Affiliations: School of Life Sciences, Research Centre for Wetland
and Ecological Engineering, Xiamen University, Xiamen 361005, China | Environmental Science Research Center, Xiamen
University, Xiamen 361005, China
Abstract: The polycyclic aromatic hydrocarbons (PAHs) concentrations were
determined in the root of three mangrove species (Kandelia candel, Avicennia
marina and Bruguiera gymnorrhiza) and their growing environment (sediment) in
mangrove wetlands of Jiulong River Estuary, Fujian, China. The total PAHs (16
parent PAHs) in mangrove sediments ranged from 193.44 to 270.53 ng/g dw, with a
mean value of 231.76 ± 31.78 ng/g dw. Compared with other mangrove and
coastal marine sediments, the PAHs concentrations of all the sampling areas in
this study were at relatively lower level. The total PAHs (13 parent PAHs)
values varied from 30.83 to 62.73 ng/g dw in mangrove roots. Benzo[a] pyrene
(five-ring), fluoranthene (four-ring) and pyrene (four-ring) dominated in
mangrove sediments. Based on ratios of phenathrene/anthracene,
fluoranthene/pyrene and fluoranthene/pyrene + fluoranthene, the main
possible sources of surface sediment PAHs were identified as grass, wood or
coal combustion for mangrove wetlands of Jiulong River Estuary. Naphthalene
(two-ring)and phenathrene (three-ring) were the most abundant compounds in
mangrove roots. Sediment-to-vegetation bioconcentration factors
(BCF_{sv}S) were calculated and their relationships with
PAHs' physico-chemical properties were investigated. The average
BCF_{sv}s of PAHs for three mangrove species roots were
almost all under the level of 1 except for naphthalene. Good linear
relationship between BCF_{sv} values for mangrove roots and
PAHs water solubility, octanol-water partitioning coefficients was derived in
present study. The solubility and the octanol-water partition coefficient were
proved to be good predictors for the accumulation of PAHs in mangrove
roots, respectively.
Keywords: mangrove, PAHs, Jiulong River Estuary, bioconcentration factors
