Comamonas Pz-1 Enhances The Biodegradation And Mineralization Of Pyridine By Activated Sludge

Pyridine and its derivatives are highly toxic and carcinogenic,which pose a great threat to the ecological environment and human health.With the widespread implementation of new discharge regulations and new environmental protection laws,the harmless disposal of pyridine wastewater has become a major topic of research in China.High mineralization efficiency of activated sludge,that is,high degradation efficiency of intermediate products and high degradation efficiency of pure bacteria on organic matter.However,there are few studies on the degradation of components of pyridine and its derivatives 2-hydroxypyridine in wastewater,and so far there are few reports on the simultaneous mineralization and degradation of such mixed strains.In this paper,various degradation rates(substrate concentration,TOC,intermediate 2-hp)of pyridine by high efficiency bacteria and activated sludge were investigated.At the same time,the static batch experiment was used to investigate the degradation rates of pyridine by high efficiency bacteria and activated sludge with different concentrations.In this paper,various degradation rates of pyridine from activated sludge enhanced by different proportions of high-efficiency bacteria were also discussed,and the metabolic mechanism of pyridine degradation rate and mineralization rate and the optimal ratio of biological enhancement were studied by combining the growth trend of intermediate products with the relationship between substrate concentration and TOC.We took sludge from coking wastewater and domesticated the activated sludge capable of degrading pyridine(2mmol).Through the acclimated activated sludge,bacteria selection,screening and enrichment,3 strains of bacteria with metabolic effects on pyridine were obtained.Through the comparison of substrate degradation rate and OD value,a dominant strain of high-efficiency pyridine degradation was finally screened.To 16 s rDNA gene sequencing of the strain,the sequencing results with 16 s NCBI databases,the bacterium was identified as the highest homology of 99% Comanonas testosteroni pz-1 is the same.It is known from the known literature that the bacteria can degrade phenols,para-benzodiazepines,trimethylquinoline and other nitrogen-containing heterocyclic compounds,but in the previous literature,there are few studies on the degradation of pyridine by the bacteria.In this experiment,we first explore respectively C.testosteron efficient bacteria and activated sludge on the degradation rate of pyridine(substrate concentration,TOC,intermediate 2-HP),it can be seen that pyridine in 1.5 h is completely degradation,the intermediates 2-hydroxy pyridine metabolism,since 2.5h basic finish degradation,TOC2 h degradation rate was 73.2%,the degradation of TOC4 h rate was 80.9%.This indicated that c.teestosteroni could not only degrade pyridine,but also the intermediate product 2-hydroxypyridine,and achieve mineralization.The biological enhancement study of pyridine wastewater was conducted after the mixture of c.teestosteron and the acclimated activated sludge was mixed.The bacteria and acclimated acclimated sludge were combined in different dry weights to form a compound bacterial agent,and the treatment of pyridine wastewater was carried out in a collaborative manner.Group A(10mg C testosteroni + 290 mg of sludge)> Group B(5mg C.Testosteroni + 295 mg of sludge)> Group C(10mg C.testosteroni)> Group D(300mg sludge)> Group E(5mg C.Testosteroni)In group A,the degradation rates of effluent TOC and pyridine 2h were 85.80% and 95.83% respectively,and the degradation rates of 4h were 91.80% and 100.00% respectively,which were far better than other combinations.It is proved that the degradation bacteria combination is effective for the simultaneous degradation and mineralization of pyridine and its derivatives 2-hydroxypyridine,which can achieve both efficient degradation and efficient mineralization,and can be used as a compound bacteria agent in the treatment of pyridine wastewater.The results showed that pyridinedegrading bacteria could enhance the biodegradation and mineralization of pyridine by activated sludge.