Biogas Recovery Research Articles

Natural pigments and biogas recovery from cyanobacteria grown in treated wastewater. Fate of organic microcontaminants.

Cyanobacterial wastewater-based biorefineries are a sustainable alternative to obtain high-value products with reduced costs. This study aimed to obtain phycobiliproteins and carotenoids, along with biogas from a wastewater-borne cyanobacterium grown in secondary effluent from an urban wastewater treatment plant, namely treated wastewater. For the first time, the presence of contaminants of emerging concern in concentrated pigment extracts was assessed. Tertiary wastewater treatment was conducted in a 3 L photobioreactor inoculated with Synechococcus sp., and operated in semi-continuous regime with a hydraulic retention time of 6 days. The carotenoid content was stable (reaching up to 4 mg g DW-1) regardless of the wastewater composition, while the phycobiliprotein content (up to 214 mg g DW-1) varied according to nitrogen availability. In concentrated pigment extracts, only 3 (out of 20) organic microcontaminants were detected. The biochemical methane potential of pigment-extracted biomass (222 NL CH4 kg VS-1) was still 72 % of raw biomass. In conclusion, a cyanobacteria culture rich in Synechococcus sp. appears as a promising source of bio-based products in a circular economy approach.

Synergetic interaction of Fe3O4 nanoparticles and activated carbon to mitigate inhibition effect of 4-nitrophenol on biogas recovery from petroleum sludge

Synergetic interaction of Fe3O4 nanoparticles and activated carbon to mitigate inhibition effect of 4-nitrophenol on biogas recovery from petroleum sludge

Electricity generation from wastewater biogas: a case study in Santa Marta, Colombia

Introduction: sanitation is one of the main global challenges in building resilience to the effects of climate change and global warming. Wastewater treatment is one of the activities that enables the production of renewable energy through the use of biogas.Objetive: the objective of this study was to estimate the amount of electricity available in the city of Santa Marta, Colombia, from the production of biogas generated at a wastewater treatment plant and to estimate the avoided emissions with biogas recovery and the non-use of local electricity.Methodology: a case study was conducted in Santa Marta, Colombia, where the potential for electricity generation from biogas produced at a wastewater treatment plant was estimated. Both the annual electricity generation potential and the avoided CO2eq emissions from using biogas instead of local electricity were calculated.Results: the results of the case study show significant potential for biogas recovery, with an annual energy generation potential of 5,348.345 MWh. Additionally, it was estimated that 25,101.16 tonnes of CO2eq could be avoided each year.Conclusions: the use of wastewater for electricity generation is crucial for environmental sustainability, and its application in the circular bioeconomy presents a significant opportunity. This study highlights the importance of implementing sustainable technologies for renewable energy production from unconventional sources, such as biogas from wastewater.

Life Cycle Assessment of Methanol Production from Municipal Solid Waste: Environmental Comparison with Landfilling and Incineration

Inadequate waste management strategies play a significant role in exacerbating environmental challenges, such as increased greenhouse gas emissions, resource depletion, and other adverse ecological impacts. These issues are aggravated by the global rise in municipal solid waste (MSW) generation, surpassing the rate of population growth. Simultaneously, there is an urgent demand for sustainable energy solutions to combat climate change and its wide-ranging impacts. In response, this study addresses a critical question: is methanol production from MSW, a waste-to-chemical (WtC) alternative based on circular economy principles, a more environmentally sustainable approach compared to traditional waste-to-energy (WtE) methods like landfilling with biogas recovery and incineration? To answer this, this study evaluates the environmental performance of MSW-to-methanol technologies using life cycle assessment (LCA), focusing on key indicators such as global warming potential, resource depletion, and impacts on human health and ecosystem quality. The results reveal that methanol production from MSW significantly reduces global warming potential (GWP) by 87% compared to landfilling and 56% compared to incineration. Additionally, the process demonstrates high energy efficiency in electricity generation, achieving 80% of the output of incineration. These findings position MSW-to-methanol as a promising alternative for advancing sustainable waste management and renewable energy transitions. While the technology is still in its developmental stages, this research highlights the need for further advancements and policy support to enhance feasibility and scalability. By providing a comparative environmental analysis, this study contributes to identifying innovative pathways for addressing pressing waste management and energy sustainability challenges.

Study of the methanogenic potential of urban waste from the city of N’Djamena for recovery into biogas

The different types of urban waste as well as household waste are generally disposed of in open landfills affecting environmental sustainability. These wastes, by the release of contaminants such as leachates and greenhouse gases, increase the pollution potential of the sites. We recovered a quantity to carry out our experiments. The recovery of waste into biogas inevitably takes place in hermetically sealed enclosures called biodigesters. In this work we highlighted several types of waste at room temperature in a 0.75l can equipped with an empty inflatable balloon used for the recovery of biogas, which constituted our biodigester. Then a second experiment was carried out on the mesophilic temperature and the results were compared. The aim is to see the waste with the best biogas potential in terms of quality and quantity of production. The experiment consisted of working at an ambient temperature around 35°C±2 °C and up to 45 °C (mesophilic temperature). For this experiment we found that some bio-digesters started producing after two hours of time, the inflatable balloon increased in volume every hour up to 24 hours before and remained constant. We used the resources in terms of substrate and equipment of the Afric-Lab laboratory and that of the Physics-Chemistry department of the Higher Normal School of N'Djamena.

