Use of wood shaving and water lily (Eichhornia crassipes) as bulking agents in aerobic treatments of horticultural waste

In aerobic treatments for solid waste with high humidity content and low lignine and cellulose, bulking agents must be applied in order to improve the aeration and the performance of the process. In the present work, a mixture of wood shaving and dry water lily (Eichhornia crassipes) was tested as bulking agent at different percentages (5, 10, 15 and 20 %). Each assay was prepared by triplicate and was composed by a mixture of the six most important horticultural waste from a big market (Central de Abasto de la Ciudad de Mexico). The assays were run in acrylic cells where 1200 g of organic waste and bulking agent were mixed. During the process, pH, temperature, density, humidity content, leachate generation and mass reduction were measured. Results showed that the high rate of humidity of this mixture could be regulated by adding dry materials. These agents absorb some leachate during the first weeks of the process and the texture in the windrow was improved avoiding the anaerobic biodegradation of this kind of waste. Evaluating the leachates generation and the mass reduction, the best results have been obtained using 15 % of bulking agent, which it was composed by 6:1 wood shavings and dry water lily.