State-of-the-art of anaerobic digestion technology for industrial wastewater treatment K.V. Rajeshwari*, M. Balakrishnan, A. Kansal, Kusum Lata, V.V.N. Kishore Tata Energy Research Institute, Darbari Seth Block, Habitat Place, Lodi Road, New Delhi 110 003, India Received 10 February 1999; received in revised form 3 May 1999; accepted 7 July 1999 Abstract Anaerobic digestion is the most suitable option for the treatment of high strength organic euents. The presence of biodegradable components in the euents coupled with the advantages of anaerobic process over other treatment methods makes it an attractive option. This paper reviews the suitability and the status of development of anaerobic reactors for the digestion of selected organic euents from sugar and distillery, pulp and paper, slaughterhouse and dairy units. In addition, modi®cations in the existing reactor designs for improving the eciency of digestion has also been suggested. # 2000 Elsevier Science Ltd. All rights reserved. Keywords: Anaerobic digestion; Reactors; Euents; Sugar; Distillery; Pulp and paper; Slaughterhouse; Dairy 1. Introduction There is a growing interest in alternate energy sources as a result of increased demand for energy coupled with a rise in the cost of available fuels. Rapid industrialization has resulted in the generation of a large quantity of euents with 1364-0321/00/$ - see front matter # 2000 Elsevier Science Ltd. All rights reserved. PII: S1364-0321(99)00014-3 Renewable and Sustainable Energy Reviews 4 (2000) 135±156 www.elsevier.com/locate/rser * Corresponding author. Tel.: +91-11-4622-246/4601-550 ext. 2141; fax: +91-11-4621-770/4632-609. E-mail address: rajikv@teri.res.in (K.V. Rajeshwari).