Papers by Rodrigo braz carneiro
Journal of Environmental Management, 2020
Antibiotic compounds, notably sulfamethoxazole (SMX) and ciprofloxacin (CIP), are ubiquitous emer... more Antibiotic compounds, notably sulfamethoxazole (SMX) and ciprofloxacin (CIP), are ubiquitous emerging contaminants (ECs), which are often found in domestic sewage. They are associated with the development of antimicrobial resistance. Operational parameters, e.g. organic loading rate (OLR), hydraulic retention time (HRT) and sludge retention time, may influence EC biodegradation in wastewater treatment plants. This study assessed the impact of the OLR variation on the biodegradation of CIP and SMX, applying two configurations of anaerobic fixed bed reactors: anaerobic packed bed biofilm reactor (APBBR) and anaerobic structured bed biofilm reactor (ASBBR). A significant reduction in the biodegradation of SMX (APBBR: 93-69%; ASBBR: 94-81%) and CIP (APBBR: 85-66%; ASBBR: 85-64%) was observed increasing OLR from 0.6 to 2.0 kgCOD m-3 d-1. The decrease in the HRT from 12 to 4 h resulted in higher liquid-phase mass transfer coefficient (APBBR: ks from 0.01 to 0.05 cm h-1; ASBBR: ks from 0.07 to 0.24 cm h-1), but this was not enough to overcome the decrease in the antibiotic-biomass contact time on biofilm, thus reducing the bioreactors' performance. The ASBBR favored biomethane production (from 7 to 17 mLCH4 g-1VSS L-1 d-1) and biodegradation kinetics (kbio from 1.7 to 4.2 and for SMX and from 2.1 to 4.8 L g-1VSS d-1 for CIP) due to the higher relative abundance of the archaea community in the biofilm and the lower liquid-phase mass transfer resistance in the structured bed. CIP and SMX cometabolic biodegradation was associated to the hydrogenotrophic methanogenesis (mainly Methanobacterium genus) in co-culture with fermentative bacteria (notably the genera Clostridium, Bacillus, Lactivibrio, Syntrophobacter and Syntrophorhabdus). The anaerobic fixed bed biofilm reactors proved to be highly efficient in biodegrading the antibiotics, preventing them from spreading to the environment.
Bookmarks Related papers MentionsView impact
Brazilian Journal of Chemical Engineering, 2017
Bookmarks Related papers MentionsView impact
Bioresource Technology Reports, 2022
Bookmarks Related papers MentionsView impact
Brazilian Journal of Chemical Engineering, 2021
Sulfamethoxazole (SMX) is one of the antibiotics most frequently detected in effluents from conve... more Sulfamethoxazole (SMX) is one of the antibiotics most frequently detected in effluents from conventional wastewater treatment plants, which increases the concern about the possible impacts on the aquatic biota and public health regarding the emergence of bacteria resistant to this drug. Anaerobic fixed bed reactors are supposed to enhance antibiotic biodegradation due to the biofilm formation in the reactor. In this context, this study evaluated the dynamics of the microbial community in the biofilm of three inoculum sources taken from Upflow Anaerobic Sludge Blanket (UASB) reactors for the biodegradation of SMX in anaerobic structured bed biofilm reactor (ASBBR) with: poultry slaughterhouse sludge (PS), brewery sludge (BS) and domestic sewage sludge (SS). The ASBBR reached high COD (Chemical Oxygen Demand) removal (> 84%) and biomethane yield (> 276 mLCH4 g−1 CODremoved) for all inocula. The bioreactor operation with PS inoculum presented the best SMX removal (90 ± 5%), while the BS and SS inocula resulted in 84 ± 6% and 70 ± 5% removal, respectively. The kinetic profiles of COD and SMX removal indicated the occurrence of cometabolic biodegradation of sulfonamide. The molecular biology analysis showed that the microbial community of the SS inoculum suffered significant changes during the ASBBR operation for the Archaea and Bacteria domains and the biomass of PS presented more similarity to the inoculum, indicating a better SMX adaptation, in agreement with the higher SMX removal. Furthermore, the diversity of the Archaea domain (mainly Methanosaeta and Methanosarcina) increased in the biomass after each reactor operation compared to the raw inocula, indicating that the methanogenic pathway was favored during the anaerobic digestion. The experimental results showed that the inoculum source plays an important role in the SMX biodegradation during the biological wastewater treatment.
Bookmarks Related papers MentionsView impact
Water, Air, & Soil Pollution, 2021
This study evaluated the ecotoxicity effects of effluent from an anaerobic fixed bed biofilm reac... more This study evaluated the ecotoxicity effects of effluent from an anaerobic fixed bed biofilm reactor (AFBBR) removing the sulfamethoxazole (SMX - 403 ± 104 ng L−1) and ciprofloxacin (CIP - 294 ± 123 ng L−1) antibiotics from domestic sewage in some microorganisms (Brevundimonas sp., Escherichia coli, Ochrobactrum sp., Sphingomonas sp.) and benthic organisms (Allonais inaequalis and Chironomus sancticaroli). The AFBBR showed high removal efficiency of SMX (85 ± 10%) and CIP (81 ± 16%) and completely eliminated the acute ecotoxicological effect on the C. sancticaroli insect larvae. The bioreactor effluent did not cause any inhibition on the cell growth of the microorganisms. Nonetheless, the A. inaequalis was extremely sensitive to the reactor effluent (100% mortality), probably due to the death of bacteria and algae essential to the nutrition of the Oligochaeta. Regarding the adult insect emergency of C. sancticaroli, a reduction of 50% was observed after 17 days of exposure to the effluent with 40 μgSMX L−1, inhibiting the larval development, which did not occur for CIP. The antimicrobial inhibition by CIP present in the domestic sewage resulted in EC50 (median effective concentration) values of 2.5, 0.9, 3.1 and 0.1 mgCIP L−1 for Ochrobactrum sp., Brevundimonas sp., Sphingomonas sp. and E. coli, respectively. Assessing the effect of antibiotics in the effluent on the microorganisms’ growth by a disk diffusion test, only E. coli culture showed inhibition at the concentration of 5.0 mgCIP L−1. The study emphasized the potential of AFBBR to reduce ecotoxicity in the sewage on aquatic biota.
