Application of iron nanaoparticles in landfill leachate treatment - case study: Hamadan landfill leachate

This study was performed with the objective of determining the efficiency of iron nanoparticles for reducing chemical oxygen demand (COD), 5-day biological oxygen demand (BOD(5)), total solids (TS) and color of Hamadan city landfill leachate. Experiments were performed in a batch reactor and the main effective factors of pH, reaction time and concentration of iron nanoparticles were investigated. The obtained data were analyzed with One-Way ANOVA statistical test and SPSS-13 software. Maximum removal efficiencies were 47.94%, 35%, 55.62% and 76.66% for COD, BOD(5), TS and color, respectively (for 2.5 g/L iron nanoparticles dosage, pH = 6.5 and 10 min reaction time). The results showed that the removal of COD, BOD(5) and color had reverse relationship with contact time and TS removal followed a direct relationship (P < 0.05). Iron nanoparticles could remove averagely 53% of leachate COD, BOD(5), TS and color in a short contact time (10 min) increasing pH up to 6.5, increased the removal efficiency for COD, BOD(5), TS and color and then removal efficiency decreased with increasing pH to 8.5. Increasing the dosage of nanoparticles to 2.5 g/L increased the efficiency of process. High compatibility and efficiency of this process was proven by landfill leachate pre-treatment or post-treatment, so this removal method may be recommended for municipal solid waste landfill leachate treatment plants.