The Study Of Functional Microorganism Bioaugmantation In Coking Wastewater Activated Sludge

To screen some functional microbes from coking wastewater activated sludge and to screen some activator that the functional microbes in coking wastewater activated sludge could be activated by those activators, at the same time for the sake of researching the functional microorganisms strengthen effect in the coking wastewater activated sludge, three approachs have been used to screen and study as follow:Firstly,Four domainent bacteria strains A, B, C, D has been isolated after enriched from the enrichment environment. And six domainent bacteria strains A1, B1, C1, D1, E1, F1 has been isolated by TYG, Gao1 or Beef-cream peptone medium but not enriched from the enrichment environment. Ten strains A, B, C, D A1, B1, C1, D1, E1, F1 has been identify by PCR-DGGE in theory. Two strains A1and C1 are dominent functional microorganism, three strains B1, D1and E1 are non-dominent functional microorganism and five strains F1, A, B, C, D, is non- functional microorganism. As it shows from experiment result that strengthened with dominent functional microorganism A1 in activated sludge, the COD of coking wastewater decreases to 128 mg/L after 40 hours of aeration and it go stable; In the same way, strengthened with functional microorganism B1, C1, D1, E1 the COD decreases to 160 mg/L, 118 mg/L, 156 mg/L, 170 mg/L after 48 h, 32 h, 40 h , 48 h of aeration and they go stable respectively; strengthened with non-functional microorganism F1, A, B, C, D the COD decreases to 218 mg/L , 216 mg/L ,215 mg/L ,219 mg/L 217 mg/L after 56 hours of aeration and they go stable respectively, basically the same with the COD when no candidates bacteria are present in the activated sludge, which decreases to 220 mg/L after 56 h of aeration and it go stable. Conclusions: The presence of dominant functional microbes in activated sludge is the key factor in strengthening its capability of biological treatment; and the significance of the presence of non-dominant ones is second compared with dominant ones; the presence of non-functional microbes shows no effects. This study suggests that PCR-DGGE is effective as a new supplementary means of screening functional microbes from activated sludge. More importantly, the profile of PCR-DGGE allows the researchers to be conscious of whether the screened microbes are functional ones in the habitat of original activated sludge in advance, so that the non-functional microbes and functional ones can be identified clearly.Seeondly,This study employed the BIOLOG micro-plate technique to screen out the activators from growth factors (amino acids, bases), vitamins, macroelements, trace elements, which are the necessities of microorganism reproduction. Six sorts of coking wastewater activated sludge activators were screened out. PCR-DGGE and molecular phylogenetic tree were used for the analysis of microorganism functional bacteria that have been already activated by the screened activators. The analysis suggests that it is possibly for activatorsγ-Ami,VB12,L-Pro,DL-Ala to respectively activate phenol degradation functional bacteria Rhodococcus erythropolis,Alcaligenes faecalis,Uncultured Pseudomonas sp.,Pseudomonas sp. in activated sludge; and it is possibly for activators A and L-His to respectively activate non-phenol degradation functional bacteria Micrococcus Sp.,Uncultured Bacillus sp in activated sludge. The research results suggest also that Biolog micro-plate screening program is characterized by simplicity, convenience, small space and less materials. Especially, multiple objects to be screened can be placed into only one micro-plate to perform high throughout screening simultaneously.The rare-earth salt is a special activator of activated sludge. It is not need the BIOLOG micro-plate technique to screen out. In this study,PCR-DGGE, built phylogenetic tree has been used in this study to analyze its biological diversity and to make molecular ecology study on the effects of rare-earth salt lanthanum chloride (LaCl₃·3H₂O) on the growth of some coking wastewater activated sludge microorganisms in TGY culture. It shows that at low dose of 5mg/L and 10mg/L, LaCl₃·3H₂O could stimulate the growth of coking wastewater activated sludge in TYG culture medium to some extent, and its diversity was more than the control group; at high dose of 200mg/L and 400mg/L, LaCl₃·3H₂O could inhibit the growth of coking wastewater activated sludge in TGY culture medium to some extent, and its diversity was less than control group. At the low dose of 5mg/L and 10mg/L, LaCl₃·3H₂O could stimulate the more representative microorganism groups, non-culturable microorganism group Uncultured Pseudomonas sp., Uncultured Bacillus sp. and Uncultured bacterium clone SR40 and culturable microorganism group Bacterium rJ11..