Rainwater samples collected directly from the atmosphere and through various roof catchments (aluminium, zinc, asbestos and thatch) were analysed for their physico-chemical and microbiological qualities. Results showed that the physico-chemical qualities of the rainwater, except for colour, were within the limits approved by the World Health Organization. Asbestos and thatch materials caused an increase in colour of the rainwater. A near neutral pH (7.02–7.45) was obtained in all the samples. Higher levels of aluminium were obtained in the samples collected from the aluminium roof catchment while zinc was only detected in the rainwater collected from the zinc roof catchment. Manganese and iron were present in all the samples. Microbiological analysis showed varying degrees of contamination in the different samples. All the samples contained a high number (5.8×102–7.6×103 cfu/ml) of heterotrophic bacteria. The filamentous fungi population was in the range of 1.0×10–4.0×102 cfu/ml. Pseudomonas spp. were found in the samples in the range of 1.0×10–8.8×102 cfu/ml, except for the samples from the zinc roof where none (0 cfu/ml) were recorded. Rainwater samples from the roof catchments also contained high numbers of pathogenic bacteria, Salmonella spp. Shigella spp and Vibrio spp. This result therefore suggests that the purity of the rainwater should not be taken for granted. Microbiological analysis of all rainwater should be undertaken and appropriate treatment measures adopted before rainwater can be declared potable. Zinc appears to be a better material for rainwater collection than aluminium, asbestos and thatch. Direct collection, however, is the best option when low volumes of water are required.
Rainwater quality from different roof catchments in the Port Harcourt district, Rivers State, Nigeria
Beatrice Nnene Uba, Onakufe Aghogho; Rainwater quality from different roof catchments in the Port Harcourt district, Rivers State, Nigeria. Journal of Water Supply: Research and Technology-Aqua 1 August 2000; 49 (5): 281–288. doi: https://doi.org/10.2166/aqua.2000.0024
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