1 / 26

Sediment Toxicity in Rivers Draining Ibadan Metropolis, Nigeria

This study examines the mineralogical and trace metal contents of sediments in rivers draining Ibadan, Nigeria. The pollution status and influence of land use and human activities on metal concentration are evaluated. The results show anthropogenic metal enrichment in the sediments, with high concentrations of Cu, Pb, Zn, Cd, and As in the bio-available fractions. Efforts should be made to mitigate pollution in the area.

wingham
Download Presentation

Sediment Toxicity in Rivers Draining Ibadan Metropolis, Nigeria

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Sediments Toxicity of the rivers draining Ibadan Metropolis Southwestern, Nigeria. 1Ajibade, O.M and 2Abimbola, A.F. 1 Department of Earth Sciences, Olabisi Onabanjo University 2The Department of Geology,University of Ibadan, Nigeria

  2. INTRODUCTION Ibadan is a mega-city and one of the largest cities in Nigeria. A densely populated city with numerous distorted land use plan

  3. STUDY AREAThe study area is drained by RiversOmin, Ona, Ogunpa, Ogbere. Old City Center Industrial New City Center Agricultural

  4. RIVER OMIN - AGRICULTURAL FISHING PLANTATION- Cocoa

  5. RIVER ONA - INDUSTRIAL INDUSTRIAL EFFLUENT

  6. RIVER OGUNPA - OLD CITY CENTER Unplanned urban setting High traffic Density Indiscriminate solid/liquid waste

  7. A B RIVER OGBERE - NEW CITY CENTER D

  8. OBJECTIVES OF THE STUDY • To determine the mineralogical and trace metal contents of the sediments. • To evaluate the pollution statusand identify the possible influence of Land use/human activities on metal concentration. • MATERIALS AND METHODS • 233 bottom river sediment samples was collected along the stream and river channels • Omin-29, Ona-53, Ogunpa-91, Ogbere-60. • A sample was collected as control from a natural spring devoid of contamination. • MINERALOGICAL/GEOCHEMICAL • XRD (NGSA Laboratory) • ICP-MS (ACME Laboratory Canada) • SEQUENTIAL LEACH (5-Methods) • Leach Methods • Sulphides • Residuals • Reducibles • Organics • Exchangeables

  9. MINERALOGICAL DATA kaolinite, illite, chlorite, mica, calcite, paragonite, diaspore and quartz Kaolinite, illite, were diminant in Rivers Omin and Ogbere Quartzis the dominant mineral in Rivers Ona and Ogbere. .

  10. SAND-CLAY CONTENT - (Si:Al) • Si/Al controls the sand-clay content of any given sediment. • Mean Si/Al values in the sediment include: ≤14.09(Omin), ≤17.44(Ona), ≤18.73(Ogunpa), ≤15.0(Ogbere) indicating high degree of sand • High sandy content was recorded for Ogunpa and Ona rivers, controlled by the lithology (Quartzite and quartz schist).

  11. River Omin

  12. River Ona Idiishin Oluyole New garage

  13. River Ogunpa A 250m

  14. RIVER OGBERE

  15. GEOCHEMICAL MAP

  16. GEOCHEMICAL MAP

  17. PLI COMPARISON Comparison between the Pollution Load Index (PLI)

  18. Comparison between the mean concentration and PLI values of trace metals in the four Rivers.

  19. Comparison of Geo-accumulation Indices of the four rivers

  20. Sediment fractions for Cu, Pb, Zn, Cd, As, Mn

  21. Table 3:Sediment Guidelines TEC-Threshold Effect Concentration; PEC-Probable Effect Concentration CBSQG-Canadian Sediment Quality Guideline

  22. Are the concentration of these metals in the sediments truly anthropogenic? • Enrichmentof Pb, Zn, Cr, Co, Ni, As in the sediments, attributed to anthropogenic sources(Table 3; Fig. 16). • High concentration of Cu, Pb and Znis in agreement with earlier findings of Odewande and Abimbola (2008); Fadina, (2008);Olatunji, et al., (2011) on road dust, outdoor and indoor particulate matter andsoils of the urban city. Table 4: Lithogenic and anthropogenic contributions of metals in theRiver sediments of Ibadan metropolis River Lithogenic and anthropogenic contributions

  23. CONCLUSION Weathering & Land-use; Urbanization: Population density; Human activities; Toxicity of sediment has occured in River Ogunpa (Old City Center) drainage channel Anthropogenic metal enrichment is greater than the lithogenic metal enrichment in sediment derived from the drainage channels. Cu, Pb, Zn, Cd and As: dominates the Bio-available sediment fractions Efforts should be made to reduce pollution level: through mitigation

  24. THANK YOU FOR LISTENING

More Related