Microbiological and Antimicrobial Analysis of Hospital Wastewater Discharged into the Soil Environment

Abstract

This study evaluated the microbiological effects of hospital wastewater discharged into the soil environment using standard microbiological procedures. The highest total bacterial count (8.3±0.5×1010 cfu/ml) of the wastewater samples was observed in the collation point sample while the laundry wastewater sample had the least number of 5.4±0.5×107 cfu/ml. The collation point wastewater sample had the highest total coliform count (4.1±0.1×108 cfu/ml)while the laundry wastewater sample produced the least count of 2.3±0.1×101 cfu/ml. The highest total coliform faecal count of 4.2±0.3×105 cfu/ml was observed in the collation point wastewater sample while the least count of 2.4±1.2×103 cfu/ml was seen in the laundry wastewater sample. The mortuary wastewater had the highest total fungal count of 3.1±0.2×105 cfu/ml while the least count was seen in the collation point wastewater 2.9±0.2×102 cfu/ml. The total viable numbers of the soil samples ranged from 5.0±0.0×108 cfu/g (200m away from the point of discharge) to 8.4±1.6×1012 cfu/g (point of release) while the total coliform counts ranged from 2.3±0.0×104 cfu/g (200m away from the point of discharge) to 3.9±0.8×108 cfu/g (point of discharge). The highest total faecal count of 3.7±0.5×104 cfu/g was observed in the sample from the point of discharge while the least count was seen in the sample collected 200m away from point of discharge 2.3±0.1×102 cfu/g. Total fungal count ranged from 2.4±0.5×107 cfu/g (200m away from the point of discharge) to 3.4±0.5×108 cfu/g (point of discharge). The bacterial species isolated were Escherichia coli, Erwinia, Serratia, Enterococcus, Staphylococcus, Streptococcus, and Salmonella. Others were Pseudomonas aeruginosa, Proteus, Neisseria, Actinomycetes, Shigella, Bacillus and Enterobacter species. The fungi isolated include Aspergillus niger, Aspergillus fumigatus, Trichophyton rubrum, Candida, Penicillium and Rhizopus species. Bacillus spp., Staphylococcus epidermidis, Penicillium spp. and Rhizopus species were the most frequently distributed (100%), followed by S. species, Enterococcus spp., E. coli, Pseudomonas aeruginosa, Proteus spp. and Candida spp. (80%). Salmonella spp., Shigella spp., Enterobacter spp. and Trichophyton rubrum had the same rate of 60%, respectively while the least occurrence was seen in Streptococcus spp., Neisseria spp., Actinomyces spp. and Aspergillus niger with the rate of 40%, respectively. The high microbial loads of the isolates and the high densities of the coliforms indicate there is, therefore, contamination of the soil environment as a result of the discharged hospital wastewater, which could probably be hazardous to human health.