The objectives of this study were to determine the effect of pretreatment to the garden wastes under thermal and alkali conditions and to evaluate biochemical methane potential. In thermal pretreatment different temperatures and application times were examined and solubilisation improved by heating. Soluble chemical oxygen demand (sCOD) concentration upgraded by increasing temperature with ...
The biodegradability and bioavailability of hydrolysis-limited substrates under anaerobic (and aerobic) conditions can be represented by two key parameters – degradability (fd), or the percentage that can be effectively be destroyed during digestion, and first order hydrolysis coefficient (khyd), or the speed at which material breaks down. Biochemical methane potential (BMP) testing uses a batch ...
To the authors' knowledge, there is no published work, relating biodegradation and settlement of municipal solid waste (MSW) in bioreactor landfills together. The present mathematical model is developed to simulate the biodegradation of MSW in anaerobic bioreactor landfills and predict the strength of leachate in terms of volatile fatty acid (VFA). The hydrolysis rate constant (kh) has been found ...
The objective of this study was to investigate the effects of nutrient supplementation on anaerobic biomass. While many studies emphasized the importance of supplementing trace metals such as iron, cobalt, and nickel for maximum methanogenic activity, there is no evidence whether such supplements, even at relatively low concentration, could perturb anaerobic biomass. Effects of supplementing ...
Anaerobic biodegradability and hydrolysis rates of wastewater screenings were determined using the biochemical methane potential test at 37 °C. The extent and rate of screenings conversion to methane of this complex and particulate substrate were investigated and since two stages of hydrolysis were identified, corresponding to the different types of materials in screenings, a linear and ...
In this work, biochemical methane potential (BMP) tests with cellulose as a model substrate were performed with the aid of three manually operated or conventional experimental setups (based on manometer, water column and gas bag) and one automated apparatus specially designed for analysis of BMP. The methane yields were 340 ± 18, 354 ± 13, 345 ± 15 and 366 ± 5 ml ...
The possibility of coupling a physicochemical pretreatment (ozonation) with a biological treatment (anaerobic digestion) was investigated for the case of olive mill wastewaters (OMW). Batch ozonation experiments were performed in a glass bubble reactor. The parameters which were tested included the ozone concentration in the inlet gas stream, the reactor temperature and the composition of the ...
Due to the chemical and physical structure of a lignocellulosic biomass, its anaerobic digestion (AD) is a slow and difficult process. In this paper, the results obtained from a batch biochemical methane potential (BMP) test and fed-batch mesophilic AD assays of sunflower oil cake (SuOC) are presented. Taking into account the low digestibility shown during one-stage experiments the methane ...
Some of the key factors affecting the adaptation of anaerobic digestion processes to increasing levels of salinity were determined in batch tests using brown seaweed as a feedstock. It was found that cultures seeded with non-saline anaerobic inoculum required an adaptation period of up to two months to reach the same level of methane production rate as in those cultures seeded with ...
Sludge with low organic content always results in an unsatisfactory performance, even failure of anaerobic digestion. The alkaline pretreatment effect on anaerobic digestion of sludge with low organic content has seldom been studied although it gives many benefits for sludge with high organic content. In this study the influence of alkaline pretreatment (pH 10, an effective alkaline pH) on the ...
In this study, a comparison of methane (CH4) generation rates for two test cells, one operated with (enhanced) and another without leachate recirculation at Odayeri Sanitary Landfill were compared using their bio-chemical methane potentials (BMP). Initial methane potential is approximately 34.5 m³ CH4/wet ton of solid waste. The remaining methane potential for the control (C1) and the enhanced ...
In light of global warming mitigation efforts, increasing sludge disposal costs, and need for reduction in the carbon footprint of wastewater treatment plants, innovation in treatment technology has been tailored towards energy self-sufficiency. The AB process is a promising technology for achieving maximal energy recovery from wastewaters with minimum energy expenditure and therefore ...
Biochemical methane potential (BMP) tests have been carried out on sewage sludge from two wastewater treatment plants to assess the effect of additives (FeCl3 and two cationic polyelectrolytes) used in sludge dewatering. BMP tests were also carried out on the concentrated solid phase from the enzymic hydrolysis pre-treatment (42 °C, 48 h). FeCl3 had no significant effect on specific ...
Dilute manure is classified as wastewater due to the large quantity of water used in livestock production in Korea. Livestock wastewater treatment is required in order to reduce high moisture content and treat fluids discharged from the digestion process. In livestock wastewater treatment plants, large quantities of CO2 gas are produced at combined heat and power facilities as well as in the ...
Grease waste (GW) is an adequate substrate for sewage sludge co-digestion since, coming from a waste water treatment plant, it has a high methane potential (489 NmLCH4/gVSin); however, no synergistic effect takes place when co-digesting with 52%VS grease. Conversely, thermal hydrolysis (TH) improves the anaerobic digestion of GW (43% higher kinetics) and biological sludge ...
This study investigates the use of UV absorption and fluorescence spectroscopy to assess the early development of recalcitrant organic compounds in leachates formed during the anaerobic biodegradation of municipal solid waste. Biochemical methane potential tests were carried out on fresh waste (FW) and composted waste (CW) over a period of 150 days and leachates produced from the degradation of ...
The impact of changing microwave (MW) operational parameters such as temperature, intensity, contact time, and sludge concentration on the physic–chemical and microbiological properties of waste activated sludge (WAS), as well as on biogas production have been investigated. Results obtained indicated that sludge solubility increases with the increase of MW contact time and temperature. At an ...
This paper presents the results of lab-scale experiments on low temperature thermal pre-treatment (less than 100 °C) prior to anaerobic digestion of sewage sludge. Two heating ways, microwave heating (MH) and conventional heating (CH), and two types of sludge, primary and waste activated sludge, were compared under the same experimental conditions. The degree of solubilisation produced ...
The efficacy of sonication as a pre-treatment to anaerobic digestion (AD) was assessed using thickened waste activated sludge (TWAS). Efficiency was measured in relation to solubilisation, dewaterability, and AD performance. Eighteen experimental conditions were evaluated at low frequency (20 kHz), duration (2–10 s), amplitude (∼8–12 μm) and applied pressure (0.5–3.0 barg), using a sonix™ ...
The objective of this study was to determine the effectiveness of anaerobic digestion in the treatment of polyphenols (PP) present in olive mill wastewater (OMW) and wine distillery wastewater (WDW). Anaerobic Toxicity Assay (ATA) was conducted to assess the impact of the most representative phenolic compounds present in OMW and WDW: catechol, tannins and p-Coumaric acid, on biogas production. ...