Evolution of temperature and chemical parameters during composting of the pig slurry solid fraction amended with natural zeolite
The research paper presents a study conducted over three months to investigate the composting processes of pig slurry solids that were amended with natural zeolite (clinoptilolite) at two different concentrations (1% and 2% by weight) compared to a control group with no amendments. The experiment was carried out outdoors in static piles, with ambient temperatures ranging from 8.0 to 34.7 °C. The initial water content of the pig slurry solid fraction (SF) was 77.1%, and no additional water was added during the composting process.
Key findings include:
- The temperature in the zeolite-amended substrates (S1 and S2) rose above 55 °C within 3 to 5 days, remaining elevated for 15 days, which is significant for pathogen destruction. In contrast, the control substrate only reached a maximum temperature of 29.8 °C.
- Chemical analyses revealed that the pH levels in the zeolite-amended substrates were generally lower than in the control during the thermophilic phase, likely due to the zeolite's affinity for ammonium ions.
- A notable decrease in ammonia nitrogen levels was observed in the zeolite-amended substrates compared to the control, indicating effective nitrogen retention.
- The study also monitored changes in dry matter content, ash content, and total nitrogen and phosphorus levels, showing that the zeolite amendments influenced the decomposition processes and nutrient retention.
The results suggest that the addition of natural zeolite can enhance the composting process of pig slurry solids by improving temperature management, reducing ammonia losses, and potentially increasing the hygienic quality of the final compost product.
This research paper is significant in the field of agricultural waste management and composting technology. It contributes to ongoing discussions about sustainable practices in livestock waste management, particularly in reducing environmental pollution and enhancing nutrient recovery. The findings highlight the potential of natural zeolites as an effective amendment in composting processes, which can lead to improved compost quality and reduced nitrogen losses. This research is beneficial for farmers, agricultural scientists, and environmentalists seeking to optimize waste management practices and improve soil health through better composting strategies.
