Search Results (72)

There is still a need to develop scenarios and models aimed at substituting fuelwood and reducing the use of fossil fuels such as liquefied petroleum gas (LPG), on which low-income rural households in the Global South often depend. The use of these fuels for cooking and heating in domestic and productive activities poses significant health and environmental risks. This study validated, in three different phases, the sustainability of a model for the production and use of biogas from the treatment of swine-rearing wastewater (WWs) on a community farm: (i) A Multi-Criteria Analysis (MCA), incorporating environmental, social/health, technical, and economic criteria, identified the main weighted criterion to C8 (use of small-scale technologies and low-cost access), with a score of 0.44 points, as well as the Tubular biodigester (Tb) as the most suitable option for the study area, scoring 8.1 points. (ii) Monitoring of the Tb over 90 days showed an average biogas production of 2.6 m³ d⁻¹, with average correlation 0.21 m³ Biogas kg Biomass⁻¹. Using the experimental biogas production rate (k = 0.0512 d⁻¹), the process was simulated with the BgMod model, achieving an average deviation of only 10.4% during the final production phase. (iii) The quantification of benefits demonstrated significant reductions in firewood use: in Scenario S1 (kitchen energy needs), biogas replaced 83.1% of firewood, while in Scenario S2 (citronella essential oil production), the substitution rate was 24.1%. In both cases, the avoided emissions amounted to 0.52 tons of CO_2eq per month. Finally, this study proposes a synthesised, community-based rural biogas framework designed for replication in regions with similar socio-environmental, technical, and economic conditions. Full article

This study provides a comprehensive panorama of wastewater treatment on swine farms in Pará de Minas, MG, focusing on the performance of the anaerobic digester technologies adopted. Considering the economic and environmental importance of swine production, wastewater treatment is critical for mitigating environmental impacts while providing renewable energy opportunities. Data compilation from the Minas Gerais Institute of Agriculture (IMA), technical visits, and physicochemical analyses were conducted. Our results indicate that the region has significant potential to increase biogas production by expanding the number of plants and improving the efficiency of existing systems. Investments in scalable technological solutions tailored for small-scale operations are essential to enhance both wastewater treatment and biogas generation. This study demonstrates the potential for new business opportunities within the biogas value chain in Brazilian agribusiness. Full article

Swine wastewater (SW) has a high chemical oxygen demand (COD) content and is difficult to degrade; an effective strategy to address this issue is through biodegradation, which poses negligible secondary pollution risks and ensures cost-efficiency. The objectives of this study were to isolate an effective COD-degrading strain of SW, characterize (at the molecular level) its transformation of SW, and apply it to practical production. A strain of Corynebacterium xerosis H1 was isolated and had a 27.93% ± 0.68% (mean ± SD) degradation rate of COD in SW. This strain precipitated growth in liquids, which has the advantage of not needing to be immobilized, unlike other wastewater-degrading bacteria. Based on analysis by Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS), this bacterium removed nitrogen-containing compounds in SW, with proteins and lipids decreasing from 41 to 10% and lignins increasing from 51 to 82%. Furthermore, the enhancement of the sequencing batch reactor (SBR) with strain H1 improved COD removal in effluent, with reductions in the fluorescence intensity of aromatic protein I, aromatic protein II, humic-like acids, and fulvic acid regions. In addition, based on 16S rRNA gene sequencing analysis, SBR_H1 successfully colonized some H1 bacteria and had a higher abundance of functional microbiota than SBR_C. This study confirms that Corynebacterium xerosis H1, as a carrier-free efficient strain, can be directly applied to swine wastewater treatment, reducing carrier costs and the risk of secondary pollution. The discovery of this strain enriches the microbial resource pool for SW COD degradation and provides a new scheme with both economic and environmental friendliness for large-scale treatment. Full article

