Efficiency of an up-flow Anaerobic Sludge Blanket reactor coupled with an electrochemical system to remove chloramphenicol in swine wastewater.

The application and design of treatment systems in wastewater are necessary due to antibiotics' potential toxicity and resistant genes on residual effluent. This work evaluated a coupled bio-electrochemical system to reduce chloramphenicol (CAP) and chemical oxygen demand (COD) on swine wastewater (SWW). SWW characterization found CAP of <10 µg/L and 17,434 mg/L of COD. The coupled system consisted of preliminary use of an Up-flow Anaerobic Sludge Blanket Reactor (UASB) followed by electrooxidation (EO). The UASB reactor (primary stage) was operated for three months at an organic load of 8.76 kg of COD/m3d and 50 mg CAP/L as initial concentration. In EO, we carried out a 22 (time operation and intensity) factorial design with a central composite design; we tried two Ti cathodes and one anode of Ti/PbO2. Optimal conditions obtained in the EO process were 240 min of operation time and 1.51 A of current intensity. It was possible to eliminate 44% of COD and 64.2% of CAP in the preliminary stage. On bio-electrochemicals, total COD and CAP removal were 82.35 and >99.99%, respectively. This coupled system can be applied to eliminate antibiotics and other organic pollutants in agricultural, industrial, municipal, and other wastewaters.

Modification of Graphene Oxide Membranes by the Incorporation of Nafion Macromolecules and Conductive Scaffolds.

Stable, reproducible and low-cost graphene oxide (GO)/Nafion (N) membranes were fabricated using electronically conductive carbon paper (CP) matts as a scaffold. The presence of polar groups in the Nafion molecule facilitates the strong interaction with functional groups in the GO, which increases GO dispersion and aids the retention of the composite into the CP scaffold. Distribution of GO/N was carefully characterized by X-ray diffraction work function measurements, Raman and scanning electron microscopy analyses. The performance of these membranes was tested with 1 M NaCl at standard conditions, finding 85% ion removal in the best membranes by a mixed ion rejection/retention mechanism. The Nafion provided mechanical stability and fixed negative charge to the membranes, and its micellar organization, segregation and confinement favored ion rejection in Nafion-rich areas. The good electronic conductivity of these membranes was also demonstrated, allowing for the application of a small potential bias to enhance membrane performance in future studies.

A novel nanocomposite based on NiOx-incorporated P3HT as hole transport material for Sb2S3 solar cells with enhanced device performance.

To achieve superior photovoltaic performance on Sb2S3 solid state solar cells (ssSCs), the concomitant development of efficient hole transport materials (HTMs) is required. Herein, a novel solution processed HTM obtained by mixing NiOx nanoparticles (NiOx-NP) and poly(3-hexylthiophene) (P3HT) is reported. These P3HT:NiOx-NP nanocomposite HTMs were obtained with different controlled concentrations of NiOx-NP using a common solvent. Incorporation of NiOx-NP significantly impacts on the structural and hole-transport layer properties of the nanocomposite films, which in turn contributes to improve the photovoltaic performance of the corresponding devices. Thus, Sb2S3 ssSCs based on HTM with an optimum concentration of NiOx-NP in P3HT, i.e. P3HT:2% NiOx-NP, yield a 50% improvement in the power conversion efficiency relative to control devices fabricated with pristine P3HT. The improved hole separation and injection at the Sb2S3/HTM interface, determined by steady-state photoluminescence quenching and electrochemical impedance spectroscopy studies, correlate well with the higher hole mobility of the nanocomposite and the current density and fill factor enhancements.