Title: TREATMENTS OF BASIC DYES BY MICROBIAL POPULATIONS IN ACTIVATED SLUDGE
Abstract: To elucidate the culture conditions and the inhibitive mechanism in the biological treatments of basic dyes, the dye concentration, cell concentration and the uptake of oxygen in media were measured in the course of cultures on a reciprocating shaker. The cultures were performed at 30°C by the use of media prepared from peptone, meat extract, glucose and mineral salts. In order to treat effectively the dye solution of about 20 ppm, it was necessary to use media, that were the concentration of 100 times of the BOD in the usual sewerage and were adjusted to pH 7.5. Basic Violet 1 owing to the high biofloculation despite the strong toxicity power induced the decrease ratio of 90% by the culture for 24 hours, while Basic Orange 22 did only about 10% owing to the low biofloculation despite the weak toxicity power. This difference of the biofloculations leaded Basic Violet 1 and Basic Orange 22 respectively to non- and unantagonistic inhibition. By the repeated inoculations in media of the same composition containing a certain dye, lag phases of the growth curves of the microbes became shorter to result from the acclimatization of microbes to the media. When the microbes acclimated to Basic Violet 1 were inoculated to the medium containing the other dye, acclimatization of the microbes was maintained for the basic dyes of a homologous series with Basic Violet 1 that was a triphenylmethane derivatives, but not for the basic dyes of the other series, the acid dyes and the direct dyes.