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This study was conducted to determine the effect of iron and aluminum on odor generation from anaerobically digested and dewatered sludge cakes. Blended primary and waste activated sludge samples obtained from 12 different wastewater utilities was batch digested in the laboratory for 30 days at 37 o C, conditioned, dewatered and the organic sulfur odor generation potential measured. In addition to sulfur gas analysis, all sludge samples were analyzed for total and volatile solids, Fe and Al concentrations in the solids, mono and divalent cations in solution and soluble biopolymer (proteins and polysaccharides). A correlation between iron and peak organic sulfur gas concentrations in the headspace of incubation vials was found. Following anaerobic digestion, a significant increase in solution protein occurred and correlations between solution protein, ammonium production, percentile volatile solids reduction and iron content in sludge were observed. These data suggested that iron plays an important role in anaerobic digestion and in odor generation from dewatered sludge cake. Aluminum reduced the odor potential for sludges that were high in iron, suggesting that proteins associated with aluminum are resistant to degradation following shear.

Abstract-To attain scalable performance efficiently, the HPC community expects future exascale systems to consist of multiple nodes, each with different types of hardware accelerators. In addition to GPUs and Intel MICs, additional candidate accelerators include embedded multiprocessors and FPGAs. End users need appropriate tools to efficiently use the available compute resources in such systems, both within a compute node and across compute nodes. As such, we present MetaMorph, a library framework designed to (automatically) extract as much computational capability as possible from HPC systems. Its design centers around three core principles: abstraction, interoperability, and adaptivity. To demonstrate its efficacy, we present a case study that uses the structured grids design pattern, which is heavily used in computational fluid dynamics. We show how MetaMorph significantly reduces the development time, while delivering performance and interoperability across an array of heterogeneous devices, including multicore CPUs, Intel MICs, AMD GPUs, and NVIDIA GPUs.

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