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J R Campos

Publications and source records attributed to J R Campos.

10 recordsLinked to original sources
PubMed2006

Behaviour of a full-scale expanded bed reactor with overlaid anaerobic and aerobic zones for domestic wastewater treatment.

This paper presents the behaviour of a full-scale expanded bed reactor (160 m3) with overlaid anaerobic and aerobic zones used for municipal wastewater treatment. The research was carried out in two experimental steps: anaerobic and anaerobic-aerobic conditions, and the experimental results presented in this paper refer to four months of reactor operation. In the anaerobic condition, after inoculation and 60 days of operation, the reactor treating 3.40 kg CODm(-3)d(-1) for thetaH of 2.69 h, reached mean removal efficiencies of 76% for BOD, 72% for COD, and 80% for TSS, when the effluent presented mean values of 225 mg.L(-1) of COD, 98 mg.L(-1) of BOD and 35 mg.L(-1) of TSS. Under these conditions, for nitrogen loading of 0.27 kgN.m(-3)d(-1), the reactor generated an effluent with mean N-org. of 8 mg.L(-1) and N-ammon. of 37 mg.L(-1), demonstrating high potential of ammonification. For the anaerobic-aerobic condition (118th day) the system was operated with thetaH of 5.38 h presented mean removal efficiencies of 84% for BOD, 79% for COD, 76% for TSS, and 30% for TKN. The reactor's operation time was less than two months, which was not long enough to reach nitrification. Regarding the obtained results, this research confirmed that this reactor is configured as a flexible and adequate alternative for the treatment of sewage, requiring relatively small area and only thetaH of 10 h that can be adjusted to the local circumstances.

Aerobiosis↗
PubMed2004

Development and analysis of anaerobic biofilms onto hydrophobic and hydrophilic surfaces.

Fluorescent in situ hybridization (FISH) with domain and group specific probes that target intracellular 16S rRNA were used to investigate microbial composition of anaerobic biofilms developed on polypropylene (hydrophobic) and glass (hydrophilic) surfaces fitted inside a Modified Robbins Device (MRD). Crushed anaerobic granular sludge was used as inoculum for biofilm development in the MRD. The inoculum and biofilms formed showed nearly the same microbial composition, both were dominated by hydrogenotrophic methanogenic Archaea related to the Methanobacteriaceae as detected by the specific probe (MB1174). This group accounted for 44 to 90% of the DAPI-stained cells. Cells which hybridized to the Bacteria specific probe (EUB338) accounted for 3-18% of the DAPI-stained cells. After the first day of the biofilm formation experiment, a larger number of cells, 4.6 x 10(4) cells mm-2, could be seen colonizing the polypropylene coupon compared to the glass, 8.2 x 10(3) cells mm-2. However, after 9 days these numbers were very similar, i.e. 6.3 x 10(5) cells mm-2 and 7.2 x 10(5) cells mm-2, for the glass and polypropylene coupons, respectively. Our data suggest that the hydrophobicity of the support material did not influence the initial development and the microbial composition of anaerobic biofilms developed in the MRD.

Bacteria, Anaerobic↗
PubMed2004

Full scale fluidized bed anaerobic reactor for domestic wastewater treatment: performance, sludge production and biofilm.

This paper describes the performance, sludge production and biofilm characteristics of a full scale fluidized bed anaerobic reactor (32 m3) for domestic wastewater treatment. The reactor was operated with 10.5 m x h(-1) upflow velocity, 3.2 h hydraulic retention time, and recirculation ratio of 0.85 and it presented removal efficiencies of 71+/-8% of COD and 77+/-14% of TSS. During the apparent steady-state period, specific sludge production and sludge age in the reactor were (0.116+/-0.033) kgVSS. kgCOD(-1) and (12+/-5)d, respectively. Biofilm formed in the reactor presented two different patterns: one of them at the beginning of the colonization and the other of mature biofilm. These different colonization patterns are due to bed stratification in the reactor, caused by the difference in local-energy dissipation rates along the reactor's height, and density, shape, etc. of the bioparticles. The biofilm population is formed mainly of syntrophic consortia among sulfate reducing bacteria, methanogenic archaea such as Methanobacterium and Methanosaeta-like cells.

Bacteria, Anaerobic↗
PubMed2003

Influence of flocculation conditions in the performance of an experimental domestic sewage treatment plant consisting of an anaerobic expanded bed reactor followed by dissolved air flotation.

