Earthy/musty odour bioaccumulation in Plecoglossus altivelis grown in a land-based aquaculture fed by reclaimed secondary effluent in wastewater treatment plant

Reclaimed wastewater (RWW) has been used globally for centuries, though its application in aquaculture is less extensive. Limited study has addressed impacts of RWW-derived volatile odour compounds (VOCs), such as 2,4,6-trichloroanisole (TCA), 2-methylisoborneol (MIB), and geosmin (GSM), on fish quality. This study aims to (1) assess the feasibility of reusing secondary effluent from a municipal wastewater treatment plant (WWTP) for Plecoglossus altivelis aquaculture in a land-based flow-through system and (2) evaluate the sensory effects of selected VOCs on fish quality. Results showed that increased temperature and ammonia levels in summer RWW negatively affected fish growth, while autumn RWW did not. Heavy metals in fish did not cause health issues. TCA, MIB, and GSM concentrations in fish tissues were 4.7–5.7, 0.3–40.5, and 1.1–1.9 mg kg−1, respectively. TCA emerged as the most concerning odorant, with higher relative odour intensity than MIB and GSM in RWW-cultured fish, regardless of seasonal change. This study is the first to report on a self-constructed aquaculture system using RWW at a WWTP, recommending effective VOC and ammonia removal for sustainable RWW use in aquaculture. Additionally, the study highlighted TCA's impact as an anthropogenic indicator in aquatic environments amid increasing WWTP prevalence in developed cities.