@article{cheng_call_2021, title={Developing microbial communities containing a high abundance of exoelectrogenic microorganisms using activated carbon granules}, volume={768}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2020.144361}, abstractNote={Microorganisms that can transfer electrons outside their cells are useful in a range of wastewater treatment and remediation technologies. Conventional methods of enriching exoelectrogens are cost-prohibitive (e.g., controlled-potential electrodes) or lack specificity (e.g., soluble electron acceptors). In this study a low-cost and simple approach to enrich exoelectrogens from a mixed microbial inoculum was investigated. After the method was validated using the exoelectrogen Geobacter sulfurreducens, microorganisms from a pilot-scale biological activated carbon (BAC) filter were subjected to incubations in which acetate was provided as the electron donor and granular activated carbon (GAC) as the electron acceptor. The BAC-derived community oxidized acetate and reduced GAC at a capacity of 1.0 mmol e− (g GAC)−1. After three transfers to new bottles, acetate oxidation rates increased 4.3-fold, and microbial morphologies and GAC surface coverage became homogenous. Although present at <0.01% in the inoculum, Geobacter species were significantly enriched in the incubations (up to 96% abundance), suggesting they were responsible for reducing the GAC. The ability to quickly and effectively develop an exoelectrogenic microbial community using GAC may help initiate and/or maintain environmental systems that benefit from the unique metabolic capabilities of these microorganisms.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Cheng, Qiwen and Call, Douglas F.}, year={2021}, month={May} }
 @article{de la cruz_cheng_call_barlaz_2021, title={Evidence of thermophilic waste decomposition at a landfill exhibiting elevated temperature regions}, volume={124}, ISSN={0956-053X}, url={http://dx.doi.org/10.1016/j.wasman.2021.01.014}, DOI={10.1016/j.wasman.2021.01.014}, abstractNote={There have been several reports of landfills exhibiting temperatures as high as 80 to 100 °C. This observation has motivated researchers to understand the causes of the elevated temperatures and to develop predictive models of landfill temperature. The objective of this research was to characterize the methanogenic activity of microbial communities that were derived from landfill samples excavated from a section of a landfill exhibiting gas well temperatures above 55 °C. Specific objectives were to: (1) determine the upper temperature limit for methane production; (2) evaluate the kinetics of methane generation when landfill-derived microcosms are incubated above and below their excavation temperature and derive a temperature inhibition function; and (3) evaluate microbial community shifts in response to temperature perturbations. Landfill microcosms were derived from 57 excavated landfill samples and incubated within ±2.5 °C of their excavation temperature between 42.5 °C and 87.5 °C. Results showed an optimum temperature for methane generation of ~57 °C and a 95% reduction in methane yield at ~72 °C. When select cultures were perturbed between 5 °C below and 15 °C above their in-situ temperature, both the rate and maximum methane production decreased as incubation temperature increased. Microbial community characterization using 16S rRNA amplicon sequencing suggests that thermophilic methanogenic activity can be attributed to methanogens of the genus Methanothermobacter. This study demonstrated that from a microbiological standpoint, landfills may maintain active methanogenic processes while experiencing temperatures in the thermophilic regime (<72 °C).}, journal={Waste Management}, publisher={Elsevier BV}, author={De la Cruz, Florentino B. and Cheng, Qiwen and Call, Douglas F. and Barlaz, Morton A.}, year={2021}, month={Apr}, pages={26–35} }
 @article{schupp_de la cruz_cheng_call_barlaz_2020, title={Evaluation of the Temperature Range for Biological Activity in Landfills Experiencing Elevated Temperatures}, volume={1}, ISSN={2690-0645}, url={http://dx.doi.org/10.1021/acsestengg.0c00064}, DOI={10.1021/acsestengg.0c00064}, abstractNote={There have been reports of municipal solid waste landfills with waste and gas wellhead temperatures of at least 80–100 °C, which is in excess of temperatures reported at typical landfills. Landfill...}, number={2}, journal={ACS ES&T Engineering}, publisher={American Chemical Society (ACS)}, author={Schupp, Sierra and De la Cruz, Florentino B. and Cheng, Qiwen and Call, Douglas F. and Barlaz, Morton A.}, year={2020}, month={Oct}, pages={216–227} }
 @article{cheng_de los reyes_call_2018, title={Amending anaerobic bioreactors with pyrogenic carbonaceous materials: the influence of material properties on methane generation}, volume={4}, ISSN={2053-1400 2053-1419}, url={http://dx.doi.org/10.1039/c8ew00447a}, DOI={10.1039/c8ew00447a}, abstractNote={The impact of pyrogenic carbonaceous material amendments on methane production in short-term anaerobic batch reactors depended on multiple material properties, including, but not limited to, electrical conductivity.}, number={11}, journal={Environmental Science: Water Research & Technology}, publisher={Royal Society of Chemistry (RSC)}, author={Cheng, Qiwen and de los Reyes, Francis L. and Call, Douglas F.}, year={2018}, pages={1794–1806} }
 @misc{cheng_call_2016, title={Hardwiring microbes via direct interspecies electron transfer: mechanisms and applications}, volume={18}, ISSN={["2050-7895"]}, DOI={10.1039/c6em00219f}, abstractNote={Direct interspecies electron transfer (DIET) has important implications for the design and operation of biological treatment processes.}, number={8}, journal={ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS}, author={Cheng, Qiwen and Call, Douglas F.}, year={2016}, month={Aug}, pages={968–980} }