This paper presents the results of a study performed with an experimental domestic sewage treatment plant (240 m3 x d(-1) flow) consisting of expanded bed anaerobic reactor (EBAR) followed by dissolved air flotation (DAF) unit. For the flotation step, the anaerobic reactor effluent was previously coagulated with 50 mgFeCl3 x l(-1) and flocculated under different conditions (mean velocity gradient, Gf, and flocculation time, Tf). The Gf values were from 60 to 100 s(-1) associated with 13 and 20 min Tf values. During the tests, the following operational conditions of the flotation unit were maintained: chemical addition (50 mgFeCl3 x l(-1)), 18% recirculation rate associated with a pressure of 450 +/- 10 kPa in the saturation chamber and overflow rate of 180 m3 x m(-2) x d(-1). Temperature ranged from 23.8 degrees C to 30.0 degrees C. Best results were achieved for Gf = 80 s(-1) and Tf = 20 min. For these conditions, the DAF unit removal efficiencies were: 94.4% for chemical oxygen demand (with 53 mg x l(-1) COD residual), 87% for phosphorus (with 0.80 mgP x l(-1) residual), 96.7% for total suspended solids (with 9 mg x l(-1) TSS residual) and 96.4% for turbidity (with 12.9 NTU residual), when the anaerobic reactor effluents have worst quality during the whole day.

Air↗
PubMed2001

Sewage treatment by anaerobic biological process associated with dissolved air flotation.

This paper presents the results of a study performed with a lab-scale batch DAF unit fed with previously coagulated (with FeCl3 or cationic polymer) effluent from a pilot scale up-flow anaerobic sludge blanket (UASB) reactor treating domestic sewage. The adequate coagulation/flocculation conditions--chemical dosage, time (Tf) and mean velocity gradient (Gf) in the flocculation step--and air requirements for flotation process were investigated. Best results were achieved for 65 mg.l-1 of FeCl3 at Tf around 15 min and Gf of 80 s-1. In the assays where only polymer was applied, 7 mg.l-1 of cationic polymer dosage gave optimum removals with Tf around 15 min and Gf of 30 s-1. Air requirements ranged from 9.5 to 19.0 g of air.m-3 wastewater. Best TSS (95% and residual of 2 mg.l-1), COD (85% and residual of 20 mg.l-1) and total phosphate (95% and residual of 0.6 mg.l-1) removals were obtained when applying FeCl3, although the use of cationic polymer also produced good level of TSS (74% and residual of 14 mg.l-1) and COD (75% and residual of 45 mg.l-1) removals. For the UASB-DAF (batch) system and FeCl3, global efficiencies would be 97.2% for COD, 97.9% for phosphate and 98.9% for TSS.

Air↗
PubMed1997

Identification of a novel glucocorticoid response unit (GRU) in the 5'-flanking region of the mouse IL-2 receptor alpha gene.

Glucocorticoid hormones inhibit the production of IL-2 and upregulate mouse interleukin 2 receptor alpha (IL-2Ralpha) gene expression in T cell lines by increasing its transcription rate. Now, the authors have used functional approaches to search for regulatory elements present in the 5'-flanking region of the IL-2Ralpha gene responsible for this effect. An important regulatory region was detected between -1382 and -1100 bp from the transcription initiation site. Within this region the authors characterized two 20 bp long cis-acting regulatory elements, named G1 and G2, which are involved in the modulation of the expression of the IL-2Ralpha gene by glucocorticoids. G1 contains a relatively well-conserved GRE half palindrome site, able to bind a partially purified glucocorticoid receptor but giving rise to an unstable complex. The G2 regulatory element contains no consensus sequences of binding sites for GR nor for any other described transcriptional factors but is able to form complexes with factors present in liver or T cells. Whereas G1 or G2 alone were unable to induce a glucocorticoid-response, the contiguous presence of G1 and G2 gave rise to an efficient response. Therefore, it is postulated that the glucocorticoid-induction of IL-2Ralpha gene is mediated, at least partly, through G1 and G2 elements which constitute a novel multicomponent glucocorticoid response unit (GRU).

Animals↗
PubMedDate not supplied

[Esophagectomy using videosurgery].

This is a report of 10 cases of esophagetomy by videosurgery. Five patients had esophageal carcinoma and five had achalasia. The patients who had neoplasia were submitted to thoracoscopic, laparoscopic and cervicotomy and the others who had benign pathology were submitted to laparoscopic with transdiafragmatic approach and cervicotomy. The evolution was very satisfactory but there were complications that had no relation with the method. The follow up is being made and we have no sure about real results.

Adult↗
PubMedDate not supplied

[Mediastinoscopy: technical aspects and current indications].

Mediastinoscopy is an useful tool for mediastinal exploration with minimal surgical trauma. The anatomical and Technical basis of this procedure are simple and safe, and can be adapted to specific purposes. Surgical intervention is performed under general anesthesia and is carried out direct visual inspection. Mediastinoscopy is a diagnostic routine procedure in lung cancer staging and mediastinal adenopathy investigation. Since Carlens described the method of cervical mediastinoscopy, other authors developed new techniques, in order to improve and extend the range of mediatinal exploration. The mediastinoscope and the other tools used to perform the classic mediastinoscopy can also be used to perform pleuroscopy and even the transmediastinal esophagectomy.

Equipment Design↗