Biodegradation and COD removal of p-Cresol in a denitrification baffled reactor: Performance evaluation and microbial community. (June 2018)

• Record Type: Journal Article
• Authors: Mahdavianpour, Mostafa; Moussavi, Gholamreza; Farrokhi, Mehrdad
• Is Part Of: Process biochemistry. Volume 69(2018)
• Page Start: 153
• Page End: 160
• Publication Date: 2018-06
• Subjects: Biodegradation -- p-Cresol -- Denitrification baffled reactor -- Dehydrogenase activity -- Bacillus sp.; Biochemical engineering -- Periodicals; Biotechnology -- Periodicals; Biochemistry -- periodicals; Biotechnology -- periodicals; Chemical Engineering -- periodicals; Génie biochimique -- Périodiques; Biotechnologie -- Périodiques; Biochemical engineering; Biotechnology; Periodicals; 660.63
• DOI: 10.1016/j.procbio.2018.03.016
• Languages: English
• ISSNs: 1359-5113

Abstract

Graphical abstract: Highlights: Main parameters on DnBR were optimized for biodegradation and COD removal of p -Cresol from wastewater. Enzymatic activity of bacterial community was investigated using dehydrogenase activity (DHA). COD/NO3 − ratio was optimized for effective removal of p -Cresol through denitrification. p -Cresol degradation and COD removal was proved using confirmatory experiments. p -Cresol degrader bacteria were identified by PCR. Abstract: A denitrification baffled reactor (DnBR) was developed to treat p -Cresol-laden wastewater. The effects of different operational parameters including p -Cresol initial concentration, hydraulic retention time (HRT), COD/NO3 −, salinity and nitrate-free influent were studied on biodegradation and COD removal of p -Cresol. The results show that complete degradation of 1000 mg/L p -Cresol could be reached at HRT of 24 h. Also, in this condition, corresponding COD and nitrate concentration (2500 mg/L for both) were decreased to about 83 mg/L and 4.5 mg N/L, respectively. There was not a significant failure in the performance of the bioreactor at HRT value of 4 h and nitrate removal rate of 1.65 kg N/m 3 d was reached. The highest dehydrogenase activity of the DnBR was 17.65 μgTF/gVS d for organic loading rate (OLR) of 7.5 kgCOD/m 3 d. DnBR could tolerate salinity concentration of 10 g NaCl/L, however increasing of salinity from 10 to 20 g/L caused moderate failure in the reactor performance. The optimum COD/NO3 − was 0.9. Microbial community was also investigated and PCR results revealed that Bacillus megaterium, Bacillus aryabhattai, and Bacillus cereus were the predominant bacteria in degradation and mineralization of p -Cresol. Accordingly, DnBR could be considered as a promising technique for biodegradation and COD removal of p -Cresol in wastewater.