Treatment of Effluent Water from Futo Hostel Using Carica papaya (Pawpaw) Seeds as Coagulant

Abstract

Access to clean water remains a critical challenge in many communities, particularly in densely populated areas like university hostels where wastewater often contains high levels of contaminants. This study explores an eco-friendly solution by investigating the effectiveness of Carica papaya (pawpaw) seed powder as a natural coagulant for treating effluent water from the Federal University of Technology, Owerri (FUTO) hostel. The untreated effluent exhibited high turbidity (722.75 NTU, Nephelometric Turbidity Units), elevated microbial counts (E. coli: 7.0 × 10⁴ cfu/mL; Klebsiella: up to 9.0 × 10⁶ cfu/mL), and non-compliant Chemical Oxygen Demand vs. (COD: 848 mg/L vs. NESREA, National Environmental Standards and Regulations Enforcement Agency Standard of 90 mg/L). Through systematic batch experiments, we evaluated the impact of coagulant dosage (0.1–2.0 g/L), stirring time (5–60 minutes), and pH (2, 4, 6) on treatment efficiency. Remarkably, the highest turbidity reduction of 86.70% (achieving 96.2 NTU) occurred at pH 2 with just 0.1 g/L coagulant after 10 minutes of stirring. At pH 6—a more practical range for real-world applications—a 71.24% reduction (99.9 NTU) was attained using 2.0 g/L after 60 minutes. Notably, treated water met NESREA standards for Biochemical Oxygen Demand (BOD: 0.30–0.40 mg/L) and Dissolved Oxygen (DO: 2.00–2.10 mg/L), though microbial levels remained above permissible limits. These findings highlight the promise of Carica papaya seeds as a sustainable, low-cost alternative to conventional chemical coagulants like alum. By leveraging locally available resources, this approach aligns with global efforts to promote green technologies in water treatment. However, further research is needed to address residual microbial contamination and optimize large-scale implementation. This work not only advances the scientific understanding of natural coagulants but also offers practical insights for communities seeking affordable wastewater solutions.