Fermentation Of Chicken Manure Research Articles

The Effect of a Combination of Coconut Dregs and Fermented Chicken Manure on Population, Weight and Length of Maggots (Hermetia illucens)

Maggot is an organism that originates from the eggs of the BSF fly (Black Soldier Fly) which is usually known as a rotting organism because of its habit of consuming organic materials. Maggots can be an alternative feed because they have a fairly high protein content and are suitable as fresh fish feed or as raw fish feed ingredients. The study aims to determine the effect of the proportion of the combination of coconut pulp and fermented chicken manure on the population, weight and length of maggot (Hermetia illucens). This research method used an experiment with 6 treatments, 5 replicates for each treatment. The treatments applied were T1: 100% coconut pulp, T2: 95% coconut pulp + 5% chicken manure, T3: 90% coconut pulp + 10% chicken manure, T4: 85% coconut pulp + 15% chicken manure, T5: 80% coconut pulp + 20% chicken manure, T6: 75% coconut pulp + 25% chicken manure. Maggot maintenance started from 0-14 days of age. The observed paramameter of the population were weight and length of maggot (Hermetia illucens). This study used a Complete Random Design (RAL) with 5 replicates and the data was analyzed using Analysis of Variance (ANOVA). Based on the results of statistical analysis, the combination of coconut pulp and fermented chicken manure on the population, weight and length of manggot (Hermetia illucens) (P < 0.05). The results of the research on the combination of coconut pulp and fermented chicken manure with different combinations showed that there were some differences. T6 treatment was able to show the highest results in population, weight and length of maggot (Hermetia illucens).

A sustainable, zero-waste approach for production of biohydrogen from chicken manure slurry by hybrid recycling of digestate

This study provides a sustainable approach to produce biohydrogen through the long-term hydrogenic fermentation of chicken manure (CM) in a semi-continuous stirred tank reactor (CSTR) under different organic loading rates (OLRs). To ensure the zero-waste route and sustainability, the total digestate was mechanically separated into liquid and solid fractions. The solid digestate fraction was thermally treated to produce biochar, while the liquid digestate fraction was biologically treated through bioaugmentation with a novel heterotrophic nitrification-aerobic denitrification (HD-AN (bacterial strain (Alcaligenes sp. ME-1). The results showed that the high concentration of free ammonia nitrogen (FAN) contents of CM could inhibit methanogenesis and induce hydrogen production. The ORLs of 2.5, 3.5, 4.5, and 5.5 gVS/L.d imposed to the CSTR resulted in volumetric hydrogen production (VHP) of 643.3 ± 37, 908.8 ± 64.5, 1077.8 ± 95.17, and 1383.3 ± 156.8 mL/L.d, respectively. The microbial community structures indicated the long-term adaptation of hydrogen-producing bacteria and methanogenesis inhibition. The bioaugmentation process removed 83.3 % of total ammonia and 66.2 % of the chemical oxygen demand (COD) from the liquid digestate fraction. The characteristics of the biochar derived solid digestate is suitable for land applications as fertilizer. The hybrid approach combining biohydrogenation, pyrolysis, and bioaugmentation, maximizes the utilization of chicken manure slurry while conforming to the sustainable development goals.

Effect of hydrothermal carbon on biogas production from agricultural waste by anaerobic fermentation

In this study, biogas residue was used as raw material to prepare biogas residue by hydrothermal carbonization at 190℃ with different treatment time. The effects of hydrothermal carbon addition on gas production characteristics during medium temperature anaerobic fermentation (straw, straw + chicken manure, chicken manure) were studied, and the differences of surface formation of biogas residue hydrothermal carbon were observed by SEM. The results showed that the duration of gas generation peak was prolonged in the straw + chicken manure fermentation group and the chicken manure fermentation group after adding biogas residue hydrothermal charcoal, and the total gas production in the 8h, 12h and 24h hydrothermal charcoal groups increased more (P < 0.05), and the total gas production increased 39.2% at most. There was no significant difference in cumulative gas production among groups in straw fermentation group. According to the actual production, the optimal HTC process for anaerobic fermentation is 8 h at 190℃.

