A comprehensive review of algal biochar for soil improvement: bottlenecks and opportunities

Author(s):  
Jiacheng Sun ◽  
Ondrej Masek

<p>In recent years, the rapid increase of CO<sub>2</sub> emission in the atmosphere and the resulting issues such as global warming and climate change have now become significant barriers to environmental sustainability. Although fossil CO<sub>2</sub> emissions have decreased in some of the world's largest emitters, including 11% in the EU, 12% in the US and 1.7% in China annually, the estimated global CO<sub>2</sub> emission amount still reached 40 G tonnes in 2020. The purpose of studying biochar produced by pyrolysis is essential to develop the knowledge of carbon cycles and nutrient components in soil. Among all types of feedstocks, algae grow incredibly rapidly compared to other biological materials, about 500-1500 times higher, which will boot the carbon sequestration rate. Therefore, the study of algal biochar production through pyrolysis has great significance for migrating climate change and developing carbon capture and storage.</p><p>This study focuses on a comprehensive review of previous literature on conventional and advanced macroalgae and microalgae pyrolysis for producing biochar and related valuable by-products like bio-oil and bio-syngas, aiming to establish a state-of-the-art of algal biochar for different soil-related applications and demonstrate the bottlenecks and opportunities. Specifically, a thorough comparison of algae species (20 microalgae and 20 macroalgae) is developed to benefit future researchers, involving chemical compositions, proximate analysis, solid-product fraction, physical properties and chemical properties. Redox conditions, surface functional groups and pH conditions are determined in lab-scale. Moreover, different algal biochar applications on soil and plant are analysed to optimise the commercial value of algal biochar, including soil conditioner, compositing additives, carrier for fertilisers, manure treatment and stable blending. Due to the abundant mineral contents (0.23-1.21% Na, 0.03-2.92% K, 0.75-7.17% Al, 0.19-1.24% Mg, 6.5-7% Ca and 0.04-0.69% Fe) of algal biochar, this study not only reviews the positive effects on soil improvement but also negative effects such as phytotoxic effect and heavy-metal pollution. A laboratory-based chemical oxidation approach (Edinburgh Stability Tool) is used to assess relatively long-term biochar stability and the influence of nutrient cycling. The optimal pyrolysis conditions (temperature, retention time and heating rate) and potential future commercial applications are obtained through the comprehensive review of algal biochar for soil improvement.    </p>

2021 ◽  
Author(s):  
◽  
Gregory Severinsen

<p>This thesis concerns the regulation of a technology called carbon capture and storage (CCS). The technology is one way to mitigate anthropogenic climate change, by capturing carbon dioxide (CO2) emissions at point sources (such as power or industrial plants) and injecting them into deep underground geological formations. Specifically, the thesis looks at the framework of public environmental law that is needed for CCS in New Zealand where injection occurs offshore in its coastal marine area and exclusive economic zone. The thesis concludes that, when tested against existing principles in New Zealand's environmental law and the requirements of international law, current provisions in domestic law contain both significant barriers and gaps. These barriers must be removed and gaps must be filled.  The thesis identifies three broad features of New Zealand's law that give rise to a range of barriers and that need to be addressed. First, there is substantial uncertainty as to how existing provisions would apply to CCS. Greater certainty is needed. Secondly, the classification of CCS as a form of marine dumping presents a significant barrier. The technology needs to be classified differently, and more positively. Thirdly, the law contains a general prohibition on considering the effects of activities on climate change. This may prevent CCS being deployed in practice, and needs to be reconsidered.  New Zealand's existing law also contains three potential gaps, which must be filled. First, there is a dearth of CCS-specific regulatory and policy provisions within existing regimes such as the Resource Management Act 1991. This means operators and regulators would be operating in a regulatory and policy vacuum. Decisions may be inconsistent, fail to impose appropriate environmental standards, or fail to give appropriate weight to relevant considerations. Secondly, there are limitations in the ability of existing regimes to regulate the positive effects of activities – such as climate change mitigation - to ensure that they are actually achieved. Thirdly, existing law does not facilitate the kind of targeted and comparative decision-making process needed for CCS. This means that it does not provide an effective process for resolving tensions between competing resource interests in the sub-seabed.</p>


