Nitrogenous Waste Research Articles

Selective electrosynthesis of hydroxylamine from aqueous nitrate/nitrite by suppressing further reduction.

The electrocatalytic reduction of nitrogenous waste offers a sustainable approach to producing nitrogen-containing chemicals. The selective synthesis of high-value hydroxylamine (NH2OH) is challenging due to the instability of NH2OH as an intermediate. Here, we present a rational electrocatalyst design strategy for promoting NH2OH electrosynthesis by suppressing the competing pathways of further reduction. We screen zinc phthalocyanines (ZnPc) with a high energy barrier for NH2OH reduction by regulating their intrinsic activity. Additionally, we discover that carbon nanotube substrates exhibit significant NH3-producing activity, which can be effectively inhibited by the high coverage of ZnPc molecules. In-situ characterizations reveal that NH2OH and HNO are generated as intermediates in nitrate reduction to NH3, and NH2OH can be enriched in the ZnPc electrode. In the H-cell, the optimized ZnPc catalyst demonstrates a Faradaic efficiency (FE) of 53 ± 1.7% for NH2OH with a partial current density exceeding 270 mA cm-2 and a turnover frequency of 7.5 ± 0.2 s-1. It also enables the rapid electrosynthesis of cyclohexanone oxime from nitrite with a FE of 64 ± 1.0%.

Concentrating Nitrogen Waste with Electrodialysis for Fertilizer Production

Concentrating Nitrogen Waste with Electrodialysis for Fertilizer Production

Characteristics and biological mechanism of protein degradation by the black solider fly (Hermetia illucens L.) larvae gut strain Bacillus subtilis S4

The black solider fly larvae (BSFL) can efficiently convert nitrogen in organic waste into insect protein. Bacillus subtilis S4, an efficient protein-degrading bacterium from the BSFL gut, was isolated and identified to explore the mechanism of nutrient metabolism underlying BSFL nitrogen utilization. Results showed that B. subtilis S4 could effectively increase larval biomass in a bean stem bioconversion system. In vitro high-performance liquid chromatography analysis showed that B. subtilis S4 completely degraded casein into Val, Ile, Phe, Leu, Tyr, Lys, Gly, and Met. Various protease genes with secretion expression ability were annotated in B. subtilis S4. They included peptidoglycan DL - endopeptidase, aminopeptidase, extracellular metalloprotease, peptidoglycan endopeptidase, and peptidase M15. Therefore, the BSFL intestinal microbe B. subtilis S4 could effectively degrade protein and promote larval biomass accumulation, which could provide novel insights into the combined conversion of organic waste into proteins by microbes and insects.

Waste Nitrogen Upcycling to Amino Acids during Anaerobic Fermentation on Biochar: An Active Strategy for Regulating Metabolic Reducing Power.

This study proposes a novel strategy that utilizes biochar (BC) during anaerobic fermentation (AF) to generate amino acids (AAs) toward nitrogen upcycling. The BC, pyrolyzed at 800 °C (BC800) to enhance graphite structures and electron-accepting sites, effectively addresses issues related to biosynthetic reducing power nicotinamide adenine dinucleotide phosphate insufficiency by altering cellular conditions and alleviates feedback inhibition through the immobilization of end products. This process establishes unique microbial signaling and energy networks, with Escherichia coli becoming dominant in the biofilm. The conversion rate of ammonia-N to AAs-N within the biofilm reached 67.4% in BC800-AF, which was significantly higher compared to the levels in other AF reactors with BC pyrolyzed at 600 and 400 °C (45.9 and 22.5%, respectively), as well as a control AF reactor (<5%). Furthermore, in BC800-AF, the aromatic AAs (Aro-AAs) were as high as 70.8% of the AAs within the biofilm. The activities of key enzymes for Aro-AAs biosynthesis uniquely positively correlated with the electron-accepting capacity on BC800 (R2 ≥ 0.95). These findings hold promise for transforming existing AF reactors into factories that produce BC-based AAs, providing a more sustainable fertilizing agent than chemical fertilizers.

