Degradation of 2, 4-dinitrophenol (2, 4-DNP) by non-acclimated activated sludges augmented with 2, 4-DNP degrades

摘要

Two bacterial strains, D3213 and E22, which have constitutive and inducible degradability of 2, 4 -dinitrophenol (2, 4-DNP) respectively were isolateds from activated sludge acclimated to 2, 4-DNP. To evaluate effects of those isolateds on 2, 4-DNP treatment in activated sludge, each strain was introduced into activated sludge taken from a municipal sewage plant. When each strain was inoculated at 0.3 or 0.4 percent of total biomass, 2, 4-DNP was completely degraded in a day. Even when inoculum fraction was 0.03 or 0.04 percent, 2, 4-DNP was degraded in 5 or 6 days irrespective of the strain, which had either constitutive or inducible degradability of 2, 4-DNP. No degradation was appeared in the activated sludge without inoculation of either strain up to 11 days. The results obtained suggest that the induction period of strain E22 was too short to be neglected in the 2, 4-DNP treatment and / or a lag period prior to the initiation of 2, 4-DNP degradation by strain D3213 may exist under the coexistence of more degradable substrate which repress the catabolism of 2, 4-DNP.