The key metabolic pathway for enhanced anaerobic digestion of chicken manure with coal slime for methane production

Coal slime can significantly enhance anaerobic digestion (AD) of chicken manure (CM) for methane production; However, the underlying mechanism is still unclear. This study has mainly discussed variation characteristics of key metabolic pathways in the AD process of CM by coal slime. Dry CM and coal slime (CS) were selected and coal seam mine water was applied as bacteria source. CS effects on the metabolic pathway of CM fermentation system were studied by biogas production simulation experiments and metagenomic analyses. The results indicated that variations in pH and CS amount exerted significant effects on the biogas generation in the contest of CM fermentation. Optimal conditions for enhanced biogas production were observed when the pH approached neutrality, and the CS quantity was 0.2 g, highlighting substantial potential of CM for biogas generation. The addition of CS resulted in a 13.1%, 1.9%, and 1.8% increase in the relative abundance of Bacteroides, Aminobacterium, and Methanothrix. This, in turn, elevated gene abundance of essential enzymes in the glycolytic pathway (glycolysis and pyruvate metabolism), promoting acetic acid production and providing a foundational basis for methanogen metabolic gas production. Furthermore, the addition of CS lead to a notable increase in the abundance of the pilA gene in Methanocorpusculuma (111.5%) and Methanothrix (66.1%). This suggested the involvement of CS in DIEF, thereby augmenting the anaerobic methane production potential of CM. These outcomes offer valuable theoretical insights for optimizing the biogas production potential of CM and maximizing the resource utilization of CS.

Biogas Production based on Thermophilic Methanogenic Fermentation of Chicken Manure

Biogas Production based on Thermophilic Methanogenic Fermentation of Chicken Manure

Effect Of Managing Fertilizer Types And Dosages Of Kno3 On Plant Growth And Results Red Onion (Allium ascalonicum L)

This research was carried out on the basis of the increasing national market need for shallots while production still needs to be increased. This research was carried out from August 2022 to October 2022 in Semono Hamlet, Tempursari Village, Sambi District, Boyolali Regency. Altitude 184 above sea level, soil pH
 6, Vertisol soil type (PPT = Grumosol). This study used a Complete Randomized Block Design (RAKL) consisting of two factors, the first factor being the type of manure which is divided into three levels, namely Fermentation of Chicken Manure, Fermentation of Goat Manure, Fermentation of Cow Manure ( P1, P2, P3). The second factor is the dose of KNO3 fertilizer which is divided into three levels, namely dose 75 kg/ha, dose 150 kg/ha, and dose 225 kg/ha (K1, K2, K3). each with 3 replications. The parameters observed in this study were the response of shallot plants to each type of manure to the addition of KNO3 fertilizer including Growth Parameters which included plant height, number of tillers (Kaplings), Fresh Stove Weight, and Stove Weight dry while the plant yield parameters include wet tuber weight per sample (g), dry tuber weight per sample (g), tuber wet weight per plot (g), tuber dry weight per plot (g), tuber diameter (cm) to determine the most effective dosage of manure in combination with KNO3 doses to increase shallot crop yields. The results showed that the KNO3 dose of 225 kg/ha had a significant effect on the parameters of wet stover weight and dry stover weight.

Impact of Varying Mass Concentrations of Ammonia Nitrogen on Biogas Production and System Stability of Anaerobic Fermentation

High ammonium release from chicken manure poses a significant limitation to aerobic digestion, impeding microbial processes and inhibiting biogas production. In this study, we conducted anaerobic digestion of a mixture consisting of chicken manure and corn straw as the fermented raw material. The inoculum used was obtained from the residue of previously fermented chicken manure. To assess the inhibitory effect, we varied the ammonia levels within the range of 750–4250 mg/L by introducing ammonium chloride. The efficiency of aerobic digestion was monitored through the measurement of volatile fatty acids (VFA), chemical oxygen demand (COD), total inorganic carbon (TOC), and methane yield. Our results indicated that elevated levels of ammonia nitrogen had a suppressive impact on methane release, and this decrease followed a linear relationship with the increasing ammonia nitrogen load. Moreover, the addition of ammonia led to a slower release, with the maximum daily ammonia concentration observed at 15 days compared to the 6th day at lower ammonia levels. Furthermore, on the 40th day of aerobic digestion, the cumulative methane production at 4250 mg/L was inhibited by 41% compared to the 750 mg/L condition. The patterns of VFA, inorganic carbon, and COD reduction were consistent across all ammonia levels, with VFA and TOC levels being highest at the highest ammonia concentration and lowest at the lowest ammonia concentration. The accumulation of VFA resulted in a decrease in pH and a decline in methanogenic activity. Additionally, high ammonia levels altered the relative abundance of methanogens. Acetoclastic methanogens (Methanosaeta) exhibited a decrease in abundance, while hydrogenotrophic methanogens (Methanosaeta, Methanoculleus) and methylotrophic methanogens (Candidatus Methanoplasma) demonstrated an increase in abundance. Overall, our findings highlight the inhibitory effects of high ammonia concentrations on biogas production, providing insights into the changes in microbial composition and activity during anaerobic fermentation.