Anaerobic Digestion of Lime Waste in Batch Assay Digestion for Potential Biogas Recovery

The term" lime" includes a wide variety of materials produced by calcining or burning limestone or dolostone. Lime and products containing lime have been widely employed in landfill covers (caps), wastes, and liners. The accumulation of lime wastes, an environmental hazard on dumpsites, causes economic and environmental problems. Nonetheless, there is a potential to recover biogas from lime wastes due to their high concentration in soluble sugars. The liming of waste is supposed to stop biodegradation and reduce the impacts of landfilling activity. D-Limonene, a chemical compound present in lime peels, is, however, known to negatively affect the anaerobic digestion and conversion of lime waste to biogas. This study is aimed at reducing the effect of DLimonene on biogas production from lime wastes. The study assessed the impact of lime waste pre-treatment and co-digestion with poultry litter on improving biogas recovery. This study further describes the adoption of a biodigestion system for the degradation of organic matter and biogas production. In co-digestion, an equal mass of lime waste was mixed with that of poultry litter. The pre-treatment of lime waste was done using a solid-liquid extraction process to filter out essential oil, containing D-Limonene, from lime wastes. Different samples from untreated, pre-treated, and mixed wastes were digested in laboratory under mesophilic conditions. The results indicate that the pre-treatment process alone increased biogas yield by about 40% while the co-digestion of untreated lime waste with poultry litter did not affect improving biogas yield. The use of these pre-treated samples in co-digestion with other nutrients filled and high energy yielding biomass would provide a better nutrient balanced and microbial diversity. Economic estimation of the biogas production process from lime waste that was carried out indicated lesser cost than the current market price of cooking gas in Nigeria. The findings show that there is economically viable recovery option of biogas from lime waste, which would boost the drive of government towards an alternative source of energy.

Consequential life cycle assessment of urban source-separating sanitation systems complementing centralized wastewater treatment in Lund, Sweden

This study examined various source-separating sanitation systems to evaluate their environmental performance, providing decision-makers with insights for selecting an appropriate system for a newly developed neighborhood in Sweden. A full consequential LCA was conducted to account for resource recovery and substitution. The local wastewater treatment plant WWTP was modeled as a reference. Secondly, a urine recycling system was introduced to treat 75 % of the collected urine, with the remainder piped to the WWTP. Thirdly, a black and greywater (BW&GW) treatment system handling all generated wastewater was examined. Finally, a hybrid source-separating system combining urine, black, and greywater was investigated. The results indicated that the four scenarios exhibited global warming potentials (GWP) of 78, 62, 32, and 24 kg CO2-eq per PE/ y. Recycling urine as fertilizer led to a 20 % reduction in the GWP of the reference. It also reduced other impact categories, with a 55 %, 65 %, and 45 % reduction in eutrophication, ozone depletion, and acidification, respectively. The BW&GW system achieved a 60 % reduction over the reference GWP, mainly due to fertilizer, biogas, and cleanwater recovery. Integrating urine, black, and greywater recycling in the final scenario achieved a 25 % reduction compared to the BW&GW scenario, primarily due to lowering of the ammonia stripping GWP and the additional fertilizer recovery. Based on sensitivity analyses, switching citric acid for sulfuric acid reduced the GWP of the urine stabilization unit process by 101 %, from 15.47 to -0.14 kg CO2-eq per PE/ y. Ultimately, the findings suggest that the fully decentralized source-separating sanitation system incorporating urine, blackwater, and greywater recycling, particularly when combined with 70 % energy recovery at the urine concentrator, is most favorable.

Integration of bioflocculation with anaerobic digestion guided by physicochemical profiling enhances valorization potential of domestic wastewater

Integration of bioflocculation with anaerobic digestion guided by physicochemical profiling enhances valorization potential of domestic wastewater

Cheese whey generation, management and potential for biogas production in Mexico and the State of Jalisco

ABSTRACT Pollution of water bodies and process upset in treatment plants in Mexico by cheese whey discharges is a matter of concern where scant inspection and law enforcement may aggravate the situation. This study analyzes the current state of environmental regulatory compliance and the impacts of whey discharges with particular emphasis on the country’s leading dairy-producing state, Jalisco. Subsequently, cheese whey characteristics and current valorisation volume and uses are discussed in detail. From there, anaerobic digestion is presented as a key technology for cheese whey treatment mainly to comply with wastewater regulations, with recovery of biogas as bonus. From there, the volume of cheese whey discharged to the environment and potential equivalence in biogas and electricity production is calculated considering both the technologies commonly used in industrial applications and for farms and small producers. Also, the potential electricity generation and prevented atmospheric impact are calculated and framed against the current Mexican energy and emissions inventory. Finally, a review of past efforts to disseminate the use of anaerobic digesters to produce biogas from organic waste in Mexico is undertaken, followed by a discussion of the basic requirements for a strategy to sustainably manage and treat whey discharges.

