Manure Research Articles

Box-Behnken design (BBD) for optimization and simulation of biolubricant production from biomass using aspen plus with techno-economic analysis

The growing concern and limitations for existing lubricants have driven the need for biolubricants, extensively proposed as the most suitable and sustainable lubricating oils. Biolubricant refers to lubricants that quickly biodegrade and are non-toxic to humans and aquatic habitats. Over the last decade, there has been a significant increase in the production of biolubricants due to the rising demand for replacing petroleum-based lubricants with those derived from renewable sources like vegetable oils and lipase that are used in various applications. In this study biodiesel (FAME) produced from blending animal fats and waste cooking was used as a raw material with ethylene glycol for biolubricant production using a transesterification reaction in the presence of calcium oxide which considers the newest and novel part as there is no production of biolubricant from animal fats and waste cooking oil in previous researches. The reaction parameters of biolubricant production were optimized using response surface methodology (RSM) with the aid of Box Behnken Design (BBD) to study the effect of independent variables on the yield of biolubricant. These variables are temperature ranging from (100–150 °C), reaction time ranging from 1 to 4 h, and FAME (Fatty Acid Methyl Ester) to alcohol molar ratio ranging from (2:1) to (4:1). The highest biolubricant yield is 91.56% at a temperature of 141 °C, a FAME/alcohol molar ratio of 2:1, and 3.3 h. Various analyses were performed on the produced biolubricant at the optimum conditions. The results include a pour point of -9 °C, a flash point of 192 °C, a kinematic viscosity at 40 °C of 10.35 cSt, a viscosity index of 183.6, an ash content of 0.76 wt.%, and a carbon residue of 1.5 wt.%, comparing favorably with the ISO VG 10 standard. The production process of biolubricant was simulated with Aspen Plus version 11 using a Non-Random Two-Liquid (NRTL) fluid package. The simulation results indicated that the production process can be applied on an industrial scale. Economic analysis was performed on the biolubricants production plant. The total capital investment was $12.7 M with a payback period of 1.48 years and an internal rate of return (IRR) of 67.5% indicating the suitability and profitability of the biolubricant production.

Integrated Farming System: A Sustainable Approach towards Modern Agriculture

Integrated farming system (IFS) is an integrated approach towards sustainable agriculture in this modern era. It is the integration of various agricultural enterprises or practices such as crops, livestock, Poultry, fish, agroforestry, horticulture, vermicomposting, Mushroom cultivation and beekeeping, in a single farming system. IFS is considered as the efficient tool for enhancing the profitability of farming systems especially for small and marginal farmers. The purposes or objectives of the IFS are: It enhances the productivity per unit area; Agriculture waste management; Soil health management and soil conservation; Generation of diversified income round the year; less use of chemicals; Increasing the yield of all integrated components and food security. IFS include various components or enterprises. These enterprises not only increase the farmer’s income but also increase employment generation of a family. The juadicious integration of these agricultural enterprises improves the socio-economic status of the farmers. The crop production component of IFS includes the cultivation of various economically important crops such as cereals, pulses, vegetables, fruits, and herbs. To maintain the soil health & fertility and management of Plant diseases and pests, various cultural methods such as intercropping, crop rotation, soil solarisation, organic amendment, Mulching, etc. Mushroom cultivation is also one of the important enterprises in IFS that contribute towards increase in farmer’s income. Another important component of IFS includes the rearing of different types of livsestock such as cows, goats, sheep, Duckery, Piggery, Apiary, and poultry. Livestock provides a source of income and produces manure, which can be used as fertilizer for crops. Biogas is another enterprise which is the use of agricultural and animal waste to produce energy. This Bioenergy helps to reduce the dependence on fossil fuels and provide a source of income for farmers. There are various models that can be used in IFS like Horticulture+ Piggery+ Fisheries+ Plantation crops and Agriculture+ Horticulture+ Poultry+ Fishery+ Mushroom. Hence, Integrated Farming System is a promising approach for increasing productivity, increasing farmer’s income by utilizing the agricultural and animal waste, recycling farm by-products and efficient utilization of available resources.

