This study evaluates the environmental impact assessment of sustainable pig farm via management of nutrient and co-product flows in the farm. Manure management and biogas production are among the most promising pathways towards fully utilizing organic waste within a circular bioeconomy as the most environmentally friendly solution mitigating gaseous emissions and producing bioenergy and high-quality bio-fertilizers. The concept of farm management includes rearing pig, growing all the feeds needed, and managing the nutrients and co-product flows in the farm. A consequential life cycle assessment (LCA) was performed to examine three scenarios in which all the generated manure is used as fertilizer for barley cultivation and mineral fertilizer is used where necessary (SC1); produced surplus straw is used for thermal energy generation and maize is used for sale, substituting maize biomass in the market (SC2); and all co-products are circulated in a closed system (SC3). The functional unit (FU) was defined as a “farm with 1000 fattening pigs at farm gate”. The analysis showed that heat generation from wheat, barley and legumes straw has a significantly higher positive environmental impact than the use of these cereal straw for biogas production. The partial replacement of mineral fertilizers with digestate has positive environmental effects in terms of abiotic depletion, photochemical oxidation, terrestrial ecotoxicity, freshwater aquatic ecotoxicity, human toxicity, and marine aquatic ecotoxic aspects. The amount of digestate generated on a farm is not sufficient to completely eliminate the use of mineral fertilizers for plant fertilization. The generated pig manure (SC1) and digestate (SC2) is only enough for the fertilization of 8.3% of the total cultivated land of farm applying 22.9 t/ha rate.
Chicken manure and pig fat are found abundantly around the globe, and there is a challenge to get rid of them. This waste has considerable energy potential to be recovered into fuel, but extracting this energy from some by-products, especially fat, isn’t an easy task. When anaerobic digestion technology stepped to the level of anaerobic co-digestion, the utilisation of hardly degradable waste became feasible. Our research was conducted on anaerobic co-digestion of chicken manure as the primary substrate with pig fat as a fat reach supplement in a semi-continuous mode at different organic load rates. The influence of fat waste on the process of biogas production from chicken manure and the composition of the obtained products was determined using an organic load rate of 3.0–4.5 kg VS·(m3·day)−1. A sturdy and continuously growing biogas production was observed at all organic load rates, implying the synergetic effect on chicken manure and pig fat co-digestion. The highest specific methane yield, 441.3 ± 7.6 L·kg VS−1, was observed at an organic load rate of 4.5 kg VS·(m3·day)−1. The research results showed that co-digestion of chicken manure with pig fat is an appropriate measure for fat utilisation and contributes to the increase in biogas yield, methane concentration, and overall methane yield at investigated organic load rates.
The race is on to achieve an important level of efficiency in the attainment of a circular economy in agriculture especially with the aim of sustainable nitrogen management. This cycle in the agricultural sector cuts across livestock farming, agriculture-induced waste generation, recycling and utilization, energy generation, crop production, ecosystem protection and environmental management through the mitigation of climate changes. In this work, we assess the process and functionalities of livestock waste generated from the piggery farm and their combinations with other by-products such as biochar and ash in comparison with mineral fertilization as sources of nitrogen applied in agricultural soil. The experiment was performed in a controlled environment with wheat ( Triticum aestivum L.) grown in a neutral and an acidic soil. Pig manure was used as the primary feedstock, fed and processed to biogas and nutrient-rich digestate by the anaerobic digestion process. The results revealed that the co-amendments of pig manure digestate with biochar and ash had complimentary positive effect on measured indices such as mobile potassium, phosphorus, biomass yield and nitrogen use efficiency. The mineral nitrogen fertilizer significantly induced carbon dioxide emissions from day 35 when compared to emissions from the organic amendments. In contrast, the organic amendments influenced nitrous oxide emissions from the onset till day 30 before flattening out. The individual combination of pig manure digestate with biochar and ash had a negative influence on enzymatic activity (dehydrogenase). Soil microbial biomass carbon was induced across all treatments in both soil types. Pig manure digestate + ash and pig manure digestate had 32.1 and 48.8% soil microbial biomass increase in neutral soil and acidic soil, respectively. Overall, the processing and application of single-use amendment or in combination with biochar and ash holds huge potential in the optimization of nitrogen and carbon efficiency towards sustainable soil management via improving soil quality, carbon sequestration and climate change.