Upcycling lignocellulosic palm biomass via Black Soldier Fly Larvae (BSFL) composting incorporated with Ex-situ fermentation by Bacillus Subtilis

The growing demand of palm oil has caused expanding deforestation- one of the root causes for global warming. Drawn from the recent Conferences of the Parties (COP) 28, 39 % reduction in global carbon emission would need to be met by 2030 and this requires cooperation from all nations. Hence, the palm oil-producing nations could play their parts by upcycling palm waste biomass to promote sustainable palm oil production. Oil palm frond (OPF), a highly abundant biomass resulted from fruit pruning remains underutilized – mainly due to the undesirable biomass moisture level and low conversion technology readiness in the region. Composting OPF via Black Soldier Fly Larvae (BSFL) was proposed to overcome the technological barrier. However, OPF was not palatable for BSFL mainly being nutritionally deficient and highly lignocellulosic. Hence, ex-situ fermentation via Bacillus subtilis followed by blending with decanter cake (DC), nitrogenous palm waste was studied prior to BSFL composting. Results showed that treatment E (OPF:DC 3:7 wt) led to the highest BSFL weight gain (49 %) and biomass degradation (58 %) after 20 rearing days. The reared larvae consisted of 30 % and 22 % crude protein and lipid, respectively – making them an ideal insect meal. Overall, this research aims to give a preliminary overview of employing BSFL in composting highly recalcitrant palm waste biomass.

Virtual Sensing of Nitrite: A Novel Control for Safe Denitrification in Recirculating Aquaculture Systems (RASs)

Recirculating aquaculture system (RAS) technology is seen worldwide as a solution for sustainable fish production. However, there are still deficiencies in the process technology imperiling consistent operation and thus economic results. Drawbacks are linked to essential processes of the water treatment systems such as denitrification. Nitrogenous waste needs to be removed from RAS process water to maintain an adequate production environment for fish and to mitigate the environmental impact of discharged process water. At present, denitrification lacks reliable process control, especially regarding the organic carbon feed to heterotrophic denitrification processes. An investigation into heterotrophic denitrification in an experimental RAS resulted in the discovery of a virtual sensor based on measurements of the oxidation reduction potential (ORP). The virtual sensor responds to an insufficient carbon feed to denitrification. It is based on the oxidation of nitrite in an ozone-enhanced foam flotation installed downstream of the denitrification. The sensor essentially delivers a binary signal denoting either a complete or an incomplete denitrification process. The virtual sensor can be used for reliably controlling heterotrophic denitrification. It requires an upgraded process chain employing ozone-enhanced foam flotation (protein skimmer) downstream of the denitrification. However, the virtual sensor does not require any additional instrumentation.

Environmental impacts of the filamentous fungi Paecilomyces variotii (PEKILO®) as a novel protein source in feeds for Atlantic salmon (Salmo salar)

The present study investigated environmental impacts associated with greenhouse gas (GHG) emission, economic Fish in Fish out ratio (eFIFO), waste outputs, and food-feed competition of feeding diets containing the filamentous fungus Paecilomyces variotii (PEKILO®) to Atlantic salmon (Salmo salar) pre-smolts. To achieve this, a feeding trial was conducted using four experimental diets. The control diet was based on fishmeal, soy protein concentrate, and wheat gluten meal. Diets 1, 2, and 3 were formulated so that P. variotii replaced 5, 10, and 20 % of the crude protein (CP) content of the control diet originating mainly from fishmeal, soy protein concentrate, and wheat gluten meal. Dietary inclusion of P. variotii affected simulated environmental indices such as GHG emission (P < 0.001); this index was P. variotii-dose-dependent, as illustrated by negative linear models (P < 0.001, adjusted R-squared = 0.96). Dietary inclusion of P. variotii was negatively correlated with eFIFO (P < 0.001, adjusted R-squared = 0.82). Dietary inclusion of P. variotii reduced food-competition feedstuff (FCF) in the diets (P < 0.001), as well as the amount of FCF to produce one kg of Atlantic salmon (P < 0.001). Relative to the control diet, solid nitrogen waste output, expressed as g kg−1 fish produced, was increased (P < 0.0001) in fish fed Diet 3. Conversely, linear decreases in solid phosphorous, magnesium and potassium (P < 0.0001) wastes expressed as g kg−1 fish produced were associated with increasing dietary inclusion of P. variotii. Likewise, linear decreases in dissolved nitrogen, magnesium, and potassium (P < 0.0001) wastes were observed with increasing replacement of the CP content of the control diet with P. variotii. Based on this assessment, P. variotii is a relevant alternative protein source with a low environmental footprint for use in Atlantic salmon feeds. Future novel feeds for Atlantic salmon should expand the use of alternative protein- and lipid-rich materials with a low ecological footprint that are produced according to a circular bioeconomy principle and utilize non-food-competing feedstuff (NFCF) such as P. variotii to move the industry toward sustainability.