Bookmarks Related papers MentionsView impact
Water, Air, & Soil Pollution, 2021
Biological nitrogen and phosphorus removal often requires an external carbon source to be effecti... more Biological nitrogen and phosphorus removal often requires an external carbon source to be effective during wastewater treatments. The purpose of this work was to evaluate a sequencing batch reactor (SBR) operated in a non-conventional anoxic/aerated (An/O) regime (alternated condition) treating synthetic wastewater simulating secondary anaerobic effluent mainly composed by P-phosphate and N-nitrate. The focus was to report the achieved biological efficiency removal of phosphorus and nitrate from the synthetic inlet when adding pre-fermented glycerol as the sole external carbon source. Experimental phase I aimed at the glycerol fermentation in batch reactors, leading to the formation of ethanol and volatile fatty acids. During experimental phase II, a non-acclimated (C1) and an acclimated biomass (C2) were used as inoculum of the SBR operated in the (An/O) regime. The anoxic phase was set to couple denitrification and P-release/uptake. The aerated phase was set to remove any remaining phosphorus. The fermented glycerol was applied in 15 gCOD g−1 N-NO3− and 29 gCOD g−1P-PO4−3 ratios in a sequential batch reactor during a non-aerated phase. This operation favored the development and maintenance of phosphorus-accumulating organisms (PAO), as well as denitrifying organisms, resulting in approximately 90 ± 11% and 98 ± 3% for phosphorus and nitrogen removal, respectively. The study showed that the fermented glycerol can be successfully applied as an electron donor for biological nitrogen and phosphorus removal during wastewater treatments.
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Science of The Total Environment, 2019
This study assessed the applicability of fixed bed bioreactors in two configurations - anaerobic ... more This study assessed the applicability of fixed bed bioreactors in two configurations - anaerobic structured bed reactor (ASBR) and anaerobic packed bed reactor (APBR) - in the removal of Sulfamethoxazole (SMX) and Ciprofloxacin (CIP), two antibiotics frequently detected in sanitary sewage. The problem of these pharmaceuticals as emerging contaminants in conventional sewage treatment systems is mainly because they encourage the development and spread of resistance genes in bacteria. Both reactors had similar performances, and the antibiotics were highly removed - APBR: 85 ± 10% for SMX and 81 ± 16% for CIP; ASBR: 83 ± 12% for SMX and 81 ± 15% for CIP. The ASBR showed to be potentially more feasible in operating and economic terms compared to the APBR, as the former presents a smaller amount of support material in the bed. SMX was completely biotransformed, while the influence of the sorption mechanism was observed for CIP, as its presence was detected sorbed onto biomass throughout the reaction bed of the reactors, with a partition coefficient (log KD) of around 2.8 L·kg-1TSS. The degradation kinetics of the pharmaceuticals were fitted using a first-order kinetic model, whereby the reactors behaved as plug flow ones, indicating the possibility of optimizing the operation for a hydraulic retention time of 6 h. The removal kinetics was more favorable for CIP (higher apparent constant kinetic - kCIPapp > kSMXapp), since its biodegradation is linked to the biomass, which is more concentrated in the bed bottom layer. The experimental results showed the potential of anaerobic fixed bed reactors in removing environmentally relevant concentrations of SMX and CIP found in sewage.
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Os sistemas de tratamento de esgotos compostos por reator anaerobio compartimentado sao considera... more Os sistemas de tratamento de esgotos compostos por reator anaerobio compartimentado sao considerados promissores para a zona rural brasileira ou localidades nao atendidas por rede coletora de esgotos por apresentar configuracao simples e facil operacao. Nesta pesquisa foi desenvolvido um sistema de tratamento composto de reator anaerobio compartimentado seguido de decantador. Como pos-tratamento biofisico do esgoto, estudou-se o cultivo da camomila. Tambem, foi realizado ensaio jar-test com cloreto ferrico como uma alternativa de pos-tratamento fisico-quimico do efluente anaerobio. Durante o monitoramento do sistema, que durou aproximadamente cinco meses, o reator anaerobio atingiu eficiencia maxima de remocao de DQO e de turbidez, de 68,4% e 96,3%, respectivamente. Verificou-se que o reator apresentou boas condicoes de tamponamento, mantendo o pH por volta do neutro (7,34 ± 0,17), apesar de ter ocorrido uma diminuicao da alcalinidade ao longo do tempo. O desenvolvimento da planta o...
Bookmarks Related papers MentionsView impact
Uploads
Papers by Rodrigo braz carneiro