Browsing by Author "Pinheiro, Antonio Luiz Barbosa"
Now showing 1 - 4 of 4
Results Per Page
Sort Options
- Oilfield carbonated produced water recycling coupled to exopolysaccharide transformation by lelliottia amnigenaPublication . Sampaio, Igor Carvalho Fontes; Ferreira, Joalene de Azevedo Santos; Crugeira, Pedro Jorge Louro; Oliveira, Ian M. da Silva; Santos, Jacson Nunes; Matos, Josilene Borges Torres Lima; Pinheiro, Antonio Luiz Barbosa; Almeida, Paulo Fernando deIt was tested the production of a viscous exopolysaccharide (EPS) by Lelliottia amnigena using different concentrations (10, 15, 25, 50 and 100%) of produced water (PW) and Dialyzed PW (DPW) at 100% concentration, with a nutrient medium based on glycerin and sucrose as carbon sources in 44 h batches. There was an increase in EPS recovery when used PW up to a concentration of 25%. The viscosity of the EPS solutions was maintained with DPW and up to 15% of PW, such a condition resulted in 9.34 gL− 1 of EPS, representing an increase of 84.9% compared to the control (P < 0.0001). The PW 15% increased the viscosity per produced liter by 114.3% (P < 0.0001). Scanning electron microscopy and Energy-dispersive X-ray spectroscopy analysis showed that EPS adsorbed mineral constituents of the substrate and its characterization by Fourier Transform Infrared Spectroscopy was similar to an external control of a commercial EPS produced by an Enterobacter A47 strain. PW at 15% becomes an alternative to increase the EPS production process and can contribute to the mitigation of environmental damage through sustainable PW management in the oilfield chain.
- Photodynamic antimicrobial therapy (A-PDT) using 1,9-Dimethyl-Methylene Blue zinc chloride double salt - DMMB and λ640 ± 5ηm LED light in patients undertaking orthodontic treatmentPublication . Soares, Luiz G.P.; Almeida, Cristiane G. de; Crugeira, Pedro Jorge Louro; Nunes, Iago P.F.; Silva, Anna P.L.T. da; Almeida, Jeovana A.; Cangussu, Maria C.T.; Almeida, Paulo Fernando de; Habib, Fernando A.L.; Pinheiro, Antonio Luiz BarbosaOrthodontic treatment involves the use of apparatuses that impairs oral hygiene making patients susceptible to periodontal diseases and caries. To prevent increased antimicrobial resistance A-PDT has shown itself a feasible option. The aim of this investigation was to assess the efficiency of A-PDT employing 1,9-Dimethyl-Methylene Blue zinc chloride double salt -DMMB as a photosensitizing agent combined with red LED irradiation (lambda 640 +/- 5 eta m) against oral biofilm of patients undertaking orthodontic treatment. Twenty-one patients agreed to participate. Four biofilm collections were carried out on brackets and gingiva around inferior central incisors; first was carried out before any treatment (Control); second followed five minutes of pre-irradiation, the third was immediately after the first AmPDT, and the last after a second AmPDT. Then, a microbiological routine for microorganism growth was carried out and, after 24-h, CFU counting was performed. There was significant difference between all groups. No significant difference was seen between Control and Photosensitizer and AmpDT1 and AmPDT2 groups. Significant differences were observed between Control and AmPDT1 and AmPDT2 groups, Photosensitizer and AmPDT1 and AmPDT2 groups. It was concluded that double AmPDT using DMBB in nano concentration and red LED was capable to meaningfully decrease the number of CFUs in or-thodontic patients.
- Photoinactivation of sulfate-reducing bacteria using 1,9-dimethyl-methylene blue – DMMB and laser lightPublication . Santos, Gustavo Vital dos; Moura, Hesrom Fernandes Serra; Crugeira, Pedro Jorge Louro; Silva, Anna Paula Lima Teixeira da; Castro, Isabele Cardoso Vieira de; Costa, Wellington Luís Reis; Almeida, Paulo Fernando de; Pinheiro, Antonio Luiz BarbosaAnnually, the oil and gas industry faces equipment losses and product quality degradation due to the presence of sulfate-reducing bacteria (SRB). Given the negative impact of SRB, this study evaluates the use of photoinactivation (PI) with zinc chloride double salt of 1,9-Dimethyl-Methylene Blue (DMMB) as a photosensitizer (PS) in varying concentrations and combined with Laser light at different exposures in an SRB consortium. For culture growth, a modified Postgate C medium (without ferrous sulfate) was used, and cell quantification was performed on 100 μL aliquots of the consortium, read on a spectrophotometer (λ600 nm) in an oxygen- and lightfree environment at room temperature. Statistical analyses included two-way ANOVA and ANOVA with interaction to separately and jointly evaluate the effects of PS and light in PI. Results indicated microbial activity in all groups, with an antimicrobial inhibition rate exceeding 50 % (p < 0.05) for concentrations above 1.5 μg/mL of DMMB. PI efficacy significantly depended on DMMB concentration and light density, achieving a 70.58 % (55.73–70.58, with a mean of 66.71 %) reduction (p < 0.05) with 1.5 μg/mL of DMMB and a 70.15 % (65–70.15, with a mean of 68.21 %) reduction with 2.0 μg/mL at an intensity of 21.6 J/cm2. In conclusion, PI presents a promising alternative to biocides in the oil and gas industry, offering easy application, avoiding bacterial resistance, being environmentally safe, and compatible with other SRB population control techniques.
- Up‐recycling oil produced water as the media‐base for the production of xanthan gumPublication . Sampaio, Igor Carvalho Fontes; Crugeira, Pedro Jorge Louro; Ferreira, Joalene de Azevedo Santos; Santos, Jacson Nunes; Matos, Josilene Borges Torres Lima; Pinheiro, Antonio Luiz Barbosa; Chinalia, Fabio Alexandre; Almeida, Paulo Fernando deProduced water (PW) and crude glycerin (CG) are compounds overproduced by the oil and biodiesel industry and significant scientific efforts are being applied for properly recycling them. The aim of this research is to combine such industrial byproducts for sustaining the production of xanthan by Xanthomonas campestris. Xanthan yields and viscosity on distinct PW ratios (0, 10, 15, 25, 50, 100) and on 100% dialyzed PW (DPW) in shaker batch testing identified DPW treatment as the best approach for further bioreactor experiments. Such experiments showed a xanthan yield of 17.3 g/L within 54 h and a viscosity of 512 mPa s. Physical-chemical characterization (energy dispersive X-ray spectroscopy, scanning electron microscopy and Raman spectroscopy) showed similarities between the produced gum and the experimental control. This research shows a clear alternative for upcycling high salinity PW and CG for the generation of a valued bioproduct for the oil industry.