Biofloc Technology in Improving Shellfish Aquaculture Production – A Review

Abstract Biofloc technology is instrumental in improving growth performance and yield in shellfish aquaculture, while leading to enhanced water quality through maintaining the nutrients level within a safe range. More specifically, toxic nitrogenous wastes are converted into beneficial microbial biomass known as “biofloc”, contributing to improve shellfish immune system. Among the various parameters affecting the efficiency of the process is the carbon source and C:N ratio. In light of these, the present work critically reviews the effects of biofloc systems on growth performance, immunity and diseases resistance in shellfish production. Moreover, it scrutinizes the microbial diversity and nutritional composition of biofloc. Then, the application of the technology in various shellfish cultures, including shrimp, freshwater prawn, crabs, crayfish, clam, and oyster, is presented. Overall, biofloc systems contribute to enhanced shellfish survival rate to the highest value of 96–100% for marine shrimp, 95–99% for freshwater prawn, 70–83% for crayfish, 83–100% for oyster, Crassostrea sp. and up to 2% for mud crabs larvae through substantially reducing the ammonia level in the culture (summarized in Table 1 – Table 5). Finally, the main challenges in utilizing biofloc systems, i.e., suitable aeration and mixing and microbial mechanisms involved are also explained to shed light on future research directions in the field.

Study of some physiological parameters in renal failure patients with hepatitis C virus infection

Renal failure is defined as the kidneys' inability to execute excretory functions, resulting in the retention of nitrogenous waste products in the blood. Therefore, the current study was aimed at detecting the hepatitis C virus in renal failure patients and investigating measurements of urea, creatinine, phosphorus, calcium and albumin. Also, Hb and ABO blood groups were investigated. In this study, 20 blood samples were collected from people aged (24–83) of both sexes and included (10) renal failure, (10) renal failure with hepatitis C and (10) controls aged (23–66). A highly significant increase (P&lt;0.01) was observed in urea, creatinine and phosphorus levels in patients infected with renal failure without HCV and renal failure with hepatitis C virus infection groups in comparison to the control group. The other parameters albumin and hemoglobin concentration showed a highly significant decrease in renal failure patients with hepatitis C virus infection when compared to the healthy group. Calcium displayed a non-significant increase (P&lt;0.05) in patients with renal failure without HCV when compared to renal failure with HCV infection. But albumin, urea and hemoglobin showed a nonsignificant decrease (P &gt; 0.05) in patients with renal failure without hepatitis C infection when compared to those with renal failure. The ABO blood groups results for renal failure patients without hepatitis C virus infection showed the highest percent in the O+ blood group (60%) followed by A+, B+, AB+ and Arecorded as 10% for each one. The renal failure patient with hepatitis C virus infection group showed the highest percent of the O+ blood group (50%) followed by A+, B+, AB+ and A- recorded as (20%), (10%), (10%) and (10%) respectively.

Achieving over 90% Faradaic Efficiency in Cyclohexanone Oxime Electrosynthesis Using the Cu-Mo Dual-Site Catalyst.