The growing global demand for food has driven an increase in both swine and agricultural production, although swine wastewater poses a significant environmental risk. This study employed elemental mapping techniques to evaluate the effects of swine wastewater irrigation on the spatial distribution and concentration of essential and non-essential elements, as well as on the morphological responses of habanero pepper (Capsicum chinense Jacq.) seedlings. Six treatments were tested, ranging from 0% to 100% swine wastewater (T1 = 20%, T2 = 40%, T3 = 60%, T4 = 80%, T5 = 100%, and T6 = control with conventional fertilization), using a completely randomized design with five replications. Emergence, elemental distribution, morphology, and seedling quality were evaluated. The highest emergence percentages and rates were observed in the 20% wastewater treatment and the control groups. Diluted wastewater treatments promoted potassium and calcium uptake, which correlated with improved seedling growth and vigor, while irrigation with 100% wastewater led to excessive chlorine and sulfur accumulation, negatively affecting morphology. These results indicate that the controlled dilution of swine wastewater optimizes nutrient availability and seedling development, offering an environmentally sustainable alternative for producing high-quality habanero pepper seedlings. This study provides novel insights into the environmental implications of swine wastewater reuse through elemental mapping, underscoring its potential to support sustainable and regenerative agriculture. Full article

Extensive antibiotic use in swine production contaminates manure and wastewater with antibiotics. Discharging this waste into the environment, even after treatment, potentially fuels the spread of antibiotic resistance. This study investigated a full-scale swine wastewater treatment plant that combines coagulation–sedimentation, sand filtration, ozonation, activated carbon filtration, and a deaeration process. At each stage of this process, samples were collected and analyzed to determine their water quality parameters, antibiotic concentrations, and antibiotic resistance genes (ARGs). The experimental results showed coagulation–sedimentation effectively removed suspended solids (92.2%) and total phosphorus (96.9%). Ozonation significantly reduced antibiotic levels, including sulfamethazine by over 99.9%, although ARGs such as tetM, sul1, and sul2 were only removed at levels up to 95.9%. Interestingly, partial rebounds of sulfamethazine (438.9 μg/L) and marbofloxacin (0.40 μg/L) appeared in the final effluent, suggesting that desorption or operational factors (e.g., hydraulic fluctuation, filter media saturation, and pH) may affect the treatment process. In addition, strong correlations emerged between the levels of suspended solids and those of certain antibiotics (lincomycin, tiamulin), indicating particle-mediated sorption as a key mechanism. Even though ozonation and coagulation–sedimentation were found to contribute to the substantial removal of pollutants, the observed rebounds and residual ARGs highlight the need for optimized operational strategies and multi-barrier approaches to fully mitigate antibiotic contamination and inhibit the proliferation of resistant bacteria in swine wastewater. Full article

This study investigated anaerobically digested swine wastewater (ADSW) as a nutrient source for Chlorella vulgaris FACHB-8 cultivation under mixotrophic conditions with carbon supplementation. The microalgal strain was grown in ADSW supplemented with six carbon sources, followed by concentration optimization. Under optimized conditions (20 g/L glucose), FACHB-8 demonstrated a high biomass productivity (271.31 mg/L/day) and a specific growth rate of 0.42 per day. The system achieved an 88.70% total nitrogen removal and an 82.93% total phosphorus removal. The biomass contained 45.59% lipids, 29.72% proteins, and 13.05% carbohydrates, with fatty acid methyl esters showing balanced proportions of saturated (50.77%) and unsaturated fatty acids (49.23%). These findings highlight the potential of glucose-based mixotrophic cultivation for simultaneous wastewater treatment, renewable biomass production, and value-added lipid production. This work proposes a scalable swine wastewater treatment system that synergizes bioremediation and renewable energy production via carbon-enhanced microalgae cultivation, offering a dual-functional strategy for sustainable livestock wastewater reuse. Full article

