Performance improvement of thickening and dewatering processes of biological excess sludge and anaerobic digested sludge of municipal wastewater using acid-thermally modified Nano- Montmorillonite
Journal of Behdasht dar Arseh (i.e., Health in the Field),
Vol. 12 No. 4 (1403),
7 July 2025
,
Page 51-63
https://doi.org/10.22037/jhf.v12i4.47279
Abstract
Background and Aims: The optimal performance of sludge thickening and dewatering processes is of great importance. Due to the poor dewaterability of sludge, synthetic coagulants are commonly used to enhance the efficiency of these processes. However, because of financial and quality-related limitations of these chemicals, extensive efforts are underway to replace them with natural materials. This study aimed to evaluate the feasibility of using modified Nano-Montmorillonite as a sludge conditioner.
Materials and Methods: Sludge samples were collected from the South Tehran Wastewater Treatment Plant and conditioned using varying doses of the modified Nano-Montmorillonite (50–400 mg/g dry). The optimal dose was determined based on the specific resistance to filtration (SRF). Further tests were conducted to assess the effects on the extracellular polymeric substances (EPS) of the conditioned sludge. All phases of the study were conducted in full compliance with ethical standards.
Results: At the optimal dose of modified Nano-Montmorillonite (200 mg/g dry solids), the highest reduction in SRF was observed: 62.82% for waste activated sludge and 66.47% for anaerobically digested sludge. At this dose, zeta potential and bound water content were reduced by 93.75% and 80.38% for waste activated sludge, and by 89.74% and 77.93% for anaerobically digested sludge, respectively.
Conclusion: The results demonstrate that modified Nano-Montmorillonite, by altering the total organic carbon, protein, and polysaccharide content of extracellular polymeric substances, can significantly enhance the performance of thickening and dewatering processes in municipal wastewater sludge.
- Sludge thickening
- Sludge dewatering
- Nano-Montmorillonite
- Extracellular polymeric substances
How to Cite
References
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