Aerobic thermophilic composting of waste sludge from gelatin-grenetine industry

The objective of this research has been to prove that the waste sludge from the waste water treatment plant of Leiner Davis Gelatin Mexico, S.A. de C.V. (gelatin-grenatine manufacturers), represents an adequate substratum for aerobic composting with the static pile method and to evaluate the quality of the obtained product (compost). In addition, the aim of this work was to verify that composting is a suitable biotechnology, applicable to the exploitation of the mentioned sludge. The process of composting was carried out normally; only the thermophilic and mesophilic phases, characteristic for composting, were observed. The texture of the obtained product was satisfactory. The experiment served to establish the 'ideal' conditions for the process of solid fermentation (composting) under the conditions and the method used. The obtained compost, with a high content of calcium and alkaline pH, can be used as a conditioner for acidic or calcium lacking soils and as fertilizers (when applied in agronomic percentages), as well as for the recovery of eroded soils. (C) 2002 Elsevier Science B.V. All rights reserved.