Treatment Evaluation of Aluminium Can Manufacturing Wastewater

Authors: *Ekebafe, O.L., Uduma, A., Mahmud, H. And Nworie, E.C.

DOI Info: http://doi.org/10.5281/zenodo.18061001

ABSTRACT

Untreated aluminium can manufacturing effluent can threaten both the environment and public health. This study assessed the physicochemical and biological characteristics of wastewater from the rinse–mobility sections of two aluminium packaging plants, referred to as alpha and beta, and evaluated the effectiveness of their treatment processes. Representative samples were collected before and after treatment and analysed for potential of hydrogen (pH), total suspended solids (TSS), chemical oxygen demand (COD), biochemical oxygen demand over five days (BOD₅), nutrients, heavy metals, and microbial presence using standard procedures. Post-treatment, pH values approached neutrality: 6.25 at alpha and 6.62 at beta, both within the discharge limits of the National Environmental Standards and Regulations Enforcement Agency (NESREA) (6.0–9.0) and the Ogun State Environmental Protection Agency (OGEPA) (6.5–8.5). BOD₅ values were below the permissible 30 mg/L, at 18 mg/L for alpha and 22 mg/L for beta. COD varied: alpha recorded 80 mg/L, exceeding OGEPA’s limit (50 mg/L) but within NESREA’s allowance (250 mg/L), while beta achieved 70 mg/L. TSS reductions were notable, at 12 mg/L (alpha) and 6 mg/L (beta). Both plants achieved compliance for iron, zinc, copper, chromium (VI), nickel, and aluminium, with final aluminium levels of 0.05 mg/L (alpha) and 0.06 mg/L (beta). Microbial loads also fell significantly, with bacteria reduced from 10⁶ to 10³ colony-forming units per millilitre (CFU/mL) at alpha and from 10³ to 10² CFU/mL at beta, alongside similar yeast reductions. Overall, treatment substantially improved effluent quality, though further optimisation is required to achieve full compliance and ensure environmental safety.

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