Abstract
<title>Abstract</title> <p>Water scarcity affects more than 2.7 billion people worldwide, highlighting the need to identify alternative water sources such as greywater (GW), which represents a potential resource for domestic use. In this study, a domestic-scale hybrid electrochemical reactor combining electrocoagulation (EC) and anodic oxidation (AO) was fabricated and evaluated for the treatment of real household GW. The reactor performance was investigated by varying the active electrode area using three configurations (140, 280, and 420 cm²), referred to as single (SCE), double (DCE), and triple (TCE) electrochemical treatments. The TCE configuration was identified as the optimal operating condition, achieving maximum removals of turbidity (95.3%), chemical oxygen demand (COD, 67.9%), and biochemical oxygen demand (BOD₅, 67.9%) within 2.5–4 h of treatment, while reducing the energy consumption per cubic meter of treated water by 58% compared to the SCE configuration. Identified degradation by-products included monoterpenes/terpenoids, aromatic esters, substituted phenols, and aliphatic ester-containing carboxylic acids. Finally, kinetic parameters and models were developed to enable scaling of the reactor to different sizes. This work demonstrates the simultaneous application of anodic oxidation and electrocoagulation in a single system pilot plant, opening new opportunities for implementation in decentralized GW treatment plants.</p>