- Dissertation
3
- 10.14264/uql.2017.54
FNA-based pre-treatment of primary, secondary and digested sludge
- Dec 21, 2016
- The University of Queensland
- Tingting Zhang
FNA-based pre-treatment of primary, secondary and digested sludge
The main object of this study was to offer information about incoming waste in landfill and to evaluate biochemical methane and hydrogen sulfide potentials of landfill wastes. We examined brick, soil, mixed waste (C&D waste and MSW) samples for the study. The leaching experiments showed that BOD, COD and sulfate were determined in the range of 0~18,816 mg/kg, 85~21,100 mg/kg and 160~1,205 mg/kg, respectively in 6hr extraction test. An accumulated extraction tests for 140day were determined BOD 226~197,219 mg/kg, COD 436~242,588 mg/kg and Sulfate 1,090~25,140 mg/kg. Also, BMP (biochemical methane potential) tests were carried out to examine methane and hydrogen sulfide yields for the 3 different wastes. As a result, methane yield was determined to 262.68 mL <TEX>$CH_4/g$</TEX> VS of MSW and 0~17.75 mL <TEX>$CH_4/g$</TEX> VS in brick, soil and C&D waste. Higher hydrogen sulfide yield was observed to 0.079mL <TEX>$H_2S/g$</TEX> VS in C&D waste. This result indicate that brick and soil could be sources of sulfate, and higher production of hydrogen sulfide could be odor problem and inhibitor of methane production.
FNA-based pre-treatment of primary, secondary and digested sludge
FNA-based pre-treatment of primary, secondary and digested sludge
Towards eliminating systematic errors caused by the experimental conditions in Biochemical Methane Potential (BMP) tests
Towards eliminating systematic errors caused by the experimental conditions in Biochemical Methane Potential (BMP) tests
Biological pretreatments and co-digestion with bovine manure for improving the anaerobic digestion of sargassum
Biological pretreatments and co-digestion with bovine manure for improving the anaerobic digestion of sargassum
Early prediction of BMP tests: A step response method for estimating first-order model parameters
Early prediction of BMP tests: A step response method for estimating first-order model parameters
Forecasting the Methane Yield of a Commercial-Scale Anaerobic Digestor Based on the Biomethane Potential of Feedstocks
With rising energy demand and the need for sustainable waste treatment, anaerobic digestion (AD) has emerged as a key technology for converting organic residues into renewable energy. However, predicting methane yield in full-scale facilities remains challenging due to the complexity of AD processes, the variability of feedstocks, and the impracticality of frequent biochemical methane potential (BMP) testing. In this study, we developed a simple, data-driven approach to forecast methane production in a commercial-scale digester co-digesting manure and food waste. The model employs weekly cumulative BMP of feedstock mixtures, calculated from literature values, as the explanatory variable. The model achieved an R2 of 0.70 and a forecast mean absolute percentage error (MAPE) of 7.4, indicating its potential for full-scale AD prediction. Importantly, the analysis revealed a long-run equilibrium between BMP and methane yield, with deviations corrected within roughly one month—closely matching the system’s hydraulic retention time. These findings demonstrate that literature-based BMP values can be used to reliably predict methane yield in operating AD systems, offering a low-cost and scalable tool to support decision-making in waste management and biogas plant operations.
Read moreFallen Leaves as a Substrate for Biogas Production
Fallen leaves in cities are often treated as waste; therefore, they are collected, transported outside urban areas, and composted, which contributes to greenhouse gas (GHG) emissions. Instead of this conventional management approach, fallen leaves could be utilized as a feedstock in biogas production, helping to reduce GHG emissions, increase renewable energy generation, and provide fertilizer. The aim of this study was to compare the mono-digestion of fallen leaves from three tree species commonly found in parks and along streets—northern red oak (Quercus rubra L.), small-leaved lime (Tilia cordata Mill.), and Norway maple (Acer platanoides L.)—in both wet and dry anaerobic digestion (AD) systems. A biochemical methane potential (BMP) test was conducted in batch assays for each of the three substrates in both AD technologies at a temperature of 38 ± 1 °C. The highest specific methane yield (SMY) was obtained from Quercus leaves in wet AD technology, with a methane yield of 115.69 ± 4.11 NL kgVS−1. The lowest SMY (55.23 ± 3.36 NL kgVS−1) was observed during the dry AD of Tilia leaves. The type of technology had no significant impact on the SMY of Acer and Tilia leaves; however, the methane yield from Quercus leaves in wet AD was significantly higher (p < 0.05) than that from dry AD. Studies on the use of fallen leaves from Tilia cordata, Quercus rubra, and Acer platanoides as substrates in mono-digestion technology have shown their limited suitability for biogas production. Nevertheless, this feedstock may be more effectively used as a co-substrate, mainly due to the low concentrations of ammonia (NH3) and hydrogen sulfide (H2S) in the biogas produced from these leaves, both of which are considered inhibitors of the AD process.
