Anaerobic digestion (AD) of swine waste allows obtaining renewable energy, biofertilizer and the reduction of environmental impacts. However, the low C:N ratio of pig manure generates high concentrations of ammonia nitrogen in the digestion process, reducing methane production. Zeolite is an effective ammonia adsorbent; thus, in this research the ammonia adsorption capacity of natural Ecuadorian zeolite was studied under different operating conditions. Subsequently, its effect on methane production from swine waste was evaluated using three doses of zeolite, 1.0, 4.0 and 8.0 g, in 1 L batch bioreactors. The results showed that the Ecuadorian natural zeolite has an adsorption capacity of around 19 mgNH-N gZ when using ammonium chloride solution and, an adsorption capacity between 37 and 65 mgNH-N gZ using swine waste. On the other hand, the addition of zeolite had a significant effect on methane production (p < 0.01). The zeolite doses that provided the highest methane production were 4.0 and 8.0 g L, which led to values of 0.375 and 0.365 NmCH kgVS, compared to the values of 0.350 and 0.343 NmCH kgVS that were obtained for the treatments without addition of zeolite and using a dose of 1.0 g L, respectively. Addition of natural Ecuadorian zeolite meant not only a significant increase on methane production in the AD of swine waste, but also a better quality of the biogas with higher percentages of methane and lower concentrations of HS.
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http://dx.doi.org/10.1016/j.chemosphere.2023.139098 | DOI Listing |
Photoacoustics
February 2025
College of Control Science & Engineering, China University of Petroleum (East China), Qingdao 266580, PR China.
Traditional beat frequency quartz-enhanced photoacoustic spectroscopy (BF-QEPAS) are limited by short energy accumulation times and the necessity of a decay period, leading to weaker signals and longer measurement cycles. Herein, we present a novel optomechanical energy-enhanced (OEE-) BF-QEPAS technique for fast and sensitive gas sensing. Our approach employs periodic pulse-width modulation (PWM) of the laser signal with an optimized duty cycle, maintaining the quartz tuning fork's (QTF) output at a stable steady-state level by applying stimulus signals at each half-period and allowing free vibration in alternate half-periods to minimize energy dissipation.
View Article and Find Full Text PDFJ Environ Manage
December 2024
Chemical and Biochemical Engineering Department, University of Western Ontario, London, ON, N6A 5B9, Canada; Civil and Environmental Engineering Department, University of Western Ontario, London, ON, N6A 5B9, Canada. Electronic address:
The convergence of sustainability and climate change has catalyzed the pursuit of inventive strategies for waste management and sustainable energy production. Hereby, we explored the effect of coupling biochar addition and thermal pretreatment in anaerobic mono-digestion and co-digestion of thermally pretreated thickened waste activated sludge (PTWAS) with food waste (FW). Six semi-continuous lab-scale digesters were operated for 161 days at various organic loading rates (OLR of 2, 3, 4 and 8 kgCOD/m/day) with and without biochar (BC) addition.
View Article and Find Full Text PDFPol J Vet Sci
June 2024
School of Veterinary Medicine, Azabu University, 1-17-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa, 252-5201, Japan.
The environmental impact of methane, a greenhouse gas emitted from ruminants, is a pressing issue and methods to control methane emissions from ruminants are being investigated worldwide. In this study, we investigated the effects of the administration of spent coffee grounds (SCG) on methane production in the rumen in two cows. In the control condition (days 1 and 2), the cows were fed a basic diet twice daily (roughage and concentrate), and in the SCG condition (days 1 and 2) sequentially, the cows were fed the same basic diet and administered SCG into the rumen twice daily.
View Article and Find Full Text PDFFundam Res
November 2024
Department of Geographical Sciences, University of Maryland, College Park, MD 20742, USA.
Mitigating methane (CH) emissions from China's coal mines as the largest contributor to anthropogenic CH emissions is vital for limiting global warming. However, the knowledge about CH mitigation potentials and economic costs of Chinese coal mines remain poorly understood, which hinders the formulation of tailored CH mitigation strategies. Here, we estimate and project China's provincial coal mine methane (CMM) emissions, mitigation potentials and costs under various coal production scenarios, by integrating the dynamic emission factors of CMM and key abatement technologies.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Department of Petroleum Engineering, School of Energy Technology, Pandit Deendayal Energy University, Gandhinagar, Gujarat 382426, India. Electronic address:
Naturally occurring gas clathrates are a significant methane resource-the primary component of natural gas, regarded as the cleanest hydrocarbon and a key feedstock for producing gray and blue hydrogen. Despite the global abundance of gas hydrate reserves, extraction via depressurization has yet to achieve commercially viable production rates. The primary limitation lies in the low permeability of hydrate-bearing sediments, where solid clathrates obstruct porous pathways, hindering dissociation and slowing gas recovery.
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