Life cycle assessment of biochar for sustainable agricultural application: A review.

Biochar application is an effective strategy to address Agro-climatic challenges. However, the agro-environmental impacts of different biochar technology models are lacking of systematic summaries and reviews. Therefore, this paper comprehensively reviews recent developments derived from published literature, delving into the economic implications and environmental benefits of three distinct process namely technologies-pyrolysis, gasification, and hydrothermal carbonization. This paper specifically focuses on the agricultural life cycle assessment (LCA) methodology, and the influence of biochar preparation technologies and products on energy consumption and agricultural carbon emissions. LCA analysis shows that process and feedstock pose a predominant role on the properties and production rate of biochar, while gasification technology exhibits excellent economic attributes compared to the other two technologies. Biochar applications in agricultural has the beneficial effect of sequestering carbon and reducing emissions, especially in the area of mitigating the carbon footprint of farmland. However, the complexity of the composition of the prepared feedstock and the mismatch between the biochar properties and the application scenarios are considered as potential sources of risks. Notably, mechanism of carbon sequestration and emission reduction by soil microorganisms and agro-environmental sequestration by biochar application remains unclear, calling for in-depth studies. We review novel aspects that have not been covered by previous reviews by comparing the technical, economic, and environmental benefits of pyrolysis, gasification, and hydrothermal carbonization systematically. Overall, this study will provide a valuable framework to environmental implications of biochar preparation, application, and life cycle assessments.

Coupling of biogas residue biochar and low-magnitude electric fields promotes anaerobic co-digestion of sewage sludge and food waste.

Biochar-assisted anaerobic digestion (AD) remains constrained due to the inefficient decomposition of complex organics, even with the direct interspecies electron transfer (DIET) pathway. The coupling of electrochemistry with the anaerobic biological treatment could shorten lengthy retention time in co-digestion by improving electron transfer rates and inducing functional microbial acclimation. Thus, this work investigated the potential of improving the performance of AD by coupling low-magnitude electric fields with biochar derived from the anaerobically digested biogas residue. Different voltages (0.3, 0.6, and 0.9 V) were applied at various stages to assess the impact on biochar-assisted AD. The results indicate that an external voltage of 0.3 V, coupled with 5 g/L of biochar, elevates CH4 yield by 45.5% compared to biogas residue biochar alone, and the coupled approach increased biogas production by up to 143% within 10 days. This finding may be partly explained by the enhanced utilization of substrates and the increased amounts of specific methanogens such as Methanobacterium and Methanosarcina. The abundance of the former increased from 4.0 to 11.3%, which enhances the DIET between microorganisms. Furthermore, the coupling method shows better potential for enhancing AD compared to preparing iron-based biochar, and these results present potential avenues for its broader applications.

Optimizing the co-digestion supply chain of sewage sludge and food waste by the demand oriented biogas supplying mechanism.

Co-digestion of sewage sludge with food waste is a beneficial pathway for sewage plants to enhance their biogas yield. This paper employs hybrid programming with system dynamics simulation to optimize such a co-digestion system from the perspective of demand-oriented biogas supply chain, thus to improve the efficiency of the biogas utilization. The optimum operational parameters of the co-digestion system are derived from the simulation model. It is demonstrated that the demand-oriented biogas supply mechanism can be effectively driven under market-oriented incentive policy. For better compensation of the external cost to assist the operations of the co-digestion supply chain, it is suggested that the substrate collection and transportation subsidy should be combined with the renewables portfolio standard to be implemented as the optimum incentives. The limitations of the study are discussed to lay the foundation for future improvements.

Determination of methane emission rates on a biogas plant using data from laser absorption spectrometry.