Read moreThe role of inoculum’s origin on the methane yield of different substrates in biochemical methane potential (BMP) tests
The role of inoculum’s origin on the methane yield of different substrates in biochemical methane potential (BMP) tests
Synergistic Effects of Magnetic Nanomaterials on Post-Digestate for Biogas Production
Digestate is characterized by high water content, and in the water and wastewater treatment settings, necessitates both large storage capacities and a high cost of disposal. By seeding digestate with four magnetic nanoparticles (MNPs), this study aimed to recover biogas and boost its methane potential anaerobically. This was carried out via biochemical methane potential (BMP) tests with five 1 L bioreactors, with a working volume of 80% and 20% head space. These were operated under anaerobic conditions at a temperature 40 °C for a 30 d incubation period. The SEM/EDX results revealed that the morphological surface area of the digestate with the MNPs increased as compared to its raw state. Comparatively, the degree of degradation of the bioreactors with MNPs resulted in over 75% decontamination (COD, color, and turbidity) as compared to the control system result of 60% without MNPs. The highest biogas production (400 mL/day) and methane yield (100% CH4) was attained with 2 g of Fe2O4-TiO2 MNPs as compared to the control biogas production (350 mL/day) and methane yield (65% CH4). Economically, the highest energy balance achieved was estimated as 320.49 ZAR/kWh, or 22.89 USD/kWh in annual energy savings for this same system. These findings demonstrate that digestate seeded with MNPs has great potential to improve decontamination efficiency, biogas production and circular economy in wastewater management.
Read moreInfluence of headspace pressure on methane production in Biochemical Methane Potential (BMP) tests
Influence of headspace pressure on methane production in Biochemical Methane Potential (BMP) tests
Effect of temperature and bagasse addition on anaerobic co-digestion of brewery waste by biochemical methane potential test
Effect of temperature and bagasse addition on anaerobic co-digestion of brewery waste by biochemical methane potential test
Read moreCommon Reed and Maize Silage Co-Digestion as a Pathway towards Sustainable Biogas Production
The key factor in sustainable biogas production is a feedstock whose production has no adverse impact on the environment. Since maize cultivation harms the environment, biogas plant operators seek a more sustainable feedstock. Common reed is an invasive species mown as part of wetland conservation measures, or it can be harvested from paludiculture. This study aimed to investigate wet co-digestion of maize silage with 10%, 30%, and 50% content of common reed silage using the biochemical methane potential (BMP) test. In addition, the potential energy generated and avoided greenhouse gas (GHG) emissions were calculated. The substitution of maize silage with 10%, 30%, and 50% content of reed silage reduced the methane (CH4) yield by 13%, 28%, and 35%, respectively. A disadvantage of reed silage addition was increased ammonia (NH3) and hydrogen sulfide (H2S) concentrations in biogas. Although substituting maize silage with reed silage decreases the CH4 yield, the co-digestion of maize and reed biomass from conservation or paludiculture may positively affect environmental aspects of energy generation. The substitution of maize with reed in biogas plants decreases the area used for maize cultivation and reduces GHG emissions.
Read moreBMP tests of source selected OFMSW to evaluate anaerobic codigestion with sewage sludge
BMP tests of source selected OFMSW to evaluate anaerobic codigestion with sewage sludge
Pre-treatments for enhanced biochemical methane potential of bamboo waste
Pre-treatments for enhanced biochemical methane potential of bamboo waste
Compositional and physicochemical changes in waste materials and biogas production across 7 landfill sites in UK
Compositional and physicochemical changes in waste materials and biogas production across 7 landfill sites in UK
Mass Loss Controlled Thermal Pretreatment System to Assess the Effects of Pretreatment Temperature on Organic Matter Solubilization and Methane Yield from Food Waste
The effects of thermal pretreatment (TP) on the main characteristics of food waste (FW) and its biochemical methane potential (BMP) and distribution of volatile fatty acids (VFAs) under mesophilic condition (35 ⁰C) were investigated. The TP experiments were carried out at 80 °C, 100 °C, 120 °C for 2 hour and 140 °C for 1 hour. The designed TP set-up was able to minimize the organic matter loss during the course of the pretreatments. Soluble organic fractions evaluated in terms of chemical oxygen demand (COD) and soluble protein increased linearly with pretreatment temperature. In contrast, the carbohydrate solubilization was more enhanced (30 % higher solubilization) by the TP at lower temperature (80 °C). A slight increment of soluble phenols was found, particularly for temperatures exceeding 100 °C. Thermally pretreated FW under all conditions exhibited an improved methane yield than the untreated FW, due to the increased organic matter solubilization. The highest cumulative methane yield of 442 (± 8.6) mL/gVSadded, corresponding to a 28.1 % enhancement compared to the untreated FW, was obtained with a TP at 80 °C. No significant variation in the VFAs trends were observed during the BMP tests under all investigated conditions.
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