Sawdust and natural zeolite as a bulking agent for improving quality of a composting product from anaerobically stabilized sewage sludge
The research paper investigates the use of sawdust (SWD) and natural zeolite (clinoptilolite, Cli) as bulking agents to enhance the quality of compost produced from dewatered anaerobically stabilized primary sewage sludge (DASPSS). The study aims to increase the humic substances in the final compost product, which is crucial for its agricultural application. The methodology involved mixing DASPSS with 20% Cli and varying concentrations of SWD (10%, 30%, and 40% w/w).
Results indicated that increasing the concentration of sawdust led to a corresponding increase in humic substances in the final compost. The addition of clinoptilolite effectively reduced heavy metal concentrations, which is significant given the environmental risks associated with heavy metals leaching into ecosystems. The maturity of the compost was assessed using a germination index through oat cultivation, revealing that the compost was non-phytotoxic after 75 days of maturation.
The study also employed the generalized acid neutralization capacity procedure to evaluate metal leachability, finding that higher pH levels corresponded with decreased heavy metal concentrations. The article concludes that the combination of sawdust and clinoptilolite not only improves the quality of compost but also mitigates the risks associated with heavy metal contamination, making it a viable option for sustainable waste management.
This research paper is significant in the field of environmental technology and waste management, particularly in addressing the challenges associated with sewage sludge disposal. It contributes to ongoing discussions about sustainable practices in composting and the utilization of organic waste materials. By demonstrating the effectiveness of sawdust and natural zeolite in enhancing compost quality and reducing heavy metal leachability, the study provides valuable insights for researchers, policymakers, and practitioners in waste management. The findings support the development of eco-friendly composting methods that can be applied in agricultural practices, thereby promoting soil health and reducing environmental pollution.
