Application of zeolites in organic waste composting: a review

While composting is one of the sustainable solutions for the recycling of organic solid waste (OSW) however, it has some drawbacks that need to be addressed properly. For instance, nitrogen loss, mobility of heavy metals (HMs), greenhouse gases emissions, low productivity, and antibiotic-resistant gens enrichment are some of the technical issues of traditional composting processes. The application of zeolite and other additives to the OSW composting process is a very interesting interdisciplinary research topic that are studied by many researchers worldwide. This review intends to discuss the latest advancements on the applications of zeolites to the OSW composting processes and the its effect on the compost quality, soil remediation, nutrient management and plants growth. According to the published reports, modification of OSW compost with zeolite not only improves physicochemical properties of the compost product but also enhances microbial activities by promoting OSW decomposition and reduce the duration of the composting process. Furthermore, zeolitic additives can reduces greenhouse gases and ammonia emissions of the composting process. Zeolite-modified compost has reduced total and available HMs and reduced antibiotic resistance genes. Zeolite can upgrade the compost quality by enhancing maturity, and decreasing salinity. Last but not least, zeolite contributes to the optimization of anaerobic digestion for the production of biogas. Compost modified with zeolite exhibited improved crop yield and water retention and prevent soil nutrient losses. Overall, addition of natural zeolites to composting products are beneficial to agricultural soils and for soil remediation purposes. It is noteworthy that the addition of zeolitic aluminosilicate to soil might change the soil texture in the long term. Therefore, more in-depth researches are necessary to evaluate the cumulative effect of the addition of zeolitic minerals to agricultural lands.