Effect of Chicken Manure Fermentation Extract as an Alternative to Chemical Fertilizer on Cucumber Growth and Soil Microbiome Environment

ABSTRACT In recent years, the destruction of the soil environment caused by excessive application of chemical fertilizers has attracted attention to using organic fertilizers to replace chemical fertilizers. Previous studies have shown that chicken manure fermentation extract (CMFE) as an organic fertilizer may also directly influence soil nutrient availability from the soil native pool and fertilizer application. However, it is unclear whether application CMFE can partially replacing chemical fertilizer to reduce the amount of chemical fertilizer without reducing cucumber yield. Therefore, an experiment was conducted in Yantai Agricultural Science Academy of Shandong Province in 2018 and 2019. In 2018, five fertilization combinations were set up, namely CK (900 kg·ha−1 chemical fertilizer), T1 (750 kg·ha−1 chemical fertilizer +150 L·ha−1 CMFE), T2 (675 kg·ha−1 chemical fertilizer +225 L·ha−1 CMFE), T3 (600 kg·ha−1 chemical fertilizer +300 L·ha−1 CMFE) and T4 (525 kg·ha−1 chemical fertilizer +375 L·ha−1 CMFE). Selected the optimal combination T3 for testing in 2019. The yield, quality, photosynthesis and growth indicators of cucumber, as well as soil nutrients and microbial content were determined. The results showed that the fertilization combination of 600 kg·ha−1 chemical fertilizer +300 L·ha−1 CMFE (T3) can minimize the amount of chemical fertilizer used without reducing yield. Compared with conventional fertilizer application, CMFE partially replacing chemical fertilizer did not reduce cucumber yield, but significantly increased cucumber vitamin C and protein content. CMFE partially replacing chemical fertilizer increased the root to shoot ratio as well as the fresh and dry weight of vegetative organs in cucumber, optimizing the growth and development of cucumber. Compared with conventional fertilizer application, CMFE partially replacing chemical fertilizer increased the content of soil organic matter, improved the composition structure of soil microbial community, increased the relative abundance of Actinomycete and Acinetobacter, and reduced the relative abundance of Bacteroides, Ascomycota, and Basidiomycetes. Overall, CMFE partially replacing chemical fertilizer optimized the growth and development of cucumbers, increased the root to shoot ratio, increased soil organic matter content, increased microbial abundance and diversity, and improved the composition structure of soil microbial communities. Therefore, in order to reduce the use of fertilizers, it is recommended to partially replacing chemical fertilizers with CMFE, with the optimal combination of 600 kg·ha−1 chemical fertilizer +300 L·ha−1 CMFE (T3).

Dynamic Changes in Antibiotic Resistance Genes During Biological Fermentation of Chicken Manure and Pig Manure

