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This study anticipates cooperative manure management as a process for generating bioenergy from livestock manure, thereby reducing greenhouse gas (GHG) emissions in Bangladesh. Therefore, this study’s main objective was to identify clusters for cooperative society development and optimize suitable locations for biogas plant establishment within a cooperative system. Scenarios were explored based on manure types using cluster and network analyses of geographic information systems (GIS). The study observed 13 clusters, which have the potential to produce 6045 million m3 of biogas that can be converted to 9068.64 GWh of electricity yearly. Biogas plants additionally produced 5491.04 kilotons of biofertilizer by reducing GHG emissions estimated to be 10.16 million tons of CO2eq in 2024. This study also optimized 10, 6, and 8 optimum locations for biogas plants according to the scenarios. To implement the findings, this study recommended a coordinated action plan based on the circular economy, which helps to obtain both environmental and economic benefits for a cooperative society. These cooperatives can be implemented for renewable energy production from livestock manure at the community level for sustainable energy generation in Bangladesh.

Biochar production and use are part of the modern agenda to recycle wastes, and to retain nutrients, pollutants, and heavy metals in the soil and to offset some greenhouse gas emissions. Biochars from wood (eucalyptus sawdust, pine bark), sugarcane bagasse, and substances rich in nutrients (coffee husk, chicken manure) produced at 350, 450 and 750°C were characterized to identify agronomic and environmental benefits, which may enhance soil quality. Biochars derived from wood and sugarcane have greater potential for improving C storage in tropical soils due to a higher aromatic character, high C concentration, low H/C ratio, and FTIR spectra features as compared to nutrient-rich biochars. The high ash content associated with alkaline chemical species such as KHCO3 and CaCO3, verified by XRD analysis, made chicken manure and coffee husk biochars potential liming agents for remediating acidic soils. High Ca and K contents in chicken manure and coffee husk biomass can significantly replace conventional sources of K (mostly imported in Brazil) and Ca, suggesting a high agronomic value for these biochars. High-ash biochars, such as chicken manure and coffee husk, produced at low-temperatures (350 and 450°C) exhibited high CEC values, which can be considered as a potential applicable material to increase nutrient retention in soil. Therefore, the agronomic value of the biochars in this study is predominantly regulated by the nutrient richness of the biomass, but an increase in pyrolysis temperature to 750°C can strongly decrease the adsorptive capacities of chicken manure and coffee husk biochars. A diagram of the agronomic potential and environmental benefits is presented, along with some guidelines to relate biochar properties with potential agronomic and environmental uses. Based on biochar properties, research needs are identified and directions for future trials are delineated.

Changes in physicochemical characteristics, chemical structures and maturity of swine, cattle and chicken manures and composts during 70-day composting without addition of bulking agents were investigated. Physicochemical characteristics were measured by routine analyses and chemical structures by solid-state 13C NMR and FT-IR. Three manures were of distinct properties. Their changes in physicochemical characteristics, chemical structures, and maturity were different not only from each other but also from those with addition of bulking agents during composting. Aromaticity in chicken manure composts decreased at first, and then increased whereas that in cattle and swine manure composts increased. Enhanced ammonia volatilization occurred without addition of bulking agents. NMR structural information indicated that cattle and chicken composts were relatively stable at day 36 and 56, respectively, but swine manure composts were not mature up to day 70. Finally, the days required for three manures to reach the threshold values of different maturity indices were different.

A feasible and rapid analysis for the simultaneous determination of sulfonamides (SAs), tetracyclines (TCs), fluoroquinolones (FQs), macrolides (MACs) and nitrofurans (NFs) in livestock manure and soils was established by solid-phase extraction (SPE)-ultra-performance liquid chromatography (UPLC)-tandem mass spectrometry (MS/MS). A total of 32 manure and 17 amended soil samples from the Liaoning and Tianjin areas in Northern China were collected for analysis. The largest detected frequencies and concentrations in manure samples were those of TCs (3326.6 ± 12,302.6 μg/kg), followed by FQs (411.3 ± 1453.4 μg/kg), SAs (170.6 ± 1060.2 μg/kg), NFs (85.1 ± 158.1 μg/kg), and MACs (1.4 ± 4.8 μg/kg). In general, veterinary antibiotics (VAs) were detected with higher concentrations in swine and chicken manure than in cattle manure, reflecting the heavy usage of VAs in swine and chicken husbandry in the studied area. Furthermore, higher residues of antibiotics were found in piglet and fattening swine manure than in sow manure. In addition, TCs were the most frequently (100 %) detected antibiotics in amended soil with higher concentrations (up to 10,967.1 μg/kg) than any other VAs. The attenuation of SAs was more obvious than TCs in amended soil after fertilization, which can most likely be attributed to the stronger sorption of TCs than SAs to soil organic matter through cation exchange. This study illustrated the prevalence of TCs detected in both animal manure and fertilized agricultural soils in Northern China, which may increase the risk to human health through the food chain. Thus, TCs should be given more attention in the management of veterinary usage in livestock husbandry.

