## 1 Introduction
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**CEC Class** & **Example Compound** & **Definition/Use** \\ \hline Antibiotics & Tetracycline, Erythromycin & Medication. Inhibits or stops bacterial growth \\ \hline Antimicrobials & Tridosan & Biochemical. Kill/inhibit microorganisms, incl. bacteria and fungi \\ \hline Detergent metabolites & Nonylphenol & Chemical, formed by break-down of detergents by WW treatment of environmental processes \\ \hline Disinfectants & Alcohols, Aldehydes, oxidizing agents & Chemicals used on non-living surfaces to destroy/ neutralize/inhibit growth of disease-causing microorganisms. \\ \hline Disinfection By-Products (DBPs) & Chloroform, Nistrosodimethylamine (NDMA) & Chemicals resulting from interaction of organic matter with disinfection agents (e.g., chloride) in water \\ \hline Estrogenic Compounds & Estrone, Estradiol, Nonylphenol, Bisphenol A & Natural/synthetic chemicals that can elicit an estrogenic response \\ \hline Explosives & TNT, RDX & TNT (2,4,6-trinitrotoluene), best known as an explosive material, is sometimes used also as reagent in chemical synthesis. RDX (cyclo trimethylenetrintramine) is also a powerful explosive often used in mixtures with plasticizers \\ \hline Fire and Flame retardants & Polybrominated Diphenyl & Coatings that inhibit/resist the spread of fire \\ \hline Fragrances & Galaxolide & Chemicals imparting sweet or pleasant odor \\ \hline Insect repellents & DEET & Chemicals applied to skin or other surfaces to repel insects from that surface \\ \hline PAHs (Poly-aromatic hydrocarbons) & Benzo(a)pyrene, Fluoranhene, Naphthalene & Chemical substances found in environment as result of incomplete burning of carbon-containing materials (fossil fuels, wood, garbage, etc.) \\ \hline Personal Care Products (PCPs) & Para-hydroxybenzoate & Chemicals used in many personal items including toiletries and cosmetics \\ \hline Per-and poly-fluoroalkyl substances & PFASs, PFOSs and PFOAs & Used in emulsion polymerization to produce fluoropolymers, characterized by high resistance to solvents, acids, and bases (e.g., polytetrafluoro-ethylene, commercially known as Teflon). \\ \hline Pesticides and insecticides & Permethrin, Fenitrothon, Bacillus thuringiensis israelensis (B.t.i.) & Chemical substances/microbiological agents that kill/incapacitate/prevent pests from causing damage \\ \hline Pharmaceuticals & Fluoxetine (Prozac), Carbamazepine, Diphenylydramine & Chemicals used in the prevention/treatment of physiological conditions \\ \hline Plasticizers & Dicotyl Phthalate & Additives that increase plasticity or fluidity of materials \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Common CEC classes (elaborated from [4]). Most currently used water and wastewater process technologies, including state-of-the-art advanced oxidation processes (AOPs), have some, and occasionally significant, technological drawbacks: Almost all require extended process time (up to several hours) to achieve destruction of contaminants and often they require costly addition of chemicals or catalyzers to enhance treatment performance. This paper presents a review of some of the most common AOP process technologies used for the removal of emerging contaminants from water and wastewater, and introduces discussion about two lesser-known classes of processes, advanced reduction processes (ARPs) and advanced oxidation-reduction processes (AORPs), that may offer a similar or better performance than the former.