Livestock manure is a major carrier that stores and transmits antibiotic resistance genes (ARGs). The aim of this study was to identify the crucial environmental factors that result in the change in relative abundance of ARGs and MGEs to explore effective methods to reduce the occurrence of ARGs. The abundance of ten ARGs and five MGEs were measured using real-time quantitative PCR with 0, 3, 7, 10, 14, 21, 28, 45, 60, and 75 d in CM and PM aerobic composting. The succession law of the bacterial community was analyzed using 16S rRNA high-throughput sequencing. Furthermore, the abundance of ARGs and MGEs was correlated with the properties (temperature, moisture content, pH, and DOC) of composting piles to identify the crucial factors affecting the variation in ARGs and MGEs. The results showed that the abundance of ARGs and MGEs in PM was higher than that in CM. Composting significantly reduced the relative abundance of nine ARGs and five MGEs. The removal ratios of three ARGs (tetM, tetT, and aacA) and four MGEs (ISEcp1, IS1216, IS613, and tnp614) in CM reached 99%. The removal ratios of nine ARGs[tetB(P), tetL, tetM, tetO, tetT, aacA, aadD,aphA3, and sat4] and four MGEs (ISEcp1, IS26, IS1216, and tnp614) reached 99% in PM. However, the abundance of the genes tetG, intI1, and IS6100 increased. Firmicutes and Actinobacteria were dominant in CM and PM during composting. Actinobacteria and Proteobacteria may have been the major host bacteria of tetG and intI1. The redundancy analysis showed that moisture and pH were the crucial factors that could influence the differences in the abundance of ARGs and MGEs. The composition and abundance of ARGs were driven by physicochemical properties, bacterial community, and MGEs. Composting could significantly reduce the abundance of ARGs in CM and PM, thus reducing the risk of ARGs being distributed via livestock manure application. However, some ARGs and MGEs remained in high abundance. Therefore, it is necessary to further optimize the composting process, improve the harmless treatment effect of livestock manure, and promote the safe agricultural use of organic fertilizers.

Effects of organic composite fertilizer on soil nitrogen status and mineralization

A short-term soil incubation experiment was set up to obtain information to clarify the effect of our developed organic composite fertilizer on soil nitrogen mineralization. The composite was designed to have beneficial effects on the properties of chicken manure and to improve soil water management properties in addition to organic matter replenishment. In the incubation experiment, two different additives, bentonite, and super absorbent polymer, were used to enhance the properties of fermented chicken manure. Developed prototype products were tested in a four-week-long soil incubation experiment in two typical Hungarian soils: brown forest soil with a sandy texture and chernozem soil at two different water capacities (40 w/w % and 60 w/w %). Soil pH, and inorganic nitrogen forms, like nitrate and ammonium, were measured weekly. Furthermore, the potentially mineralized nitrogen and net mineralization rate were calculated. The applied composite was not affected the soil pH significantly in the examined period. The soil nitrate and ammonium ratio was changed during the incubation as the ammonium content in the soil decreased while nitrate content increased continuously throughout the experiment. This suggests that the incubation experiment successfully monitored the delicate balance of soil nitrogen forms. It was found that the chernozem soil type had a higher mineralization potential compared to brown forest soil due to its higher nutrient and organic matter contents. Moreover, our results pointed out that soil moisture content did not significantly affect the mineralization process. The amount of mineral nitrogen, generated per week can be described by a linear relationship for both soil types and water regimes. The composite product showed efficacy in promoting mineralization processes, particularly in soils with low nutrient status and mineralization potential.

Volatile Fatty Acids (VFA) Production and Recovery from Chicken Manure Using a High-Solid Anaerobic Membrane Bioreactor (AnMBR).

Acidogenic fermentation of chicken manure (CM) for production and recovery of volatile fatty acids (VFA) is an interesting biological waste-to-value approach compared to benchmark organic waste management strategies. Considering the wide range of high value applications of VFA, a semi-continuous immersed anaerobic membrane bioreactor (AnMBR) was applied to boost VFA productivity and yield, while reducing downstream processing stages assisting the recovery of VFA. In this regard, the effect of parameters such as pH and organic loading rates (OLR) on the overall bioconversion and filtration performance was investigated. Thermal-shocked CM was applied both as inoculum and substrate. A very high VFA yield (0.90 g-VFA/g-VS) was obtained in the treatment with no pH control (~8.2) at an OLR of 2 g-VS/(L·d), presenting 24% higher yield compared to that of the controlled pH. Batch assays further demonstrated the enhanced hydrolysis and acidogenesis activities at weak alkaline conditions. A long-term (78 days) fermentation and filtration was successfully performed, where stable membrane filtration performance was experienced for about 50 days under high-solid (suspended solid of 37-45 g/L) and high flux (20 L/(m2·h)) conditions. Results suggest that AnMBR of CM is a feasible and promising process for VFA production and recovery.