Anaerobic digestion of poultry manure is a potentially-sustainable means of stabilizing this waste while generating biogas. However, technical, and environmental protection challenges remain, including high concentrations of ammonia, low C/N ratios, limited digestibility of bedding, and questions about transformation of nutrients during digestion. This study evaluated the effect of primary biological treatment of poultry manure on the biogas production process and reduction of ammonia emissions. Biogas yield from organic matter content in the aerobic pretreatment groups was 13.96% higher than that of the control group. Biogas production analysis showed that aerobic pretreatment of poultry manure has a positive effect on biogas composition; methane concentration increases by 6.94–7.97% after pretreatment. In comparison with the control group, NH3 emissions after aerobic pretreatment decreased from 3.37% (aerobic pretreatment without biological additives) to 33.89% (aerobic pretreatment with biological additives), depending on treatment method.
Increasing control of localized air pollution caused by ammonia is identified, including limiting the maximum emissions from agriculture. In EU countries, the agricultural sector is the source of above 94% of the total anthropogenic emissions of ammonia, of which manure removal systems account for 56%. In view of the reason for the agricultural waste management by formation and propagation of ammonia gas—the bacterial and enzymatic degradation of organic components in excrement—it is important to evaluate the effect of biotreatment of 100% natural composition (contain Azospirillum sp. (N) (number of bacterial colonies −1 × 109 cm−3), Frateuria aurentia (K) (number of bacterial colonies −1 × 109 cm−3), Bacillus megaterium (P) (bacterial colony count −1 × 109 cm−3), seaweed extract (10% by volume), phytohormones, auxins, cytokinin, gibberellins, amino acids, and vitamins) on the emission of ammonia from organic waste. Experimental research was carried out to determine significant differences of dynamics in agrochemical composition of manure, NH3 gas emissions, depending on biotreatment, manure storage duration, and ventilation intensity of the barn. Gas emission was obtained via laser gas analyzer using a spectroscopic method in a specially reconstructed wind tunnel chamber. About 32% manure biotreatment effect on reduction of ammonia emissions was established. The maximum effect of the biodegradable compound on gaseous propagation was assessed after 28–35 days of manure storage and proved all biotreatment effect time of 49–56 days. By the saving nitrogen loses priority, manure biotreatment could reduce nitrogen losses from manure and inorganic N fertilizers by approximately 5%, also could reduce approximately 5911.1 thousand tones nitrogen fertilizer in the world and reduce approximately 5.5 Eur ha−1. “The biotreatment impact assessment confirmed that proper application of biotreatment can reduce ammonia emissions from manure and environmental pollution from agriculture”.
Manure is considered a by-product or organic waste in cattle, pig, chicken or other animal breeding farms, which can be a valuable product as compost or feedstock for biogas production. The production of biomethane from biogas always copes with the formation of carbon dioxide (CO2) as a by-product. This CO2 may be recycled through the feedstock as a pretreatment to maximize homogeneity, and improve biogas yield and biogas quality. The CO2-pretreatment process of cow manure (CoM), chicken manure (ChM) and pig manure (PM) was performed in the continuously fed agitated reactor at 25 °C temperature and ambient barometric pressure. Biogas yield and composition exploration were performed in an anaerobic continuous feeding digester with controlled mesophilic (37 °C) environmental conditions. The CO2 pretreated PM, CoM and ChM yielded 234.62 ± 10.93 L/kgVS, 82.01 ± 3.19 L/kgVS and 374.53 ± 9.27 L/kgVS biomethane from feedstock volatile solids, respectively. The biomethane yield from CO2 pretreated CoM, ChM and PM achieved was higher over untreated manure by +33.78%, +28.76% and +21.78%, respectively. The anaerobic digestion process of tested feedstocks was stable, and the pH of the substrate was kept steady at a pH of CoM 7.77 ± 0.02, PM 8.07 ± 0.02 and ChM 8.09 ± 0.02 during all the experiment. The oxidation-reduction potential after pretreatment was within the optimal range (−255 ± 39.0 to −391 ± 16.8 mV) for anaerobic digestion. This process also had a positive effect on the energy generated from the feedstock, with ChM showing the greatest increase, from 2.38 MJ/kg to 3.06 MJ/kg.
Fossil fuel demand growth in and price fluctuation, depletion resources and supply monopolize, climate change is forcing the restructuring of energy and other industrial and transport area, seeking for renewable energy sources. Using phytoremedial methods in biomass engineering, there is a possibility to create a sustainable method of biomass growth in mid-low contaminated sites soil system. Main aim of the research was to assess the oil-contaminated soil treatment herbaceous plants and their subsequent use for biogas production in order to create a closed cleaning and plant biomass utilization cycle. After the evaluation of the biogas yield and energy conversion efficiency performance it was found that all of the selected herbaceous plant biomass is suitable as raw material for the production of biogas. The biogas potential of selected plants ranged from 377.2 to 822.9 l/kg dry organic matter with an energy value ranging from 7.1 MJ/kg to 17.1 MJ/kg.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.