The management of swine wastewater (SW) presents significant environmental challenges, requiring solutions that combine effective treatment with resource recovery. This study highlights the dual role of microalgae in wastewater remediation and bioenergy production. H. rubescens KNUA214 was cultivated in media containing varying concentrations of diluted swine wastewater (DSW; 0%, 25%, 50%, and 100%). Cultivating with Blue Green-11 (BG-11) medium + 50% DSW maximized biomass growth, the chlorophyll content, and carotenoid production. Nutrient removal efficiency in 100% DSW over 8 days demonstrated reductions of 59.3% in total nitrogen, 67.7% in ammonia nitrogen, and 40.7% in total phosphorus, confirming the species’ capacity for effective wastewater treatment. The carotenoid analysis using HPLC revealed that astaxanthin, lutein, canthaxanthin, and beta-carotene exhibited the highest levels in BG-11 + 50% DSW. Furthermore, the biomass analyses confirmed its potential for bioenergy applications, with high calorific values and significant polyunsaturated fatty acid concentrations, enhancing its utility for bioenergy and biolubricant production. These findings position H. rubescens KNUA214 as an effective resource for integrating SW management with the sustainable production of high-value biochemicals, offering environmental and economic benefits. Full article

The swine industry generates millions of gallons (thousands of cubic meters) of wastewater every day, posing significant environmental risk due to high concentrations of organics and nutrients. This study aims to investigate the effectiveness of attached-growth anaerobic bioreactors for treating swine wastewater by utilizing sulfate-reducing bacteria, focusing on the impact of chemical oxygen demand (COD)/sulfate mass ratios on organics degradation. A series of lab-scale anaerobic bioreactors were employed to treat swine wastewater for a 14-day period. The study evaluated changes in pH, acidity, alkalinity, COD, sulfate, and various nutrients along with total suspended solids (TSS) and volatile suspended solids (VSS) before and after treatment. At a COD/sulfate mass ratio of 2:1, the bioreactors achieved optimum removal efficiencies of 80% for TSS, 83% for VSS, 86–88% for COD, 82–87% for sulfate, 73% for sulfide, and 73% for sulfite. The nutrient removal efficiency was 67% for nitrate and 72% for nitrite. The acidity and alkalinity were effectively controlled, with alkalinity values reaching up to 2161 ± 92.5 mg/L and pH within the range of 7–7.24. The findings demonstrated that anaerobic bioreactor at a COD/sulfate mass ratio of 2:1 significantly enhanced the degradation of organic matter coupling with sulfate reduction in swine wastewater, providing an efficient and sustainable treatment method. Full article

The study aimed to evaluate and compare the co-digestion of swine wastewater (SW) and other co-substrates: grass residue (GR), food waste (FW), and poultry litter (PL). The comparisons were performed using the biochemical methane potential (BMP) test. The maximum accumulated methane (CH₄) production was submitted to a joint analysis of variance. Tukey’s test (α = 0.05) was used to compare the results of the treatments, and Dunnett’s test (α = 0.05) was used to compare the ratios (100:0, 75:25, 50:50, 25:75, and 0:100) (based on volatile solids—VS). In addition, both the synergistic effect and kinetic adjustment of some models were evaluated. The results indicated that the co-digestion of all substrates (GR, FW, and PL) with SW improved the methane production yield in comparison with mono-digestion (GR, FW, and PL). A positive synergistic effect was observed for the FW:SW (25:75 and 75:25). According to both Tukey’s and Dunnett’s tests (α = 0.05), the FW:SW ratio of 25:75 did not show statistical difference compared with the mono-digestion (SW), which exhibited the largest CH₄ production. Among the models evaluated, the modified Gompertz function presented the best fit. For the co-digestion treatments, the ratio of FW:SW of 25:75 exhibited the most promising potential for integrated management, demonstrating the best synergistic effect among the substrates. In this context, methane production from co-digestion equalled that of mono-digestion, while enabling integrated residue management. Full article

