Use of life cycle assessment to evaluate environmental impacts associated with the management of sludge and biogas

2018 ◽  
Vol 77 (9) ◽  
pp. 2292-2300 ◽  
Author(s):  
Karina Cubas do Amaral ◽  
Miguel Mansur Aisse ◽  
Gustavo Rafael Collere Possetti ◽  
Marcelo Real Prado
Keyword(s):  
Global Warming ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Sewage Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Baseline Scenario ◽  
Low Efficiency ◽  
By Products

Abstract Upflow anaerobic sludge blanket (UASB) reactors used in sewage treatment generate two by-products that can be reused: sludge and biogas. At the present time in Brazil, most of this resulting sludge is disposed of in sanitary landfills, while biogas is commonly burned off in low-efficiency flares. The aim of the present study was to use life cycle assessment to evaluate the environmental impacts from four different treatment and final destination scenarios for the main by-products of wastewater treatment plants. The baseline scenario, in which the sludge was sanitized using prolonged alkaline stabilization and, subsequently, directed toward agricultural applications and the biogas destroyed in open burners, had the most impact in the categories of global warming, terrestrial ecotoxicity, and human non-carcinogenic toxicity. The scenario in which heat resulting from biogas combustion is used to dry the sludge showed significant improvements over the baseline scenario in all the evaluated impact categories. The recovery of heat from biogas combustion decreased significantly the environmental impact associated with global warming. The combustion of dried sludge is another alternative to improve the sludge management. Despite the reduction of sludge volume to ash, there are environmental impacts inherent to ozone formation and terrestrial acidification.

scholarly journals Life Cycle Assessment of Households in Santiago, Chile: Environmental Hotspots and Policy Analysis

2021 ◽  
Vol 13 (5) ◽  
pp. 2525
Author(s):  
Camila López-Eccher ◽  
Elizabeth Garrido-Ramírez ◽  
Iván Franchi-Arzola ◽  
Edmundo Muñoz
Keyword(s):  
Global Warming ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Food Consumption ◽  
Household Income ◽  
Resource Scarcity ◽  
Life Cycles ◽  
The Impact ◽  
Freshwater Eutrophication

The aim of this study is to assess the environmental impacts of household life cycles in Santiago, Chile, by household income level. The assessment considered scenarios associated with environmental policies. The life cycle assessment was cradle-to-grave, and the functional unit considered all the materials and energy required to meet an inhabitant’s needs for one year (1 inh/year). Using SimaPro 9.1 software, the Recipe Midpoint (H) methodology was used. The impact categories selected were global warming, fine particulate matter formation, terrestrial acidification, freshwater eutrophication, freshwater ecotoxicity, mineral resource scarcity, and fossil resource scarcity. The inventory was carried out through the application of 300 household surveys and secondary information. The main environmental sources of households were determined to be food consumption, transport, and electricity. Food consumption is the main source, responsible for 33% of the environmental impacts on global warming, 69% on terrestrial acidification, and 29% on freshwater eutrophication. The second most crucial environmental hotspot is private transport, whose contribution to environmental impact increases as household income rises, while public transport impact increases in the opposite direction. In this sense, both positive and negative environmental effects can be generated by policies. Therefore, life-cycle environmental impacts, the synergy between policies, and households’ socio-economic characteristics must be considered in public policy planning and consumer decisions.

scholarly journals Distinct microalgae species for food—part 1: a methodological (top-down) approach for the life cycle assessment of microalgae cultivation in tubular photobioreactors

2020 ◽  
Vol 32 (5) ◽  
pp. 2977-2995 ◽  
Author(s):  
S. Schade ◽  
T. Meier
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Baseline Scenario ◽  
Season Length ◽  
Microalgae Cultivation ◽  
Top Down ◽  
Tubular Photobioreactor ◽  
The Impact ◽  
Tubular Photobioreactors

