Comparison of effluent organic matter from parallel activated sludge and integrated fixed-film activated sludge (IFAS) processes

The non-targeted ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR MS) technique can provide a detailed chemical characterization of wastewater effluent organic matter (EfOM) that is essential to the understanding of dynamics and treatment efficiency during treatment. Samples were collected from parallel and independently operating full-scale activated sludge process (ASP) and the integrated fixed-film activated sludge (IFAS) system treating the same wastewater influent. The flow in the IFAS system had doubled flow of the ASP. The FT-ICR MS results for these samples demonstrated that, due to the doubled flow of IFAS, the transformation of organics was delayed in the early stages of the IFAS compared to ASP. However, both treatment trains had similar chemical composition at the end of the treatment. The data also showed that the chemical molecular complexity and diversity increased at the end of the treatment although the COD was removed as expected.