2021 ◽  
Author(s):  
◽  
Gregory Severinsen

<p>This thesis concerns the regulation of a technology called carbon capture and storage (CCS). The technology is one way to mitigate anthropogenic climate change, by capturing carbon dioxide (CO2) emissions at point sources (such as power or industrial plants) and injecting them into deep underground geological formations. Specifically, the thesis looks at the framework of public environmental law that is needed for CCS in New Zealand where injection occurs offshore in its coastal marine area and exclusive economic zone. The thesis concludes that, when tested against existing principles in New Zealand's environmental law and the requirements of international law, current provisions in domestic law contain both significant barriers and gaps. These barriers must be removed and gaps must be filled.  The thesis identifies three broad features of New Zealand's law that give rise to a range of barriers and that need to be addressed. First, there is substantial uncertainty as to how existing provisions would apply to CCS. Greater certainty is needed. Secondly, the classification of CCS as a form of marine dumping presents a significant barrier. The technology needs to be classified differently, and more positively. Thirdly, the law contains a general prohibition on considering the effects of activities on climate change. This may prevent CCS being deployed in practice, and needs to be reconsidered.  New Zealand's existing law also contains three potential gaps, which must be filled. First, there is a dearth of CCS-specific regulatory and policy provisions within existing regimes such as the Resource Management Act 1991. This means operators and regulators would be operating in a regulatory and policy vacuum. Decisions may be inconsistent, fail to impose appropriate environmental standards, or fail to give appropriate weight to relevant considerations. Secondly, there are limitations in the ability of existing regimes to regulate the positive effects of activities – such as climate change mitigation - to ensure that they are actually achieved. Thirdly, existing law does not facilitate the kind of targeted and comparative decision-making process needed for CCS. This means that it does not provide an effective process for resolving tensions between competing resource interests in the sub-seabed.</p>


Author(s):  
N. Maidanovych ◽  

The purpose of this work is to review and analyze the main results of modern research on the impact of climate change on the agro-sphere of Ukraine. Results. Analysis of research has shown that the effects of climate change on the agro-sphere are already being felt today and will continue in the future. The observed climate changes in recent decades have already significantly affected the shift in the northern direction of all agro-climatic zones of Europe, including Ukraine. From the point of view of productivity of the agro-sphere of Ukraine, climate change will have both positive and negative consequences. The positives include: improving the conditions of formation and reducing the harvesting time of crop yields; the possibility of effective introduction of late varieties (hybrids), which require more thermal resources; improving the conditions for overwintering crops; increase the efficiency of fertilizer application. Model estimates of the impact of climate change on wheat yields in Ukraine mainly indicate the positive effects of global warming on yields in the medium term, but with an increase in the average annual temperature by 2 ° C above normal, grain yields are expected to decrease. The negative consequences of the impact of climate change on the agrosphere include: increased drought during the growing season; acceleration of humus decomposition in soils; deterioration of soil moisture in the southern regions; deterioration of grain quality and failure to ensure full vernalization of grain; increase in the number of pests, the spread of pathogens of plants and weeds due to favorable conditions for their overwintering; increase in wind and water erosion of the soil caused by an increase in droughts and extreme rainfall; increasing risks of freezing of winter crops due to lack of stable snow cover. Conclusions. Resource-saving agricultural technologies are of particular importance in the context of climate change. They include technologies such as no-till, strip-till, ridge-till, which make it possible to partially store and accumulate mulch on the soil surface, reduce the speed of the surface layer of air and contribute to better preservation of moisture accumulated during the autumn-winter period. And in determining the most effective ways and mechanisms to reduce weather risks for Ukrainian farmers, it is necessary to take into account the world practice of climate-smart technologies.


2012 ◽  
Vol 3 (3) ◽  
pp. 225-238 ◽  
Author(s):  
Vivek Shandas ◽  
Meenakshi Rao ◽  
Moriah McSharry McGrath

Social and behavioral research is crucial for securing environmental sustainability and improving human living environments. Although the majority of people now live in urban areas, we have limited empirical evidence of the anticipated behavioral response to climate change. Using empirical data on daily household residential water use and temperature, our research examines the implications of future climate conditions on water conservation behavior in 501 households within the Portland (OR) metropolitan region. We ask whether and how much change in ambient temperatures impact residential household water use, while controlling for taxlot characteristics. Based on our results, we develop a spatially explicit description about the changes in future water use for the study region using a downscaled future climate scenario. The results suggest that behavioral responses are mediated by an interaction of household structural attributes, and magnitude and temporal variability of weather parameters. These findings have implications for the way natural resource managers and planning bureaus prepare for and adapt to future consequences of climate change.


2019 ◽  
Vol 11 (18) ◽  
pp. 4998 ◽  
Author(s):  
Federica Borgonovo ◽  
Cecilia Conti ◽  
Daniela Lovarelli ◽  
Valentina Ferrante ◽  
Marcella Guarino

Ammonia (NH3), methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) emissions from livestock farms contribute to negative environmental impacts such as acidification and climate change. A significant part of these emissions is produced from the decomposition of slurry in livestock facilities, during storage and treatment phases. This research aimed at evaluating the effectiveness of the additive “SOP LAGOON” (made of agricultural gypsum processed with proprietary technology) on (i) NH3 and Greenhouse Gas (GHG) emissions, (ii) slurry properties and N loss. Moreover, the Life Cycle Assessment (LCA) method was applied to assess the potential environmental impact associated with stored slurry treated with the additive. Six barrels were filled with 65 L of cattle slurry, of which three were used as a control while the additive was used in the other three. The results indicated that the use of the additive led to a reduction of total nitrogen, nitrates, and GHG emissions. LCA confirmed the higher environmental sustainability of the scenario with the additive for some environmental impact categories among which climate change. In conclusion, the additive has beneficial effects on both emissions and the environment, and the nitrogen present in the treated slurry could partially displace a mineral fertilizer, which can be considered an environmental credit.


