Effect of Climate Change through Temperature Increase on Heavy Metals Concentrations in Water and Sediment of Ekpan Creek, Delta State, Nigeria

Abstract

Climate change affect the physiochemical characteristics of water bodies directly through temperature increase with resultant effect in reducing heavy metals concentrations in surface water temporarily, and indirectly changing the physical and chemical processes related to temperature in the water columns. This scenario concomitantly increase the rate of biochemical processes with a significant decrease in oxygen concentration, as well as the composition and distribution of metals in water and sediment. The concentrations of heavy metals in water and sediment of Ekpan Creek was investigated from December 2009 to May 2010 at monthly interval. Five sampling stations was designated along the water stretch for water and sediment collection. The Varian Techron Spectr AA – 10 Atomic Absorption Spectrometer (S/N.902 1318) with a printer attached was used for the determination of phosphate, sulphate, nitrate, copper, iron, chromium, manganese, lead, zinc and cadmium. At the stations, air temperature ranged from 27.9°C to 33.4°C, water temperature from 28°C to 34°C; TDS, 463 to 503 mg/L; DO, 4.12 to 7.44 mg/L; hardness, 85.47 to 125 mg/L; phosphate, in water (0.03 to 0.18 mg/L) sediment, 17.85 to 2484 mg/L); Nitrate in water 0.02 to 0.04 mg/L, sediment 1.47 to 9.51 mg/L; Sulphate in water 19.26 to 50.66 mg/L, sediment 1.47 to 9.51 mg/L; iron in water 0.65 to 0.43 mg/L, sediment 380.37 to 239.17 mg/L; Zinc in water 0.32 to 0.13 mg/L, sediment 8.11 to 3.14 mg/L; Copper in water 0.0038 to 0.0014 mg/L, sediment 1.33 to 0.05 mg/L; lead in water 0.0042 to 0.001 mg/L; Sediment 0.16 to 0.02 mg/L; Cadmium in water 0.028 to 0.001 mg/L, 0.504 to 0.019 mg/L; Chromium in water 0.0038 to 0.0012 mg/L, sediment 0.801 to 0.001 mg/L; Manganese 2.44 to 0.86 mg/L. The present study recommend enforcement of strict regulation of anthropogenic input of these metals to the river and more in-depth study of the impacts of climate change on metals concentrations in aquatic systems.