Hierarchical graphene oxide/nano-pyramidal stainless-steel on nickel foam substrate: A flexible electrochemical sensor for arsenic compound detection

The organoarsenic compound roxarsone (ROX) is added to chicken feed to enhance nutritional value. Although organic arsenic is generally less harmful than inorganic arsenic, concerns have arisen about its potential to transform into inorganic forms when excreted in animal waste, raising environmental and human health concerns. The potential dangers of long-term ROX exposure require reliable methods for the detection of the target analyte. In the current study, fabricated nanoscale graphene oxide (GO)/stainless steel (SS) pyramidal structures on nickel foam (NF) is used as an electrode in the electrochemical detection of ROX. The proposed sensor was shown to outperform existing devices in terms of electrochemical activity, resulting in a wider linear range of detection for ROX (0.05–83.15 µM) and lower detection limit (LOD) (0.006 µM). Further, real sample analysis on water and meat samples confirmed the feasibility of the proposed GO/SS/NF sensor for the real-time detection of ROX in real-world applications. This research provides evidence to support the development of heterojunctions to improve ion transport channels and surface-active sites to promote ion mobility to enhance electrochemical responses.

The Environmental Footprint of Available Food Waste in Young Households: A Diary Case Study of Schleswig-Holstein (Germany)

As households contribute significantly to food waste, it can be assumed that they bear considerable responsibility for the environmental footprint of it. In Germany, household food waste comprises over half of all food loss and waste, with a notable share attributable to young people. To explore their environmental footprint, data from fifty young households in Schleswig-Holstein, northern Germany, is analyzed using the Food Loss and Waste Value Calculator with an integrated life cycle assessment. We evaluate the environmental footprint of animal and plant food waste across five categories: climate change, water scarcity footprint, soil quality index, phosphorus and nitrogen eutrophication. Surprisingly, animal food waste, though representing only 18% of the total volume of all available food waste in our study, exhibits a more substantial impact in all categories except water scarcity. Specifically, animal food waste is found to be an important factor in soil degradation. Our results generally indicate an inverse relationship between the volume of animal-based and plant-based food waste in young households and its environmental footprint. However, the case study highlights a troubling connection between plant food waste and significant water scarcity issues in European agriculture.

Simultaneous Production of Biogas and Electricity from Anaerobic Digestion of Pine Needles: Sustainable Energy and Waste Management.

Power scarcity and pollution can be overcome with the use of green energy forms like ethanol, biogas, electricity, hydrogen, etc., especially energy produced from renewable and industrial feedstocks. In hilly areas, pine needles are the most abundant biomass that has a low possibility of valorization due to high lignin content. On the other hand, anaerobic digestion (AD) of lignin and animal waste has low biogas yield due to poor conductivity. This study focuses on the simultaneous production of biogas and electricity through the co-digestion of cow dung and pine needles. The digester was initially established and stabilized in the lab to ensure a continuous supply of inoculum throughout the experiment. The optimization process involved the determination of an ideal cow dung-to-water ratio and selecting the appropriate conductive material that can enhance the energy generation from the feedstock. Afterward, both batch and continuous anaerobic digestion experiments were conducted. The results revealed that the addition of powdered graphite (5 mM), activated charcoal (15 mM), and biochar (25 mM) exhibited maximum voltage of 0.71 ± 0.013 V, 0.56 ± 0.013 V, and 0.49 ± 0.011 V on the 30th, 25th and 20th day of AD, respectively. The batch experiment showed that 5 mM graphite powder enhanced electron transfer in the AD process and generated a voltage of 0.77 ± 0.014 V on the 30th day, indicating an increase of ~1.5-fold as compared to the control (0.56 ± 0.019 V). The results from the continuous AD process showed that the digester with cow dung, pine needle, and a conductive material in combination exhibited the maximum voltage of 0.76 ± 0.012 V on the 21st day of AD, while the digester with cow dung only exhibited a maximum voltage of 0.62 ± 0.015 V on the 22nd day of AD, representing a 1.3-fold increase over the control. Furthermore, the current work used discarded plastic items and electrodes from spent batteries to emphasize waste management and aid in attaining sustainable energy and development goals.