Coupling with the nitrate electroreduction reaction (NitRR), the electrosynthesis of cyclohexanone oxime (CHO, the vital feedstock in the nylon-6 industry) from cyclohexanone provides a promising alternative to the traditional energy consumption process. However, it still suffers from low efficiency because selective production of *NH2OH intermediate from NitRR under large current densities is challenging. We here report a Cu1MoOx/nitrogen-doped carbon (NC) electrocatalyst with high-density Cu-Mo dual sites for NitRR to selectively produce and stabilize *NH2OH, with the subsequent cyclohexanone oximation achieving the highest CHO Faradaic efficiency of 94.5% and a yield rate of 3.0 mol g-1 h-1 at an industrially relevant current density of 0.5 A cm-2. Furthermore, in situ characterizations evidenced that the Cu-Mo dual sites in Cu1MoOx/NC effectively inhibited hydrodeoxygenation of hydroxyl-containing intermediates of NitRR, selectively producing *NH2OH and thus achieving cyclohexanone oximation with high efficiency. This work provides a high-performance catalyst for CHO electrosynthesis from nitrogenous waste, showing promising application potential in industrial production of CHO.

Enabling the circular nitrogen economy with organic and organo-mineral fertilisers

AbstractThe circular nutrient economy repurposes organic (formerly alive, containing organic carbon) and inorganic (mineral) recycled materials as fertilisers and soil ameliorants, and halving nitrogen (N) waste is a global goal. Our focus was unavoidable food waste and garden waste (FOGO food organics garden organics) as suitable feedstock for compost and use for cropping. We hypothesised that to realise benefits of compost, organic and organo-mineral fertilisers (OF/OMF) must be optimised for target crops and biophysical environments. We explored compost and organic recyclates (dried bacterial biomass PPB, chicken litter manure) as N sources for vegetable, fruit and grain crops in controlled experiments with single or combinations of contrasting N release and carbon-to-N ratios of 20, 13.5 (compost), 13.5 (poultry manure), 6.1 (PPB) and 0.5 (mineral N). With standardised N input (0.5–1 g N/pot and plant), compost as the sole N source resulted in less yield than all other N sources, while suitable mixtures of organic recyclates with/without added mineral N matched the yield of crops grown with mineral N. Adding 5% compost to sand growth substrate modulated crop growth and phenology, increased tillering and panicle production, or accelerated fruit ripening. This confirmed effects beyond nutrient supply, likely crop-growth modulating substances are present. Exploring effects of crop species, N source and water supply confirmed statistically significant interactions on yield, biomass and N use efficiency (NUE). This means a robust strategy for optimising OF/OMF is testing target crops with compost and recyclates to identify crop-specific responses. We recommend that applying such strategy allows manufacturers targeting N-efficient OF/OMF to service the expanding market for recyclate-based organo-mineral fertilisers and soil ameliorants for the circular N economy.

The effects of dissolved organic carbon and model compounds (DOC analogues) on diffusive water flux, oxygen consumption, nitrogenous waste excretion rates and gill transepithelial potential in Pacific sanddab (Citharichthys sordidus) at two salinities.

Many flatfish species are partially euryhaline, such as the Pacific sanddab which spawn and feed in highly dynamic estuaries ranging from seawater to near freshwater. With the rapid increase in saltwater invasion of freshwater habitats, it is very likely that in these estuaries, flatfish will be exposed to increasing levels of dissolved organic carbon (DOC) of freshwater origin at a range of salinities. As salinity fluctuations often coincide with changes in DOC concentration, two natural freshwater DOCs [Luther Marsh (LM, allochthonous) and Lake Ontario (LO, autochthonous) were investigated at salinities of 30 and 7.5 ppt. Optical characterization of the two natural DOC sources indicate salinity-dependent differences in their physicochemistry. LO and LM DOCs, as well as three model compounds [tannic acid (TA), sodium dodecyl sulfate (SDS) and bovine serum albumin (BSA)] representing key chemical moieties of DOC, were used to evaluate physiological effects on sanddabs. In the absence of added DOC, an acute decrease in salinity resulted in an increase in diffusive water flux (a proxy for transcellular water permeability), ammonia excretion and a change in TEP from positive (inside) to negative (inside). The effects of DOC (10mg C L-1) were salinity and source-dependent, with generally more pronounced effects at 30 than 7.5 ppt, and greater potency of LM relative to LO. Both LM DOC and SDS increased diffusive water flux at 30 ppt but only SDS had an effect at 7.5 ppt. TA decreased ammonia excretion at 7.5 ppt. LO DOC decreased urea-N excretion at both salinities whereas the stimulatory effect of BSA occurred only at 30 ppt. Likewise, the effects of LM DOC and BSA to reduce TEP were present at 30 ppt but not 7.5 ppt. None of the treatments affected oxygen consumption rates. Our results demonstrate that DOCs and salinity interact to alter key physiological processes in marine flatfish, reflecting changes in both gill function and the physicochemistry of DOCs between 30 and 7.5 ppt.