The pollution of antibiotic resistance genes (ARGs) in livestock farms is a problem which need to be paid more attention to, due to the severe resistance dissemination and the further human health risk. In this study, all the relevant exposure matrices (manure, soil and water) of sixteen animal farms in Southeastern China were sampled to determine twenty-two ARGs conferring resistance to five major classes of antibiotics including tetracyclines, sulfonamides, quinolones, aminoglycosides, and macrolides. The results showed that the spread property of sul genes was most extensive and strong, followed by tet and erm genes. The abundance of tet genes expressing ribosomal protection proteins (tetM, tetO, tetQ, tetT and tetW) was higher than that expressing efflux pump proteins (tetA, tetC, tetE and tetG) in each type of samples. The high abundance and frequency of ermB gene in the matrices should be paid more attention, because macrolides is a major medicine for human use. For manures, it was found that the similar ARGs distribution rules were existing in poultry manure or porcine manure samples, despite of the different origins of these two types of livestock farms. Meanwhile, it was interesting that the distribution rule of tet genes in animal manure was nearly the same as all the ARGs. For soils, the result of nonmetric multi-dimensional scaling (NMDS) analysis showed that the pollution of ARGs in the soils fertilized by poultry and cattle manures were more substantial in northern Jiangsu, but no significant ARGs diversity was observed among porcine manured soils of five different regions. Furthermore, most ARGs showed significant positive relationships with environmental variables such as concentration of sulfonamides, tetracyclines, Cu, Zn and total organic carbon (TOC). The pollution profile and characteristics of so many ARGs in livestock farms can provide significative foundation for the regulation and legislation of antibiotics in China.

Organic waste is a rapidly increasing problem due to the growth of the agricultural production needed to meet global food demands. Development of sustainable waste management solutions is essential. Black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae) (BSF), larvae are voracious consumers of a wide range of organic materials ranging from fruits and vegetables to animal remains, and manure. Thanks to this ability and considering the larval high protein and lipid content, BSF larvae are a useful additive in animal feeds and biodiesel production. Unfortunately, the feasibility of using the black soldier fly as a tool for waste valorization and feed production has primarily been investigated at the benchtop scale. Thus, mobilization of current practices to an industrial scale is challenging because scaling up from small laboratory studies to large industrial studies is not necessarily linear. The goal of this study was to demonstrate the ability of the BSF to recycle organic waste at an industrial scale. To accomplish this goal, three organic waste streams were used (e.g., apples, bananas, and spent grain from a brewery) to test six diet treatments (1) apple, (2) banana, (3) spent grain, (4) apple and banana, (5) apple and spent grain, and (6) banana and spent grain. Working at scale of 10,000 BSF larvae life history traits, waste valorization, protein and lipid profiles were measured for each diet treatment. Differences were recorded across all variables, except substrate conversion, for larvae fed on fruit and spent grain (alone or with fruit). Growth rate significantly differed across treatments; larvae reared on spent grain grew twice as fast as those fed apples alone, but those reared on the apple and spent grain mixture produced twice as much insect biomass. However, it should be noted that larvae resulting from the apple diet contained 50% more fat than larvae fed the fruit and spent grain mixtures. Commonly-available organic wastes were successfully used at an industrial scale to produce BSF larvae that have the potential to substitute other sources of protein and lipids in different industrial applications. Industrialization efforts are encouraged to assess these impacts when integrating diverse ingredients into larval diets as a means to more precisely predict output, such as larval development time and final larval biomass.

A survey was conducted in regions of North China to better understand the effect of antibiotic residue pollution from swine feedlots to nearby groundwater environment. A total of nine experimental sites located in the regions of Beijing, Hebei, and Tianjin were selected to analyze the presence of residues of 11 most commonly used antibiotics, including tetracyclines (TCs), fluoroquinolones (FQNs), sulfonamides (SAs), macrolides, and fenicols, by using liquid chromatography spectrometry. The three most common antibiotics were TCs, FQNs, and SAs, with mean concentrations of 416.4, 228.8, and 442.4 μg L −1 in wastewater samples; 19.9, 11.8, and 0.3 μg L −1 in groundwater samples from swine feedlots; and 29.7, 14.0, and 0 μg L −1 in groundwater samples from villages. Ordination analysis revealed that the composition and distribution of antibiotics and antibiotic resistance genes (AGRs) were similar in groundwater samples from swine feedlots and villages. FQNs and TCs occurred along the path from wastewater to groundwater at high concentrations and showed correlations with ARGs, with a strong correlation between FQN resistance gene (qnrA) copy number. FQN concentration was also found ( P  < 0.01) in wastewater and groundwater in villages ( P  < 0.01). Therefore, antibiotics discharged from swine feedlots through wastewater could disseminate into surrounding groundwater environments together with ARG occurrence (i.e., qnrA, sulI, sulII, tetG, tetM, and tetO). Overall, this study suggests that the spread of veterinary antibiotics from swine feedlots to groundwater environments should be highly attended and controlled by restricting excess antibiotic usage or improving the technology of manure management.

