Primary filtration of municipal wastewater with sludge fermentation – Impacts on biological nutrient removal
Artikel i vetenskaplig tidskrift, 2023

Primary filtration is a compact pre-treatment process for municipal wastewater, which can lead to high removal of total suspended solids (TSS) if polymer is added prior to filtration. Extensive carbon removal with rotating belt filter (RBF) can be combined with filter primary sludge fermentation at ambient temperature, in order to produce volatile fatty acids (VFAs) as carbon source for biological nutrient removal (BNR). This process was implemented at large pilot-scale and operated for more than a year. The results showed that the RBF efficiently removed particles >10 μm, and that the TSS removal had a strong linear correlation to the influent TSS concentration. Fermentation of the sludge at ambient temperature and five days retention time and addition of the fermentate to the wastewater could nearly double the VFA concentration in the wastewater by adding 31 ± 9 mg VFA-COD/L. Meanwhile, an increase of 2 mg/L of ammonium nitrogen, and 0.7 mg/L of phosphate phosphorus would be added to the wastewater with the fermentate. Adding the fermented sludge to the wastewater stream and removing the particles with RBF makes it possible to utilize nearly all the produced VFAs for BNR, and the feasibility of this configuration was shown at pilot-scale. According to simulations of subsequent BNR, the pre-treatment would lead to lower effluent total nitrogen concentrations. Alternatively, the required BNR volume could be reduced by 11–18 %. The estimated total biogas production was similar for pre-treatment with primary settler and RBF with fermentation. RBF without fermentation gave the most favourable energy balance, but did not reach the same low effluent value for total nitrogen as RBF with fermentation.

Benchmark simulation model no 1FermentationHydrolysisEnergy balancePrimary sludgeRotating belt filter

Författare

Elin Ossiansson

Chalmers, Arkitektur och samhällsbyggnadsteknik, Vatten Miljö Teknik

Simon Bengtsson

VA SYD

Frank Persson

Chalmers, Arkitektur och samhällsbyggnadsteknik, Vatten Miljö Teknik

Michael Cimbritz

Lunds universitet

David J. I. Gustavsson

Sweden Water Research

VA SYD

Science of the Total Environment

00489697 (ISSN) 18791026 (eISSN)

Vol. 902 166483

Idealt KolUtnyttjande (ICU) på avloppsreningsverk - förfiltrering och fermentering

Svenskt Vatten (19-112), -- .

Naturvårdsverket (NV-02084-18), -- .

Drivkrafter

Hållbar utveckling

Ämneskategorier

Vattenteknik

Vattenbehandling

DOI

10.1016/j.scitotenv.2023.166483

PubMed

37611717

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Senast uppdaterat

2023-09-07