November 2017
·
106 Reads
The largest wine alcohol distillery in the Americas is located in Mendoza and processes more than 150,000 tons of grape marc and lees from the region's wineries, generating large volumes of organic waste. These are traditionally mixed in different proportions and stockpiled over a lapse of time until their return to the wineries. This material is not stable and its use as an agricultural amendment can generate undesirable effects in the vineyards. The objective of the experiment was to characterize these residues and to evaluate their suitability for stabilization through large scale composting. A compost pile 3 m wide, 1.6 m high and 18 m long was used, spending 6 parts of fresh grape marc, 3 parts of depleted lees and 1 part of depleted grape marc. Periodic irrigations and turnings using different methods were performed. During the process, physical-chemical and microbiological parameters were monitored. The temperature of the thermophilic stage never exceeded 50 °C, stabilizing from the fourth month of elaboration. The highest microbial activity was recorded at the beginning of the process and decreased gradually during composting, with a higher abundance of bacteria compared to fungi. The final electrical conductivity was 9 dS m-1 , with a nitrogen content of 2 %. Removals with a turning machine optimized moisture, oxygenation and mixing of the material. Large-scale composting allowed obtaining a stable and mature compost although relatively saline; therefore, it was necessary to adjust the process.