Effect of Tetracycline Antibiotics on Anaerobic Digestion of Chicken Manure Based on Data Mining.

Although anaerobic bioengineering treatment of chicken manure has the advantages of low energy consumption, less pollution, and recyclable biomass energy, antibiotics are usually added in the process of modern intensive farming. And antibiotics still exist in feces and pose a threat to human health. Therefore, this study aimed to deeply understand the role of TC in the anaerobic digestion of chicken manure and to analyze the effect of tetracycline antibiotics on the anaerobic digestion of chicken manure based on data mining. In this study, chicken manure was used as raw material for anaerobic fermentation, and the effects of tetracycline (TC) on anaerobic and anaerobic fermentation of chicken manure were compared through batch and sequence experiments. Also, this study analyzes the fermentative transformation to elucidate the effect of TC on anaerobic manure conversion in chicken manure, which further studies the effect of TC on the anaerobic fermentation of chicken manure. The experimental results in this study show that when the TC concentration is 50–150 mg/L, the content of tryptophan and tyrosine proteins in the treatment group is also higher than that in the control group. It shows that at low concentrations (10, 25 mg/L), TC mainly promotes the degradation of LEPS by promoting the dissolution of intracellular substances in the sludge. With the increase of TC concentration (50–300 mg/L), TC mainly promotes the breakdown of the sludge cell membrane by promoting the rupture of the sludge cell membrane, thereby promoting the degradation of LEPS.

Early evaluation of use of fermented chicken manure products in practice of apple nutrient management

According to the Green Deal efforts, the importance and relevance of organic fertilization will increase in the near future. Therefore, the investigation of the effects of different organic fertilizers on soil productivity and nutrient supply is a priority area of agricultural research. Organic fertilizer experiment was conducted in an eight-year-old apple (Malus domestica Borkh.) orchard at Debrecen-Pallag. In the trial Pinova cultivar was used. In this study, two different fermented chicken manure products were added to the soil (in 20 cm depth) to test their effects on soil nutrient status, plant uptake and fruit quality. It was found that the applied treatments slightly increased the pH and nutrient levels in almost all cases, but significant effect was not observed in all treatments compared to the control. Leaf nutrient contents (N, P, K, Ca and Mg) were measured in the experiment. Leaf nutrient status was not affected by the fermented chicken manure treatments. However, used treatments had strong effects on the fruit characteristics and inner parameters, such as fruit diameter and Brix value. Moreover, it was established that the applied organic fertilizers increased the yield significantly.

Effects of fermented chicken manure products on the N mineralization rate of the soil using the incubation method

In our study, the effect of fermented and specially added poultry manure products (superabsorbent polymer (SAP), bentonite and Aegis as a mycorrhizal inoculum) were investigated in a short soil incubation experiment – at 60% water capacity level - on sandy soil. Soil samples were collected from two layers of the incubation pots after the second and fourth week to check the status of the tested products and the processes in the soil. The pH and the electric conductivity (EC) of the samples were measured using an electrochemical method, while the ammonium and nitrate content of the samples was determined with a photometric method. Soil pH and EC values slightly were decreased during the experiment. Our results pointed out that the increasing dose of SAP caused lower soil pH. The nitrate content of the soil did not change significantly during the experiment. It was found that the increasing SAP content in the products, due to its cross-linked structural property, protected the nitrate ions from leaching. Our results suggest that applied SAP does not bind the nutrient ions so tightly in its structure that it competes with the plant for uptake.

Pertumbuhan Cacing Sutra (Tubifex sp) Pada Substrat Lumpur, Pasir, dan Kombinasinya

