Reducing nitrogen loss and salinity during ‘struvite’ food waste composting by zeolite amendment
The research paper investigates the effects of zeolite amendment on the composting process of food waste supplemented with struvite-forming salts (magnesium and phosphate). The study aims to address two significant issues in food waste composting: nitrogen loss and increased salinity (electrical conductivity, EC) due to the addition of struvite salts. The authors conducted experiments using synthetic food waste mixed with zeolite at concentrations of 5% and 10%, comparing these treatments to controls with no amendments and those with only struvite salts.
Key findings include:
- The addition of zeolite at 10% significantly reduced nitrogen loss to approximately 18% and lowered the final EC of the compost to 2.82 mS/cm, making it suitable for agricultural use.
- The study highlighted that while struvite salts effectively buffered pH levels, they also raised the EC to levels detrimental to plant growth. Zeolite's ability to adsorb ammonium ions played a crucial role in mitigating nitrogen loss and salinity.
- The composting process was monitored over 56 days, revealing that zeolite not only improved nitrogen conservation but also accelerated compost maturity, as indicated by a high seed germination index (SGI) of over 80% in treated composts.
- The research emphasizes the importance of balancing nitrogen conservation with salinity control to enhance the viability of struvite composting as a sustainable waste management practice.
This research paper is significant in the field of waste management and environmental science, particularly in composting practices. It contributes to ongoing discussions about sustainable food waste management by providing insights into how zeolite can be used to improve the composting process. The findings are particularly relevant for urban areas facing challenges with food waste disposal and the need for effective composting methods that minimize environmental impact. By demonstrating a practical solution to reduce nitrogen loss and salinity, the study offers valuable information for researchers, practitioners, and policymakers aiming to enhance compost quality and promote sustainable agricultural practices.
