title: Polyhydroxyalkanoate as a slow-release carbon source for in situ bioremediation of contaminated aquifers: From laboratory investigation to pilot-scale testing in the field.
abstract: A pilot-scale study aiming to evaluate the potential use of poly-3-hydroxy-butyrate (PHB) as an electron donor source for in situ bioremediation of chlorinated hydrocarbons in groundwater was conducted. Compared with commercially available electron donors, PHB offers a restricted fermentation pathway (i.e., through acetic acid and molecular hydrogen) by avoiding the formation of any residual carbon that could potentially spoil groundwater quality. The pilot study was carried out at an industrial site in Italy, heavily contaminated by different chlorinated aliphatic hydrocarbons (CAHs). Prior to field testing, PHB was experimentally verified as a suitable electron donor for biological reductive dechlorination processes at the investigated site by microcosm studies carried out on site aquifer material and measuring the quantitative transformation of detected CAHs to ethene. Owing to the complex geological characteristics of the aquifer, the use of a groundwater circulation well (GCW) was identified as a potential strategy to enable effective delivery and distribution of electron donors in less permeable layers and to mobilise contaminants. A 3-screened, 30-m-deep GCW coupled with an external treatment unit was installed at the site. The effect of PHB fermentation products on the in situ reductive dechlorination processes were evaluated by quantitative real-time polymerase chain reaction (qPCR). The results from the first 4 months of operation clearly demonstrated that the PHB fermentation products were effectively delivered to the aquifer and positively influenced the biological dechlorination activity. Indeed, an increased abundance of Dehalococcoides mccartyi (up to 6.6 fold) and reduced CAH concentrations at the installed monitoring wells were observed.
authors.affiliation: Department of Chemistry "Stanislao Cannizzaro", Sapienza University of Rome, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Pierro
authors.affiliation: Water Research Institute-National Research Council, IRSACNR, Monterotondo, Italy.
authors.forename: Bruna
authors.initials: B
authors.lastname: Matturro
authors.affiliation: Water Research Institute-National Research Council, IRSACNR, Monterotondo, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Rossetti
authors.affiliation: EDF-Fenice SpA, Torino, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Sagliaschi
authors.affiliation: EDF-Fenice SpA, Torino, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Sucato
authors.affiliation: IEG Technologie GmbH Gruibingen, Germany.
authors.forename: Eduard
authors.initials: E
authors.lastname: Alesi
authors.affiliation: IEG Technologie GmbH Gruibingen, Germany.
authors.forename: Ernst
authors.initials: E
authors.lastname: Bartsch
authors.affiliation: Department of Chemistry "Stanislao Cannizzaro", Sapienza University of Rome, Italy.
authors.forename: Firoozeh
authors.initials: F
authors.lastname: Arjmand
authors.affiliation: Department of Chemistry "Stanislao Cannizzaro", Sapienza University of Rome, Italy. Electronic address: marco.petrangelipapini@uniroma1.it.
authors.forename: Marco Petrangeli
authors.initials: MP
authors.lastname: Papini
mesh_terms: D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D001709:Biotechnology; D002244:Carbon / Q000378:metabolism; D041862:Chloroflexi / Q000378:metabolism; D005285:Fermentation; D060587:Groundwater / Q000737:chemistry; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism; D006885:Hydroxybutyrates / Q000378:metabolism; D007558:Italy; D010865:Pilot Projects; D011091:Polyesters / Q000378:metabolism; D054813:Polyhydroxyalkanoates / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000295:instrumentation; D000094122:Polyhydroxybutyrates
chemical_list: D002244:Carbon; D006843:Hydrocarbons, Chlorinated; D006885:Hydroxybutyrates; D011091:Polyesters; D054813:Polyhydroxyalkanoates; D014874:Water Pollutants, Chemical; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates
keywords: Biological reductive dechlorination; Chlorinated aliphatic hydrocarbons; Groundwater circulation well; Poly (3-hydroxybutyrate); Real-time PCR