Xu-dong Li | Search PubMed

PubMed2006

[Relationship between several biologic indices and degradation efficiency of bioaugmentation system].

Because of the existence of some unstable factors, the effluent water from a bioaugmentation refinery wastewater treatment system usually exceeds the provided standard. To solve this problem, the relationship between the bacteria number, dehydrogenase, catechol 1,2-dioxygenase(C12O), catechol 2,3-dioxygenase(C23O) and the degradation efficiency of the bioaugmentation and control system is investigated and discussed. Using ERIC-PCR technology, we studied the changes of the microbial populations before and after treatment. The results show addition of microorganisms agent can increase the bacteria number, enzyme efficiency and the efficiency of the reactor. There exists a positive relationship between the bacteria number, C23O and the degradation efficiency in the bioaugmentation reactor. The microbial populations in both the reactors are stable before and after run. C12O is a kind of induction enzyme and its efficiency declines while the degradation efficiency increases.

Bacteria, Anaerobic↗

PubMed2005

[Isolation of PVA-degrading symbiotic bacteria and examination of degradation characters].

From printing and dyeing actived sludge, PVA- degrading symbiotic bacteria was isolated. The symbiotic bacteria is composed of B1 and B2. During PVA biodegradation, B1 produces a certain growth factor for B2, B2 produces PVA-degrading enzyme. The PVA-degrading characters of the symbiotic bacteria are examined. When the concentration of PVA was 0.1, 0.5, 1g/L respectively,more than 80% of PVA was degradated after 7days. During the treatment of the dyeing and printing wastewater, when the temperature was 30 degree C ,the removal of COD(Cr) was 69.75%, the proper treating time was 12h.

Bacteria↗

PubMed2003

[A nested case-control study on child sensory integrative dysfunction].

OBJECTIVE: To explore risk factors and protective factors of sensory integrative dysfunction (SID) among preschool and school children in Beijing, and to identify potential risk factors of SID. METHODS: Three hundred and ten kindergarten children were investigated twice in 1993 and 1999 by "The Child Sensory Integration Check List" and "General Information Questionnaire". A nested case-control study was carried out by single variable and multivariate conditional logistic regression analysis to find out the risk factors of SID. RESULTS: In the SID incidence group, the risk factors of SID were edema during pregnancy (OR = 7.06), paternal age (OR = 1.28), suffering from diseases before 3 years old (OR = 1.13), while the protective factor was family support network during school age (OR = 0.54). In the SID self-recovery group, the risk factors of SID were suspected attention-deficit hyperactivity disorder (ADHD) among maternal cousins (OR = 3.02), social ethos (OR = 1.69), consistency of parental discipline (OR = 1.45), while the protective factors were living condition and environment for entertainment (OR = 0.37), parental care during school age. In the SID negative group, the risk factors of SID were maternal contracted pelvis (OR = 3.45), less chance in enjoying audio and video entertainment during school age (OR = 1.98), suspected ADHD among paternal cousins (OR = 1.89), consistency of parental discipline (OR = 1.75), suspected ADHD among maternal cousins (OR = 1.48), paternal occupation during school age (OR = 1.19), while the protective factors were family support network (OR = 0.56) and maternal educational background (OR = 0.38) during preschool age. CONCLUSION: Our data showed that the risk factors of child SID were mainly associated with biological and genetic factors. Psychosocial factors seemed to be the secondary risk factors of SID.

Attention Deficit Disorder with Hyperactivity↗