Advanced characterization techniques for understanding electrocatalytic behavior of oxidized nitrogen waste upcycling processes

Advanced characterization techniques for understanding electrocatalytic behavior of oxidized nitrogen waste upcycling processes

Integrated process of Tetrasphaera-dominated in-situ waste activated sludge fermentation, biological phosphorus removal and endogenous denitrification in single reactor for treatment of wastewater with limited carbon sources

An integrated process of sludge in-situ fermentation, biological phosphorus removal and endogenous denitrification (ISFPR-ED) was developed to treat low ratio of chemical oxygen demand to nitrogen (COD/N) wastewater and waste activated sludge (WAS) in a single reactor. Nutrient removal and WAS reduction were achieved due to Tetrasphaera-dominated sludge fermentation provided organic carbon in extending the anaerobic duration. The WAS reduction efficiency, effluent orthophosphate (PO43−-P) and total inorganic nitrogen reached 28.1 %, less than 0.4 and 7.2 mg/L, respectively. While organic carbon was reduced by 67 %. Tetrasphaera, conventional polyphosphate accumulating organisms (PAOs) stored glycogen, amino acids, and PHA for nutrient removal. Excess energy from fermentation enhanced anaerobic PO43−-P uptake by Tetrasphaera. Tetrasphaera was the dominant PO43−-P removal and fermentation bacteria, working synergistically with conventional PAOs and fermenting microorganisms. This integrated process improves nutrient removal efficiency and reduces operating costs for carbon addition and WAS disposal in wastewater treatment.

Study on the Formation Mechanism of NOx Precursors During Density Functional Theory Pyrolysis of Leucine and Proline

ABSTRACT Incineration is an efficient method of resource utilization for kitchen waste. As an important stage of incineration, pyrolysis not only degrades kitchen waste but also generates pollutants such as nitrogen oxides. It is necessary to conduct in-depth research on the nitrogen conversion mechanism during its pyrolysis process. Most of the nitrogen in kitchen waste is concentrated in protein/amino acids. This article is based on the density functional theory calculation method, selecting typical compounds leucine and proline in kitchen waste as research objects, and studying their pyrolysis mechanism and the formation path of NOx precursors. A possible path for the cleavage of C-C/C-N bonds caused by hydrogen transfer to form NH3 and HCN has been proposed. Finally, it has been theoretically proven that the pyrolysis process of leucine tends to generate NH3 rather than HCN. And it was clarified that low energy barriers and high reaction rates are the reasons for the difference in production of these two NOx precursors. Meanwhile, the differences in the generation characteristics of NOx precursors for proline at different pyrolysis temperatures were theoretically explained. Finally, it was elucidated that leucine and proline preferentially undergo decarboxylation to complete the deoxygenation process, and the reason for the difference in CO production during the pyrolysis of the two amino acids was explained. In addition, this study found that the pyrolysis of leucine occurred preferentially than that of proline under the same conditions, and the yield of NOx precursor produced by leucine was higher than that of proline.

