Effect of Mild-Temperature Thermo-Alkaline Pretreatment on the Solubilization and Anaerobic Digestion of Spent Coffee Grounds

Mild-temperature thermo-alkaline pretreatment of spent coffee grounds (SCG) was studied to improve its solubilization and methanation. The simultaneous effects of NaOH concentration (0-0.2 M) and temperature (60-90 ??C) were investigated. Significant solubilization of SCG was achieved by the pretreatment, particularly under high-NaOH-concentration and high-temperature conditions. However, adding NaOH above a certain concentration adversely affected the methane production. Therefore, the degree of solubilization (SD) correlated poorly with methane yield (Ym). Response surface models of SD and Ym were successfully generated. The maximum response of SD (36.4%) was obtained at 0.18 M NaOH and 90.0 ??C, while that of Ym (263.31 mL CH4/g COD added) was obtained at 0.13 M NaOH and 70.5 ??C. Hydrogenotrophic Methanospirillum species were the dominant methanogens in all the SCG digestion tests. It is likely that NaOH concentration had a more significant influence on the development of microbial community structure, particularly of methanogens than temperature

An experimental method for evoking and characterizing dynamic color patterning of cuttlefish during prey capture

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Kim, D., Buresch, K. C., Hanlon, R. T., & Kampff, A. R. An experimental method for evoking and characterizing dynamic color patterning of cuttlefish during prey capture. Journal of Biological Methods, 9(2), (2022): e161, https://doi.org/10.14440/jbm.2022.386.Cuttlefish are active carnivores that possess a wide repertoire of body patterns that can be changed within milliseconds for many types of camouflage and communication. The forms and functions of many body patterns are well known from ethological studies in the field and laboratory. Yet one aspect has not been reported in detail: the category of rapid, brief and high-contrast changes in body coloration (“Tentacle Shot Patterns” or TSPs) that always occur with the ejection of two ballistic tentacles to strike live moving prey (“Tentacles Go Ballistic” or TGB moment). We designed and tested a mechanical device that presented prey in a controlled manner, taking advantage of a key stimulus for feeding: motion of the prey. High-speed video recordings show a rapid transition into TSPs starting 114 ms before TGB (N = 114). TSPs are then suppressed as early as 470–500 ms after TGB (P < 0.05) in unsuccessful hunts, while persisting for at least 3 s after TGB in successful hunts. A granularity analysis revealed significant differences in the large-scale high-contrast body patterning present in TSPs compared to the camouflage body pattern deployed beforehand. TSPs best fit the category of secondary defense called deimatic displaying, meant to briefly startle predators and interrupt their attack sequence while cuttlefish are distracted by striking prey. We characterize TSPs as a pattern category for which the main distinguishing feature is a high-contrast signaling pattern with aspects of Acute Conflict Mottle or Acute Disruptive Pattern. The data and methodology presented here open opportunities for quantifying the rapid neural responses in this visual sensorimotor set of behaviors.KCB and RTH acknowledge partial support from the Sholley Foundation

Standards Education Policy Development: Observations based on APEC Research

This paper stems from a research project carried out for the Asia Pacific Economic Cooperation (APEC) to make an inventory of national standards education policies. Twenty countries - sixteen Asia-Pacific economies and four European nations – have been investigated. The paper relates similarities and differences between these policies to the standardization education activities in place. The paper concludes with policy recommendations

Racial differences in long-term social, physical, and psychological health among adolescent and young adult cancer survivors

Background The current guidelines for survivorship in adolescents and young adults (AYA) cancer are based on studies conducted in the United States and European AYA survivors. However, previous studies have shown that the health-related quality of life in cancer survivors can vary depending on race, yet the long-term health differences among AYA survivors by race/ethnicity have not been fully explored. Therefore, our aim is to compare the psychosocial and physical health of AYA survivors and their matched controls across different racial and ethnic groups. Methods We conducted a cross-sectional study using US National Health and Nutrition Examination Survey (NHANES) and the Korea NHANES from 2007 to 2018. We included AYA cancer survivors who were diagnosed with any type of cancer aged between 15 and 39 years, and who were adult with aged over 18 years old at survey year. We then stratified the study population by race/ethnicity with Non-Hispanic White (NHW, n = 310), African American (AA, n = 42), Hispanic (n = 81) from NHANES, and Asian (n = 389) from the Korea NHANES. We also selected 5 times age-, sex-, race-, and survey year-matched general population among participants who had never been diagnosed with cancer (N = 4110). Variables were defined using questionnaire data, physical exams, and laboratory tests. Results Compared to NHW, Hispanics (aOR 1.15, 95% CI 1.00–1.32) had poor or fair general health, lower education (aOR 1.23, 95% CI 1.07–1.40), and lower household income (aOR 1.16, 95% CI 1.01–1.33). AA survivors were more likely to be non-coupled (aOR 1.35, 95% 1.15–1.60) and have hypertension (aOR 1.18, 95% CI 1.03–1.36). Asians were more former/current drinkers (aOR 1.21, 95% CI 1.05–1.40). NHW are more likely to experience psychological limitation. Compared to matched general, NHW and Asian survivors had poor general health and psychological health. Conclusions This study provides evidence for future studies concerning long-term health after AYA cancer survivorship that may vary according to race.This work was supported by the National Research Foundation of Korea Grant funded by the Korean Government (NRF-2022R1A2C1013119

