An Italian seafood factory processing frozen fish and fresh clams was investigated. Specific water consumption (SC) and pollutant emission factors (EF) are evaluated. Results evidence high SC values, in the range 18-74 1/Kg, due to defrost and extensive washing and cleaning practised; EFs appear high although not directly comparable with data reported by other authors. Two high-rate trickling filters, cross flow (CF) and vertical flow (VF), are examined over a two years period. Results suggest a pseudo half-order kinetic reaction with a superior performance of CF plastic media. From the elaboration of the experimental data a semiempirical correlation between specific surface removal (SSR) and operative parameters is obtained.