Combined high-rate contact stabilization and chemically enhanced primary treatment for enhanced recovery of organic matter and biogas from sewage

Combined high-rate contact stabilization and chemically enhanced primary treatment for enhanced recovery of organic matter and biogas from sewage

Valorization of paper-mill sludge laden with 2-chlorotoluene using hydroxyapatite@biochar nanocomposite to enrich methanogenic community: A techno-economic approach

Valorization of paper-mill sludge laden with 2-chlorotoluene using hydroxyapatite@biochar nanocomposite to enrich methanogenic community: A techno-economic approach

Flexible supply-demand side management towards a sustainable decentralized distribution network: A net-negative Water-energy-emissions Nexus assessment

Flexible supply-demand side management towards a sustainable decentralized distribution network: A net-negative Water-energy-emissions Nexus assessment

Mechanism underlying the sustained stimulatory effects of energization on biomethane recovery from food waste post-energization cessation

Mechanism underlying the sustained stimulatory effects of energization on biomethane recovery from food waste post-energization cessation

Resource recovery and contaminants of emerging concern mitigation by microalgae treating wastewater

Resource recovery and contaminants of emerging concern mitigation by microalgae treating wastewater

Optimization Study of BOG Treatment Technology in LNG Receiving Station

The use of regasified liquefied natural gas (LNG) and biogas (BOG) as fuel for LNG-fueled ships often results in wasted cooling energy. To address this problem, BOG recovery and treatment is required. This paper focuses on BOG recovery and purification processes, outlines current recovery technologies and discusses further developments.

Former landfills as environmental liabilities in central Chile: Evidence from a pilot study in Lepanto

AbstractThe former Lepanto landfill in the Santiago Metropolitan Region in Central Chile ceased operations in 2002 after 24 years. Currently, a biogas recovery center operates on this site. The objective of this pilot study was to evaluate the atmospheric concentrations of two polycyclic aromatic hydrocarbons (PAHs, i.e., phenanthrene and fluoranthene) at three points downwind from the former Lepanto landfill using passive air samplers and polyurethane foam disks to provide 3‐month average concentrations of contaminants during winter months. The results showed concentrations ranging between 2 and 65 ng m−3 and decreasing with distance from the former landfill. Given that the distance to other potential sources was similar in all sampling sites, the evidence found suggested that the former Lepanto landfill may contribute to the local PAH inventory. Thus, we suggest that former landfills are potential candidates for long‐term monitoring as they can represent a less‐known environmental liability for residents. Additionally, we provide insights on how the Chilean environmental protection system can establish reclamation steps for their management after closure.

Carbon redirection pathway, energy recovery potential, and microbial population dynamics in high-rate activated sludge

Carbon redirection pathway, energy recovery potential, and microbial population dynamics in high-rate activated sludge

Synergism of floated paperboard sludge cake /sewage sludge for maximizing biomethane yield and biochar recovery from digestate: A step towards circular economy

Synergism of floated paperboard sludge cake /sewage sludge for maximizing biomethane yield and biochar recovery from digestate: A step towards circular economy

The biofactories: Quantifying environmental benefits of the wastewater circular economy in Chile using life cycle assessment

The biofactories: Quantifying environmental benefits of the wastewater circular economy in Chile using life cycle assessment

Syntrophic Jiont of Sulfate-Reducing Bacteria and Hydrogen-Producing Acetogen Stimulated Methane Production from Waste Activated Sludge Digestion

Anaerobic digestion of waste-activated sludge (WAS) towards biogas recovery is constrained by the limited hydrolysis and inhibited acetogenesis steps that hinder subsequent energy recovery. This study employed Fe(VI)/S(IV) oxidation to enhance the WAS solubilization and coupled it with the syntrophic interaction of hydrogen-producing acetogen (HPA) and sulfate-reducing bacteria (SRB) to stimulate the successive procedure towards methane production. Results showed that the dosage ratio of HPA-SRB to WAS (H-S-W) with 1:1:50 outperformed with the highest methane production potential (11.63 ± 1.87 mL CH4/(g VSS·d). Meanwhile, the efficient and sequential process from acetogenesis to methanogenesis stimulated by HPA-SRB was evidenced by a significant decrease of 30.2% in the acetate concentration. The microbial community structure further manifested the crucial role of HPA-SRB with increased abundance of Desulfobulbus (2.07%), Syntrophomonas (1.24%) and Smithella (1.63%), which stimulated acetophilic methanogen boost with Methanobacterium dominating with 77.51% in H-S-W100. Furthermore, the positive syntrophic relationships among HPA-SRB and acetophilic methanogens towards methane production were confirmed via molecular ecological network and canonical correspondence analysis. This study highlighted the syntrophic cooperation of the mixed consortia of HPA and SRB on methane production based on Fe(VI)/S(IV) pretreatment and provided the theoretical and technical basis for the potential implementation of novel methanogenesis technology for WAS treatment.