Abstract Specific microalgae species are an adequate source of EPA and DHA and are able to provide a complete protein, which makes them highly interesting for human nutrition. However, microalgae cultivation has also been described to be energy intensive and environmentally unfavorable in pilot-scale reactors. Moreover, production in cold temperature zones has not been sufficiently investigated. In particular, the effects of tube materials and cultivation season length have rarely been previously investigated in the context of a comparative LCA of microalgae cultivation. A computational “top-down” model was conducted to calculate input flows for Nannochloropsis sp. and Phaeodactylum tricornutum cultivation in a hypothetical tubular photobioreactor. Cultivation processes were calculated according to detailed satellite climatic data for the chosen location in Central Germany. This model was applied to a set of different scenarios, including variations in photobioreactor material, tube diameter, microalgae species, and cultivation season length. Based on these data, a life cycle assessment (LCA) was performed following ISO standard 14040/44. The impact assessment comprised the global warming potential, acidification, eutrophication, cumulative energy demand, and water scarcity. The results showed that a long cultivation season in spring and fall was always preferable in terms of environmental impacts, although productivity decreased significantly due to the climatic preconditions. Acrylic glass as a tube material had higher environmental impacts than all other scenarios. The cultivation of an alternative microalgae species showed only marginal differences in the environmental impacts compared with the baseline scenario. Critical processes in all scenarios included the usage of hydrogen peroxide for the cleaning of the tubes, nitrogen fertilizer, and electricity for mixing, centrifugation, and drying. Microalgae cultivation in a tubular photobioreactor in a “cold-weather” climate for food is sustainable and could possibly be a complement to nutrients from other food groups. The added value of this study lies in the detailed description of a complex and flexible microalgae cultivation model. The new model introduced in this study can be applied to numerous other scenarios to evaluate photoautotrophic microalgae cultivation in tubular photobioreactors. Thus, it is possible to vary the facility location, seasons, scale, tube dimensions and material, microalgae species, nutrient inputs, and flow velocity. Moreover, single processes can easily be complemented or exchanged to further adjust the model individually, if, for instance, another downstream pathway is required.

scholarly journals Process simulation and gate-to-gate life cycle assessment of hydrometallurgical refractory gold concentrate processing

2019 ◽  
Vol 25 (3) ◽  
pp. 456-477 ◽  
Author(s):  
Heini Elomaa ◽  
Pia Sinisalo ◽  
Lotta Rintala ◽  
Jari Aromaa ◽  
Mari Lundström
Keyword(s):  
Global Warming ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Process Simulation ◽  
Development Stage ◽  
Environmental Indicators ◽  
Gold Recovery ◽  
Pressure Oxidation ◽  
Refractory Gold

Abstract Purpose Currently, almost all cyanide-free gold leaching processes are still in the development stage. Proactively investigating their environmental impacts prior to commercialization is of utmost importance. In this study, a detailed refractory gold concentrate process simulation with mass and energy balance was built for state-of-the-art technology with (i) pressure oxidation followed by cyanidation and, compared to alternative cyanide-free technology, with (ii) pressure oxidation followed by halogen leaching. Subsequently, the simulated mass balance was used as life cycle inventory data in order to evaluate the environmental impacts of the predominant cyanidation process and a cyanide-free alternative. Methods The environmental indicators for each scenario are based on the mass balance produced with HSC Sim steady-state simulation. The simulated mass balances were evaluated to identify the challenges in used technologies. The HSC Sim software is compatible with the GaBi LCA software, where LCI data from HSC-Sim is directly exported to. The simulation produces a consistent life cycle inventory (LCI). In GaBi LCA software, the environmental indicators of global warming potential (GWP), acidification potential (AP), terrestrial eutrophication potential (EP), and water depletion (Water) are estimated. Results and discussion The life cycle assessment revealed that the GWP for cyanidation was 10.1 t CO2-e/kg Au, whereas the halogen process indicated a slightly higher GWP of 12.6 t CO2-e/kg Au. The difference is partially explained by the fact that the footprint is calculated against produced units of Au; total recovery by the halogen leaching route for gold was only 87.3%, whereas the cyanidation route could extract as much as 98.5% of gold. The addition of a second gold recovery unit to extract gold also from the washing water in the halogen process increased gold recovery up to 98.5%, decreasing the GWP of the halogen process to 11.5 t CO2-e/kg Au. However, both evaluated halogen processing scenarios indicated a slightly higher global warming potential when compared to the dominating cyanidation technology. Conclusions The estimated environmental impacts predict that the development-stage cyanide-free process still has some challenges compared to cyanidation; as in the investigated scenarios, the environmental impacts were generally higher for halogen leaching. Further process improvements, for example in the form of decreased moisture in the feed for halide leaching, and the adaptation of in situ gold recovery practices in chloride leaching may give the cyanide-free processing options a competitive edge.

scholarly journals Comparative Life Cycle Assessment of Steel and Concrete Construction Frames: A Case Study of Two Residential Buildings in Iran

Buildings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 54
Author(s):  
Amir Oladazimi ◽  
Saeed Mansour ◽  
Seyed Abbas Hosseinijou
Keyword(s):  
Global Warming ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Global Warming Potential ◽  
Residential Buildings ◽  
Steel Frame ◽  
Complete Analysis ◽  
Environmental Damage ◽  
Concrete Frame

