Studies were carried out to evaluate the environmental impact of abattoir effluents discharge on the quality of well water in Abakpa, Enugu State-Nigeria using standard analytical procedures and instrumentation. The samples were collected and the physiochemical parameters were analyzed using standard techniques. The heavy metals analyzed in the water samples involved wet digestion and aspiration of the digest onto the spectrophotometer for the determination of the concentration of the studied metals. The mean range of values for samples S1, S2, S3, and control were 6.64-7.07, 3.03-6.26NTU, 71.02-117.32, μ5/cm and 116.29-200.61mg/l, 41.04-53.08mg/l, 1.04-2.88mg/l and 22.14-29.12 mg/l for pH, turbidity, electrical conductivity, total dissolved solids, chloride ions, biological oxygen demand and nitrate ions respectively. The mean range of values for the heavy metals analyzed in the water samples were 2.14-12.31, 0.38-1.59, 1.03-2.81, 0.06-0.26 and 0.003-0.008μg/g for Zn, Cu, Fe, Pb and As respectively. Sampling points S1 and S2 consistently exhibited higher values for all the studied physiochemical parameters and heavy metals than other sampling points (S3 and control). Of all the studied physicochemical parameters and heavy metals, only turbidity and Zn in sampling point S1 and Pb in sampling points S1 and S2 exceeded the recommended permissible limits for a safe drinking water. The study reveals that the proximity of sampling points S1 and S2 to the abattoir, where effluent discharge occurs, could have been the reason for the higher values they exhibited for all the studied parameters than the other sampling points (S3 and control). The levels of the studied physicochemical parameters and heavy metals in samples S1, S2, S3 and control were statistically significant. The study therefore recommends that environmental health agencies should ensure that future sitting of abattoir around residential areas are prohibited and those still operational are strictly supervised to ensure that they operate within standard sanitary guidelines in order to protect the health of the people from water and food borne illnesses.

Studies were carried out to evaluate the structural effects of four inhibitors (Mono ethanolamine (MEA), phenyl glycidyl ether (PGE), N – (2- hydroxy – 3- phenoxy propyl) ethanolamine (NHPE) and N, N' – (-2 hydroxy – 3 – phenoxy propyl) ethanolamine (N N' HPE) in inhibiting the corrosion of mild steel in 0.1M HCl. Appropriate analytical procedures and instrumentation such as the use of Fourier transform infrared (FTIR) spectrophotometer were employed in the analysis of the structures of the inhibitors.Quantum chemical modeling calculation was employed to better understand the variation in the inhibition efficiencies of the studied inhibitors.After eight weeks of immersing the mild steel sheets in 0.1M HCl with each of the four studied inhibitors, the mean percentage weight loss of the mild steel were 17.74, 30.13, 5.39 and 1.08% for MEA, PGE, NHPE and NN1HPE respectively. The FTIR analysis of the structure of the inhibitors shows that the presence of functional groups such as –OH, -NH, Ar—C = C – and –OCH3 significantly helped to increase the inhibition efficiencies of NHPE and NN' HPE respectively.From the weight loss experiment, it was observed that the inhibition efficiencies of the four studied inhibitors on the mild steel in the acidic media decreased in the following order: N N1HPE > NHPE > MEA > PGE which was further confirmed by the FTIR analysis.The lower values of parameters such as ELUMO, energy gap, ionization potential, global hardness and total energy and as well as the higher valves of parameters such as EHOMO, dipole moment, electro affinity, electro negativity, chemical softness, total surface area and polarizability, obtained for NHPE and NN1HPE respectively greatly increased the adsorption and donation of their electrons to the metal substrate surface thus were able to more efficiently inhibit the rapid corrosion of the mild steel in the acidic media than the two other studied inhibitors (MEA and PGE).