Intestinal Protozoa and Schistosoma Mansoni (Sambon 1907) Infections Among Some Pupils in Akko Local Government Area of Gombe State, Nigeria

The prevalence of intestinal protozoa and Schistosoma mansoni infections among primary school pupils in Akko Local Government Area of Gombe State, Nigeria was investigated. Stool samples were collected from 450 pupils aged 5–13 years in the three (3) districts of Akko Local Government Area. A structured questionnaire was used to collect relevant demographic and risk factor data associated with intestinal protozoa and S. mansoni infections. The stool samples were processed using the formol-ether concentration technique and microscopically examined for protozoan cysts and S. mansoni eggs; 12.4 % of the stool samples were positive for cysts and eggs. The prevalence of intestinal protozoa were: Entamoeba histolytica (4.9 %), Entamoeba coli (3.8 %) and Balantidium coli (2 %); Schistosoma mansoni eggs had a prevalence of 1.6 %. The prevalence of infection with protozoa and S. mansoni infections in individual schools was not uniform despite the similarity in the local topography and weather conditions. Source of drinking water and type of toilet used significantly associated with infection by intestinal protozoa and S. mansoni (Odd’s Ratio value for Pit-latrine was 18.959). The prevalence of intestinal protozoa and Schistosoma mansoni infections among the primary school pupils was associated with poor personal hygiene habits at home and in school, and improper disposal of human and animal waste as implied by the responses to the questionnaire. It is therefore recommended that a concerted health education effort is necessary in order to curb the infections within the schools and the communities.

Characterization of fresh biowastes for biogas production and environmental health in Niger Delta, Nigeria

BackgroundEnvironmental pollution is a public health problem in Niger Delta, Nigeria. Therefore, the aims of the present study were to: identify the major fresh biowastes in Bayelsa State, Niger Delta; quantify the biogas yields from mono-digestion and co-digestion of identified biowastes; determine the first day of biogas production during hydraulic retention time; assess pH variations during anaerobic digestion; and evaluate biogas flame colours.MethodsFifteen communities in Bayelsa State were randomly selected, and on-the-spot assessment and quantification of the biowastes found in each community were carried out daily per week. Mono-digestion of 20 kg of each biowaste and co-digestion of 10 kg of animal waste with 10 kg of plant waste were carried out respectively under anaerobic conditions. Cumulative biogas yield and pH were measured using a pH meter and weighing scale respectively. Biogas flame colours during combustion were visually assessed.ResultsExactly 120.61 metric ton of fresh biowastes was found to be generated per week in Bayelsa State, Niger Delta. Industrial biowastes were the highest [47.6 tonnes, (39.46%)], followed by abattoir biowastes [33 tonnes (27%)], market and roadside sellers biowastes [25.5 tonnes (21.14%)], and farm biowastes [14.51 (12.03%)]. Biogas yields (kg) were: 0, 0, 0, 0, 0, 17, 14, 2, 18, 16, 17, 15 and 1 kg for palm oil mill effluent (POME), orange fruit waste (OFW), pineapple peels (PP), plantain peels, cassava mill effluent (CME), rumen digesta (RD), cow dung, sewage, PP-RD, plantain peels-cow dung, POME-rumen digesta, OFW-cow dung, and CME-sewage respectively. The first day of biogas production for RD, cow dung, sewage, PP-RD, plantain peels-cow dung, POME-RD, OFW-cow dung, and CME-sewage was on the 6th, 32nd. 56th, 1st, 26th, 18th, 25th, and 60th day of hydraulic retention time respectively. A dominant blue flame colour mixed reddish yellow or orange flames were found during biogas combustion. A slight increase in pH was found in all the biodigester media.ConclusionsIn the present study, a variety of biowastes yielding various quantities and qualities of biogas were identified in Bayelsa State, Niger Delta. The study’s findings have provided evidence-based data that might be explored as a road map and catalyst for policy creation against inadequate biowaste management and as sustainable alternatives to the expensive liquefied petroleum gas. The potential of current research study to be scaled up for commercial use is implicated in the present study.