Anaerobic digestion of spent coffee grounds : A study on long-term stable operation and improved methanation

Department of Urban and Environmental Engineering (Environmental Science and Engineering)With the increase in world coffee consumption, the global spent coffee grounds (SCG) produced worldwide is estimated at 18 million wet tons in 2021. The annual production of SCG in the Republic of Korea also increased approximately 1.6-fold from 93,397 tons in 2012 to 149,038 tons in 2019. Although SCG has high potential to be utilized as compost, construction material, and biofuel feedstock, most of which is disposed by incineration or landfill, potentially leading to serious environmental pollution. For a sustainable management of SCG, methanation through anaerobic digestion (AD) has been considered an attractive option to treat organic-rich SCG due to its ability to convert organic waste into biogas, a carbon-neutral energy source. However, previous studies have concluded that the stable long-term mono-digestion of SCG as a sole substrate cannot be achieved and the reasons for the failure were not suggested. Several experimental attempts have been made in recent studies to overcome the limitation of AD fed with SCG. Pretreatment of lignocellulosic biomass has been widely used to enhance its degradability by increasing its accessibility to hydrolytic bacteria. Previous studies have reported the batch test results of pretreated SCG, which showed improved methane production compared with non-pretreated SCG. However, long-term continuous methanation of pretreated SCG has not been reported yet. Anaerobic co-digestion studies have been conducted using various co-substrates including waste activated sludge, food waste (FW), and Ulva biomass. Although co-digestion studies have reported continuous operation with SCG co-feeding, stable and robust methanation of SCG has not been achieved. Therefore, the AD of SCG was investigated to achieve long-term stable operation and improved methanation. In Study I, the pretreatment method was applied to increase the hydrolysis efficiency of SCG, under the assumption that the lignocellulosic characteristic of SCG is the barrier to SCG mono-digestion. Thermo-alkaline pretreatment was chosen to minimize the chemical cost. A response surface analysis was performed using solubilization and batch test data within given range (0???0.2 M NaOH and 60???90 ???) to determine the optimum condition for the biomethanation of pretreated SCG. The batch test results showed that increasing NaOH concentrations and temperatures had positive effects on SCG solubilization and that methane production increased only when the NaOH concentration increased up to a certain level due to sodium inhibition. In addition, continuous test with the optimum pretreatment condition obtained in the batch test revealed serious deterioration after 3 volume turnovers, showing decreased methane production simultaneously with the accumulation of volatile fatty acids (VFAs). The nutrient deficiency might be the reason for the deterioration in pretreated SCG digestion. In Study II, FW and SCG (FW:SCG = 10:1, based on volatile solids (VS)) were co-digested to supplement the nutrient and dilute potential inhibitory compounds in SCG. Severe system failure with a drastic decrease in methane production and accumulation of VFAs was observed in duplicate reactors after co-feeding SCG into the existing anaerobic FW digesters, while stable operation was achieved with mono-digestion of FW. Neither the nitrogen source nor the alkalinity was the reason for the deterioration. The substrate feeding to both reactors was stopped for performance stabilization (i.e., restoration in batch mode), but different stabilization strategies were adopted for each digester. Nutrient-rich Ulva biomass (FW:SCG:Ulva = 10:1:0.5, based on VS) was co-fed to help restore stable performance, but its effects were significantly different between the digesters, presumably because of the different stabilization strategies used. Therefore, the addition of 10% SCG to the anaerobic FW digesters revealed that stable biomethanation is difficult to achieve without nutrient addition. In Study III, a very small amount of SCG was added into the anaerobic FW digesters to investigate how much SCG can be added into FW-treating digesters without compromising the process performance and stability. The anaerobic FW digesters with trace elements (Fe, Co, and Ni) were co-fed with 1%, 2%, 4%, and 10% of SCG and showed a significant increase in methane yield when 1???4% SCG was added. With the trace element supplement, co-feeding with 10% SCG demonstrated a stable operation without compromising the process performance and achieved methane yield similar to that with 4% SCG co-feeding and a slightly reduced organic removal efficiency. The improved methane yield appeared to be due to the increased protein removal efficiency as the amount of SCG increased. The results of the microbial community and functional potential analyses suggested that proteolytic bacteria possibly contributed to the enhancement of protein removal efficiency with the addition of SCG, which consequently led to the improved methane yield. In conclusion, this Ph.D. dissertation examined the long-term stability of SCG AD and proposes an optimal dose of SCG for the treatment of anaerobic FW digesters. The annual SCG production in the Republic of Korea is approximately 2.9% of FW production. Even if FW production in the country is usually managed by other methods (i.e., composting and animal feed making), the annual SCG production is still only approximately 10.5% of the annual FW handled by biogasfication facilities. Therefore, if the concentrations of trace elements in the digester can be sufficiently maintained, managing SCG using an existing anaerobic FW digester is reasonable. However, it is recommended that co-digest up to 4% of SCG in anaerobic FW digesters to maintain process stability and methane yield increases.clos

