Comparing the costs of treating biogenic waste under Swiss conditions

The cost of treating biogenic waste is subject of discussion. However, there is not much data available comparing the costs of the different treatment alternatives. In this report the costs of the following treatment alternatives are compared: Agricultural composting along the fieldpaths in two different sizes, the composting on one small and two mid-sized open plants as well as one large enclosed plant, one large plant which combines anaerobic digestion with composting and one plant which treats all the biowaste in an anaerobic digestion before a short composting part at the end. To make comparison easier, many of the cost units, such as a fulltime job, are calculated with standardized values.<br>The comparative calculations indicate the lowest costs per ton treated for the composting in a mid-sized open plant, followed by the small open plant. The anaerobic digestion and the combination digestion/composting show higher costs per ton at about the same level as the larger size of the agricultural composting. The most expensive way to treat the biowaste seems to be the large composting plant in a fully enclosed building, followed by the small size agricultural composting. The agricultural composting needs as a by-work per ton about the doublelength of time compared with thefulltime jobs on the stationary plants.