The Integration of Phosphorus-Solubilizing Rhizobacteria, Eisenia fetida and Phosphorus Rock Improves the Availability of Assimilable Phosphorus in the Vermicompost

Due to increasing soil degradation caused by unsustainable agricultural practices and the continued demand for quality food for the human population, it is imperative to find sustainable strategies for high-quality food production. For this reason, the objective of the present study was to evaluate the interaction between the factors of consortium of phosphorus-solubilizing rhizobacteria, addition of phosphate rock and worm load in horse manure to produce an organic fertilizer fortified with phosphorus. For this, consortia of phosphate-solubilizing rhizobacteria of the genus Bacillus (Bacillus aryabhattai, Bacillus subtilis and Bacillus cereus) isolated from the rhizosphere of Distichlis spicata were inoculated. Igneous phosphate rock (0 and 2%) was added in the vermicomposting process (with 25 and 50 g of E. fetida worms per kg of horse manure). The results obtained show that there is a significant interaction between the factors of inoculation with bacterial consortia (1 × 108 CFU mL−1), phosphate rock (2%) and earthworm biomass (50 g kg−1 of manure), and that this interaction promotes the production of assimilable forms of phosphorus for plants (such as monobasic phosphate ions H2PO4−1 or dibasic phosphate ions HPO4−2) within the vermicomposting process, having as a product an organic substrate supplemented with the optimal nutritional requirements for the development and growth of crops. This work can serve as a basis to produce high-quality organic fertilizer. However, field studies are required in order to observe the impact of vermicompost on the yield and quality of the fruits, and it can be compared with other types of fertilizers and the relevance of their use in different types of climates.

DETERMINATION OF THE CARBON FOOTPRINT OF ANIMAL WASTE AND CLIMATE CHANGE; KARAMAN EXAMPLE

Climate change is a major concern around the world. In this context, the carbon footprint of animal waste is of critical importance for sustainability and climate change management. The aim of this study is to estimate the carbon footprint resulting from animal breeding and animal waste in the Karaman region. In the study, 2022 data was used and there are 1019277 sheep and 81368 cattle for Karaman. In the study, Tier 1 and Tier 2 approaches were used to estimate methane gas emissions related to both enteric fermentation resulting from animal digestive processes and manure management. According to the results of the study, the results obtained using Tier 1 and Tier 2 approaches are as follows: 0.4924-0.5014 kg CO2e per 1 liter of milk for Cattle. For sheep, it is 4.5167-6.5627 kg CO2e per 1 kg of meat. For goat, it is 5.0813-6.0231 kg CO2e per 1 kg of meat. These results can be taken into account when creating strategies to reduce methane gas emissions. It is recommended to add better quality and high energy content foods to the feed ration, especially to reduce enteric fermentation. In addition, this study is a resource for relevant researchers working in the field in calculating the carbon loads of animal waste and is thought to be a guide for decision makers and practitioners.