Antibiotics are used in animal livestock production for therapeutic treatment of disease and at subtherapeutic levels for growth promotion and improvement of feed efficiency. It is estimated that approximately 75% of antibiotics are not absorbed by animals and are excreted in waste. Antibiotic resistance selection occurs among gastrointestinal bacteria, which are also excreted in manure and stored in waste holding systems. Land application of animal waste is a common disposal method used in the United States and is a means for environmental entry of both antibiotics and genetic resistance determinants. Concerns for bacterial resistance gene selection and dissemination of resistance genes have prompted interest about the concentrations and biological activity of drug residues and break-down metabolites, and their fate and transport. Fecal bacteria can survive for weeks to months in the environment, depending on species and temperature, however, genetic elements can persist regardless of cell viability. Phylogenetic analyses indicate antibiotic resistance genes have evolved, although some genes have been maintained in bacteria before the modern antibiotic era. Quantitative measurements of drug residues and levels of resistance genes are needed, in addition to understanding the environmental mechanisms of genetic selection, gene acquisition, and the spatiotemporal dynamics of these resistance genes and their bacterial hosts. This review article discusses an accumulation of findings that address aspects of the fate, transport, and persistence of antibiotics and antibiotic resistance genes in natural environments, with emphasis on mechanisms pertaining to soil environments following land application of animal waste effluent.

The common housefly, Musca domestica, is a considerable component of nutrient recycling in the environment. Use of housefly larvae to biodegrade manure presents an opportunity to reduce waste disposal while the rapidly assimilated insect biomass can also be used as a protein rich animal feed. In this study, we examine the biodegradation of dairy cattle manure using housefly larvae, and the nutritional value of the resulting larva meal as a feed ingredient. Our results demonstrated that dairy cattle manure presents a balanced substrate for larval growth, and the spent manure showed reductions in concentration of total nitrogen (24.9%) and phosphorus (6.2%) with an overall reduction in mass. Larva yield at an optimum density was approximately 2% of manure weight. Nutritional analysis of M. domestica larva meal showed values comparable to most high protein feed ingredients. Larva meal was 60% protein with a well-balanced amino acid profile, and 20% fat with 57% monounsaturated fatty acids, and 39% saturated fatty acids. Larva meal lacked any significant amount of omega-3 fatty acids. Evaluation of micronutrients in larva meal suggested that it is a good source of calcium and phosphorus (0.5% and 1.1% respectively). The nutritional value of larva meal closely matches that of fishmeal, making it a potentially attractive alternative for use as a protein-rich feed ingredient for livestock and aquaculture operations.

Noxious odors from swine farms pose significant health and environmental concerns. Hydrogen sulfide (H 2 S) is one of the major compounds causing noxious odors. Using biological inoculants offers a promising, efficient, and cost-effective method to reduce H 2 S emissions from these farms. Several studies have found that Priestia megaterium (formerly Bacillus megaterium ) can help mitigate the production of H 2 S. However, detailed knowledge regarding its mechanisms of action is still limited. In this study, the potential of novel strain of P. megaterium, strain S188, for the reduction of H 2 S in swine manure has been demonstrated. The artificial manure-based assay revealed that P. megaterium S188 significantly reduced the headspace concentration of H 2 S. Moreover, transcriptomic analysis revealed that exposure to H 2 S upregulated the expression of several cysteine and methionine biosynthesis-related genes in P. megaterium S188. Furthermore, treatment of swine manure with P. megaterium S188 was associated with significant modulation of the microbiota in the manure. Overall, this study provides insights into the putative mechanisms underlying the reduction in H 2 S levels mediated by P. megaterium S188 and its potential as a biological inoculant for H 2 S mitigation in swine farms. Key points • Priestia megaterium S188 has shown the ability to lower H 2 S  from swine manure. • Transcriptomic analysis revealed upregulation of H 2 S-related biosynthesis genes. • P. megaterium S188 treatment is associated with changes in the manure microbiota. Graphical Abstract