This study was conducted to examine the operation statuses of on-site swine wastewater treatment facilities through surveys and field surveys on pig farms and to propose effective operation models. Field analyses and surveys of pig farms indicate that technical and financial support systems are required for both farms and on-site swine wastewater treatment facilities. Public environmental services have been proposed as an effective support system, in which private sewage treatment facilities are entrusted to professional environmental management agencies, and the costs are shared by local governments and facility owners. However, securing a stable budget represents a challenge to implementing public environmental services. Thus, this study proposes a collaborative manure management model composed of individual farms, professional environmental management agencies, and local governments to address the shortcomings of public environmental services. To effectively manage pig manure, the flexible application of discharge standards, diversification of pollutant reduction management techniques (e.g., feed management), and periodic review of permits must be considered. Additionally, the reinforcement of discharge standards for individual purification facilities, control of the livestock density and number, and impacts of livestock manure discharge on riverine ecosystems must be considered. Full article

The extensive application of ceramic membranes in wastewater treatment draws increasing attention due to their ultra-long service life. A cost-effective treatment for high-strength swine wastewater is an urgent and current need that is a worldwide challenge. A pilot-scale sequencing batch flat-sheet ceramic membrane bioreactor (ScMBR) coupled with a short-cut biological nitrogen removal (SBNR) process was developed to treat high-strength swine wastewater. The ScMBR achieved stable and excellent removal of COD (95.3%), NH₄⁺-N (98.3%), and TN (92.7%), though temperature went down from 20 °C, to 15 °C, to 10 °C stepwise along three operational phases. The COD and NH₄⁺-N concentrations in the effluent met with the discharge standards (GB18596-2001). Microbial community diversity was high, and the genera Pseudomonas and Comamonas were dominant in denitritation, and Nitrosomonas was dominant in nitritation. Ceramic membrane modules of this pilot-scale reactor were separated into six layers (A, B, C, D, E, F) from top to bottom. The total filtration resistance of both the top and bottom membrane modules was relatively low, and the resistance of the middle ones was high. These results indicate that the spatial distribution of the membrane fouling degree was different, related to different aeration scour intensities demonstrated by computational fluid dynamics (CFD). The results prove that the membrane fouling mechanism can be attributed to the cake layer formation of the middle modules and pore blocking of the top and bottom modules, which mainly consist of protein and carbohydrates. Therefore, different cleaning measures should be adopted for membrane modules in different positions. In this study, the efficient treatment of swine wastewater shows that the ScMBR system could be applied to high-strength wastewater. Furthermore, the spatial distribution characteristics of membrane fouling contribute to cleaning strategy formulation for further full-scale MBR applications. Full article

Freshwater environments are primary receiving systems of wastewater and effluents, which carry low concentrations of antibiotics and antimicrobial-resistant (AMR) bacteria and genes. Aquatic microbial communities are thus exposed to environmentally relevant concentrations of antibiotics (ERCA) that presumably influence the acquisition and spread of environmental AMR. Here, we analyzed ERCA exposure with and without the additional presence of municipal wastewater treatment plant effluent (W) and swine manure run-off (M) on aquatic biofilm resistomes. Microscopic analyses revealed decreased taxonomic diversity and biofilm structural integrity, while metagenomic analysis revealed an increased abundance of resistance, virulence, and mobile element-related genes at the highest ERCA exposure levels, with less notable impacts observed when solely exposed to W or M effluents. Microbial function predictions indicated increased gene abundance associated with energy and cell membrane metabolism and heavy metal resistance under ERCA conditions. In silico predictions of increased resistance mechanisms did not correlate with observed phenotypic resistance patterns when whole communities were exposed to antimicrobial susceptibility testing. This reveals important insight into the complexity of whole-community coordination of physical and genetic responses to selective pressures. Lastly, the environmental AMR risk assessment of metagenomic data revealed a higher risk score for biofilms grown at sub-MIC antibiotic conditions. Full article