Characteristics of reactive nitrogen emissions from solid waste and its environmental impact in the Yellow River Basin, China

ABSTRACT One of the topics of concern on a global scale is the source, fate, and environmental effects of solid waste nitrogen (N). Quantitative calculation and evaluation of solid waste N (SWN) generation and its reactive N (Nr) emission characteristics, as well as their environmental effects in the basin ecosystem, are essential for the sustainable management of SWN and the improvement of the ecological environment. The accounting framework for the production of SWN and associated Nr emission was established using the Yellow River Basin of Henan section as an example. The findings revealed that SWN, with an annual average of 265.3 Gg N yr−1, grew by 17.2% over the previous ten years. The largest contributors were domestic waste N (82.5%) and livestock and poultry waste N (12.9%), with the remaining sources making up roughly 4.5%. The majority of the sources of Nr emissions were NH3 (63.2%), NOx (18.9%), and Nr lost to groundwater (12.3%), whereas N2O contributed just 5.7%. To mitigate Nr emissions from solid waste in the basin, enhancing solid waste classification, recycling, and composting treatment while reducing dumping and landfilling is vital. The study offers a scientific basis for the management and prevention of SWN in the basin.

Sustainable repurpose of waste melamine foam into bifunctional catalysts for efficient CO2 capture and conversion

Global climate change has driven the scientific community to improve the utilization of a critical C1 resource carbon dioxide (CO2) through carbon capture utilization (CCU) technology. The cycloaddition of CO2 with epoxides provides perfect atom economy and economic feasibility to produce versatile cyclic carbonates used in various industries. However, the stable nature of CO2 and epoxides requires highly active catalysts. In this work, the repurpose of nitrogenous waste melamine foams (MFs) as high-performance catalysts for the cycloaddition of CO2 was explored. The pyrolyzed MF was modified with Cu to prepare a series of acid-base bifunctional porous catalysts (MFC-X-Cu). The results demonstrate that the acid-base synergy of the MFC-X-Cu catalysts increases the efficiency of the cycloaddition of various epoxides, yielding target products at 96–99% under mild conditions. Moreover, the characterization results revealed that the superior performance of MFC-X-Cu stems from its hollow structure and acid-base synergy, which are derived from nitrogen species in the repurposed MF and the post-modified copper component. The catalyst maintained consistent catalytic efficiency over five cycles, highlighting its strong recyclability. This work presents an eco-friendly and sustainable approach towards carbon neutrality by utilizing modified waste materials for CO2 conversion into high-value chemicals.

Etiological Profile and Short-Term Outcomes of Acute Kidney Injury in Term Neonates at a Tertiary Care Centre in Western Maharashtra, India.

Background Acute kidney injury (AKI) is characterized by a sudden decline in kidney function, leading to a reduced glomerular filtration rate (GFR). This decline results in the accumulation of nitrogenous waste products in the blood, disturbs electrolyte balance, and disruptsfluid regulation. Objective To determine the etiological profile of AKI in term neonates. Methods Aprospective observational study was conducted at the Neonatal Intensive Care Unit (NICU) of our tertiary care hospital and referral and teaching center. The study spanned a period of two years, from August 2022 to July 2024, and comprised a total of 78 term babies diagnosed with AKI, all of whom were enrolled after obtaining consent using a predefined proforma. The neonatal period was defined as the time from birth up to 44 weeks of postmenstrual age (PMA), encompassing a critical developmental phase in newborns. Results In our study of 78 term neonates with AKI, we found a predominant occurrence in males (53, 67.9%) and a significant proportion with low birth weights (41, 52.6%). The most common cause of AKI was sepsis or multiple organ dysfunction syndrome (MODS) (32, 41%), followed by perinatal hypoxia (14, 17.9%) and urinary tract obstructions (12, 15.3%). Urinary tract infections (UTIs) accounted for nine cases (11.5%), hypernatremic dehydration for six cases (7.6%), acute tubular necrosis for three cases (3.8%), and congenital polycystic kidney disease for two cases (2.9%). Mortality was notably high, with 20 neonates (25.7%) dying from AKI, particularly those with sepsis/MODS and perinatal hypoxia. However, conditions such as urinary tract obstructions and UTIs generally had better outcomes. The statistical analysis revealed a significant association between the underlying etiology and outcomes (p<0.001), underscoring the importance of prompt and targeted interventions for different AKI causes in neonates. Conclusion Our findings highlight the diverse etiological spectrum of AKI in term neonates and its significant impact on mortality. Early recognition, appropriate management, and targeted interventions tailored to the underlying cause are crucial in improving outcomes for neonates with AKI.

Modeling embryo survival: Genetic and environmental influences on eye-up rate in a north American Atlantic salmon selective breeding program

Selective breeding programs improve target traits but can also unintentionally change genetically correlated traits in the selected strain. The U.S. Department of Agriculture–Agricultural Research Service National Cold Water Marine Aquaculture Center (NCWMAC) in Franklin, Maine maintains a North American Atlantic salmon selective breeding program focused on improving commercially important traits (e.g., carcass weight). However, the program has experienced a significant decline in the percent of eyed embryos over its 14 years of operation, leading to concerns that reproductive performance was being unintentionally changed by selection for the target traits. The aims of this study were to 1) model eye up success as a potentially heritable trait utilizing the recorded pedigree and 2) assess the relationship between eye-up rate and environmental conditions experienced by the broodstock. Over 14 years of data encompassing 1537 full-sib families produced by 1537 dams and 885 sires was analyzed. Counts of eyed embryos and carcass weight were analyzed with a linear multi-trait trait model that included maternal genetic effects and a spawn year effect to determine the strength of genetic and environmental influences on the eyed embryo rate. To investigate the environmental influences in more detail, we assessed the correlation between water quality parameters in the broodstock rearing system observed over the same 14-year time period and the estimated spawn year effects. There was small heritability of the direct genetic effect (0.059 ± 0.009) and the maternal genetic effect (0.039 ± 0.013). Comparatively, the proportion of phenotypic variance explained by the maternal environmental effect was moderate (0.165 ± 0.012). The genetic correlations between carcass weight and eye up rate were very small and had a large amount of uncertainty. The correlation between the direct genetic effects on eye-up and carcass weight was −0.0528 ± 0.1469 while the correlation between the maternal genetic effect on eye-up and the direct genetic effect on carcass weight was 0.2030 ± 0.1791. The correlation between maternal common environmental effects on the two traits was also low at 0.0676 ± −0.0804. The effect of spawn year was statistically significant (p < 0.01), and the values were negatively correlated with mean un-ionized ammonia (mg/L, −0.56, p = 0.04,), nitrate concentrations (mg/L r = −0.65, p = 0.01) and temperature (°C, r = −0.61, p = 0.02) experienced by the broodstock prior to spawning. Overall, the results suggest that the decrease in eyed embryos over time was not caused by inadvertent selection but instead due to increases in water temperature and/or nitrogenous waste concentrations in the broodstock rearing system. Further investigation of the mechanisms behind these apparent environmentally induced declines and potential mitigation measures to prevent decreases in eye-up rates are needed.

Novel microwave assisted carboxymethyl-graphene oxide and its hepatoprotective activity

This study reports a novel, eco-friendly; fast and cost-effective microwave method for synthesizing carboxymethylated graphene oxide (CMGO) from sugarcane residues. Fourier-transform infrared spectroscopy (FTIR) confirmed successful CMGO synthesis through the presence of characteristic peaks at 1567.93 and 1639.29 cm−1 (COONa vibrations) and increased CH2 intensity compared to unmodified graphene oxide (GO). Furthermore, CMGO derived from sugarcane residues demonstrated potential in mitigating the side effects of toxic materials like carbon tetrachloride (CCl4). Treatment with CMGO partially reduced elevated levels of liver enzymes (ALT and AST) and nitrogenous waste products (urea and uric acid) in CCl4-induced liver damage models, suggesting an improvement in liver function despite ongoing cellular damage.This work paves the way for a sustainable and economical approach to produce functionalized graphene oxide with promising biomedical applications in alleviating toxin-induced liver injury.Graphical abstract