Non-invasive techniques for studying in natural settings

"While the controlled experimental approach has successfully built and organised much knowledge about components and subsystems of the nervous system, an over- emphasis of this approach has marginalized other potentially useful approaches to the study of nervous systems. The marginalization of ethological analysis and the ethological conceptual framework has been noted in particular as a key loss to systems neuroscience [1].(...)

Co-feeding spent coffee grounds in anaerobic food waste digesters: Effects of co-substrate and stabilization strategy

Anaerobic digestion of spent coffee grounds (SCG) is considered disadvantageous, particularly under mono-digestion conditions, owing to slow degradation and nutrient imbalance. This study investigated the effect of co-feeding of SCG at a low ratio into food waste (FW) digesters, with the aim to determine whether SCG can be effectively treated and valorized using the spare capacity of existing digesters. Duplicate reactors showed stable performance under FW mono-digestion conditions but manifested severe deterioration in three volume turnovers after co-feeding of SCG (FW:SCG at 10:1 on a volatile solids basis). The reactors failed to recover despite repeated interrupted feeding and stabilization, and Ulva was added (FW:SCG:Ulva at 20:2:1) for nutrient supplementation. The two reactors subjected to different stabilization strategies (i.e., timing and intervals of interrupted feeding) responded differently to Ulva co-feeding: one recovered and maintained stable albeit suboptimal performance, whereas the other failed. Furthermore, the microbial communities developed differently in the reactors

Pretreatment of spent coffee grounds with alkaline soju bottle-washing wastewater for enhanced biomethanation

The production of spent coffee grounds (SCG) is steadily increasing, and its proper treatment has become an increasingly challenging task. This study explored the potential use of alkaline bottle-washing wastewater (BWW) from a soju (a Korean hard liquor) manufacturer as an alternative pretreatment agent to enhance the biodegradability and thus the biomethanation of SCG through anaerobic digestion. Thermo-alkaline pretreatment with BWW was effective in increasing the soluble organic fraction of SCG (i.e., improved bioavailability) at all temperatures tested (23-70 degrees C). The disintegration degree of the particulate organic matter in SCG ranged from 8.6 to 13.1% and increased with increasing pretreatment temperature. The 30-day methane yield (per g chemical oxygen demand (COD) of SCG fed) was significantly higher for the BWW-pretreated SCG (342.4-361.2 mL/g COD) than for the raw SCG (284.7 mL/g COD) and even for the NaOH-pretreated SCG (at the same pH as BWW, pH 12.3) tested for comparison (299.7-320.9 mL/g COD). This significant increase in methane production can be attributed to the presence of readily biodegradable ethanol derived from waste soju in BWW and the alkaline solubilization of SCG. Our results suggest a straightforward way to manage SCG and BWW together in a sustainable and economical manner

Enhanced methane production with co-feeding spent coffee grounds using spare capacity of existing anaerobic food waste digesters

Abstract With increasing coffee consumption worldwide, the efficient and sustainable management of spent coffee grounds (SCG) has become increasingly challenging. This study investigated the anaerobic co-digestion of small amounts of SCG with food waste (FW) at increasing co-feeding ratios of 1:100–1:10 (volatile solids basis) to assess the possibility of SCG treatment using the spare capacity of existing anaerobic digesters. Co-feeding SCG increased methane production compared to FW mono-digestion in the tested range of co-feeding ratios without compromising process stability. Methane yield did not further increase when the SCG/FW ratio increased above 4%, and process failure occurred at a 1:10 co-feeding ratio without trace element supplementation. The enhanced methanogenic performance was attributed to increased protein removal efficiency, which was potentially related to the promotion of peptide hydrolysis. The overall results suggest that co-feeding appropriate small amounts of SCG to FW digesters can be a realistic sustainable option for SCG management