Heterogeneity of zeolite combined with biochar properties as a function of sewage sludge composting and production of nutrient-rich compost
The research paper investigates the effects of combining biochar and zeolite as additives in the composting process of dewatered fresh sewage sludge (DFSS). The study utilized 130-L lab-scale reactors to assess the composting efficiency and the quality of the resulting compost. The authors found that the addition of a mixture of biochar (B) and zeolite (Z) significantly improved composting efficiency compared to treatments with biochar alone or no amendments. Specifically, the optimal combination of 12% biochar and 15% zeolite (12%B + 15%Z) enhanced temperature control, water-holding capacity, CO2 emissions, and nutrient content while reducing phytotoxicity.
During the thermophilic phase of composting, the treatments with biochar and zeolite showed a marked increase in dissolved organic carbon and nitrogen levels, indicating improved microbial activity and nutrient availability. The maturity parameters indicated that the compost with 12%B + 15%Z reached a more mature state within 35 days, meeting the permissible limits for organic farming. The study also highlighted that the final compost produced from this combination had lower pH and electrical conductivity, which are favorable for plant growth.
Greenhouse experiments demonstrated that the compost enriched with 12%B + 15%Z significantly improved the yield of Chinese cabbage (Brassica rapa chinensis L.), with the highest biomass observed in this treatment. The findings suggest that the synergistic effect of biochar and zeolite not only accelerates the composting process but also enhances the nutrient profile of the compost, making it a viable option for sustainable waste management and agricultural applications.
This research paper is significant in the field of waste management and sustainable agriculture as it addresses the pressing issue of sewage sludge disposal, which poses environmental challenges due to its heavy metal content and pathogens. By exploring the combined use of biochar and zeolite, the study contributes to ongoing discussions about innovative composting techniques that can enhance the quality of compost while reducing environmental impacts. The findings provide practical insights for farmers and waste management professionals looking to improve soil fertility and crop yields through organic amendments. The research also emphasizes the importance of utilizing waste materials in a sustainable manner, aligning with global goals for waste reduction and resource recovery.
