BIOCHEMICAL DECOMPOSITION OF COAL-TAR DYES I. : BIOCHEMICAL DECOMPOSITION AND IDENTIFICATION OF DECOMPOSED PRODUCTS

Biochemical degradation test of food coal-tar dyes using sludge was studied in order to evaluate their safty. It was found that some dyes were little decomposed under aerobic condition but four azo dyes were readily decomposed under anaerobic condition. These were Food Yellow No.4, No.5, and Food Red No.2, No.102. Decomposed products of these four azo dyes by sludge under anaerobic condition wcre identified as sulfonilic, naphthionic acids and so on.