Tag Archives: mobility factor

Sequential Analysis, Mobility Factor and Geochemistry of Heavy Metals in Ayetoro Coastal Sediments, Southwestern Nigeria (Published)

Previous geochemical investigation of Ayetoro area discovered that its coastal sediments are enriched with sulphide mineralization. However, in order to determine the geochemical phases of the heavy metals in the coastal sediments, random sampling method was utilized across 10 locations, at a depth of 40cm using Van grab sampler at a sampling density of 200m interval. Atomic Absorption Spectrophotometer (AAS) Buck Scientific Model 205A was used to analyze nine (9) heavy metal concentrations namely Ni, Zn, Co, Mn, Fe, Pb, Cr, Cd and Cu in the coastal sediments, followed by sequential extraction of the metals, using five fractional phases. The results revealed that the geochemical concentration of the heavy metals as follows: Ni (5.89ppm – 16.82ppm), Zn (2.59ppm – 115.65ppm.), Co (1.22ppm – 22.77ppm), Mn (30.95ppm – 186.49ppm), Fe (6.632ppm – 1925.96ppm), Pb (5.17ppm – 55.96ppm), Cr (0.26ppm – 28.06ppm), Cd (0.13ppm -22.23ppm), and Cu (2.26ppm – 41.94ppm) and showed the concentration order as Residual>Reducible>Organic>Exchangeable>Carbonate. Most of the heavy metals in carbonate and exchangeable phase have low concentration except for Cd. This implied that Cd is of low mobility and bioavailability which is very dangerous as its intake by man leads to kidney diseases and causes bones to become weaker. Also, Mobility factor of Cd stood out because of its high concentration in the exchangeable phase compared to other four non-residual phases. The mobility and bioavailability of the heavy metals are in this order: Cd>Co>Ni>Pb>Cr>Mn>Cu>Zn>Fe respectively. The analysis of variance (ANOVA) revealed that the heavy metals are significantly different in all the phases based on their accumulation index in the sediments  while majority of the heavy metals lacked the ability to remobilize  but can be released into the environment under reducing and oxidizing conditions

Keywords: Heavy Metals, ayetoro. coastal sediments, mobility factor, sequential extraction

Seasonal Chemical Speciation and Potential Mobility of Heavy Metals in the Surface Soil of some Poultry Farm Establishments of Osun State, Southwestern Nigeria (Published)

This work examined the presence, availableness and mobility of metals in chosen poultry farm soils areas samples from Osun State. Metals in the stratified soil samples taken in both seasons were in sequence extracted into five phases and content of the extracted metals was conducted utilizing Flame Atomic Absorption Spectrophotometer.  Quality control measures involved blank test, spike recovery test and calibration of standards. Descriptive and inferential statistics were adopted for data analyses  The range of metals extracted from each of the five soil geochemical phases in mean percentages for both seasons are in this manner: carbonate bound (0.84-19.94), exchangeable (8.43-18.84), Fe-Mn oxide (13.95-21.18), organic matter (21.43-34.14) and residual (15.45-41.48). Potential  metals in the examined soils (mgkg-1) varies between 3.56-1181.62, 0.05-2.98, 10.72-75.06, 40.38-640.52, 3.32-96.69 and 9.80-219.12 for arsenic, cadmium, copper, iron, lead and zinc, while mean % mobility factors of all the metals in both seasons examined were ranged between 30.54-33.04, 33.29-34.49, 37.11-38.74, 15.37-17.58, 35.02-35.31 and 24.48-27.02 for As, Cd, Cu, Fe, Pb and  Zn. In the poultry agro-ecological agriculture, values of metals in available forms do not vary statistically in both seasons. Nevertheless, bulk of the sampled metals have high abundance in residual and organic matter phases and for this reason, may not present ecological threat inasmuch as their overall fairly minor availableness and MFs of the metals in the examined soil.

Keywords: Heavy Metals, fractionation, mobility factor, poultry farmland, speciation