Groundwater quality assessment and characterization of shallow basement aquifers in parts of ado ekiti metropolis, Southwestern Nigeria

Abstract

Groundwater samples were collected randomly from hand-dug wells in parts of Ado Ekiti metropolis and were subjected to its quality assessment and characterization. Physicochemical and bacteriological analyses were carried out following standard methods (APHA 2012). Hydrochemistry of the present study revealed relative mean concentration of the cations in the order: Na + > Mg 2+ > Ca 2+ > K + , and that of the anions as Cl − > HCO 3 − > SO 4 2− > NO 3 − , respectively. The microbial test shows that E. coli tested positive in all the samples and their colonies are classified dominantly as satisfactory pollutant free state. Pollution index of groundwater results revealed an insignificant state of pollution of the groundwater. Deduction from the Pipers, Gibbs plots and chloro-alkaline indices results revealed the imprints of natural weathering, ion-exchange processes and anthropogenic activities influencing the groundwater quality. Factor analysis result also confirms the prevailing activities of natural geological forces and municipal contaminations acting on the groundwater. The hydrochemical processes coupled with the permeable nature of the aquifer media and high precipitation will influence groundwater flow and ultimately pose pollution risk to the aquifers and eventually the populace of these areas in years to come.

An integrated indexical investigation of selected heavy metals in drinking water resources from a coastal plain aquifer in Nigeria

“…In PIG evaluation, an overall chemical quality of groundwater (Ow) greater than 0.1 indicates a contribution of about 10% value of 1.0 of the final PIG, thereby depicting the actual influence of different parameters in the pollution of the groundwater [12,[14][15][16]. In this current study, the Ow of pH and all the heavy metals were below 0.1, except for Cu and Ni in sample 6 ( Table 3).…”

“…The pollution index of groundwater (PIG) was developed by Subba Rao [12] and has been successfully used in researches for the monitoring and assessment of drinking water quality [14][15][16]. The final PIG values express the contributions of all analyzed quality variables of groundwater samples.…”

“…where W p is the weight parameter for each of the water quality variables; R w , relative weight of a parameter; S c , the status of concentration; C, analyzed water quality variables' content in each water sample; D s , the respective water quality standard limit of parameter, as described by NIS [23] and WHO [24]; O w , overall quality of the groundwater sample [12,[14][15][16].…”

“…Such methods which are currently being adopted in water quality assessments include pollution index of groundwater (PIG), synthetic pollution index (SPI), integrated water quality index (IWQI), overall index of pollution (OIP), and hierarchical cluster analysis (HCA). Over time, these quality indexing tools have proven to be very useful in categorizing the water quality of different areas in a simple manner [1,2,6,7,[12][13][14][15][16][17]. These tools reflect the pollution statuses of different sources of drinking water, thereby providing insights for sustainable water management.…”

Pollution potential and causative hydrogeochemical processes in unconfined aquifer systems in a typical urban setting: emphasis on recharge and discharge areas

“…Groundwater pollution assessment studies have aided accurate assessment of the vulnerability of groundwater to pollution coupled with in-depth understanding and knowledge of hydrogeochemical processes which have been found important in groundwater quality assessment. Hydrogeochemical processes greatly influence the pollution or contamination of groundwater all over the world (Krishna Kumar et al 2014;Batabyal and Chakraborty 2015;Adewumi et al 2018;Batabyal 2017;Lapworth et al 2017;Olofinlade et al 2018;Oyedele et al 2019). This study is, however, aimed at the delineation of groundwater recharge and discharge areas in an urban metropolis, like Akure, the capital city of Ondo State, south-western Nigeria, for their pollution potential as well as the hydrogeochemical processes prevailing in the area.…”