TY - JOUR
T1 - Natural attenuation of contaminated marine sediments from an old floating dock - Part I
T2 - Spatial and temporal changes of organic and inorganic pollutants
AU - Wang, Ya Fen
AU - Tam, Nora Fung Yee
N1 - Funding Information:
The work described in this paper was supported by the Areas of Excellence Scheme , established under the University Grants Committee of the Hong Kong SAR, China (Project No. AoE/P-04/2004 ). The authors would like to thank Dr. Deborah Che from HKEPD for her technical advice.
PY - 2012/3/15
Y1 - 2012/3/15
N2 - Temporal and spatial changes of mixed pollutants, including eight heavy metals, 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) and tributyltin (TBT) in surface marine sediments were examined for a one-year period after the removal of an old floating dock in Hong Kong SAR, South China. The sediments from the impacted stations close to the dock were highly polluted with zinc (Zn) and copper (Cu), and were moderately polluted with TBT and total PAHs, based on their effects range-low (ERL) guideline values, while those collected in the reference stations away from the dock were lower than the ERL. Strong, positive correlations were found between the organic pollutants and heavy metals only in the impacted stations, suggesting that the old floating dock was a significant source of mixed pollutants. There was no significant decline in the levels of total PAHs, TBT and heavy metals and "hot spots" of contamination were still detected a year after the removal of the dock. However, the profiles of 16 PAHs in the impacted stations changed 6. months after the removal of the dock, with decreases of certain low-molecular-weight PAHs, especially fluorene, as a sign of biodegradation in situ. Further, principal component analysis (PCA) based on an integrated dataset of the pollutants together with general sediment properties showed that the temporal changes of the biodegradable low-molecular-weight PAHs were highly associated with the pH value and total Kjeldahl nitrogen, while heavy metals were independent of time and other sediment properties during natural attenuation in the dock area.
AB - Temporal and spatial changes of mixed pollutants, including eight heavy metals, 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) and tributyltin (TBT) in surface marine sediments were examined for a one-year period after the removal of an old floating dock in Hong Kong SAR, South China. The sediments from the impacted stations close to the dock were highly polluted with zinc (Zn) and copper (Cu), and were moderately polluted with TBT and total PAHs, based on their effects range-low (ERL) guideline values, while those collected in the reference stations away from the dock were lower than the ERL. Strong, positive correlations were found between the organic pollutants and heavy metals only in the impacted stations, suggesting that the old floating dock was a significant source of mixed pollutants. There was no significant decline in the levels of total PAHs, TBT and heavy metals and "hot spots" of contamination were still detected a year after the removal of the dock. However, the profiles of 16 PAHs in the impacted stations changed 6. months after the removal of the dock, with decreases of certain low-molecular-weight PAHs, especially fluorene, as a sign of biodegradation in situ. Further, principal component analysis (PCA) based on an integrated dataset of the pollutants together with general sediment properties showed that the temporal changes of the biodegradable low-molecular-weight PAHs were highly associated with the pH value and total Kjeldahl nitrogen, while heavy metals were independent of time and other sediment properties during natural attenuation in the dock area.
KW - Heavy metals
KW - PAHs
KW - Principal component analysis
KW - Remediation
KW - Temporal variation
UR - http://www.scopus.com/inward/record.url?scp=84862815948&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2012.01.011
DO - 10.1016/j.scitotenv.2012.01.011
M3 - Article
C2 - 22326320
AN - SCOPUS:84862815948
SN - 0048-9697
VL - 420
SP - 90
EP - 99
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -