scholarly journals Review on landfill gas formation from leachate biodegradation

2021 ◽  
Vol 4 (1) ◽  
pp. 39
Author(s):  
Nur Shuhadah Japperi ◽  
Zharif Zainulazfar Mohd Asri ◽  
Wan Zairani Wan Bakar ◽  
'Aqilah Dollah ◽  
Mohd Fazril Irfan Ahmad Fuad ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Waste Management ◽  
Landfill Gas ◽  
Anaerobic Bacteria ◽  
Methanogenic Archaea ◽  
Operating Parameters ◽  
Environmental Implications ◽  
Methane Gas ◽  
Acetoclastic Methanogen ◽  
Fermentative Bacteria

Landfill waste management is a very crucial procedure in handling Municipal Solid Waste (MSW) because it may create significant environmental issues if it is not managed properly. Landfill leachate and landfill gas (LFG) is part of the landfill waste management which triggered lot of researchers especially in terms of the environmental implications associated with the movement of the gasses during the waste constituents’ processes. Hence, this paper review is aiming to understand the behaviour of leachate itself as a decomposition agent in producing landfill gas (biogas). Biogas is naturally produced by anaerobic bacteria through anaerobic digestion which is affected by operating parameters and substrate characteristic. The results indicate that temperature, pH, and C/N ratio of leachate are the important factors that could increase the production of biogas with high content of methane. Furthermore, in terms of microbial activity during anaerobic digestion process, hydrogenotrophic and acetoclastic methanogen are the dominant substrate that contribute in producing methane gas as the final product. Firmicutes and Bacteroidetes are the common fermentative bacteria that had been found during fermentation process in hydrolysis and acidogenic phases. While, methanobacterial, methanococcal, methanomicrobial, methanosarcinal, and methanopyral are being classified as orders among 65 types of methanogenic archaea during methanogenesis stage. Overall, the relationships between operating parameters and microbial structure are important aspects that need to be considered in order to optimize the production of methane gas. 

scholarly journals Effect of Antibiotics on the Microbial Efficiency of Anaerobic Digestion of Wastewater: A Review

2021 ◽  
Vol 11 ◽  
Author(s):  
Leilei Xiao ◽  
Yiping Wang ◽  
Eric Lichtfouse ◽  
Zhenkai Li ◽  
P. Senthil Kumar ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Adverse Effects ◽  
Circular Economy ◽  
Waste Treatment ◽  
Animal Health ◽  
Methanogenic Archaea ◽  
New Materials ◽  
Fermentative Bacteria ◽  
Microbial Efficiency

Recycling waste into new materials and energy is becoming a major challenge in the context of the future circular economy, calling for advanced methods of waste treatment. For instance, microbially-mediated anaerobic digestion is widely used for conversion of sewage sludge into biomethane, fertilizers and other products, yet the efficiency of microbial digestion is limited by the occurrence of antibiotics in sludges, originating from drug consumption for human and animal health. Here we present antibiotic levels in Chinese wastewater, then we review the effects of antibiotics on hydrolysis, acidogenesis and methanogenesis, with focus on macrolides, tetracyclines, β-lactams and antibiotic mixtures. We detail effects of antibiotics on fermentative bacteria and methanogenic archaea. Most results display adverse effects of antibiotics on anaerobic digestion, yet some antibiotics promote hydrolysis, acidogenesis and methanogenesis.

scholarly journals Potential Contribution of Waste-to-Energy to Power Consumption in the Gaza Strip

2015 ◽  
Vol 09 (2) ◽  
Keyword(s):  
Anaerobic Digestion ◽  
Waste Management ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Gaza Strip ◽  
Landfill Gas ◽  
Waste To Energy ◽  
Potential Contribution ◽  
Gas Recovery ◽  
The Gaza Strip

Sustainable energy supply is one of the main challenges that people will face over the coming decades. Biomass can make a substantial contribution to supplying future energy demand in a sustainable way. Currently it is the largest global contributor of renewable energy, and has significant potential to expand the production of heat, electricity and fuels for transport. Municipal solid waste is an enormous renewable resource that has high energy capacity because it contains a high proportion of biomass materials. This kind of sustainable waste management typically called waste-to-energy is critical for reducing the reliance on fossil fuels and non-renewable materials. Waste-to-energy is a reliable and alternative form of energy that has become the basis for many of the most successful solid waste management systems in many countries. Energy recovery from waste is the conversion of waste materials into useable heat, electricity, or fuel through a variety of processes. This study assesses the potential contribution of waste-to-energy facilities to total Gaza peak power demand up to the year 2040 based on three scenarios: incineration, anaerobic digestion and landfill gas recovery. Three dumping sites are distributed along the Gaza Strip, Johr El-deek, Deir El-balah and Rafah. The analysis shows a potential to produce about 1100 MWh per day based on the anaerobic digestion scenario, about 580 MWh per day based on incineration of municipal solid waste scenario, and about 130 MWh per day based on landfill gas recovery scenario. These values accounts to 275%, 145% and 33% of the year 2014 peak electricity demand of 400 megawatt from the three scenarios, respectively. The forecasted results of the three scenarios can be used to design future waste-to- energy facilities in the main cities of the Gaza Strip. The production cost of energy was 7¢/kWh, 5¢/kWh and 17¢/kWhfor incineration, anaerobic digestion and landfill gas recovery scenarios, respectively.

The bacterial numeration and an observation of a new syntrophic association for granular sludge

1997 ◽  
Vol 36 (6-7) ◽  
pp. 133-140 ◽  
Author(s):  
Zhu Jianrong ◽  
Hu Jicui ◽  
Gu Xiasheng
Keyword(s):  
Anaerobic Bacteria ◽  
Granular Sludge ◽  
Methanogenic Bacteria ◽  
Uasb Reactor ◽  
Two Phase ◽  
Methanogenic Activity ◽  
Syntrophic Association ◽  
Group I ◽  
Acetogenic Bacteria ◽  
Fermentative Bacteria

The bacterial numeration and microbial observation were made on granular sludge from laboratory single and two-phase UASB reactors. It was shown that the fermentative bacteria (group I), H2-producing acetogenic bacteria (group II) and methanogenic bacteria (group III) of granular sludge in single UASB reactor were 9.3 × 108−4.3 × 109, 4.3 × 107−4.3 × 108, 2.0−4.3 × 108, respectively, during the granulation process. The sludge of methanogenic reactor exhibited the similar results. That indicates there is no big difference between suspended and granular sludge, and bacterial population for three groups of anaerobic bacteria are similar. The formation of granular sludge depends mainly on the organization and arrangement of bacteria. An observation of granular sludge using electron microscope revealed that the fermentative bacteria and hydrogenotrophic methanogens existed on outer surface of granules, and aceticlastic methanogens and H2-producing acetogenic bacteria occupied the inner layer. A new syntrophic association between Methanosaeta sp. and Syntrophomonas sp. (even plus Methanobrevibacter sp.) was observed. Because Methanosaeta can effectively convert the acetate (the end product of propionate and butyrate) to methane, such a new syntrophic association is supposed to support the degradation of short fatty acids and high methanogenic activity of granular sludge. Based on structural pattern, a hypothesis on mechanism of granulation called “crystallized nuclei formation” is proposed.

scholarly journals Enhancement of Food Waste Management and Its Environmental Consequences

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1790
Author(s):  
Jan den Boer ◽  
Gudrun Obersteiner ◽  
Sebastian Gollnow ◽  
Emilia den Boer ◽  
Renata Bodnárné Sándor
Keyword(s):  
Anaerobic Digestion ◽  
Waste Management ◽  
Environmental Effects ◽  
Ghg Emissions ◽  
Primary Energy ◽  
Biological Pretreatment ◽  
Environmental Benefit ◽  
Kitchen Waste ◽  
Considerable Saving ◽  
Positive Effects

This paper assesses the potential environmental effects of the optimization of the kitchen waste management in Opole. The separate collection of kitchen waste is improved by distribution of separate collection kits consisting of an in-home bin and 10 L biodegradable bags. The surplus of collected kitchen waste is diverted from treatment in a mechanical-biological pretreatment (MBP) along with the residual waste to anaerobic digestion (AD) with the biowaste. This has positive effects on European and Polish goals, ambitions, and targets, such as (i) increasing the level of renewables in the primary energy supply, (ii) decreasing the level of greenhouse gas (GHG) emissions, (iii) increasing the level of preparation for reuse and recycling of municipal waste. The environmental effects of 1 ton additionally separately collected and treated kitchen waste are determined by using life cycle assessment. It was shown that in all selected impact categories (global warming potential, marine eutrophication potential, acidification potential, and ozone depletion potential) a clear environmental benefit can be achieved. These benefits are mainly caused by the avoided emissions of electricity and heat from the Polish production mix, which are substituted by energy generation from biogas combustion. Optimization of the waste management system by diversion of kitchen waste from mechanical-biological pretreatment to anaerobic digestion can lead to considerable saving of 448 kg CO2-eq/t of waste diverted. With an estimated optimization potential for the demonstration site of 40 kg/inh·year for the city of Opole, this would lead to 680,000 t CO2-eq savings per year for the whole of Poland. The sensitivity analysis showed that with a choice for cleaner energy sources the results would, albeit lower, show a significant savings potential.

scholarly journals Life Cycle Assessment of Bioplastics and Food Waste Disposal Methods

2021 ◽  
Vol 13 (12) ◽  
pp. 6894
Author(s):  
Shakira R. Hobbs ◽  
Tyler M. Harris ◽  
William J. Barr ◽  
Amy E. Landis
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Anaerobic Digestion ◽  
Waste Management ◽  
Food Waste ◽  
Energy Demand ◽  
Anaerobic Digester ◽  
Management Scenarios ◽  
Cumulative Energy ◽  
Cumulative Energy Demand

The environmental impacts of five waste management scenarios for polylactic acid (PLA)-based bioplastics and food waste were quantified using life cycle assessment. Laboratory experiments have demonstrated the potential for a pretreatment process to accelerate the degradation of bioplastics and were modeled in two of the five scenarios assessed. The five scenarios analyzed in this study were: (1a) Anaerobic digestion (1b) Anaerobic digestion with pretreatment; (2a) Compost; (2a) Compost with pretreatment; (3) Landfill. Results suggested that food waste and pretreated bioplastics disposed of with an anaerobic digester offers life cycle and environmental net total benefits (environmental advantages/offsets) in several areas: ecotoxicity (−81.38 CTUe), eutrophication (0 kg N eq), cumulative energy demand (−1.79 MJ), global warming potential (0.19 kg CO2), and human health non-carcinogenic (−2.52 CTuh). Normalized results across all impact categories show that anaerobically digesting food waste and bioplastics offer the most offsets for ecotoxicity, eutrophication, cumulative energy demand and non-carcinogenic. Implications from this study can lead to nutrient and energy recovery from an anaerobic digester that can diversify the types of fertilizers and decrease landfill waste while decreasing dependency on non-renewable technologies. Thus, using anaerobic digestion to manage bioplastics and food waste should be further explored as a viable and sustainable solution for waste management.

The contribution of fermentative bacteria and methanogenic archaea to azo dye reduction by a thermophilic anaerobic consortium

2006 ◽  
Vol 39 (1) ◽  
pp. 38-46 ◽  
Author(s):  
André B. dos Santos ◽  
Marta P. de Madrid ◽  
Frank A.M. de Bok ◽  
Alfons J.M. Stams ◽  
Jules B. van Lier ◽  
...  
Keyword(s):  
Azo Dye ◽  
Methanogenic Archaea ◽  
Fermentative Bacteria ◽  
Dye Reduction ◽  
Anaerobic Consortium

Anaerobic digestion of orange peel in a semi-continuous pilot plant: An environmentally sound way of citrus waste management in agro-ecosystems

2018 ◽  
Vol 630 ◽  
pp. 401-408 ◽  
Author(s):  
Demetrio A. Zema ◽  
Adele Fòlino ◽  
Giovanni Zappia ◽  
Paolo S. Calabrò ◽  
Vincenzo Tamburino ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Waste Management ◽  
Pilot Plant ◽  
Orange Peel ◽  
Environmentally Sound ◽  
Citrus Waste

Life Cycle Comparison of Two Options for MSW Management in Puerto Rico: Thermal Treatment vs. Modern Landfilling

2008 ◽  
Author(s):  
Giselle Balaguer-Da´tiz ◽  
Nikhil Krishnan
Keyword(s):  
Puerto Rico ◽  
Life Cycle ◽  
Thermal Treatment ◽  
Waste Management ◽  
Life Cycle Inventory ◽  
Landfill Gas ◽  
The Body ◽  
Waste To Energy ◽  
Msw Management ◽  
Wide Range

The management of municipal solid wastes (MSW) in Puerto Rico is becoming increasingly challenging. In recent years, several of the older landfills have closed due to lack of compliance with federal landfill requirements. Puerto Rico is an island community and there is limited space for construction of new landfills. Furthermore, Puerto Rico residents generate more waste per capita than people living on the continental US. Thermal treatment, or waste to energy (WTE) technologies are therefore a promising option for MSW management. It is critical to consider environmental impacts when making decisions related to MSW management. In this paper we quantify and compare the environmental implications of thermal treatment of MSW with modern landfilling for Puerto Rico from a life cycle perspective. The Caguas municipality is currently considering developing a thermal treatment plant. We compare this to an expansion of a landfill site in the Humacao municipality, which currently receives waste from Caguas. The scope of our analysis includes a broad suite of activities associated with management of MSW. We include: (i) the transportation of MSW; (ii) the impacts of managing waste (e.g., landfill gas emissions and potential aqueous run-off with landfills; air emissions of metals, dioxins and greenhouse gases) and (iii) the implications of energy and materials offsets from the waste management process (e.g., conversion of landfill gas to electricity, electricity produced in thermal treatment, and materials recovered from thermal treatment ash). We developed life cycle inventory models for different waste management processes, incorporating information from a wide range of sources — including peer reviewed life cycle inventory databases, the body of literature on environmental impact of waste management, and site-specific factors for Puerto Rico (e.g. waste composition, rainfall patterns, electricity mix). We managed uncertainty in data and models by constructing different scenarios for both technologies based on realistic ranges of emission factors. The results show that thermal treatment of the unrecyclable part of the waste stream is the preferred option for waste management when compared to modern landfilling. Furthermore, Eco-indicator 99 method is used to investigate the human health, ecosystem quality and resource use impact categories.

scholarly journals Bioenergetic Aspects of Halophilism

1999 ◽  
Vol 63 (2) ◽  
pp. 334-348 ◽  
Author(s):  
Aharon Oren
Keyword(s):  
Free Energy ◽  
Compatible Solutes ◽  
Methanogenic Archaea ◽  
Energetic Cost ◽  
Salt Adaptation ◽  
Energy Yield ◽  
Dissimilatory Sulfate Reduction ◽  
Fermentative Bacteria ◽  
Osmotic Solutes ◽  
Dissimilatory Metabolism

SUMMARY Examinination of microbial diversity in environments of increasing salt concentrations indicates that certain types of dissimilatory metabolism do not occur at the highest salinities. Examples are methanogenesis for H2 + CO2 or from acetate, dissimilatory sulfate reduction with oxidation of acetate, and autotrophic nitrification. Occurrence of the different metabolic types is correlated with the free-energy change associated with the dissimilatory reactions. Life at high salt concentrations is energetically expensive. Most bacteria and also the methanogenic archaea produce high intracellular concentrations of organic osmotic solutes at a high energetic cost. All halophilic microorganisms expend large amounts of energy to maintain steep gradients of NA+ and K+ concentrations across their cytoplasmic membrane. The energetic cost of salt adaptation probably dictates what types of metabolism can support life at the highest salt concentrations. Use of KCl as an intracellular solute, while requiring far-reaching adaptations of the intracellular machinery, is energetically more favorable than production of organic-compatible solutes. This may explain why the anaerobic halophilic fermentative bacteria (order Haloanaerobiales) use this strategy and also why halophilic homoacetogenic bacteria that produce acetate from H2 + CO2 exist whereas methanogens that use the same substrates in a reaction with a similar free-energy yield do not.

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