<p>The increase of freshwater aquaculture leads to the increasing demand for silkworms (<em>Tubifex</em> sp) as natural feed. Unfortunately, high demand of silkworm supply is not fully fulfilled yet because its availability is relied on natural catch. Cultivation of <em>Tubifex</em> sp. outside its natural habitats requires good information on substrates and feed. We aimed to study the effect of mud, sand and their combination use as substrates in supporting <em>Tubifex</em> sp growth. This study used complete randomized design with 5 treatments, namely K1 (100% sand), K2 (100% mud), P1 (combination 75% mud-25%) sand, P2 (combination 50% mud-50% sand), and P3 (combination 25% mud-75% sand) with triplicates on each treatment. Research was conducted for 21 days using fermented chicken manure as feed. <em>Tubifex</em> sp growth was measured on biomass, number of individuals, and average body weight, while pH, temperature, dissolved oxygen and total organic matter were listed as measured environmental parameters. The use of sand and mud combination as substrate was better than a single sand or mud alone to support <em>Tubifex</em> sp growth. Combination of 75% mud and 25% sand showed the best growth of Tubifex sp as observed on biomass value of 13,244 g, 370 number of individuals, and average weight body of 2,741 mg. The application of a combination of sand and mud substrates has a potency to support the cultivation of <em>Tubifex</em> sp outside its native habitat.</p>

Co-production of Biohydrogen and Biomethane from Chicken Manure and Food Waste in a Two-Stage Anaerobic Fermentation Process.

Batch experiments were performed to evaluate the biohydrogen and biomethane production by co-digestion of chicken manure and food waste in a two-stage mesophilic fermentation process. Results showed that no hydrogen was produced in the first stage of sole chicken manure fermentation, while methane yield was 247.3 mL·g-1-VS. By comparison, the co-digestion process with food waste proportions of 50-85% obtained hydrogen yields of 15.5-57.5 mL·g-1-VS, and the methane yields and maximum specific methane production rates were also improved by 7.0-16.7% and 80%, respectively. Moreover, the highest hydrogen and methane yields were achieved during sole food waste fermentation process. The acetate was the main volatile fatty acid (VFA) produced during sole chicken manure fermentation process in the first stage. Statistical analysis revealed that hydrogen production from co-digestion process and sole food waste fermentation process followed the n-butyrate-type pathway. Meanwhile, it should be noticed that the co-fermentation of chicken manure and food waste had antagonistic effects on the hydrogen fermentation, implying that there might be some inhibition factors existing in chicken manure or produced during the co-fermentation process. At the beginning of methane fermentation, the VFA profiles were similar to those at the end of hydrogen fermentation, and the main VFA compositions changed to acetate and propionate in the latter period of methane production. The volatile solid removal efficiencies were also promoted in co-digestion process compared with sole chicken manure digestion, which were increased by 9.7-14.4% with food waste proportions of 50-80%.

Ефективність впливу різних доз біопрепарату Капелюхів Ярок на рівень виділення шкідливих газів з курячого посліду

Goal. To establish the effectiveness of the effects of different doses of the biological product Kapeliukhiv Yarok on the level of gases — methane (CH4), carbon dioxide (CO2), ammonia (NH3), hydrogen sulfide (H2S), and nitric oxide (NO) — from chicken manure during anaerobic digestion (in vitro). Methods. The research was conducted using laboratory, analytical and mathematical-statistical methods. Laboratory methods — to determine the level of emissions of harmful gases from chicken manure using different doses of the biological product Kapeliukhiv Yarok; analytical — to analyze and justify the results; mathematical and statistical — to assess the reliability of results. Results. After the addition of the biological product Kapeliukhiv Yarok to the fermented chicken manure, depending on the dose, a decrease in anaerobic fermentation processes was observed during the study period, which is confirmed by a decrease in pH to 6.9–6.55 units. Simultaneously with the lower pH level in the fermented substrate when using the biological product Kapeliukhiv Yarok, in the studied doses depending on the day of the experiment (20–26-th day) in the mesophilic regime of anaerobic fermentation (in vitro) a decrease was observed in CH4 and CO2 emissions by 11.9–18.1 %, NH3 — 14.7–31.8, H2S — 10.1–18.3, and NO — by 8.4–11.6% relative to control. Conclusions. The effect of different doses — 75 g/m3, 150, and 225 g/m3 of the biological product Kapeliukhiv Yarok on the reduction of gas emissions (CH4, CO2, NH3, H2S, and NO) during anaerobic fermentation (in vitro) has been experimentally proven and scientifically substantiated. Studies indicate the possibility of using the biological product Kapeliukhiv Yarok to reduce emissions of harmful gases and prevent environmental pollution during the storage of manure on poultry farms in storage (lagoons).