Physico-mechanical Characterization of Stabilized Earth Blocks with Snail Shell and Termite Mound Powders as Pozzolanic Binders

The aim of this study is to reduce the reliance on cement in the construction of Stabilized Earth Blocks (SEBs) by assessing the addition of snail shell and termite mound powders as a partial substitute for cement. The focus of this study is on the valorization of local materials and animal waste in sustainable construction. Laterite, used as the base material, was stabilized by substituting 0 to 80% of the cement with snail shell and termite mound powders to create blocks that were tested for their mechanical strength and water absorption. The results show that the compressive strength of the blocks remains above the required threshold of 4 MPa up to a 50% substitution, with a downward trend at higher rates. The capillary water absorption of the stabilized earth blocks remains within the limits of blocks classified as low-absorption, with coefficients ranging from 0.58 kg/m²/min at a 50% substitution to 1.14 kg/m²/min at an 80% substitution. These findings suggest that a substitution up to 50% could represent an adequate balance between mechanical performance and environmental benefits, thus ensuring the required durability and mechanical strength. Although the research is limited to the study of these materials in their raw state, future work could explore the enhancement of the pozzolanic activity of snail shell and termite mound ash through treatments such as calcination to further strengthen the eco-efficiency of the process.

Black soldier fly (Diptera: Stratiomyidae) larvae reduce cyathostomin (Nematoda: Strongylidae) eggs but develop poorly on horse manure.

Cyathostomins are common digestive tract parasites of grazing horses that spread through contact with horse feces. Horse feces are colonized by a variety of organisms, some of which could serve to reduce parasite loads in horse pastures. Black soldier fly (Hermetia illucens L.; Diptera: Stratiomyidae) larvae (BSFL) could be an ideal candidate for biological control of cyathostomins, due to their near-global distribution, low risk of pathogen transmission, ability to develop on a variety of nutrient-poor substrates (including horse manure), and dramatic effect on microbial communities that cyathostomins depend on. Here, using controlled feeding bioassays, we evaluated the effect of BSFL on cyathostomin egg densities in horse manure while also tracking BSFL performance on manure relative to standard grain-based diets. We found that BSFL consumed less substrate, were slower to reach the prepupal stage, and ultimately yielded less biomass when reared on horse manure compared to grain-based diets. However, BSFL reduced average cyathostomin egg densities in horse manure by over 3-fold. Overall, our results suggest that despite horse manure being a poor substrate for BSFL growth, BSFL effectively reduce cyathostomin egg loads in infected horse manure, though the mechanisms by which they do this are uncertain. While BSFL are known to transform the microbial communities within a diversity of rearing substrates, their effect on larger, parasitic organisms in animal manures may be underappreciated. Promoting the decomposition of infected horse manure with BSFL might be a promising approach to managing parasite populations among grazing horses.

One Health risk perception among the urban vulnerable dwellers of Gujarat, India: A cross–sectional assessment

Objective: To assess One Health risk perception and local knowledge concerning threats arising from the interaction of humans, animals, and the environment at the community level with a particular emphasis on zoonotic disease transmission at Ahmedabad and Gandhinagar City, Gujarat, India, where the majority are vegetarians. Methods: A cross-sectional design with cluster sampling was employed with 387 participants participated in a quantitative survey, comprising 192 livestock handlers and 195 non-livestock handlers. Additionally, 20 in-depth interviews explored qualitative insights. Data were processed using MS Excel and analysed using Stata version 14. Results: In our study, we observed varied risk perceptions among predominantly female participants. Among livestock handlers, 23.4% acknowledged the potential for zoonotic transmission, while this awareness increased to 41.0% among non-livestock handlers. Although handwashing after animal contact and work was common among livestock handlers, only 20.3% recognized the pivotal role of hygiene in preventing zoonotic diseases. Similarly, 37.0% of livestock handlers and 47.2% of non-livestock handlers understood the risks associated with consuming raw milk and meat, which reveals a statistical difference between these two groups (P=0.000). Another significant difference was observed in the perception on animal waste disposal sites with 58.9% of livestock keepers and 80.0% of non-livestock keepers considering such sites as risky factors (P=0.000). Furthermore, vaccination awareness was high, with 85.4% of livestock handlers and 88.7% of non-livestock handlers being aware of vaccination as a preventive measure against zoonotic diseases. Interestingly, non-livestock individuals demonstrated a higher level of awareness regarding zoonotic diseases compared to their livestock counterparts. Conclusions: This study emphasizes the urgent need for collaborative One Health interventions to address zoonotic disease risks among livestock handlers in India. By bridging knowledge gaps and promoting proactive measures, we can effectively safeguard public health and well-being in the face of emerging zoonotic threats.

