A novel integrated wastewater stabilizer coupled with fly ash–bentonite adsorption for efficient pulp effluent treatment

Wastewater treatment technologies in the pulp industry often fail to operate optimally under certain operational conditions. Therefore, the objective of this study was to improve the wastewater quality using the developed wastewater stabilizer with combined adsorbers (fly ash and bentonite). The results revealed that the application of the adsorption method using fly ash-based adsorbents has effectively improved wastewater quality through the combination of treatment (Refrigeration + Atomization + Waves + Aeration + Ionization processes) and the use of an adsorbent ratio (0.75 Fly Ash:0.25 Bentonite). Specifically, the integrated system achieved a significant reduction in the extreme influent temperature (from 53.3 °C to 23.3 °C) and neutralized the effluent pH (from 7.11 to 8.49). Furthermore, it yielded significant decreases in colour by 50.6%, chemical oxygen demand (COD) by 32.1% (down to 433 mg/L), and total suspended solids (TSS) by 92.3% (down to 8 mg/L). Continuous flow kinetic analysis further confirmed that Adsorbent C possessed a highly competitive maximum adsorption capacity of 44.8 mg/g based on the Thomas model. The integrated stabilizer–adsorption system demonstrated high efficiency and significant potential as a sustainable and scalable approach for improving industrial wastewater quality, especially in pulp processing applications.