Temperature and pH control in composting of coffee and agricultural wastes

One of the by-products of instant coffee production is a solid waste with h igh organic content. This waste is disposed of either by landfill sites or by burning as fuel. Both alternatives are considered economically and envir onmentally unsatisfactory due to the physico-chemical characteristics of th e waste. This study investigates the applicability of the forced aeration c omposting process to a mixture of this coffee waste and agricultural wastes . Approximately 40 tons of waste was used to set up the static piles. Tempe rature was used as the main parameter to enable control of the aeration rat e. Other parameters used to monitor the process were humidity, pH and carbo n/nitrogen ratio. The results obtained were satisfactory and the experiment s lead to the production of a high quality compost presenting a carbon/nitr ogen ratio of the order of 13/1 to 15/1. (C) 1999 Published by Elsevier Sci ence Ltd on behalf of the IAWQ. All rights reserved.