Examining imidacloprid behaviorally resistant house flies (Musca domestica L.) (Diptera: Muscidae) for neonicotinoid cross-resistance.

The house fly (Musca domestica L.) is a ubiquitous fly species commonly associated with confined animal and urban waste storage facilities. It is known for its pestiferous nature and ability to mechanically vector numerous disease-causing pathogens. Effective control of adult house fly populations has traditionally relied upon insecticidal food baits; however, due to the overuse of insecticides, resistance has proven to yield many insecticidal baits and chemical classes less effective. Imidacloprid, the most widely used neonicotinoid, has been formulated and commonly used in house fly baits for over 2 decades. However, widespread evidence of physiological and behavioral resistance to imidacloprid has been documented. While previous studies have investigated the mechanisms of behavioral resistance to imidacloprid in the house fly, it remains unclear whether behavioral resistance is specific to imidacloprid or if behavioral cross-resistance exists to other compounds within the neonicotinoid class of insecticides. The current study used no-choice and choice-feeding bioassays to examine a lab-selected imidacloprid behaviorally resistant house fly colony for cross-resistance to other insecticides in the neonicotinoid chemical class. All flies exhibited high mortality (97-100%) in no-choice assays, even when exposed to imidacloprid, indicating physiological susceptibility to all tested neonicotinoids. House flies exhibited high mortality (98-100%) in choice assays when exposed to all neonicotinoid insecticides tested besides imidacloprid. These results confirm that imidacloprid behavioral resistance is specific to the compound imidacloprid and that alternative neonicotinoids remain viable options for control. Our study showed no evidence of behavioral cross-resistance to other compounds in the neonicotinoid class.

Simultaneous analysis of antimicrobial residues and contaminants in poultry droppings by HPLC-MS/MS: a tool for environmental and food safety monitoring

Animal waste is a potential pollution hazard as it can harbour contaminants, such as antimicrobial residues, mycotoxins, and pesticides, becoming a risk to the public, animal, and environmental health. To assess this risk, 15 experimental broiler chickens orally received contaminants to evaluate excretion levels. An analytical method was previously developed to detect 18 substances in poultry droppings using high-performance liquid chromatography coupled to a tandem mass spectrometer (HPLC-MS/MS). Contaminants including tetracycline, 4-epi-tetracycline, oxytetracycline, 4-epi-oxytetracycline, chlortetracycline, 4-epi-chlortetracycline, tylosin, erythromycin, enrofloxacin, ciprofloxacin, flumequine, florfenicol, sulfachloropyridazine, sulfadiazine, 2,4-dichlorophenoxyacetic acid, zearalenone, alpha- and beta-zearalenol, were extracted with EDTA-McIlvain and acetonitrile. This method showed a p-value < 0.05, RSD < 25%, and R 2 > 0.95 in the calibration curves linearity for all analytes. The limit of quantification, selectivity, decision limit for confirmation, matrix effect, precision, and recovery parameters were validated according to European Union document 2021/808/EC, technical report CEN/TR 16059, SANTE/11813/2017 and according to the Veterinary International Conference on Harmonization: VICH GL2 and GL49. This method confirmed the detection of most analytes 12–36 h post-administration and simultaneously detected and quantified mixed contaminants. Thereby, poultry droppings are a potential matrix for spreading contaminants in animal production before slaughter and their control will minimize environmental impacts and mitigate antimicrobial resistance.

