Investigating natural zeolite and wood ash effects on carbon and nitrogen content in grain residue compost

Abstract

The key aim of this work is to analyze and evaluate the possibilities of using fermented wastes (grain residue) for composting, taking into account carbon and nitrogen. The key performance task was to carry out research on composting fermented waste by inserting natural zeolite or biofuel ash and using a dynamic method in designed equipment and to determine the quality of the obtained compost with regard to its suitability for fertilization. The investigations were performed using laboratory composting equipment (Lithuanian patent No. 2008 081). The compost’s composition (the content of nitrogen and carbon), humidity, and pH were determined weekly. Upon using an additive of natural zeolite, losses of nitrogen decreased 65.6% and 84.0% – when zeolite and biofuel ash mixture was used. During the investigations differences between carbon content in the control specimens and in the specimens of compost with zeolite and with ash were identified and, on average, reached 51%, and in the specimens containing only zeolite – 20%. As the investigations of grain composting show, 1 kg of grain compost mixed with apple-tree leaves produced, on average, 94.25 mg/m3 NH4. When additives zeolite and zeolite with ash were used, this amount decreased up to 1.2 and 2.11 times, respectively. The same tendencies were also established for ammonia release from compost. When grain was composted together with leaves, 1 kg of compost released 58.5 mg/m3 CH4, H2S – 25.68 mg/m3 and 15.67 mg/m3 of VOC during 4 weeks. It is determined that the use of natural zeolite reduced CH4 emissions 1.16 times and H2S emissions 1.28 times, and upon using zeolite with ash these differences reached 1.25 and 1.47 times, respectively.