Given the fact that during the recent years the majority of buildings in Iran have been constructed either on steel or concrete frames, it is essential to investigate the environmental impacts of materials used in such constructions. For this purpose, two multi-story residential buildings in Tehran with a similar function have been considered in this study. One building was constructed with a steel frame and the other was constructed with a concrete frame. Using the life cycle assessment tool, a complete analysis of all the stages of a building’s life cycle from raw material acquisition to demolition and recycling of wastes was carried out. In this research, the environmental impacts included global warming potential in 100 years, acidification, eutrophication potential, human toxicity (cancer and non-cancer effects), resource depletion (water and mineral), climate change, fossil fuel consumption, air acidification and biotoxicity. It could be concluded from the results that the total pollution of the concrete frame in all eleven aforementioned impact factors was almost 219,000 tonnes higher than that of the steel frame. Moreover, based on the results, the concrete frame had poorer performance in all but one impact factor. With respect to global warming potential, the findings indicated there were two types of organic and non-organic gases that had an impact on global warming. Among non-organic emissions, CO2 had the biggest contribution to global warming potential, while among organic emissions, methane was the top contributor. These findings suggest the use of steel frames in the building industry in Iran to prevent further environmental damage; however, in the future, more research studies in this area are needed to completely investigate all aspects of decision on the choice of building frames, including economic and social aspects.

scholarly journals Environmental performance of a full-scale wastewater treatment plant applying Life Cycle Assessment

2018 ◽  
Vol 13 (4) ◽  
pp. 1 ◽  
Author(s):  
Thaís Andrade de Sampaio Lopes ◽  
Luciano Matos Queiroz ◽  
Asher Kiperstok
Keyword(s):  
Wastewater Treatment ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Full Scale ◽  
Anaerobic Sludge ◽  
Treated Effluent ◽  
Useful Life

Life Cycle Assessment (LCA) was applied to estimate and analyze the environmental impacts from the construction and operation phases of a full-scale wastewater treatment plant (WWTP) located in the municipality of Lauro de Freitas, Bahia, Brazil. The WWTP process consists of the association of an Upflow Anaerobic Sludge Blanket (UASB) reactor followed by four constructed wetlands (CWL) and a disinfection step. The functional unit was defined as one cubic meter of treated effluent during the useful life of this WWTP (20 years). The LCA was carried out using SimaPro® software and the Centre of Environmental Science (CML) assessment method. The environmental impacts during construction phase were mainly from the wooden forms for concrete and the use of reinforcing steel. During the operation phase, the chlorine used as effluent disinfectant caused the greatest impacts in the abiotic depletion and acidification categories. Macronutrient concentrations present in the treated effluent and the methane generated also caused significant environmental impacts during the WWTP’s useful life. The results obtained highlight the importance of the application of a methodology like LCA to assist in decision-making with regard to the implementation, construction and operation of a WWTP.

scholarly journals Environmental Impacts Evaluation of Sorbitol Production from Glucose

Eksergi ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 7 ◽  
Author(s):  
Rifkah Akmalina
Keyword(s):  
Global Warming ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Global Warming Potential ◽  
Energy Demand ◽  
Electricity Consumption ◽  
Sustainable Improvement ◽  
Photochemical Oxidants ◽  
Main Consumer

A life cycle assessment (LCA) has been performed on sorbitol production from glucose, which aims to quantify and evaluate the environmental impacts that produced from the process. SuperPro Designer software was employed to perform the process simulation, while SimaPro was used to quantify the LCA.Potency of global warming, acidification, eutrophication, photochemical oxidants creation, abiotic depletion, and ozone layer depletion were evaluated. A gate-to-gate LCA study of sorbitol production showed that global warming potential (GWP) had the largest impact to environment with the value of 3.551 kg CO2 eq/kg sorbitol. Glucose and electricity consumption were known as two major contributors to GWP, and hydrogen reactor was the main consumer of electricity. The use of glucose were responsible for more than 50% of total environmentalimpact in each category. Performing heat integration in sorbitol processing is highly recommended for gate-togate system to reduce energy demand, thus decreasing the environmental impacts. Therefore, this LCA study may be applied to perform a sustainable improvement on sorbitol production process.Keywords: sorbitol; life cycle assessment; global warming potential

scholarly journals Disposable Medical Masks: Environmental Costs

2021 ◽  
Author(s):  
BURÇİN ATILGAN TÜRKMEN
Keyword(s):  
New York ◽  
Global Warming ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impact ◽  
Environmental Impacts ◽  
Global Warming Potential ◽  
Functional Unit ◽  
Environmental Costs ◽  
Inventory Data