High value-added chemical production through anaerobic codigestion of corn straw with a microbial consortium, cow manure and cow digestion solution

ObjectivesThis study investigated the codigestion of corn straw (CS) with cow manure (CM), cow digestion solution (CD), and a strain consortium (SC) for enhanced volatile fatty acid (VFA) production. The aims of this study were to develop a sustainable technique to increase VFA yields, examine how combining microbial reagents with CS affects VFA production by functional microorganisms, and assess the feasibility of improving microbial diversity through codigestion. MethodsBatch experiments evaluated VFA production dynamics and microbial community changes with different combinations of CS substrates with CM, CD, and SC. Analytical methods included measuring VFAs by GC, ammonia and chemical oxygen demand (COD) by standard methods and microbial community analysis by 16S rRNA gene sequencing. ResultsCodigesting CS with the strain consortium yielded initial VFA concentrations ranging from 0.6 to 1.0 g/L, which were greater than those of the other combinations (0.05–0.3 g/L). Including CM, and CD further increased VFA production to 1.0–2.0 g/L, with the highest value of 2.0 g/L occurring when all four substrates were codigested. Significant ammonium reduction (194–241 mg/L to 29–37 mg/L) and COD reduction (3310–5250 mg/L to 730–1210 mg/L) were observed. Codigestion with CM and CD had greater Shannon diversity indices (3.19–3.24) than did codigestion with the other consortia (2.26). Bacillota dominated (96.5–99.6 %), with Clostridiales playing key roles in organic matter breakdown. ConclusionsThis study demonstrated the feasibility of improving VFA yields and harnessing microbial diversity through anaerobic codigestion of lignocellulosic and animal waste streams. Codigestion substantially enhanced VFA production, which was dominated by butyrate, reduced ammonium and COD, and enriched fiber-degrading and fermentative bacteria. These findings can help optimize codigestion for sustainable waste management and high-value chemical production.

Experimental and Mathematical Investigation of Thermochemical Conversion for Horse Manure

Abstract Horse manure is one of the highest potential biowastes for heat and power generation. This article investigates the experimental and mathematical modeling of thermochemical conversion for horse manure. As one type of thermochemical conversions, the pyrolysis process was carried out at eight different heating rates on horse manure using three parameters: the extent of reaction, the rate change of the extent of reaction, and differential thermal analysis (DTA), all used to determine kinetic data that will be validated with a mathematical model. Slow pyrolysis: below 15 °C/min showed optimistic results of obtaining exothermic reaction over a wide range of temperature which makes it self-sustainable with steady heat generation. Also, low heating rates allowed a quasi-equilibrium state through slow heating with a minimum delay in response for any transient error that could be generated from differential thermal gravimetry (DTG) device.

Acceptance of farmed African catfish in Egypt: addressing consumer concerns and marketing challenges

African catfish farmers used animal waste as feed to reduce production costs, a practice that raised concerns among consumers, causing them to avoid it. Consequently, this study aimed to explore factors that influenced the acceptance of farmed African catfish. The data survey involving 2294 participants from Egypt was analyzed using descriptive statistics and the chi-square test. The results indicated that 67% of participants abstained from consuming it, while 2.30% consumed it regularly. The chi-square test revealed significant consumption pattern variations (p < 0.05) based on most demographic factors. Entirely, 43% were uninformed about the nutritional value, market availability, and the potential impact of using aquafeeds on pricing. About 55–57% lacked information on feeding practices, had quality concerns, viewed catfish consumption as a health risk, and were unaware of its prices. Additionally, 68% were worried about pollution, and 76% found the available information insufficient. The main reasons for this challenge lie in consumers’ health, religious, and psychological concerns. To address this, we propose a targeted marketing strategy focusing on improving safety and quality through safe and cost-effective aquafeeds. This involves requiring farmers to obtain quality certifications and adhere to best management practices, adding value to the product, and transparent communication with consumers to provide them with reliable information about cultivation practices and the nutritional value of African catfish. Effective collaboration among key stakeholders in implementation, efficient sector management, establishing an activity licensing system, and prohibiting current feeding practices will enhance sustainable demand and reverse the declining production trend of this promising species.

