title: Accelerated removal of pyrene and benzo[a]pyrene in freshwater sediments with amendment of cyanobacteria-derived organic matter.
abstract: The removal of pyrene and benzo[a]pyrene (BaP) were investigated in freshwater sediments with amendment of seven different organic matters including cyanobacteria-derived organic matter (COM), plant-derived organic matter (POM), and humic substances (HS). During the 210 days of experiments, the amendment of COM or HS enhanced significantly the removal of pyrene and BaP in sediments, especially with fresh COM (FCOM) treatment much superior to HS. On the contrary, degradation of these polycyclic aromatic hydrocarbons (PAHs) was not significantly improved and even inhibited in POM-amended sediments. The first-order rate constants of pyrene and BaP degradation in the FCOM-amended sediments reached 0.00540±0.00017d(-1) and 0.00517±0.00057d(-1), respectively, and were about three and five folds of those in the control treatment. The enhanced PAHs degradation in FCOM-amended sediments was related to higher PAH-degrading bacteria number and bioavailability with a result of biostimulation and priming effect by labile carbon and high-value nutrition in FCOM. Thus, this study improved our understanding about effects of settled biomass from cyanobacterial blooms, which occurred frequently in eutrophic aquatic ecosystems, on the natural attenuation of PAHs in sediments. Furthermore, this study would also help develop a new promising approach to remediate PAH-contaminated sediments through utilization of cyanobacterial bloom biomass.
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Zaisheng
authors.initials: Z
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: hljiang@niglas.ac.cn.
authors.forename: Helong
authors.initials: H
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Shi
mesh_terms: D001564:Benzo(a)pyrene / Q000032:analysis* / Q000737:chemistry; D001673:Biodegradation, Environmental; D001682:Biological Availability; D018533:Biomass; D019149:Bioreactors; D000458:Cyanobacteria / Q000378:metabolism*; D017753:Ecosystem; D005618:Fresh Water; D019015:Geologic Sediments / Q000737:chemistry*; D060106:Lakes; D009930:Organic Chemicals / Q000737:chemistry; D010088:Oxidoreductases / Q000378:metabolism; D011721:Pyrenes / Q000032:analysis* / Q000737:chemistry
chemical_list: D009930:Organic Chemicals; D011721:Pyrenes; D001564:Benzo(a)pyrene; C030984:pyrene; D010088:Oxidoreductases
keywords: Cyanobacterial blooms; Freshwater sediments; Natural attenuation; Polycyclic aromatic hydrocarbon (PAH); Priming effect