Removal of pathogen indicators from secondary effluent using slow sand filtration: Optimization approaches

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Eva M. Seeger - , Helmholtz-Zentrum für Umweltforschung (UFZ) (Autor:in)
  • Mareike Braeckevelt - , Professur für Siedlungswasserwirtschaft, Helmholtz-Zentrum für Umweltforschung (UFZ) (Autor:in)
  • Nils Reiche - , Helmholtz-Zentrum für Umweltforschung (UFZ) (Autor:in)
  • Jochen A. Müller - , Helmholtz-Zentrum für Umweltforschung (UFZ) (Autor:in)
  • Matthias Kästner - , Helmholtz-Zentrum für Umweltforschung (UFZ) (Autor:in)

Abstract

In many arid regions, the reuse of wastewater is an economic option for crop irrigation. To avoid health risks for consumers, pathogens must be eliminated prior to application. Slow sand filtration (SSF) represents an effective low-tech treatment technology for pathogen removal from water. To further improve the time-space yield of SSF, innovative filter configurations were investigated regarding the removal of the pathogen indicators Escherichia coli, enterococci, Clostridium perfringens spores, somatic and F-specific RNA coliphages as well as heterotrophic bacteria. A standard filter (N), a recirculating filter (R), a static cascade (N + N) and a rotating cascade (C) were tested at high and low hydraulic loading rates, two recirculation rates and two rotation frequencies. Results showed that only C and N + N concurrently complied with European standards for E. coli and enterococci, achieving mean log removal of 2.7-4.7 and 2.1-2.4, respectively. The best performance was reached by C with weekly rotation; N + N may be a promising, technically simpler alternative. The crucial role of biological removal mechanisms for E. coli and enterococci elimination was indicated by (i) the increased efficiency of the standard SSF N after 1½ years of operation and (ii) the positive impact of several Schmutzdecke layers. C. perfringens spore removal performance was good for all SSFs. Considerable sorption of spores was indicated by decreased efficiency in N and C at long operation times. Somatic coliphages were reduced to concentrations close to the detection limit, while F-specific RNA coliphage removal was ∼1.1 log. Removal of heterotrophic bacteria was generally limited.

Details

OriginalspracheEnglisch
Seiten (von - bis)635-644
Seitenumfang10
FachzeitschriftEcological engineering
Jahrgang95
PublikationsstatusVeröffentlicht - 1 Okt. 2016
Peer-Review-StatusJa

Externe IDs

ORCID /0009-0001-5656-0053/work/145224067

Schlagworte

Ziele für nachhaltige Entwicklung

Schlagwörter

  • Bacteriophages, Clostridium perfringens, Enterococci, Escherichia coli, Schmutzdecke, Wastewater reuse