Influence of Untreated Noodle Wastewater on Physicochemical, Enzymatic and Bacteriological Dynamics of Soil

The study was designed to determine the influence of untreated noodle wastewater on physicochemical, enzymatic, and bacteriological dynamics of soil. The methodology of physicochemical analysis involved APHA standard, while plant growth indices, enzyme assays, and bacteriological analyses were determined using standard microbiological techniques. The results revealed that almost all the physicochemical characteristics of the untreated noodle effluent and irrigated soil samples were found to be higher than the permissible levels according to WHO (2004) and FEPA (1996) standards. The results revealed significant (p < 0.05) increases in the mean height and leaf numbers relative to their controls of maize crop, while there were non-significant (p > 0.05) increases in the wet and dry weight during irrigation at increasing concentrations of the untreated noodle effluent. The lead metal (Pb) had the highest value of 0.46 ± 0.02, while zinc metal had the least value of 0.15 ± 0.03 absorbed in the maize plant at 100% contamination levels and were above acceptable limits. The results showed non-significant (p > 0.05) changes in the soil urease activity ranging from 4.80–21.40 mg/g; 18.00–34.20 mg/g in the soil phosphatase activity; 1.68–13.96 mg TPH/g/h in the soil dehydrogenase activity; and 0.21–0.30 mol/L in the soil catalase activity, respectively. Bacteriological profiling showed non-significant (p > 0.05) reductions in the rhizobia bacterial count ranging from 185–7.10 × 10³ CFU/g and 15.7–5.50 × 10³ CFU/g in the actinomycetes count, while there was a significant (p < 0.05) reduction in the phosphate-solubilizing bacterial count ranging from 17.50–9.8 × 10³ CFU/g, respectively, after the 8 weeks from 0%–100% noodle effluent contaminations. Therefore, noodle industry effluent at various concentrations influences soil physicochemical, enzymatic, and bacteriological properties and seed germination and seedling growth of Zea mays studied.