terrestrial life forms. Due to the increment in human consumption, the need for water resources is increasing, and it is estimated that more than 40% of the population worldwide will face water stress/scarcity within the next few decades. Water recycling and reuse may offer the opportunity to expand water resources. For that, the wastewater treatment paradigm should be changed and adequately treated wastewater should be seen as a valuable resource instead of a waste product. It is easily understandable that the exact composition and constituent concentration of wastewater vary according to its different sources (industrial, agricultural, urban usage of water). Consequently, a variety of known and emerging pollutants like heavy metals, antibiotics, pesticides, phthalates, polyaromatic hydrocarbons, halogenated compounds and endocrine disruptors have been found in natural water reservoirs, due to the limited effectiveness of conventional wastewater treatment. The conventional approach consists of a combination of physical, chemical and biological processes, aiming at the removal of large sediments such as heavier solids, scum and grease and of organic content in order to avoid the growth of microorganisms and eutrophication of the receiving water bodies. However, this approach is not sufficient to reduce the chemical pollutants and much less the emerging chemical pollutants. In this review, after some considerations concerning chemical pollutants and the problematic efficiency of their removal by conventional methods, an update is presented on the successes and challenges of novel approaches for wastewater remediation based on advanced oxidation processes. An insight into wastewater remediation involving the photodynamic approach mediated by tetrapyrrolic derivatives will be underlined. A review on novel approaches for wastewater remediation based on advanced oxidation processes (AOPs), including the photodynamic approach mediated by tetrapyrrolic derivatives.