Farm dairy effluent application

Dairy intensification produces a large amount of farm dairy effluents (FDE). The final disposal of FDE is generally to the soil as fertilizer. While this use of FDE as fertilizer has numerous benefits, such as reducing the application of synthetic fertilizers or improving soil quality, there are concerns about the environmental and health risks associated with microbial pathogens from animal waste, the spread of antibiotic resistance genes, nutrient losses and greenhouse gases (GHG) emissions. Furthermore, how this agricultural practice impacts the composition and functionality of soil microbial communities has not yet been elucidated. This thesis aimed to evaluate the impact of FDE applications on soil GHG emissions, the composition, activity and diversity of its microbial community, and health risks. The FDE were collected raw and from a two-stage stabilization lagoon. The N application rate normalized to 200 kg N ha−1 was divided into four seasonal applications compared to urea fertilization or a no-aggregate control. Soil samples were taken after each application for microbial and physicochemical characterization and GHG fluxes were measured up to twenty days after each application. The pasture was harvested according to typical grazing management. Repeated application of both types of FDE increased the soil nutrient status and enhanced microbial activity. Higher fescue pasture production and macronutrient content with FDE than the control positioned FDE application to soil as an alternative disposal. However, N2O emissions increased after applying both FDE’s, most notably with raw FDE. Soil microbial community composition was not significantly influenced by FDE applications, but functional diversity shifted with raw FDE. Lagoon storage effectively reduced organic C and total N along with pathogenic indicator bacteria and changed the bacterial community composition except in winter. Beta-lactam resistance genes were detected in both FDEs, but not in the soil after repeated applications.

Enhancing Biogas Production: An Assessment of Pasteurization Effects on Poultry, Swine, Bovine Manure and Food Waste Substrates

Within the evolving regulatory landscape of the European Union concerning animal by-product (ABP) management within the circular economy framework, this study explores the concurrent objectives of safeguarding public health and environmental integrity and maximizing final product value. Anaerobic digestion (AD) emerges as a holistic solution for ABP management, addressing sanitation concerns while enhancing end-product quality. Through laboratory-scale experimentation, the AD process applied to four substrates—poultry manure, swine manure, cattle manure, and food waste—is scrutinized. Prior to AD, pasteurization at 70 °C for 60 min ensures microbial safety. Subsequently, four experimental AD cycles compare pasteurized and unpasteurized substrates. Results highlight the efficacy of pasteurization in sanitizing final products across all substrates, emphasizing its pivotal role in product safety. However, pasteurization’s impact on system performance varies. While enhancing biogas yield from animal waste notably, its influence on food waste biogas production is less pronounced, indicating substrate-specific dynamics. This study offers insights into optimizing ABP management strategies, emphasizing the interplay between pasteurization, substrate characteristics, and AD performance. Such insights are crucial for advancing sustainable practices in the circular economy paradigm, balancing environmental stewardship with economic viability.

Analysis of an anaerobically digested animal waste-based microturbine driven-biogas energy system

The paper designs a biogas power plant that runs on anaerobically digested (AD) animal waste and integrated with a micro turbine and permanent magnet synchronous generator to generate renewable power. Cow dung, poultry manure, and swine have been explored as potential feedstocks for AD, and the various subprocesses are investigated at discrete temperature intervals that cover both the mesophilic and thermophilic temperature ranges (30 °C–50 °C). The biodegradability of animal wastes, retention time, loading rate, and the size of the reactor influence the overall biogas yield. Methane production from cow dung increased from 131.4 L/d at 30 °C to 171.12 L/d at 50 °C in 15 days. Whereas the methane output from poultry manure, and swine at 50 °C were 278.4 L/d and 284.5 L/d respectively. Moreover, a methane recovery efficiency of 75 % and a purge efficiency of 97 % were attained through pressure swing adsorption (PSA). Furthermore, the system is maintained at 25 kW at steady-state conditions, attaining saturation for a torque value of 7.77 p.u. In a dynamic setting, the load is varied for a range of 25 kW–40 kW, and stable sinusoidal waveforms are generated as outputs that indicate the system's ability to withstand load variations.