To enhance the sustainability of microalgae-based swine wastewater treatment, this study aims to address the challenges of low efficiency in treating raw swine wastewater, collection difficulties, and high energy consumption treatment processes. The microalgae with strong environmental tolerance were first screened from swine wastewater, and its cultivation conditions were optimized to examine the effect of microalgae treatment on swine wastewater under optimal cultivation conditions. Additionally, the flocculation efficiency and mechanism of microalgae were analyzed. The results showed that Tetradesmus cf. obliquus ZYY1 exhibited the most robust heterotrophic growth. In the BG11 medium supplemented with glucose, the growth rate of T. cf. obliquus ZYY1 under chemoheterotrophic conditions was superior to its growth under photoheterotrophic conditions, reaching its peak with an optimal glucose concentration of 15 g/L. The biomass concentration of T. cf. obliquus ZYY1 in raw wastewater was significantly higher than that in sterilized wastewater, which reached 1.65 ± 0.01 g/L on the 10th day of treatment, with removal efficiencies of ${\mathrm{NH}}_4^{+}$-N, ${\mathrm{PO}}_4^{3-}$-P, and the chemical oxygen demand reached 71.36%, 96.09%, and 93.13%, respectively. After raw wastewater treatment, the flocculation efficiency of T. cf. obliquus ZYY1 reached 97.71 ± 5.81%. This was attributed to the bacteria present in the raw wastewater, which induced T. cf. obliquus ZYY1 to secrete aromatic proteins. This study emphasizes the potential of microalgae as a green technology for sustainable wastewater treatment, offering a practical pathway for environmental protection and resource conservation. Full article

This study evaluates the long-term effects of swine wastewater (SWW) on relevant parameters for soil fertility, including calcium (Ca), magnesium (Mg), potassium (K) cations, cation exchange capacity (CEC), and organic matter (OM) in an agricultural area with 9 years of crop cultivation. Three types of SWW (raw, after leaving the biodigester, and after the manure plant) were analyzed with four application rates of SWW (0, 100, 200, and 300 m³.ha⁻¹), associated or not with mineral fertilization, resulting in eight treatments. The study found that the long-term use of SWW had significant effects on soil parameters. Principal component analysis (PCA) was used to summarize the data. The soil’s calcium (Ca), magnesium (Mg), and cation exchange capacity (CEC) levels were higher in soybean compared to other crops and natural soil. Similarly, the treatment with 0 m³.ha⁻¹ of pig manure and without mineral fertilization showed higher levels of these nutrients. In contrast, potassium (K) was found in greater quantities in oats, SWW from the biodigester, higher doses of manure, and with mineral fertilization. The crops had a higher organic matter (OM) content compared to the natural soil, with corn and raw SWW showing the most significant increase. Full article

Taeniasis and cysticercosis are parasitic infections that affect humans and pigs. Their global distribution constitutes a serious public health issue with significant implications for pork production. The purpose of this study was to evaluate the presence of porcine cysticercosis in backyard swine from 42 indigenous communities throughout Tuchín-Córdoba, Colombia. Between December 2020 and March 2021, free-range pigs (n = 442) were assessed using the ELISA cysticercosis Ag test; 85 pigs were examined through sublingual visual evaluation, and 4 slaughtered pig carcasses were subjected to standard operation inspection. The collected cysticercus underwent histological and PCR analysis. Furthermore, 192 surveys of knowledge, attitudes, and practices (KAP) were used to identify the factors that facilitate infection transmission. Serological investigation revealed that 9.7% (46/472) of the animals were positive for cysticerci Ag. Sublingual inspection identified cysticercus in 28.7% (25/87) of the animals, while PCR analysis indicated that cysticercus corresponded to the T. solium American/African genotype. The factors associated with T. solium infection in the pigs in the surveyed areas numbered 14. The majority are associated with factors that promote the active persistence of Taenia solium’s life cycle in an area, such as lack of environmental sanitation, a lack of coverage or care for drinking water and wastewater treatment services, and no solid waste disposal. Full article