Assessment of compost for bioremediation of polyaromatic hydrocarbon (pah) and petroleum hydrocarbon soils

• Autor(a) principal: Ferrari, Diana Noemi Guillen
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Texto Completo: http://hdl.handle.net/10400.1/10159
• topic: Biorremediação; Composto; Alk B; PAH RHD GN; PAH RHD GP; Alcanos; HAPs; qPCR

Bioremediation of petroleum and polyaromatic hydrocarbon (PAH) contaminated soils can be a cost effective and efficient treatment approach. The introduction of organic amendments which can provide available nitrogen, and potentially additional microorganisms, can contribute to improve the biodegradation process. However, little work has considered which organic amendments are best in terms of their relative abundance of degraders for specific pollutants. In this work, green waste (GW) composts of different stability were assessed for their bioremediation potential. Twelve compost samples were characterised for parameters including stability (using a modified set up validated in this project), culturable microbial Pseudomonas and Actinomycetes plate counts and degradative gene (alkB, PAH-RHD GP and PAH-RHD GN) abundance. These are important for the degradation of alkanes and PAH respectively. Comparing finished and un-finished green compost from the same site, results showed that the abundance of alkB (encoding alkane monooxygenase) was highest in the less stable compost samples, which corresponds with the higher Pseudomonas counts. Similar results were obtained for PAH-RHD GN (encoding Polycyclic Aromatic Hydrocarbon-Ring Hydroxylating Dioxygenase in Gram negative bacteria), the less stable samples presented higher abundance of degrading genes. For PAH-RHD GP (encoding Polycyclic Aromatic Hydrocarbon-Ring Hydroxylating Dioxygenase in Gram positive bacteria) abundance, it was not possible to see a clear difference between finished and un-finished samples. Given that less stable composts tend to have higher available N this would support the use of these composts for bioremediation of aliphatic petroleum hydrocarbon and Poly aromatic hydrocarbon contaminated soils.