Effects of irrigation and water content of packing materials on a thermophilic biofilter for SO2 removal: Performance, oxygen distribution and microbial population

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Zhang, J., Li, L., & Liu, J. (2017). Effects of irrigation and water content of packing materials on a thermophilic biofilter for SO2 removal: performance, oxygen distribution and microbial population.  Biochemical engineering journal,  118, 105-112.

https://www.sciencedirect.com/science/article/pii/S1369703X16303217

Abstract

The water content (WCR) of packing materials is a key factor that determines the success of biofilters, particularly thermophilic bioreactors, for off-gas treatment. An optimum WCR can be accomplished by directly irrigating packing materials. In this study, the performance of a thermophilic biofilter for SO2  removal was investigated by different irrigation times. The removal efficiency of SO2  was largely influenced by the water content of packing materials, which varied with irrigation time. An average SO2  removal efficiency of 98% could be achieved when WCR was >80%. The thermophilic biofilter required daily irrigation to maintain the optimum WCR. Oxygen distribution varied in polyurethane foam cubes (PUFCs) at different WCRs. PUFCs with a high WCR provided aerobic-low oxygen-aerobic areas. Microbial population also varied accordingly. For the thermophilic biofilter in treating SO2, over 80% was the optimal WCR which could be achieved by continuous irrigation.

My main interests in this article is the topic which looks into reducing air contaminants using biofilters. This is not a new topic but this looks at the optimization these biofilters in their use for contaminants released due to industrial processes such power plants, refineries, coal burners, etc.

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Acceleration of organic removal and electricity generation from dewatered oily sludge in a bioelectrochemical system by rhamnolipid addition

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Citation:

Zhang, Y., Zhao, Q., Jiang, J., Wang, K., Wei, L., Ding, J., & Yu, H. (2017). Acceleration of organic removal and electricity generation from dewatered oily sludge in a bioelectrochemical system by rhamnolipid addition.  Bioresource technology,  243, 820-827.

Abstract:

Conversion of biomass energy of dewatered oily sludge to electricity is the rate-limiting process in bioelectrochemical system (BES). In this study, 2  mg  g−1rhamnolipids were added to dewatered oily sludge, resulting in a significant enhancement in maximum power density from 3.84   ±  0.37 to 8.63   ±  0.81  W  m−3, together with an increase in total organic carbon (TOC) and total petroleum hydrocarbon (TPH) removal from 24.52   ±  4.30 to 36.15   ±  2.79  mg  g−1  and 29.51   ±  3.30 to 39.80   ±  2.47  mg  g−1, respectively. Rhamnolipids can also enhance the solubilization and promote the hydrolysis of dewatered oily sludge with increases in SOCD from 14.93   ±  2.44 to 18.40   ±  0.08  mg  g−1  and VFAs from 1.02   ±  0.07 to 1.39   ±  0.12  mg  g−1. Furthermore, bacteria related to substrate degradation were predominant in dewatered oily sludge, and bacteria related to the sulfate/sulfide cycle were significantly enriched by rhamnolipid addition.

Justification:

I initially found this paper interesting because the overall process being looked at uses bioremediation of petroleum waste as a mechanism for generating electricity. This covers how the addition of Rhamnolipids improves the process’s effectiveness and how the active bacterial composition changes after its addition.

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High potential for temperate viruses to drive carbon cycling in chemoautotrophy-dominated shallow-water hydrothermal vents

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https://onlinelibrary.wiley.com/doi/10.1111/1462-2920.13890/full

Citation:

Rastelli, E., Corinaldesi, C., Dell’Anno, A., Tangherlini, M., Martorelli, E., Ingrassia, M., … & Danovaro, R. (2017). High potential for temperate viruses to drive carbon cycling in chemoautotrophy’dominated shallow’water hydrothermal vents.  Environmental microbiology,  19(11), 4432-4446.

Abstract/Summary:

Viruses are the most abundant life forms in the world’s oceans and they are key drivers of biogeochemical cycles, but their impact on the microbial assemblages inhabiting hydrothermal vent ecosystems is still largely unknown. Here, we analysed the viral life strategies and virus-host interactions in the sediments of a newly discovered shallow-water hydrothermal field of the Mediterranean Sea. Our study reveals that temperate viruses, once experimentally induced to replicate, can cause large mortality of vent microbes, significantly reducing the chemoautotrophic carbon production, while enhancing the metabolism of microbial heterotrophs and the re-cycling of the organic matter. These results provide new insights on the factors controlling primary and secondary production processes in hydrothermal vents, suggesting that the inducible provirus-host interactions occurring in these systems can profoundly influence the functioning of the microbial food web and the efficiency in the energy transfer to the higher trophic levels.