Abstract A massive increase in the use and production of masks worldwide has been seen in the current COVID-19 pandemic, which has contributed to reducing the transmission of the virus globally. This paper aims to evaluate the environmental impacts of disposable medical masks using the Life Cycle Assessment (LCA) method, first for the selected functional unit related to the manufacturing of one disposable medical mask and then for the global manufacturing of this type of mask in 2020. The inventory data was constructed directly from the industry. The system boundaries include the fabric, nose wire, and ear loops parts, transportation of materials, body making, ultrasonic vending, and packaging steps. The results suggest that the global warming potential of a disposable medical mask is 0.02 g CO2-Eq. for which the main contributor is the packaging step (44%) followed by the life cycle of fabric (27%), and nose wire (14%) parts. In total, 52 billion disposable medical masks used worldwide consumes 25 TJ of energy in 2020. The global warming potential of disposable medical masks supplied in a year of the COVID-19 pandemic is 1.1 Mt CO2 eq., equivalent to around 1.3 billion return flights from Istanbul to New York. This paper assessed the hotspots in the medical mask, allowing for a significant reduction in the environmental impact of mask use. This can be used as a roadmap for future mask designs.

Comparative process-based life-cycle assessment of bioconcrete and conventional concrete

2017 ◽  
Vol 15 (5) ◽  
pp. 667-688 ◽  
Author(s):  
Milad Soleimani ◽  
Mohsen Shahandashti
Keyword(s):  
Global Warming ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Global Warming Potential ◽  
Fossil Fuel ◽  
Human Toxicity ◽  
Conventional Concrete ◽  
Content Type ◽  
Cradle To Gate

Purpose Bioconcrete is widely believed to be environmentally beneficial over conventional concrete. However, the process of bioconcrete production involves several steps, such as waste recovery and treatment, that potentially present significant environmental impacts. Existing life-cycle assessments of bioconcrete are limited in the inventory and impact analysis; therefore, they do not consider all the steps involved in concrete production and the corresponding impacts. The purpose of this study is to extensively study the cradle-to-gate environmental impacts of all the production stages of two most common bioconcrete types (i.e. sludge-based bioconcrete and cement kiln dust-rice husk ash (CKD-RHA) bioconcrete) as opposed to conventional concrete. Design/methodology/approach A cradle-to-gate life-cycle assessment process model is implemented to systematically analyze and quantify the resources consumed and the environmental impacts caused by the production of bioconcrete as opposed to the production of conventional concrete. The impacts analyzed in this assessment include global warming potential, ozone depletion potential, eutrophication, acidification, ecotoxicity, smog, fossil fuel use, human toxicity, particulate air and water consumption. Findings The results indicated that sludge-based bioconcrete had higher levels of global warming potential, eutrophication, acidification, ecotoxicity, fossil fuel use, human toxicity and particulate air than both conventional concrete and CKD-RHA bioconcrete. Originality/value The contribution of this study to the state of knowledge is that it sheds light on the hidden impacts of bioconcrete. The contribution to the state of practice is that the results of this study inform the bioconcrete production designers about the production processes with the highest impact.

scholarly journals Life Cycle Assessment of Mortars Produced Partially Replacing Cement by Treated Mining Residues

2021 ◽  
Vol 11 (17) ◽  
pp. 7947
Author(s):  
Joana Almeida ◽  
Paulina Faria ◽  
Alexandra Branco Ribeiro ◽  
António Santos Silva
Keyword(s):  
Global Warming ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Ozone Depletion ◽  
Chemical Properties ◽  
Management Options ◽  
Photochemical Ozone ◽  
Mining Residues ◽  
Abiotic Depletion

The use of secondary mining resources to replace conventional constituents in mortars production has proved the effectiveness to preserve the quality of mechanical, physical, and chemical properties. However, minimal research has been performed to quantify the environmental impacts of mortars with mining residues. In the present work, a life cycle assessment of 10 mortars was carried out. A reference mortar (100% of cement binder) and mortars with cement substitutions in 10, 25, and 50% by raw, electrodialytic treated, and electrodialytic plus thermal treated mining residues were analysed. The impacts were studied in six environmental categories: (1) abiotic depletion; (2) global warming; (3) ozone depletion; (4) photochemical ozone creation; (5) acidification; and (6) eutrophication potentials. The results demonstrated that mortars formulated with raw mining residues may decrease the environmental impacts, namely in global warming potential (55.1 kg CO2 eq./t modified mortar). Considering the treatments applied to mining residues, the major mitigations were reported in photochemical ozone creation (−99%), ozone depletion (−76 to −98%), and acidification potential (−90 to −94%), mainly due to the disposal impacts avoided in comparison to the reference mortar. Analysing all mortars’ constituents and their management options, products with electrodialytic treated mining residues showed higher influence in ozone depletion (18 to 52%). Coupling a thermal procedure, mining residues contributed for 99% of the abiotic depletion potential of mortars.

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