Synchronous COD removal and nitrogen recovery from high concentrated pharmaceutical wastewater by an integrated chemo-biocatalytic reactor systems.

Present report, an investigation of highly concentrated and low bio-degradable pharmaceutical wastewater (HCPWW) treatment; simultaneously ammoniacal nitrogen recovery for struvite fertilizer. The use of multiple solvents and many formulation processes in HCPWW, resulting highly refractory chemicals. Here, in this study focused on evaluation of chemo-biocatalysts for the removal of refractory organics, nitrogen recovery from HCPWW. The initial organics, and nitrogen content in HCPWW was 20,753 ± 4606 mg/L; BOD, 6550 ± 1500 mg/L and NH4+-N, 1057.9 ± 185.8 mg/L. Initially, the biodegradability (BOD5: COD ratio from 0.32 to 0.45) of HCPWW, which was improved by heterogeneous Fenton oxidation (HFO) processes, and porous carbon (PCC, 30 g/L), along with FeSO4.7H2O, 200 mg/L and H2O2 (30% v/v), 0.4 ml/L were used as a catalyst in a weakly acidic medium. For the biocatalytic processes, the microbial culture cultivated from sewage and incorporated into a Fluidized Immobilized Carbon Catalytic Oxidation reactor (FICCO), and dominant species are Pseudomonas Putida sp., Pseudomonas Kilionesis sp., and Pseudomonas Japonica sp., which is identified by using 16 S rDNA sequencing analysis. The COD and BOD5 removal efficiency of 65-93% and 70-82%, and follow the pseudo-second-order kinetic model with the rate constants of 1.0 × 10-4 L COD-1 h-1, 1.5 × 10-3 L COD-1 h-1 and 3.0 × 10-3 L COD-1 h-1 in the HFO-FICCO-CAACO catalytic processes. The optimized hydraulic retention time (HRT) of FICCO reactor was 24 h, and 1 h for the Chemo-Autotrophic Activated Carbon Oxidation (CAACO) reactor for maximum organics removal. MAP (Magnesium Ammonium Phosphate precipitation) process showed 90% of NH4+-N elimination and recovered it as a struvite fertilizer at an optimum molar ratio of 1:1.3:1.3 (NH4+-N: Na2HPO4.2H2O: MgO). FT-IR, UV-visible, and UV-fluorescence data confirm the effective elimination of organics. Hence, this integrated treatment system is appropriate for the management of pharmaceutical wastewater especially elimination of complex organic molecules and the recovery of nitrogen in the wastewater.

Genomic characterization of Enterobacter xiangfangensis STP-3: Application to real time petroleum oil sludge bioremediation.

Sustainable treatment of petroleum oil sludge still remains as a major challenge to petroleum refineries. Bioremediation is the promising technology involving bacteria for simultaneous production of biosurfactant and followed by degradation of petroleum compounds. Complete genomic knowledge on such potential microbes could accentuate its successful exploitation. The present study discusses the genomic characteristics of novel biosurfactant producing petrophilic/ petroleum hydrocarbon degrading strain, Enterobacter xiangfangensis STP-3, isolated from petroleum refinery oil sludge contaminated soil. The genome has 4,584,462 bp and 4372 protein coding sequences. Functional analysis using the RAST and KEGG databases revealed the presence of biosynthetic gene clusters linked to glycolipid and lipopeptide production and multiple key candidate genes linked with the degradation pathway of petroleum hydrocarbons. Orthology study revealed diversity in gene clusters associated to membrane transport, carbohydrate, amino acid metabolism, virulence and defence mechanisms, and nucleoside and nucleotide synthesis. The comparative analysis with 27 other genomes predicted that the core genome contributes to its inherent bioremediation potential, whereas the accessory genome influences its environmental adaptability in unconventional environmental conditions. Further, experimental results showed that E. xiangfangensis STP-3 was able to degrade PHCs by 82 % in 14 days during the bioremediation of real time petroleum oil sludge with the concomitant production of biosurfactant and metabolic enzymes, To the best of our knowledge, no comprehensive genomic study has been previously reported on the biotechnological prospective of this species.

Factors affecting the activation and inhibition of intracellular enzymes for degradation of 1,2 diamino benzene: kinetics and thermodynamic studies.

Citrobacter freundii, the bacterium isolated from marine sediments was capable of degrading 1,2 diamino benzene (DAB), an endocrine disruptor. The mixed intracellular enzymes from C. freundii were extracted and purified. The mixed intracellular enzymes were used for the degradation of DAB and degree of degradation was evaluated in terms of pyruvic acid, the end product, formed. The variables such as effect of pH, temperature and metal ions on the degradation of DAB using mixed intracellular enzymes (MICE) were investigated. The maximum amount of pyruvic acid formed was found to be 569 ± 5 µg with 96% degradation efficiency at pH 7; temperature 25 °C; zinc nitrate 0.1 mM; and copper sulphate ions 0.15 mM. The stability of MICE at different temperatures and the interaction of MICE with metal ions were confirmed using FT-IR spectroscopy. The formation of pyruvic acid from degradation of DAB followed pseudo-second-order rate kinetics and it was a spontaneous, exothermic process. The activation energy of degradation of DAB by MICE was found to be 82.55 kJ/mol.