Analysis of heavy metals (Pb, Cr, Cd, Cu, Zn, Fe) and metallic nutrients (Mg, Ca, K) in bottom sediments of Laguna de Bay.

Date

4-1997

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Carlito R. Barril

Co-adviser

Amelia Tejada

Committee Member

Joey H. Santos

Abstract

Sediment core samples obtained from four sites ( East, West, Central and South bays) in Laguna de Bay were cut into five 8-cm layers and analyzed for heavy metals and metallic nutrients. The sites at which highest average mean metal concentrations were found are: East bay for Cu (1.60x102+4.43 mg/kg), Cd (0.954:_0.060 mg/kg), and Cr (6.61 ±_ 0.25 mg/kg); Central bay for K (7.57+ 0.24)x103mg/kg and Mg (5.58+0.15)x103mg/kg; West bay for Ca (4.77+0.44)x103mg/kg; and South bay for Pb (100±4.05 mg/kg), Zn (92.90 + 2.32 mg/kg) and Fe (3.78+0.05)x104mg/kg. As to the sediment layer containing the highest concentration of each metal, results showed that the top 8-cm layer contained higher levels of Cu, Pb, Zn, Fe and Mg, while K has its highest concentration at 16 cm depth. Cd was found highest at 24 cm, while Ca and Cr have their highest concentrations at 32 cm. Analysis of variance showed that at 5% level of significance, metal concentrations of Pb, Cr, Cd, Cu, Fc, Zn, Ca, Mg, and K varied significantly with depth and site. Pb, Cd, Cu, Zn, Fe, and Mg concentrations showed negative correlation with depth, while Ca and Cr concentrations showed positive correlation with depth. DMRT analysis showed wide variability and significant difference among the values for each metal relative to sediment depth and site Concentrations found for each metal were compared with the Clay Universal Standard and showed that for Pb, Zn and Cu, the levels obtained were 6.0, 1.1 and 4.4 times higher, respectively, than the standard values. On the other hand, the value obtained for Cr was only 9°A, of the Standard value. For the other metals, no comparison was made due to the lack of standard data. Comparing the results of the present study with those of the SOGREA1-1 study (1978) showed that Pb, Cu. Mg and Ca concentrations were 3.3, 1.6, 1.2 and 1.9 times higher, respectively, than the SOGREAII results, while the levels found for Fe, Cr, and Zn were 1.3, 2.2 and 4.3 times lower, respectively, than the SOGREAH's values.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 1997 C4 H47

Document Type

Thesis

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