Zenodo (CERN European Organization for Nuclear Research), Jul 13, 2005
The study was conducted to assess the floral diversity of the remaining mangrove stands in the fo... more The study was conducted to assess the floral diversity of the remaining mangrove stands in the four coastal barangays of Masinloc, Zambales including Brgy. Baloganon, Brgy. Inhobol, Brgy. San Lorenzo and Brgy. San Salvador. The factors that contributed to the present state of mangrove ecosystems were likewise evaluated.
Background. Efforts are needed to evaluate heavy metal concentrations in aquatic sediments which ... more Background. Efforts are needed to evaluate heavy metal concentrations in aquatic sediments which serve as repositories and as sources of contamination of other habitats. Objectives. The present study assessed temporal changes in the pH, particle size and concentration of metals in sediments of a mining-affected river in Zambales, Philippines. Methods. Sediment samples were collected at different periods in four stations along the river using a modified Van Veen grab. The samples were subjected to quartering, air-drying, and sieved through a mesh of 40 mm prior to X-ray fluorescence spectroscopy analysis using Thermo Scientific Niton XL3t to determine metal concentrations. The sediment particle size was analyzed by the sieve method and soil pH by the electrode method. Results. Measured metal concentrations in the sediment were as follows: iron (Fe)> calcium (Ca)> chromium (Cr)> nickel (Ni)> manganese (Mn) with averages of 174.6 mg/g, 7.89 mg/g, 6.54 mg/g, 4.82 mg/g, and 2...
Phytoaccumulative capacity for heavy metals (Zn, Ni, Fe, Mn and Cr) of mangrove species (Rhizopho... more Phytoaccumulative capacity for heavy metals (Zn, Ni, Fe, Mn and Cr) of mangrove species (Rhizophora apiculata, Avicennia sp. Sonneratia alba) was evaluated on sediments collected along the riparian zone of mining-impacted river. Ni, Fe, Mn and Cr exceeded the probable effect level suggesting their potential adverse effects to aquatic organisms and ecosystem. Metal concentration in the sediments was in decreasing order of Fe>Cr>Ni>Mn>Zn. The potential for metal accumulation which was assessed using bioconcentration factor (BCF) and translocation factor was found to vary depending on metals, mangrove species and plant tissues. The tested metals highly accumulated in the roots except for Mn with higher uptake in the leaves. Highest BCF was recorded on Zn (0.7) in Avicennia sp. while metals with high mean level in sediments (4,244.1mg/kg Ni, 137,049.4mg/kg Fe and 13,985.9mg/kg dry weight Cr) registered lower BCF. Variations in metal uptake of the same species could be due to differences in metal bioavailability and sediment characteristics. Limited translocation of Cr in all species, Ni on S. alba, Fe in R. apiculata and Avicennia sp. suggests that they can potentially be used for remediation of Ni-Cr-Fe laden sediments particularly for phytostabilization. Enhancement of metal uptake by mangroves through increasing metal bioavailability should be explored in future studies.
Zenodo (CERN European Organization for Nuclear Research), Jul 13, 2005
The study was conducted to assess the floral diversity of the remaining mangrove stands in the fo... more The study was conducted to assess the floral diversity of the remaining mangrove stands in the four coastal barangays of Masinloc, Zambales including Brgy. Baloganon, Brgy. Inhobol, Brgy. San Lorenzo and Brgy. San Salvador. The factors that contributed to the present state of mangrove ecosystems were likewise evaluated.
Background. Efforts are needed to evaluate heavy metal concentrations in aquatic sediments which ... more Background. Efforts are needed to evaluate heavy metal concentrations in aquatic sediments which serve as repositories and as sources of contamination of other habitats. Objectives. The present study assessed temporal changes in the pH, particle size and concentration of metals in sediments of a mining-affected river in Zambales, Philippines. Methods. Sediment samples were collected at different periods in four stations along the river using a modified Van Veen grab. The samples were subjected to quartering, air-drying, and sieved through a mesh of 40 mm prior to X-ray fluorescence spectroscopy analysis using Thermo Scientific Niton XL3t to determine metal concentrations. The sediment particle size was analyzed by the sieve method and soil pH by the electrode method. Results. Measured metal concentrations in the sediment were as follows: iron (Fe)> calcium (Ca)> chromium (Cr)> nickel (Ni)> manganese (Mn) with averages of 174.6 mg/g, 7.89 mg/g, 6.54 mg/g, 4.82 mg/g, and 2...
Phytoaccumulative capacity for heavy metals (Zn, Ni, Fe, Mn and Cr) of mangrove species (Rhizopho... more Phytoaccumulative capacity for heavy metals (Zn, Ni, Fe, Mn and Cr) of mangrove species (Rhizophora apiculata, Avicennia sp. Sonneratia alba) was evaluated on sediments collected along the riparian zone of mining-impacted river. Ni, Fe, Mn and Cr exceeded the probable effect level suggesting their potential adverse effects to aquatic organisms and ecosystem. Metal concentration in the sediments was in decreasing order of Fe>Cr>Ni>Mn>Zn. The potential for metal accumulation which was assessed using bioconcentration factor (BCF) and translocation factor was found to vary depending on metals, mangrove species and plant tissues. The tested metals highly accumulated in the roots except for Mn with higher uptake in the leaves. Highest BCF was recorded on Zn (0.7) in Avicennia sp. while metals with high mean level in sediments (4,244.1mg/kg Ni, 137,049.4mg/kg Fe and 13,985.9mg/kg dry weight Cr) registered lower BCF. Variations in metal uptake of the same species could be due to differences in metal bioavailability and sediment characteristics. Limited translocation of Cr in all species, Ni on S. alba, Fe in R. apiculata and Avicennia sp. suggests that they can potentially be used for remediation of Ni-Cr-Fe laden sediments particularly for phytostabilization. Enhancement of metal uptake by mangroves through increasing metal bioavailability should be explored in future studies.
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