Aspects of Geo-mathematical Diagnoses and Prognoses from Physiochemical Analyses in Landfills and other Areas of Lagos, Nigeria

Abstract

Upon physiochemical analyses of groundwaters samples in active government operated landfills and other areas of Lagos, geomathematical evaluations were undertaken to ascertain the roles of the municipal solid wastes (MSW) in the differentials in concentrations with depth and / or distances away from the suspected causal mode. Novel transpositions of the correlation tables to produce composite tables revealed striking interactions amongst the analytes at depth and / or distances. The correlations between the anions and cations were essentially excellent except for K & Mn. The likely substitutions of K/Mn in the groundwater are in the sequence: Cd > Cr >Ni >Hg >Fe >Zn > Pb > As >K/Mn. Using the regression plots in the Olusosun groundwater, Cd showed that it required the most distance (802m) away from the landfill for complete attenuation among the cations while chloride required the most distance (570m) amongst the anions. The results show that attenuation is exponentially higher for depth relative to distance. Corollary, it takes a factor of 1:55 (depth : surface distance) to produce a unit change in pH, electrical conductivity- 1:117 , DO- 1:47, chloride- 1:68, nitrate/phosphate-1:107, sulphate- 1:100; and 1:37,85,64,63,40,64,89,56,37,117 for K, Zn, Fe, Ni, Cd, Hg, Pb, Cr, Mn, & As respectively. Overall, the sequence indicates attenuation of pollution away from the landfills with clayey/ lateritic lithology. The physiochemical results of areas extraneous to MSW operations implicate the landfills as major contributors to pollution in the Lagos landfill area of Nigeria.