Comparison of Bioaugmentation and Semipermeable Cover as Strategies for Micro-Pollutant Removal in Sewage Sludge Composting Angeles-De Paz, Gabriela Díaz-Moreno, Miguel Ángel Trujillo Reyes, Ángeles Postigo, Cristina Aranda, Elisabet Calvo Sáinz, Concepción Robledo-Mahón, Tatiana bioaugmentation composting Emerging pollutants Untreated sewage sludge (SS) and misused stabilization technologies have contributed to great contamination and the accumulation of various pollutants in agricultural soils. Regarding micro-pollutants’ degradation, scalable and effective technologies are still scarce. Although many attempts at composting adaptations have been discussed, only a few have been tested individually under outdoor conditions. To investigate different composting methods (bioaugmentation and semipermeable cover) for the removal of micro-pollutants frequently found in SS, we performed a set of on-site experiments. Windrows of SS and olive pruning were used as the compostable material and were subjected to (i) bioaugmentation with the fungus Penicillium oxalicum, (ii) covered composting, (iii) covered and bioaugmented composting, and (iv) a conventional composting pile, which was included as a control. The entire experiment lasted 99 days. Bioaugmentation without cover increased the phosphorus content, favored a reduction in heavy metal content, and was the only treatment that reduced carbamazepine at the end of the process. Moreover, the inoculation of P. oxalicum under semipermeable cover increased the richness, diversity, and dominance of specific microbial taxa and total bacterial abundance. The four mature composts obtained met the standards required to be classified in the B fertilizer category, showing that we reduced most of the micro-pollutants, and passed the germination test. 2025-09-18T11:54:02Z 2025-09-18T11:54:02Z 2025-07-25 journal article Angeles-de Paz, G.; Díaz-Moreno, M.Á.; Trujillo-Reyes, Á.; Postigo, C.; Aranda, E.; Calvo, C.; Robledo-Mahón, T. Comparison of Bioaugmentation and Semipermeable Cover as Strategies for MicroPollutant Removal in Sewage Sludge Composting. Toxics 2025, 13, 620. https://doi.org/10.3390/ toxics13080620 https://hdl.handle.net/10481/106448 10.3390/toxics13080620 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional MDPI