Title: Parameters evaluation of the co-composting of sewage sludge and grass clippings using the respirometric method

Authors: Edvaldo José Scoton; Rosane Aparecida Gomes Battistelle; Barbara Stolte Bezerra; Adilson Renófio; Jorge Akutsu

Addresses: Univ. Estadual Paulista (UNESP), São Paulo, Brazil ' Univ. Estadual Paulista (UNESP), São Paulo, Brazil ' Univ. Estadual Paulista (UNESP), São Paulo, Brazil ' Univ. Estadual Paulista (UNESP), São Paulo, Brazil ' Universidade Federal de São Carlos (UFSCar), São Carlos, Brazil

Abstract: Despite several previous studies, a better understanding of the sewage sludge composting process is necessary. This study evaluates the use of an automated respirometer with hermetic rotary reactor (ARHRR) to evaluate O₂ consumption and CO₂ production during the co-composting of sewage sludge and grass clippings. For this research, we used an apparatus consisting of an automated respirometer with hermetic rotary reactor (ARHRR), a gas analyser, and a microcomputer for automatic data acquisition. The results show that the use of the ARHRR reduces the composting time to 30 days and produce no odour during the process. The compost thus produced showed a carbon/nitrogen ratio of 16:1 and a pH of 8.02, making it suitable for use as an agricultural fertiliser. The evaluation of the ARHRR by means of co-composting sewage sludge and grass clippings enables its use as a parameter for the design, operation and control of the composting process applied to a real scale process.

Keywords: solid waste management; respirometry; composting time; sewage sludge; grass residue; grass clippings; hermetic rotary reactor; oxygen; CO2; carbon dioxide; nitrogen; agricultural fertilisers.

DOI: 10.1504/IJEWM.2015.073034

International Journal of Environment and Waste Management, 2015 Vol.16 No.3, pp.262 - 274

Accepted: 20 Jul 2015
Published online: 12 Nov 2015 *

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