Hydrolysis of waste activated sludge (WAS) has been regarded as the rate limiting step of anaerobic sludge digestion. Therefore, in this study, the effect of ultrasound and hydraulic residence time during sludge hydrolysis was investigated with the goal of enhancing methane production from anaerobic digestion (AD). WAS was ultrasonically disintegrated for hydrolysis, and it was semi-continuously fed to an anaerobic digesters at various hydraulic retention times (HRTs). The results of these experiments showed that the solids and chemical oxygen demand (COD) removal efficiencies when using ultrasonically disintegrated sludge were higher during AD than the control sludge. The longer the HRT, the higher the removal efficiencies of solids and COD, while methane production increased with lower HRT. Sludge with 30% hydrolysis produced 7 × more methane production than the control sludge. The highest methane yields were 0.350 m(3)/kg volatile solids (VS)(add) and 0.301 m(3)/kg COD(con) for 16 and 30% hydrolyzed sludge, respectively. In addition, we found that excess ultrasound irradiation may inhibit AD since the 50% hydrolyzed sludge produced lower methane yields than 16 and 30% hydrolyzed sludge.
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J Anim Physiol Anim Nutr (Berl)
January 2025
Department of Animal Science, Wageningen University & Research, Wageningen, The Netherlands.
White rot fungi can degrade lignin and improve the nutritional value of highly lignified biomass for ruminants. We screened for excellent fungi-biomass combinations by investigating the improvement of digestibility of wheat straw, barley straw, oat straw, rapeseed straw, miscanthus, new reed, spent reed from thatched roofs, and cocoa shells after colonisation by Ceriporiopsis subvermispora (CS), Lentinula edodes (LE), and Pleurotus eryngii (PE) (indicated by increased in vitro gas production [IVGP]). First, growth was evaluated for three fungi on all types of biomass, over a period of 17 days in race tubes.
View Article and Find Full Text PDFEnviron Res
January 2025
Research & Development Institute in Shenzhen, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, China. Electronic address:
Adding additives exogenously is an effective strategy to enhance methanogenic activity and improve AD stability. Corn straw-based biochar@MIL-88A(Fe) (BM) was synthesized herewith and used as an exogenous additive to boost methane (CH) production. After adding BM at 250 mg/g WAS VS, the accumulative CH production and maximum CH yield increased by 1.
View Article and Find Full Text PDFSci Total Environ
January 2025
Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton South, Melbourne, Victoria 3169, Australia; Department of Agricultural Economics, University of the Free State, Bloemfontein 9300, South Africa.
Agricultural systems are important emission sources of non-CO greenhouse gases (GHGs), including the relatively short-lived GHG methane (CH). As a pivotal emitter, China's CH emissions have received wide attention. For the first time, this study applied an indicator of radiative forcing-based climate footprint (RFCF) to compare the climate impacts of China's on-farm non-CO GHG emissions including CH and nitrous oxide (NO).
View Article and Find Full Text PDFEnviron Monit Assess
January 2025
Laboratory for Ecotoxicology and Environmental Forensics, University of Benin, PMB 1154, Benin City, Nigeria.
This research was carried out to assess the concentrations of carbon monoxide (CO) and formaldehyde (HCHO) in Edo State, Southern Nigeria, using remote sensing data. A secondary data collection method was used for the assessment, and the levels of CO and HCHO were extracted annually from Google Earth Engine using information from Sentinel-5-P satellite data (COPERNISCUS/S5P/NRTI/L3_) and processed using ArcMap, Google Earth Engine, and Microsoft Excel to determine the levels of CO and HCHO in the study area from 2018 to 2023. The geometry of the study location is highlighted, saved and run, and a raster imagery file of the study area is generated after the task has been completed with a 'projection and extent' in the Geographic Tagged Image File Format (.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Department of General Physics, Kazan National Research Technical University Named After A.N. Tupolev-KAI, Kazan 420111, Russia.
In this work, within the framework of a self-consistent model of arc discharge, a simulation of plasma parameters in a mixture of argon and methane was carried out, taking into account the evaporation of the electrode material in the case of a refractory and non-refractory cathode. It is shown that in the case of a refractory tungsten cathode, almost the same methane conversion rate is observed, leading to similar values in the density of the main methane conversion products (C, C, H) at different values of the discharge current density. However, with an increase in the current density, the evaporation rate of copper atoms from the anode increases, and a jump in the - characteristic is observed, caused by a change in the plasma-forming ion.
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