| 1. |
- Anacleto, Thuane Mendes, et al.
(författare)
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Boosting manure biogas production with the application of pretreatments: A meta-analysis
- 2022
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Ingår i: Journal of Cleaner Production. - Amsterdam, Netherlands : Elsevier. - 0959-6526 .- 1879-1786. ; 362
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Tidskriftsartikel (refereegranskat)abstract
- Anaerobic digestion (AD) is a versatile manure management approach that can combine waste treatment, energy generation and nutrient recovery, thus playing a central role in circular economy. The AD process is highly influenced by manure composition which, depending on the source, may contain high loads recalcitrant materials (e.g., lignocellulosic and fibers) or lead to the formation of toxic compounds (e.g., NH3), decreasing the energetic potential of the waste and requiring specific pretreatments to increase its degradability and biogas production. Although there are distinctions in the chemical composition of manure according to animal diets, different manure sources are usually grouped together, leading to a suboptimal performance of both the pretreatment and the AD process. Here, we performed a meta-analysis of 54 studies to evaluate the effects of different pretreatments on different manure types and their effect on methane (CH4) yield and we estimated the energy potential if the appropriate pretreatment is applied to largest manure producing countries. The results showed that chemical and/or biological pretreatments were more effective for omnivore manure (e.g., swine, chicken), while physical and a combination of chemical and physical pretreatments negatively affected CH4 production. Physical and/or chemical pretreatments had a positive effect on CH4 yield from herbivore manure (e. g., cattle, horses), while biological pretreatments had a negative effect. The application of the adequate pretreatment can more than double the energy recovered from manure, allowing for an important substitution of fossil fuels, while decreasing operational costs and environmental risks and ultimately improving profitability. The development of pretreatment technologies and their application are strongly related to public policies for sustainable manure management and biogas use and production.
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| 2. |
- Peruzzi de Oliveira, Vinicius, et al.
(författare)
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Bioremediation of nitrogenous compounds fromoilfield wastewater by Ulva lactuca (Chlorophyta)
- 2016
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Ingår i: Bioremediation Journal. - : Taylor & Francis. - 1088-9868 .- 1547-6529. ; 20:1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Oilfield wastewater (OFW) is a by-product of petroleum production and has a high nitrogen concentration. Bioremediation by macroalgae appears to be an option for OFW, and the genus Ulva (Chlorophyta) has strong potential as an agent of bioremediation because of its high nitrogen absorption capacity. This experimental study evaluated the efficiency of bioremediation of nitrogenous compounds in three concentrations of OFW by Ulva lactuca. One-phase decay models, photosynthetic status (assessed by pulse amplitude–modulated [PAM] fluorometry), and growth rate were used to assess bioremediation efficiency and algal physiology. All nitrogenous compounds were removed during the experimental period. The models that were applied for ammonium showed a stronger bioremediation effect for OFW at a concentration of 25% than at concentrations of 12.5% and 2.5%, and for nitrate, the models showed a stronger bioremediation effect at the 12.5% OFW concentration. The minor effects of OFW on photosynthetic performance and growth, added to high removal of nitrogen, emphasize the bioremediation capacity of U. lactuca, suggesting a new possibility of bioremediation of this waste.
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| 3. |
- Anacleto, Thuane Mendes, et al.
(författare)
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Methane yield response to pretreatment is dependent on substrate chemical composition: a meta-analysis on anaerobic digestion systems
- 2024
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Ingår i: Scientific Reports. - : NATURE PORTFOLIO. - 2045-2322. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Proper pretreatment of organic residues prior to anaerobic digestion (AD) can maximize global biogas production from varying sources without increasing the amount of digestate, contributing to global decarbonization goals. However, the efficiency of pretreatments applied on varying organic streams is poorly assessed. Thus, we performed a meta-analysis on AD studies to evaluate the efficiencies of pretreatments with respect to biogas production measured as methane yield. Based on 1374 observations our analysis shows that pretreatment efficiency is dependent on substrate chemical dominance. Grouping substrates by chemical composition e.g., lignocellulosic-, protein- and lipid-rich dominance helps to highlight the appropriate choice of pretreatment that supports maximum substrate degradation and more efficient conversion to biogas. Methane yield can undergo an impactful increase compared to untreated controls if proper pretreatment of substrates of a given chemical dominance is applied. Non-significant or even adverse effects on AD are, however, observed when the substrate chemical dominance is disregarded.
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| 4. |
- de Oliveira, Vinícius Peruzzi, et al.
(författare)
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CO2 influence on oxygen dynamics and net primary production of the microphytobenthos : an experimental approach
- 2020
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Ingår i: Journal of Research in Ecology. - 2319-1546 .- 2319-1554. ; 8:1, s. 2702-2712
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Tidskriftsartikel (refereegranskat)abstract
- Production of organic matter by phototrophs requires inorganic carbon,which in aquatic systems is taken up from the water column, sediment oratmosphere. Observations on a microphytobenthic mat overlaid with 2 mm of waterand atmospheric air showed a tight balance between consumption and production ofoxygen and, therefore, a bimodal pattern in the Net Primary Production (NPP).Enrichment of the air with CO2 led to an enhancement of the NPP of a community,while the removal of all CO2 from the air resulted in no NPP and a linear O2 gradientfrom the overlying water to the lower part of the mat. The distribution and rates ofgross photosynthetic oxygen production, measured as the oxygen decline within oneto twos after light-dark shifts, showed little response to CO2 depletion, suggesting thatthe photosynthetic electron flow was primarily redirected from CO2 fixation tophotorespiration. In nature, the observed control of NPP by atmospheric CO2concentration should be most pronounced in shallow-water and intertidal systems,and the productivity in these ecosystems may therefore be steadily increasing alongwith the increase in atmospheric CO2 concentration.
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| 5. |
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| 6. |
- Figueira, Tiphane Andrade, et al.
(författare)
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The effects of phosphate on physiological responses and carbohydrate production in Ulva fasciata (Chlorophyta) from upwelling and nonupwelling sites
- 2021
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Ingår i: Botanica Marina. - : WALTER DE GRUYTER GMBH. - 0006-8055 .- 1437-4323. ; 64:1
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Tidskriftsartikel (refereegranskat)abstract
- Phosphorus is a key macronutrient inmacroalgal physiology, including carbohydrate anabolism. To determine the effects of phosphorus on different physiological parameters, we cultivated Ulva fasciata specimens from distinct localities (upwelling and non-upwelling sites) in the presence of different phosphate concentrations (0, 2, and 4 mu MPO43-). After 15 days, growth rates were similar (approx. 12% day(-1)) and carbohydrate contents had increased in individuals fromboth sites. In individuals from the upwelling site, carbohydrate contents were high in all treatments (71% dry mass), whereas non-upwelling site individuals cultivated under the highest phosphate concentration showed the lowest carbohydrate content (46% DM). Nevertheless, we observed higher rates of phosphorus uptake in individuals from the non-upwelling site cultivated under the highest phosphate concentration, indicating a stress response to elevated nutrient concentrations. Individuals from both sites cultivated with phosphate maintained healthy photosystems over the experimental period (F-v/ F-m = 0.788), whereas those cultivated in the absence of phosphate showed evidence of photosystem impairment, as indicated by a progressive decline in maximum quantum yield. Altogether, our results indicate that site origin and phosphate concentration influence the carbohydrate content in U. fasciata and that individuals from sites with broad environmental variation, such as upwelling events, can show higher productivity.
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