Publications by authors named "Rayra E Costa"

This work investigated the treatment of azo dye-containing wastewater in an upflow anaerobic sludge blanket (UASB) reactor combined with an electro-membrane bioreactor (EMBR). Current densities of 20 A m and electric current exposure mode of 6'ON/30'OFF were applied to compare the performance of the EMBR to a conventional membrane bioreactor (MBR). The results showed that dye (Drimaren Red CL-7B) removal occurred predominantly in the UASB reactor, which accounted for 57% of the total dye removal achieved by the combined system.

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This study addressed the impact of air flow rate on the performance, membrane fouling behaviour and microbial community of a sequencing batch conventional membrane bioreactor (SB-MBR) and a sequencing batch hybrid membrane bioreactor (SB-HMBR) with carrier media for biofilm growth. Two different scenarios were evaluated: high (6.4 L min) and low (1.

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This study evaluated the effects of electrochemical processes on the mixed liquor characteristics of an electro-membrane bioreactor (e-MBR) applied to municipal wastewater treatment. A laboratory-scale e-MBR was assessed under two experimental runs: without the electric field (run I) and with electric field, controlled by the application of an electric current set in 10.0 A m under intermittent exposure mode of 6 minutes ON/18 minutes OFF (run II).

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A sequencing batch conventional membrane bioreactor (SB-CMBR) and sequencing batch hybrid membrane bioreactor (SB-HMBR) were operated in parallel under two different hydraulic retention times (HRTs) (namely 12 h and 6 h), and their chemical oxygen demand (COD) and nutrient removal performance, membrane fouling behavior, and microbial community characteristics were compared. Both systems exhibited high organic matter (> 95%) and ammonium (> 98%) removal performance regardless of the HRT applied. As the HRT was reduced from 12 to 6 h, total nitrogen removal slightly increased in both reactors, being higher in the carrier-based MBR, where anoxic zones may have been established within the biofilm.

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This study evaluated the removal of organic matter, nitrogen and phosphate from a municipal wastewater in a sequencing batch membrane bioreactor (SBMBR) operated at different solids retention times (SRTs) and subjected to different aeration profiles. The results demonstrated that SRT reduction from 80 to 20 d had a negligible effect on chemical oxygen demand (COD) removal and only a slight negative effect on nitrification. COD removal efficiency remained stable at 97%, whereas ammonium removal decreased from 99% to 97%.

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