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Binary segmentation of volumetric images of porous media is a crucial step towards gaining a deeper understanding of the factors governing biogeochemical processes at minute scales. Contemporary work primarily revolves around primitive techniques based on global or local adaptive thresholding that have known common drawbacks in image segmentation. Moreover, the absence of a unified benchmark prohibits quantitative evaluation, which further undermines the impact of existing methodologies. In this study, we tackle the issue on both fronts. First, by drawing parallels with natural image segmentation, we propose a novel, and automatic segmentation technique, 3D Quantum Cuts (QCuts-3D) grounded on a state-of-the-art spectral clustering technique. Secondly, we curate and present a publicly available dataset of 68 multiphase volumetric images of porous media with diverse solid geometries, along with voxel-wise ground truth annotations for each constituting phase. We provide comparative evaluations between QCuts-3D and the current state-of-the-art over this dataset across a variety of evaluation metrics. The proposed systematic approach achieves a 26% increase in AUROC (Area Under Receiver Operating Characteristics) while achieving a substantial reduction of the computational complexity over state-of-the-art competitors. Moreover, statistical analysis reveals that the proposed method exhibits significant robustness against the compositional variations of porous media. publishedVersion

Sustainable bioelectrogenesis was evaluated by oxidizing the organics of food waste leachate (FWL) under the influence of magnetic field (MF) and short term applied voltage (electric potential, EP). Adaptation of MF (20–220 m T) and EP (100−500 mV) had enhanced the performance of MFC in terms of power generation and reduction of organic in FWL. The best performance of MFC was noted with a MF at 220 m T and EP at 500 mV. MFC under the influence of applied EP (100−500 mV), the power generation was increased from 493 mW/m2 to 832 mW/m2. During this operation, the chemical oxygen demand removal (CODr) was also increased from 51.3 % to 80.4 %. Whereas the control MFC (MFC-C) had exhibited a maximum power generation and CODr of 224 mW/m2 and 36.3 %, respectively. MFC with MF has showed an increase in power density from 480 mW/m2 to 811 mW/m2. MFCs at 220 m T and 500 mV has exhibited, 262 % and 271 % increase in power density over control, respectively. Adaptation of MFC under the EP and MF were found to be beneficial in treating FWL which has high strength organic content.

Hybrid based bioelectrochemical system (BES) configured with embedded anode and cathode electrodes in soil was tested for the bioelectrochemical degradation of petroleum refinery wastewater (PRW). Four applied potentials were studied to optimize under batch mode operation, among which 2 V resulted in higher COD degradation (69.2%) and power density (725 mW/m2) during 7 days of operation. Further studies with continuous mode of operation at optimized potential (2 V) showed that hydraulic retention time (HRT) of 19 h achieved the highest COD removal (37%) and highest power density (561 mW/m2). BES function with respect to treatment efficiencies of other pollutants of PRW was also identified with respect to oil and grease (batch mode, 91%; continuous mode, 34%), total dissolved salts (batch mode, 53%; continuous mode, 24%) and sulfates (batch mode, 59%; continuous mode, 42%). Soil microenvironment in association with BES forms complex processes, providing suitable conditions for efficient treatment of PRW. ? 2018 Elsevier Ltd This publication was made possible by NPRP grant # 8-594-2-244 from the Qatar National Research Fund , Qatar (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the authors. Scopus

Electrochemically active anodic biofilm that has adapted under mild applied potentials in the range 100-500 mV was evaluated for its improved bioelectrogenesis and bioelectrochemical treatment of petroleum refinery wastewater (PRW) in a single chamber air cathode microbial fuel cell (MFC). MFC operation with 500 mV as supplemental voltage has exhibited a maximum power density of 132 mW/m2, which was three times higher than control MFC (45 mW/m2). Similarly, highest substrate removal efficiency (48%) was also obtained with the MFC of 500 mV, followed by 300 mV (37%), 100 mV (32%) and control (27%). Adaptation under applied potential conditions also exhibited enhanced degradation efficiency of diesel range organics (DROs)/straight chain-alkanes. The strategy efficiently reduced DROs with the maximum efficiency of 89% (500 mV), which is almost 50% higher than that of the control system (59%), demonstrating the effectiveness of using supplemented voltage in treating PRW. 2018 Elsevier Ltd This publication was made possible by NPRP grant # 6-289-2-125 from the Qatar national research fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. The Authors would like to acknowledge the Environmental Science Centre (ESC), Qatar University for evaluating the samples for diesel range organics (DROs). Scopus