Performance evaluation of an integrated aerobic biological treatment and nanosilica adsorption process: A case study of Saravan landfill leachate, Gilan province, Iran
Journal of Behdasht dar Arseh (i.e., Health in the Field),
Vol. 13 No. 4 (1404),
5 September 2026
,
Page 31-41
Abstract
Background and Aims: Landfill leachate treatment, owing to the high concentrations of recalcitrant organic and inorganic compounds, requires the application of combined treatment processes. This study aimed to evaluate the performance of an integrated aerobic biological treatment and nanosilica adsorption system for the treatment of leachate from the Saravan waste landfill.
Materials and Methods: Following physicochemical characterization, leachate samples were treated in a laboratory-scale aerobic reactor for 25 days. The reactor effluent was subsequently brought into contact with nanosilica adsorbent for further pollutant removal. The effects of operational parameters, including contact time, pH, and adsorbent dosage, on pollutant removal efficiency were investigated. Ethical principles were observed throughout the study.
Results: The results indicated that the raw leachate had moderate to high biodegradability, making it suitable for biological treatment. The aerobic biological process achieved removal efficiencies of 73% for BOD5, 60% for COD, and 57% for TSS; however, heavy-metal removal at this stage was limited. During the subsequent nanosilica adsorption step, under optimal conditions—45 min contact time, pH 4, and an adsorbent dose of 1 g/L, the removal efficiencies of BOD5, COD, and TSS increased to 89%, 87%, and 87%, respectively. Regarding heavy-metal removal, applying nanosilica at a contact time of 75 min, a fixed adsorbent dose of 0.4 g/L, and pH values ranging from 7 to 10 resulted in the maximum removal efficiencies for metals from the biologically treated effluent.
Conclusion: Integrating aerobic biological treatment with nanosilica adsorption, provided that operational variables are carefully optimized according to the target pollutant, can serve as an efficient and scalable approach for treating landfill leachate with suitable biodegradability.
- landfill leachate
- Organic load
- Aerobic biological treatment
- Nanosilica adsorption
How to Cite
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