Author(s):  
Mariya Bezgrebelna ◽  
Kwame McKenzie ◽  
Samantha Wells ◽  
Arun Ravindran ◽  
Michael Kral ◽  
...  

This systematic review of reviews was conducted to examine housing precarity and homelessness in relation to climate change and weather extremes internationally. In a thematic analysis of 15 reviews (5 systematic and 10 non-systematic), the following themes emerged: risk factors for homelessness/housing precarity, temperature extremes, health concerns, structural factors, natural disasters, and housing. First, an increased risk of homelessness has been found for people who are vulnerably housed and populations in lower socio-economic positions due to energy insecurity and climate change-induced natural hazards. Second, homeless/vulnerably-housed populations are disproportionately exposed to climatic events (temperature extremes and natural disasters). Third, the physical and mental health of homeless/vulnerably-housed populations is projected to be impacted by weather extremes and climate change. Fourth, while green infrastructure may have positive effects for homeless/vulnerably-housed populations, housing remains a major concern in urban environments. Finally, structural changes must be implemented. Recommendations for addressing the impact of climate change on homelessness and housing precarity were generated, including interventions focusing on homelessness/housing precarity and reducing the effects of weather extremes, improved housing and urban planning, and further research on homelessness/housing precarity and climate change. To further enhance the impact of these initiatives, we suggest employing the Human Rights-Based Approach (HRBA).


2021 ◽  
Vol 13 (8) ◽  
pp. 4321
Author(s):  
Murat Türköz ◽  
Seyfettin Umut Umu ◽  
Ogan Öztürk

The use of dispersive soils, which are common in many parts of the world, in engineering applications such as water structures, earthen dams and road embankments is possible with their improvement. Recently, the effects of different chemicals on the stabilization of dispersive soils have been investigated. The use of waste materials in stabilization is preferred both because of the more sustainable environment and the economic advantages it provides. The use of silica fume (SF) as a waste material in different engineering applications provides an important advantage in environmentally and economically sustainable ways. Many studies have been carried out regarding silica fume, especially in the construction industry. Although SF is used in many industries, there is no study about its potential impact on the stabilization and dynamic properties of dispersive soils. In this study, first, Atterberg limits and standard Proctor compaction tests were performed on the mixtures prepared by adding different SF percentages (0, 5, 10, 15, 20, 25 and 30%). Afterward, pinhole tests and resonant column tests were performed to determine dispersibility and dynamic properties on the samples prepared by compaction characteristics for each SF percentage reached. In general, it was determined that SF contributed to a change in soil class, and improvement in dispersibility and dynamic properties of the soil sample, depending on SF content; positive effects of SF were observed in terms of shallow soil improvement.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bendadi Hanumantha Rao ◽  
Peddireddy Sreekanth Reddy ◽  
Bijayananda Mohanty ◽  
Krishna R. Reddy

AbstractMicrolevel properties such as mineralogical and chemical compositions greatly control the macro behaviour of expansive soils. In this paper, the combined effect of mineral (i.e. montmorillonite, MMC) and chemical contents (i.e. Ca and Na in their total (T), leachable (L) and exchangeable form (CEC)) on swelling behaviour is investigated in a comprehensive way. Several 3-dimensional (3D) graphs correlating MMC and Ca/Na ratio, together, with swelling property (swelling potential, Sa, and swelling pressure, Sp) are developed. 3D plots, in general, portrayed a non-linear relationship of Sa and Sp with MMC and Ca/Na ratio, together. It is hypothesized that swelling initially is triggered by chemical parameters due to their quick and rapid ionization capability, but the overall swelling phenomenon is largely controlled by MMC. It is importantly found that expansive soils are dominant with divalent Ca++ ions up to MMC of 67% and beyond this percentage, monovalent Na+ ions are prevalent. From the interpretation of results, the maximum Sa of 18% and Sp of 93 kPa is measured at MMC of 43%, (Ca/Na)T of 10–14 and (Ca/Na)L of 2–7. It is concluded from study that total CEC + MMC for determining Sa and (Ca/Na)T + MMC for determining Sp are superior parameters to be considered. The findings of the study also excellently endorsed the results of Foster32, who stated that ionization of Na or Ca depends on the constituent mineral contents. The findings presented herein are unique, interesting and bear very practical significance, as no earlier research work reported such findings by accounting for chemical and mineralogical parameters impact, in tandem, on swelling properties.


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