The use of an algal bioindicator in the assessment of different chemical remediation strategies for PAH-contaminated soils and sediments

ROTONDO LEANDRO; MORA VERÓNICA; TEMPORETTI PEDRO; BEAMUD GUADALUPE; PEDROZO FERNANDO

Journal of Environmental Chemical Engineering

Elsevier Ltd

Año: 2023 vol. 11

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous petroleum-derived pollutants that tend to accumulate in soils and sediments. Among the in situ chemical oxidation technologies applied at PAH-contaminated sites are Fenton reagent (FN), persulfate ion (PS) and permanganate ion (PM). The natural phytoplankton of an aquatic environment is useful as a biological indicator of the treatment effiacy of pollutant degradation. The objective ofthis work was to assess the use of an algal species, native from Los Barreales Reservoir (Argentina), as an effiacy indicator of the chemical remediation of PAH-contaminated soils and sediments. Oxidations with FN, PS or PM were carried out on soils and sediments previously contaminated with two types of PAHs (phenanthrene (Ph) or Benzo(a)anthracene (Ba)), analysing pH, residual oxidant, PAH degradation and heterotrophic bacteria abundance in soils or sediments after 7 days. Then, a bioassay was carried out by incubating the obtained soils or sediments, and the native alga Scenedesmus quadricauda (Turpin, Br´ebisson), analysing its abundance after 7 days. S. quadricauda abundance was related to PAH degradation effiacy, residual oxidants and changes in system pH. In this sense, the application of PS produced the lowest growth of the indicator in assays both withsoils and sediments. Fenton reaction results varied depending on the contaminating PAH, with the best percentages of PAH degradation and growth of S. quadricauda for Ba. PM oxidation resulted in the best development of the indicator. This study constitutes a fist approach to the use of S. quadricauda as an effiiency indicator of soil/sediment chemical remediation.