Decolorization and deturbidization of untreated abattoir effluent using a locally engineered bio-based adsorbent

Untreated abattoir effluent presents significant environmental risks due to its high color and turbidity. This study evaluated the performance of P-32 Powdered Activated Carbon (PAC), a locally engineered bio-based adsorbent, for color and turbidity removal from Kumasi Abattoir Ghana (KAG) effluent. Batch adsorption experiments were conducted with incremental P-32 PAC doses (5–25 g/L), and adsorption behavior was analyzed using Langmuir, Freundlich, and Elovich isotherm models. Optimal dose prediction compared the cubic polynomial model (CPM), exponential decay model (EDM), and modified EDM (mEDM). Baseline characterization revealed elevated color (11,125 Pt-Co) and turbidity (235 NTU) levels exceeding Ghana Environmental Protection Authority (GEPA) discharge standards by 5,460% and 214%, respectively. Turbidity removal reached 94% at 25 g/L, achieving GEPA compliance, whereas color removal peaked at 68%, but remained above the regulatory threshold. Statistical analysis revealed significantly higher turbidity removal efficiency than color (p < 0.01). The nonlinear Freundlich model best described the adsorption process, with greater adsorption capacity (intensity) for color (turbidity). The three models predicted optimal compliance doses ~12 g/L─ turbidity, and 33 - 95 g/L (CPM→ mEDM)─ color. Higher (lower) pH favored color (turbidity) removal. P-32 PAC effectively remediates abattoir effluent, achieving turbidity compliance but requiring higher doses for color. • A locally engineered activated carbon reduces abattoir effluent turbidity by 93.68%, meeting Ghana’s discharge limit • Color removal attained 68.32%, but requires a higher dosage to meet the discharge limit • Higher pH boosts color removal, while lower pH helps reduce turbidity in the effluent treatment.