Thermal characterization of anaerobic sludges from wastewater treatments applied to biological generation of H2

Abstract

A wide variety of organic residues may be used as energy source such as anaerobic sludge from wastewater treatment systems. However, due to inherent differences in composition, the proper characterization of these biomasses is essential to support their reuse through any conversion process. The aim of this study was the employment of thermal analysis techniques (TG/DTG and DTA) to perform the characterization of anaerobic sludges from different wastewater treatment plants (industrial and municipal), which were further applied for biological production of H 2. The different profiles observed through thermal characterization support the application of these residues as inocula, confirming their potential for H 2 production, while demonstrating the main causes for the different yields obtained (mol H 2 mol-1 sucrose): 0.9 from sludge of brewery industry and 2.0 from sludge of municipal wastewater treatment plant, corresponding to the overall yields of 10.8 and 25%, respectively. These results confirm the versatility of thermal analysis techniques for biomass characterization, focused on its application for power generation. It is urgent to adopt more sustainable and cost-effective solutions for their management, considering a large amount of residues daily generated in both treatment processes addressed; therefore, biohydrogen production by anaerobic digestion may be a promising alternative for the reuse of both residues as it promotes their transformation from costly and potentially polluting waste into clean and renewable energy sources. The development of this anaerobic process is even more attractive in countries as Brazil, where the weather conditions are naturally favorable.

Effect of addition of surface water treatment sludge to biomass in biochar porosity

“…The thermal stability of the samples was performed on an SDT-2960 from TA Instruments, equipped with a horizontal thermobalance capable of operating simultaneously in the TG/DTG-DTA modes. The instrument is coupled to an oven that can be programmed from room temperature to 1500 C. Mass capacity of 200 mg (350 mg including the crucibles), sensitivity D of 0:001 C. For this analysis, the samples are packed in an alumina crucible under an air atmosphere in heating at 20 C min À1 , from room temperature, about 25 C, to the final temperature of 1000 C. The mass of biochar samples used was about 10.0 mg analyzed [16].…”

Valorization of brewery waste slurry with glycerol as co‐substrate for hydrogen and butyrate production using dark fermentation

“…8,9 However, methanogenic archaea can be inhibited, by either physical or chemical pretreatment, leading to a partial oxidation of the organic matter, but also to the accumulation of hydrogen. 10 This partial AD process is known as dark fermentation (DF), a process that has been gaining in interest in recent years amid the development of low-carbon energy sources.…”

“…At the end of the process, depending on the nature of the digested substrate, the methane composition can range between 0.4 and 0.8 L per gram of volatile solids processed, with a methane to carbon dioxide ratio of 2:1, and small amounts of H 2 S, N 2 , H 2 , water vapor and other residual gases 8,9 . However, methanogenic archaea can be inhibited, by either physical or chemical pretreatment, leading to a partial oxidation of the organic matter, but also to the accumulation of hydrogen 10 . This partial AD process is known as dark fermentation (DF), a process that has been gaining in interest in recent years amid the development of low‐carbon energy sources.…”

Evaluation of denitration of nitrocellulose by microbiological treatment for industrial waste effluents using calorimetry analysis

“…Therefore, wastewater decontamination and the possibility of repeated use in the technological cycle are important tasks of the modern ecological chemistry. Various microorganisms or active silt from purification plants (being a secondary power source) is used for the solution of this complicated problem [23].…”