Physico-Chemical Properties and Heavy Metals Assessment of Wastewater Discharged from Selected Cosmetic Industries in Nigeria

Abstract

In this study effluents discharge from three cosmetic industries within Lagos and
Ogun State of Nigeria were analyzed for heavy metal concentration using
Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES)
technique and measurement of selected physicochemical properties was also
carried out. The heavy metals analyzed include: Cadmium (1.173±0.737 mg/L),
Lead (1.173±0.749 mg/L), Zinc (1.154±0.691 mg/L), Nickel (1.134±0.718 mg/L),
Iron (1.186±0.746 mg/L) and Mercury (0.294±0.227 mg/L). Mercury shows the
lowest concentration among the determined heavy metals while Iron (Fe) has
the highest concentration in the effluents. The effluents from two industries
located in Lagos State (sample C and B) contain higher concentrations of all
heavy metals under study compared to the effluents from the cosmetic industry
located in Ogun State (sample A) with total mean concentrations of 1.72 mg/L,
0.88 mg/L and 0.46 mg/L respectively. One way ANOVA analysis of the heavy
metal distribution in the effluents of the three cosmetic industries shows no
statistical significant difference indicating that difference observed in the
concentrations of the heavy metals is not dependent on the location but rather
due to the process of production. The physicochemical properties: Electrical
conductivity (EC), Biological oxygen demand (BOD), Chemical oxygen demand
(COD), Total solid (TS) and Total dissolved solid (TDS) shows average values
of 3034.9±14.27 µS/cm, 92.90±3.57 mg/L, 206.67±1.42 mg/L, 8791.78±23.46
mg/l and 1350.35±6.97 mg/L respectively which are above the regulatory
bounds of World Health organization and Standard organization of Nigeria.