Effects of effluent discharge on man and soil ecosystem in Calabar, south southern Nigeria

Abstract

The impact of Flour Mill Effluent (FME) on soil physicochemical properties at Ekorinim in Calabar, Cross River State, Nigeria, were analyzed at the depths of 0-15cm and 15-30cm. Conventional analytical methods were employed for the determination of these physicochemical parameters. The results of the physicochemical analysis showed that the Bulk density in polluted soil ranged from the mean SD 1.23 ± 1.45mg/dm 3 and the mean value of non-contaminated soil was 7.4.1±1.20 (mg/dm 3), the porosity of polluted soil 0.48 ± 0.55(mg/dm 3) and non-polluted soil 0.48 ± 0.33mg/dm 3. The pH values in all the sites ranged from 5.01 to 5.70, indicating acidity of the soils. The Soil Organic Carbon concentration values ranged from of O.57%-2.39% in both polluted and non-polluted soils, indicating presence of some organic matter and microbiological activities in the soil samples. The Electrical Conductivity of contaminated soil is extremely saline, while the one of non-polluted soil is very saline indicating significant presence of some soluble inorganic salts in soils studied. Minerals such as Nitrogen, Phosphorus and Potassium recorded highest concentration in soil with effluent discharged. CEC in polluted and non-polluted soil have mean standard deviation of 2.15 ± 0.74 cmol kg-¹, 1.79 ± 0.74 cmol kg¯¹ respectively, lower than the critical limit of <0.6 cmol kg¯¹ which is low in nature. Significant differences in the levels of manganese, iron, chromium, magnesium, nitrate, clay and sand, temperature, conductivity pH, and CEC across the different Sampling locations and the topsoil of Flour Mill Effluent were observed (ANOVA, p ≤ 0.05) Overall results indicated that, Flour Mill Effluent can add nutrients to the soils if properly harnessed to eliminate heavy metals which constitute a major health risk to the local population through pollution.