Assessment of Physicochemical Parameters and Heavy Metals in Sagamu Abattoir Waste Water Ogun State, Nigeria

Abstract

Abattoir wastewater is a great threat to environmental safety. This study was aimed at assessing the physiochemical constituents using standard methods and some heavy metals using Agilent Microwave Atomic Emission Spectrometer (MP-AES) 4200 model after sample digestion of wastewater from three (3) major abattoirs in Sagamu, Ogun State, Nigeria. The sample was digested using a mixture of nitric acid, hydrochloric acid and hydrogen peroxide. The digested samples were then analyzed for heavy metals. Data from the physicochemical characterization show that pH, TS, TDS, TSS and COD ranged from; (5.8 – 6.2), (11500 – 27733.33), (5500 – 9066.67), (6000 – 18666.67), and (1507.67 – 3671) respectively. The assessed heavy metals are in the range (mg/L): Zn (0.132-0.337), Cu (0.091 – 0.516), Mn (0.410 – 0.994), Fe (5.294 – 15.44), V (0.132 – 0.32), Cd (0.036 – 0.119), Ni (0.029 – 0.17), Pb (0.136 – 0.234), Cr (0.299 – 1.277), and Co (0.015 – 0.079). Zn, Cu and Fe are essential metals within tolerable limits except Mn that exceeded the limits of World Health Organization (0.04 mg/L) but below Federal Ministry of Environment (5 mg/L) while Ni, Pb and Chromium are above permissible limits in all samples.  The pretreatment of the wastewater before discharging into environment is highly recommended and more research should be done on remediation to reduce the abattoir wastewater heavy metals concentration and the effect it is having on the ecosystem and the environment at large.