Application of Immobilized White Rot Fungi in the Treatment of Anaerobic Digestion Sludge

• • Cotton thread immobilization outperformed PVA, wood chips, and sodium alginate, yielding earlier and more sustained enzyme activity, higher biomass, and minimal loss, leading to a 10.09% TCOD removal from ADS. • • WRF treatment selectively degraded soluble EPS, reducing total protein and polysaccharide content by 8.9 mg·L−1, and decreased capillary suction time by 27.33%, significantly enhancing sludge dewaterability. • • Periodic replacement of half the carrier every 4 days maintained fungal activity over a 16-day treatment, achieving 12.7% TCOD removal, 16.5% ammonia nitrogen removal, and 59.4% UV254 reduction. • • The dual action of WRF—organic matter degradation and physical conditioning—promoted sludge floc aggregation and particle homogenization, addressing both recalcitrant organics and dewatering bottlenecks.