The aim of the work was to establish a method for emission control of biogas plants especially the observation of fugitive methane emissions. The used method is in a developmental stage but the topic is crucial to environmental and economic issues. A remote sensing measurement method was adopted to determine methane emission rates of a biogas plant in Rhineland-Palatinate, Germany. An inverse dispersion model was used to deduce emission rates. This technique required one concentration measurement with an open path tunable diode laser absorption spectrometer (TDLAS) downwind and upwind the source and basic wind information, like wind speed and direction. Different operating conditions of the biogas plant occurring on the measuring day (December 2013) could be represented roughly in the results. During undisturbed operational modes the methane emission rate averaged 2.8 g/s, which corresponds to 4% of the methane gas production rate of the biogas plant.

Translation of ERC resuscitation guidelines into clinical practice by emergency physicians.

PURPOSE: Austrian out-of-hospital emergency physicians (OOHEP) undergo mandatory biannual emergency physician refresher courses to maintain their licence. The purpose of this study was to compare different reported emergency skills and knowledge, recommended by the European Resuscitation Council (ERC) guidelines, between OOHEP who work regularly at an out-of-hospital emergency service and those who do not currently work as OOHEP but are licenced. METHODS: We obtained data from 854 participants from 19 refresher courses. Demographics, questions about their practice and multiple-choice questions about ALS-knowledge were answered and analysed. We particularly explored the application of therapeutic hypothermia, intraosseous access, pocket guide use and knowledge about the participants' defibrillator in use. A multivariate logistic regression analysed differences between both groups of OOHEP. Age, gender, years of clinical experience, ERC-ALS provider course attendance and the self-reported number of resuscitations were control variables. RESULTS: Licenced OOHEP who are currently employed in emergency service are significantly more likely to initiate intraosseous access (OR = 4.013, p < 0.01), they initiate mild-therapeutic hypothermia after successful resuscitation (OR = 2.550, p < 0.01) more often, and knowledge about the used defibrillator was higher (OR = 2.292, p < 0.01). No difference was found for the use of pocket guides.OOHEP who have attended an ERC-ALS provider course since 2005 have initiated more mild therapeutic hypothermia after successful resuscitation (OR = 1.670, p <0.05) as well as participants who resuscitated within the last year (OR = 2.324, p < 0.01), while older OOHEP initiated mild therapeutic hypothermia less often, measured per year of age (OR = 0.913, p <0.01). CONCLUSION: Licenced and employed OOHEP implement ERC guidelines better into clinical practice, but more training on life-saving rescue techniques needs to be done to improve knowledge and to raise these rates of application.

The effectiveness of ERC advanced life support (ALS) provider courses for the retention of ALS knowledge.

PURPOSE: Out-of-hospital emergency physicians in Austria need mandatory emergency physician training, followed by biennial refresher courses. Currently, both standardized ERC advanced life support (ALS) provider courses and conventional refresher courses are offered. This study aimed to compare the retention of ALS-knowledge of out-of-hospital emergency physicians depending on whether they had or had not participated in an ERC-ALS provider course since 2005. METHODS: Participants (n=807) from 19 refresher courses for out-of-hospital emergency physicians answered eight multiple-choice questions (MCQ) about ALS based on the 2005 ERC guidelines. The pass score was 75% correct answers. A multivariate logistic regression analyzed differences in passing scores between those who had previously participated in an ERC-ALS provider course and those who had not. Age, gender, regularity of working as an out-of-hospital emergency physician and the self-reported number of real resuscitation efforts within the last 6months were entered as control variables. RESULTS: Out-of-hospital emergency physicians who had previously attended an ERC-ALS provider course had a significantly higher chance of passing the MCQ test (OR=1.60, p=0.015). Younger age (OR=0.95, p<0.001), regular work as an out-of-hospital emergency physician (OR=2.66, p<0.001) and a higher number of self-reported resuscitations within the last 6months (OR=1.08, p=0.002) were also significant predictors of passing the test. CONCLUSION: Out-of-hospital emergency physicians that had attended an ERC-ALS provider course since 2005 had a higher retention of ALS knowledge compared to non-ERC-ALS course participants.