Enhancing sewer low-loss transportation by food waste microencapsulation treatment: Dual suppression of organic leaching and biofilm architecture-function for mitigating hazardous gases and blockage risks

Food waste management posed a critical global sustainability challenge, with significant environmental, economic, and social impacts. The installation of food waste disposers emerged as a primary strategy for source-separated food waste transfer to wastewater treatment systems through municipal pipelines. However, this approach accelerated the transformation of sewer systems into bioreactors and induced sewer pipe deterioration. Therefore, a novel microencapsulation method was developed and optimized to rapidly immobilize comminuted food waste particles. The stability of FW-encapsulated microcapsules was evaluated for their capacity to suppress organic leaching, destabilize functional biofilm architectures, and mitigate hazardous gas emissions and pipeline blockages in sewer systems during sewage conveyance. Results showed that FW-loaded microcapsules exhibited physicochemical stability against hydrodynamic shear and microbial degradation during sewer transport. It suppressed 33.62 mg/L organic matter release based on COD, reduced fluorescent substance accumulation/degradation, and limited macromolecular organics leakage. Microencapsulation destabilized sewer biofilm integrity via EPS reduction, disrupted humic acid stabilization, altered microbial dominance, and induced protein conformational loosening, impairing biofilm resilience. The technology mitigated sewer risks by curbing 3078.3 ppm VOC. It eliminating 100 % and 98.80 % increments of CH₄ and CO compared to crushed FW discharge increments(2.55 mg/L and 0.09 mg/L), suppressing 0.80 mg/L sulfide conversion increments, and minimizing sedimentation through particle size and suspended solids control. Integration with food waste disposers enhanced source-segregated organic collection, optimized hydro-transport to alleviate pipe deterioration, reduced 0.915 MtCO₂-eq transport-related carbon emissions, and improved treatment efficiency of wastewater treatment plants. This microencapsulation strategy provided a sustainable solution for FW management, combining infrastructure preservation, emission control, and resource recovery.