These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Potential of biochar filters for onsite wastewater treatment: Effects of active and inactive biofilms on adsorption of per- and polyfluoroalkyl substances in laboratory column experiments.
    Author: Dalahmeh SS, Alziq N, Ahrens L.
    Journal: Environ Pollut; 2019 Apr; 247():155-164. PubMed ID: 30669083.
    Abstract:
    This study investigated the potential of biochar filters as a replacement for, or complement to, sand filters for removal of per- and polyfluoroalkyl substances (PFASs) from wastewater in on-site wastewater treatment systems (OWTSs). Concentrations and removal of nine perfluoroalkyl carboxylates (PFCAs; C3-11) and three perfluoroalkane sulfonates (PFSAs; C4, 6, 8) and one perfluorooctanesulfonamide (FOSA; C8) were investigated over 22 weeks in four treatments with column filters: biochar (BC) without biofilm (BC-no-biofilm), biochar with active biofilm (BC-active-biofilm), biochar with inactive biofilm (BC-inactive-biofilm) and sand with active biofilm (Sand-active-biofilm). The filters were operated under hydraulic loading (50 L m-2 day-1) to mimic the loading rate in on-site filtration beds. The initial concentrations of the ΣPFASs in the influent were in the range of 1500-4900 ng L-1. In BC-no-biofilm, the removal efficiency (20-60%) and adsorption capacity (0-88 ng ΣPFASs g-1 BC) of short-chain PFCAs (C3-6) and PFSA (C4) was low, whereas the removal efficiency (90-99%) and the adsorption capacity (73-168 ng g-1) was high for C7-C11 PFCAs, C6, C8 PFSAs and FOSA. The relative removal was generally lower for C3-9 PFCAs and C4, C6, C8 PFSAs using BC-active-biofilm and BC-inactive-biofilm compared with BC-no-biofilm. This can be explained by the presence of biofilm and solids in BC-active-biofilm and the presence of wastewater solids in BC-inactive-biofilm, which decreased the availability and number of adsorption sites for PFASs compared with BC-no-biofilm. On the other hand, inactivation of the biofilm resulted in lower removal efficiencies for C5-11 PFCAs, C4, C6, C8 PFSAs and FOSA, probably because the biofilm degraded organic matter and thus increased the availability and number of adsorption sites compared with BC-inactive-biofilm. Sand-active-biofilm showed poor removal (0-70%) for all PFASs except FOSA (90%) and its adsorption capacity was low (0.0-7.5 ng g-1). In general, for all biochar treatments, shorter-chain PFASs were more resistant to removal than longer-chain PFASs. In addition, C4, C6 and C8 PFSAs showed 10-30%, 10-50% and 20-30% higher average removal efficiency, respectively, than PFCAs with corresponding perfluoroalkyl chain length. In conclusion, biochar is a promising filter medium for removal of PFASs in OWTSs, especially for PFASs with a perfluorocarbon chain longer than C6.
    [Abstract] [Full Text] [Related] [New Search]