Hydro-geochemical evaluation of groundwater quality in Akoko North West local government area of Ondo State, Nigeria

Avaliação hydrogeoquímica da qualidade da água subterrânea na área Akoko North West do governo local do estado Ondo, Nigéria

Abstracts

A sudden geometric increase in population of Akoko North West Local Government Area of Ondo State has led to an increase in demand for water and harnessing of subsurface water reserve. A total of twenty six water samples obtained from both boreholes and hand-dug wells were analyzed for their physico-chemical characteristics with the aim of assessing their quality, usability and also to determine the level of their contamination in the local government which is dominated by granite gneisses, charnockites, and augen gneisses as the main rock types. The following physico-chemical properties were analyzed for in the samples collected: electrical conductivity (EC), pH, total alkalinity (TA), total dissolved solids (TDS), total suspended solids (TSS), acid neutralizing capacity (ANC) with major cations (Na+, Mg2+, Ca2+), anions (PO4³-, HCO3-, SO4³-) and several heavy metals (Zn2+, Fe2+, As+, Ni+, Pb2+, Cd+, Cu2+). The following results were obtained from the analysis: Zn2+ (0.109 - 0.437 ppm), Fe2+ (0.216 - 0.726 ppm), As+ (0.01 - 0.03 ppm), Ni+ (0.036 - 0.074), Pb2+ (0.003 - 0.010), Cd+ (0.002 - 0.007), Cu2+ (0.086 - 0.241) with appreciable abundances of PO4³-, Cd+, Fe2+and Ni+ some exceeding while some others are below the WHO acceptable level for drinking water, thereby making it a serious source of concern as it indicates varying levels of faecal contamination (from leaky septic tanks, interception with pit latrines) and heavy metal liberation into the water consumed by the residents. It was also noticed that the water was fresh based on the analysis of the Total Dissolved Solids and the Pb2+ concentrations almost exceeded the standard permissible limit. Generally, it was concluded that the overall quality of the ground water is averagely good physico-chemically.

water samples; physico-chemical properties; water quality

Um aumento geométrico e repentino da população da área de Akoko North West do Governo Local do Estado de Ondo levou a um aumento pela procura de água e aproveitamento de reserva de água subterrânea. As características físico-químicas de vinte e seis amostras de água obtidas de poços perfurados e cavados à mão foram analisadas com a finalidade de avaliar sua qualidade, usabilidade e determinação de seu nível de contaminação na área do governo local, que é dominado principalmente pelas rochas de granito, gnaisses, charnockitos e augen gnaisse. As seguintes propriedades físico-químicas das amostras coletadas foram analisadas: condutividade elétrica (CE), pH, alcalinidade total (AT), sólidos totais dissolvidos (TDS), sólidos suspensos totais (SST), a capacidade de neutralização de ácido (CNA), com os principais cátions (Na+, Mg2+, Ca2+), ânions (PO4³-, HCO3-, SO4³-) e vários metais pesados (Zn2+, Fe2+, As+, Ni+, Pb2+, Cd+, Cu2+). Os seguintes resultados foram obtidos: Zn2+ (0,109 - 0,437 ppm), Fe2+ (0,216 - 0,726 ppm), As+ (0.01 - 0.03 ppm), Ni+ (0,036 - 0,074), Pb2+ (0,003 - 0,010), Cd+ (0,002 - 0,007), Cu2+ (0,086 - 0,241), com concentrações apreciáveis de PO4³-, Cd+, Fe2+e Ni+ algumas superiores, enquanto outras abaixo do nível aceitável da WHO para água potável, fato que se constitui em grande preocupação, pois indica níveis variáveis de contaminação fecal (de vazamento de fossas sépticas e de latrinas) e contaminação de metais pesados na água consumida pelos moradores. Também foi observado que a água era doce com base na análise dos sólidos totais dissolvidos e que as concentrações de Pb2+quase ultrapassaram o limite padrão estabelecido. Observou-se que a qualidade físico-química global da água do solo é medianamente boa.

amostras de água; propriedades físico-químicas; qualidade da água

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Publication Dates

• Publication in this collection
  16 Sept 2014
• Date of issue
  Mar 2012