The aim of this paper is the study of a sustainable process for the treatment of urban wastewater able to reduce surfactant concentrations close to the back-ground levels or, at least, lower than the values allowed by law for a reuse in agriculture. The considered process is based on the adsorption of surfactants (water diluted) on commercial iron oxide powders and their removal in a magnetic filtration system. The powders of hematite and magnetite used have a diameter of 0.5 µm, 1 µm. 5 µm, respectively; they are non-toxic for humans and the environment and they have a relatively low cost. The removal of surfactants on a laboratory scale at concentrations in the wastewater range (0.2 mg/l - 4.2 mg/l) was studied applying the treatment on pure surfactants, mixtures of pure surfactants and detergents. With regard to the adsorption on magnetite, despite the large quantity of powder required (17-51 g/l), the tests led to positive results for cationic surfactants (up to 90% of removal) and relatively good for the anionic (up to 20%) and non ionic ones (up to 40%). Adsorption on hematite has shown encouraging results with regard to all surfactants (from 50% to higher than 90% of removal) with a much lower amount of powder required (1-17 g/l). In all cases the adsorption took 10 minutes and the magnetic separation of the iron oxides was fully achieved after 10 minutes of filtration.

Magnetic removal of surfactants from wastewater using micrometric iron oxide powders

BORGHI, CHIARA CATERINA;FABBRI, MASSIMO;FIORINI, MAURIZIO;MANCINI, MAURIZIO;RIBANI, PIER LUIGI
2011

Abstract

The aim of this paper is the study of a sustainable process for the treatment of urban wastewater able to reduce surfactant concentrations close to the back-ground levels or, at least, lower than the values allowed by law for a reuse in agriculture. The considered process is based on the adsorption of surfactants (water diluted) on commercial iron oxide powders and their removal in a magnetic filtration system. The powders of hematite and magnetite used have a diameter of 0.5 µm, 1 µm. 5 µm, respectively; they are non-toxic for humans and the environment and they have a relatively low cost. The removal of surfactants on a laboratory scale at concentrations in the wastewater range (0.2 mg/l - 4.2 mg/l) was studied applying the treatment on pure surfactants, mixtures of pure surfactants and detergents. With regard to the adsorption on magnetite, despite the large quantity of powder required (17-51 g/l), the tests led to positive results for cationic surfactants (up to 90% of removal) and relatively good for the anionic (up to 20%) and non ionic ones (up to 40%). Adsorption on hematite has shown encouraging results with regard to all surfactants (from 50% to higher than 90% of removal) with a much lower amount of powder required (1-17 g/l). In all cases the adsorption took 10 minutes and the magnetic separation of the iron oxides was fully achieved after 10 minutes of filtration.
C. C. Borghi; M. Fabbri; M. Fiorini; M. Mancini; P. L. Ribani
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11585/106407
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 47
  • ???jsp.display-item.citation.isi??? 40
social impact