A Gas Chromatographic Method for the Determination of Bicarbonate and Dissolved Gases

Loughrin, John H.; Antle, Stacy; Polk, Jason

doi:10.3389/fenvs.2017.00065

Cited by 10 publications

(7 citation statements)

References 10 publications

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“…Gas production was measured daily during the workweek and averaged over the weekends. Gas and wastewater quality was measured weekly as described in Loughrin et al [18].…”

Section: Digester Operationmentioning

confidence: 99%

“…All analyses were performed weekly prior to feeding of the digesters as described previously [18,19]. Briefly, biogas and dissolved gases (solvated CO 2 , bicarbonate) were analyzed by injection of 1.0-mL samples onto a Varian Model CP-3800 (Agilent Technologies, Santa Clara, CA) gas chromatograph (GC) modified for greenhouse gas (GHG) analysis by RSC Group LLC (Katy, TX) while hydrogen sulfide and sulfide were analyzed by injection of 1.0-mL samples onto a SRI Instruments 8610c GC equipped with a flame photometric detector (SRI Instruments, Torrance, CA).…”

Section: Chemical Analysesmentioning

confidence: 99%

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Sound enhances wastewater degradation and improves anaerobic digester performance

et al. 2019

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Biogas production and wastewater quality from anaerobic digesters were studied to determine whether sound at sonic frequencies (< 20,000 Hz) could enhance their performance. In three trials with increasing waste loading rates, each of 100-day duration, the performance of control and sound-treated digesters was compared. Anaerobic digesters exposed to sound produced approximately 12% more biogas than did non-exposed digesters, and sound-treated digestate had significantly lower chemical oxygen demand. Sludge at the end of the 100-day digestion averaged 19% less carbon and 18% less nitrogen in sound-treated digesters as compared to sludge from untreated digesters. Although the mechanism(s) responsible for enhanced biogas production due to sound exposure are unknown, recordings of sound-treated digesters indicate that acoustically induced cavitation may play a role.

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“…Gas production was measured daily during the workweek and averaged over the weekends. Gas and wastewater quality was measured weekly as described in Loughrin et al [18].…”

Section: Digester Operationmentioning

confidence: 99%

Section: Chemical Analysesmentioning

confidence: 99%

Sound enhances wastewater degradation and improves anaerobic digester performance

et al. 2019

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“…All samples for analyses were collected prior to the once-weekly feeding. Dissolved gases were analyzed using gas chromatography (GC) as described [17]. A volume of 0.5 mL of water was withdrawn from the wastewater sampling port on the side of the digesters and injected using an 18-gauge needle through the septum on a 20 mL headspace vial containing 9.5 mL 0.1 N HCl.…”

Section: Analysesmentioning

confidence: 99%

Improving Anaerobic Digestion of Brewery and Distillery Spent Grains through Aeration across a Silicone Membrane

et al. 2022

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An increase in the number of independent breweries and distilleries has led to an increase in the amount of spent grains with inadequate means of disposal. One option for disposal is as feedstock for anaerobic digestion if digester stability is ensured. In this study, brewers’ spent grain and distillers’ spent grain were used as substrate for anaerobic digestion for 32 weeks. The digestate was treated by recirculation through a silicone hose located in an external tank filled with saline solution. The hose served as a permeable membrane allowing for the passage of gases. The recirculation tanks were fitted with check valves to maintain three pressure/gas regimes: 26 mm Hg N2, 26 mm Hg aeration or 100 mm Hg aeration. A fourth digester was operated with no recirculation as the control. These treatments were chosen to determine if differences in digester stability, wastewater treatment efficiency, and biogas production could be detected. A combination of dairy and swine manure was used as seeding to provide a methanogenic consortium and bicarbonate buffering. However, despite trying to provide for adequate initial bicarbonate buffering, all four digesters had low initial buffering and consequently low pH as short-chain fatty acids accumulated. After six weeks, bicarbonate buffering and pH increased as methane production increased, and short-chain fatty acids decreased. Later, despite the fluxes of O2 and N2 across the silicone membrane being very low, differences between the various treatments were noted. The pH of the digestate treated by N2 recirculation was lower than the other digesters and decreased further after distillers’ spent grain was substituted for brewers’ spent grain. Aeration at a pressure of 26 mm Hg and 100 mg Hg increased biogas production compared to other treatments but only significantly so at 100 mm Hg. These results suggest that partial purging of dissolved gases in anaerobic digestate by the small fluxes of N2 or O2 across a permeable membrane may affect digester performance.

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“…Weather data was obtained from the Kentucky Mesonet's Warren County weather station also located on the Western Kentucky University Farm (www.kymesonet.org). Biogas and wastewater quality analyses were performed weekly prior to feeding of the system, as described previously [18,19]. Samples for dissolved gas and biogas analysis were taken by means of a Luer fitting with 3-way connector and attached syringe.…”

Section: Analysesmentioning

confidence: 99%

In Situ Acoustic Treatment of Anaerobic Digesters to Improve Biogas Yields

et al. 2020

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Sound has the potential to increase biogas yields and enhance wastewater degradation in anaerobic digesters. To assess this potential, two pilot-scale digestion systems were operated, with one exposed to sound at less than 10 kHz and with one acting as a control. Sounds used were sine waves, broadband noise, and orchestral compositions. Weekly biogas production from sound-treated digesters was 18,900 L, more than twice that of the control digester. The sound-treated digesters were primarily exposed to orchestral compositions, because this made cavitational events easier to identify and because harmonic and amplitude shifts in music seem to induce more cavitation. Background recordings from the sound-treated digester were louder and had more cavitational events than those of the control digester, which we ascribe to enhanced microbial growth and the resulting accelerated sludge breakdown. Acoustic cavitation, vibrational energy imparted to wastewater and sludge, and mixing due to a release of bubbles from the sludge may all act in concert to accelerate wastewater degradation and boost biogas production.

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A Gas Chromatographic Method for the Determination of Bicarbonate and Dissolved Gases

Cited by 10 publications

References 10 publications

Sound enhances wastewater degradation and improves anaerobic digester performance

Sound enhances wastewater degradation and improves anaerobic digester performance

Improving Anaerobic Digestion of Brewery and Distillery Spent Grains through Aeration across a Silicone Membrane

In Situ Acoustic Treatment of Anaerobic Digesters to Improve Biogas Yields

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