 

Justification:

I thought the topic of viral influence on biogeochemical cycling sounded fun. Familiar material within the paper include a focus on carbon cycling and the use of metagenomics for analyzing bacteria.

 

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ThingLink Soil Microbiology Technical Summary

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https://www.nature.com/articles/srep38811

Summary

As environments globally become subjected to urban infrastructure, the biodiversity of flora and fauna have visibly plummeted, yet microbes are often overlooked. To see if urbanization has any effects on soil microbial diversity, researchers in Beijing studied microbial samples from the Forbidden City and the surrounding 5 ring roads. These ring roads were each constructed during different periods of time, following mass urbanization starting from 1970, and serve as a temporal gradient for comparing microbial samples. The further out from the Forbidden City a ring road is, the more recently it was built. Soil samples were taken across a transect from the forbidden city out into the surrounding ring roads and the 16s rRNA genes were sequenced. Alpha and beta diversity tests showed that samples from outer and inner roads displayed the highest diversity values. This observation rejected the idea that diversity levels could be explained by an urbanization age based gradient but it was found that acidity may partially explain the variance values of the microbial samples. Overall, their major findings were that variances in diversity can only partially be explained by urbanization and pH, leaving most of the variation related to the unexplained complexity of urban environments.

ThingLink Soil Microbiology Non-Technical Summary

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https://www.nature.com/articles/srep38811

Summary

Research has shown that the diversity of life has diminished with increased urbanization, but the focus has mainly been on plants and animals. This study focuses on the changes to soil microbial diversity in city or human-altered environments, because human alteration of the environment (pollution, construction, landscaping, etc)can drastically influence living conditions of local microorganisms. Focusing on Beijing, a city that rapidly urbanized from 1970 onwards, the study examined soils relating to how long ago the part of the city was build. Centered on the Forbidden City as the oldest point, moving outwards are ring roads that were added at different times outward with a total number of 5 roads. These researchers took samples from the different road levels to compare how microbial samples differ across different levels of urbanization. Overall, the main bacterial groups stayed the same across all samples, but microbial diversity differed. Analyses showed that differences in microbial communities could be explained by changes in soil acidity and these differences were not related to the age of the city area. The conclusion was that urbanization in Beijing has complex effects on the microbial diversity and these effects varied based on the layout of specific locations.

Microbial mediation of biogeochemical cycles revealed by simulation of global changes with soil transplant and cropping

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Zhao, M., Xue, K., Wang, F., Liu, S., Bai, S., Sun, B., … & Yang, Y. (2014). Microbial mediation of biogeochemical cycles revealed by simulation of global changes with soil transplant and cropping.  The ISME journal,  8(10), 2045.

Abstract:

Despite microbes’ key roles in driving biogeochemical cycles, the mechanism of microbe-mediated feedbacks to global changes remains elusive. Recently, soil transplant has been successfully established as a proxy to simulate climate changes, as the current trend of global warming coherently causes range shifts toward higher latitudes. Four years after southward soil transplant over large transects in China, we found that microbial functional diversity was increased, in addition to concurrent changes in microbial biomass, soil nutrient content and functional processes involved in the nitrogen cycle. However, soil transplant effects could be overridden by maize cropping, which was attributed to a negative interaction. Strikingly, abundances of nitrogen and carbon cycle genes were increased by these field experiments simulating global change, coinciding with higher soil nitrification potential and carbon dioxide (CO2) efflux. Further investigation revealed strong correlations between carbon cycle genes and CO2efflux in bare soil but not cropped soil, and between nitrogen cycle genes and nitrification. These findings suggest that changes of soil carbon and nitrogen cycles by soil transplant and cropping were predictable by measuring microbial functional potentials, contributing to a better mechanistic understanding of these soil functional processes and suggesting a potential to incorporate microbial communities in greenhouse gas emission modeling.

 

I chose this paper because it looks at simulating climate changes to study how microbe biogeochemical cycles react to these changes. This paper mainly looks at the effects of southward soil cropping and maize cropping. I also thought this would be a good paper to look at because geochips were used which were recently talked about in class.

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Hello Class!

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I’m Mark Velasco, a General Biology major, with interests in cell and molecular. Additionally, I’m both a mathematics and music minor.Currently, I am doing undergraduate research in Podlutsky lab studying DNA repair and hibernation using cultured Arctic Ground Squirrels cells.  My main non-biology interests is playing percussion, specifically with Ensemble 64.8 at UAF. This semester we plan on playing Threads by Paul Lanskey and some TBD Toru Takemitsu pieces arranged by Robin Engelman.

For the course, i’m excited to see if the interdisciplinary setup of the class brings us to look into more technical/ industrial uses of microbes in our environment, knowing that we have engineers in the class.

Haiku:

The unseen shapers,

Helpful sometimes destructive,

important for life