BACTERIOLOGICAL AND PHYSICOCHEMICAL IMPACT ASSESSMENT OF INDUSTRIAL AND DOMESTIC WASTES
ABSTRACT
Bacteriological analysis of the water samples such as heterotrophic counts, coliform counts, Faecal Coliform/Faecal Streptococci (FC/FS) ratio were carried out following standard procedures. Gram-negative bacteria and Gram-positive Staphylococcal species were identified using ID 32E and Microbact 12S kits respectively. Susceptibility of the isolates to ceftazidime, ceftriaxone, cefuroxime, erythromycin, gentamicin, amoxycillin/clavulinate, cloxacillin, ampicillin, ciprofloxacin, ofloxacin and nitrofurantoin were carried out using the agar diffusion method. Susceptibility of the isolates to Dettol®, Savlon® and Izal®was also determined using agar dilution method. Resistant bacteria were subjected to molecular analysis to further ascertain their status.Physicochemical properties of the river water such as pH, temperature, electrical conductivity, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solids (TS), total suspended solids (TSS), hardness, sulphate, chloride, nitrates and alkalinity were analysed using standard methods. Elemental analyses of water samples and bottom soil sediments were carried out using Atomic Absorption Spectrometer (AAS). Analysis of variance (ANOVA) was carried out on the elemental data to determine the level of impact of the wastes on the river water quality. The study revealed generally high levels of heterotrophic and coliform counts throughout the year with sampling point P1 around farmland having the highest counts and P4 on the stream that carried effluents from Sokoto Cement Factory, having the least. FC/FS ratios were generally very high (above 4.0). Of the 434 bacteria isolated, E. coli among theEnterobacteriaceaewashighest (11.98%).Pseudomonas aeruginosa(7.37%) constituted the majority of non-EnterobacteriaceaeGram-negative organisms whileStaphylococcus aureus(6.91%) was the highest among the Gram-positive organisms. The antibiotic susceptibility profiles showed that most of the Enterobacteriaceae isolates (˃60%) were sensitive to ceftazidime, gentamicin, amoxycillin/clavulinate,