Anaerobic Fermentation of Chicken Manure and Methods for Intensifying Methane Output

A considerable share in the formation of food security of the population is occupied by the poultry industry, which is one of the most economically attractive and competitive, as evidenced by the annual steady growth dynamics of the production of valuable food products – poultry meat and eggs, characterised by high nutritional value, excellent dietary and taste qualities. The increase in poultry production leads, respectively, to the intensification of production on the one hand, and on the other hand – the accumulation of waste due to an increase in the number of poultry. One of the priority areas for solving the problem of environmental safety in the poultry industry is the processing of animal by-products through enzymatic fermentation, which yields an added energy product and organic-mineral fertiliser, thereby preventing methane emissions into the atmosphere, and therefore global warming. Therefore, the search for ways to intensify the methane output from chicken manure upon anaerobic fermentation, namely by adding various substances, was the purpose of the planned study. The experiment was conducted using laboratory, analytical, and mathematical-statistical methods. According to the results of experimental studies, a positive effect of FeO, Fe2O3 was established, Basidiomycota fungal-based bio-compositions, biologics – Meganit Nirbator, Reduklin T, Reduklin Compost and a complex preparation for activating enzymatic processes in chicken manure on the processes of anaerobic bio-fermentation and growth of methane content (CH4) from chicken manure (in vitro) against the background of an increase in the pH value to 9.05-9.3 with a simultaneous lower level of carbon dioxide (CO2). Best results for increasing the volume of CH4 output from the fermented substrate, by 15.7-18.8%, was observed in variants with a complex preparation for activating enzymatic processes in chicken manure. Application of Basidiomycota fungal-based bio-composition contributes to an increase in methane emissions from the test substrate by 5.4-9.6%, and biologics – Meganit Nirbator, Reduklin T and Reduklin Compost cause an increase in the volume of this gas output, respectively, by 5.6-9.4%, 9.5-14.2%, and 7.1-12%. Adding FeO and Fe2O3 to chicken manure causes an increase in the level of CH4 emissions by 4.1-7.4% and 5.8-11.2%, respectively. Thus, the results obtained indicate the expediency of using the studied substances in the processing of chicken manure in biogas plants to intensify the methane yield, which will minimise the adverse impact of intensive management of the poultry industry on the state of the environment

Development of a technology for producing organic fertilizers based on catalytic processes

The article is devoted to the development of a technology for obtaining organic fertilizers from poultry waste based on biocatalytic processes. Currently, many poultry farms have become sources of environmental pollution, thereby causing serious environmental problems and economic and social damage. The problem of reliable protection of the natural environment from pollution by bird droppings is currently relevant. In the area of operation of large poultry farms, air pollution by microorganisms, dust, foul-smelling organic compounds, which are decomposition products of organic waste, as well as nitrogen, sulfur, and carbon oxides, is possible. Bird droppings contain acids, nitrogen, phosphorus and potassium, heavy metals. The content of nitrogen, phosphorus and potassium changes dramatically depending on the quantity and quality of the feed. Humic substances isolated from brown coal have a sufficiently high sorption activity and are used as cheap sorbents for solving a number of environmental problems in industry. These studies are aimed at minimizing the main disadvantage of the anaerobic digestion process, the low reaction rate, which leads to the need to create large-volume bioreactors. On the basis of the research carried out, a technology has been developed for obtaining organic fertilizers from poultry waste by the method of anaerobic fermentation of chicken manure with humidity at a temperature of 27 °C - 50 °C with the addition of sodium humate. The resulting fertilizer is intended for use in agricultural production, horticulture, floriculture, forestry, municipalities, in household plots in order to increase the yield and quality of crop production. For the developed technology, an application has been submitted for obtaining a Patent for the invention of the Republic of Kazakhstan «Method for producing organic fertilizers» (priority No. 2021-22818, dated July 13, 2021). The invention allows to significantly reduce the time of fermentation, to enrich the product with organic and mineral products contained in sodium humate, to convert the salts of heavy metals into an insoluble state, to improve the environmental friendliness of the method.

Optimization of Biomethane Production via Fermentation of Chicken Manure Using Marine Sediment: A Modeling Approach Using Response Surface Methodology

In this study, marine sediment (MS) was successfully used as a source of methanogenic bacteria for the anaerobic digestion (AD) of chicken manure (CM). Using MS showed high production in liquid and semi-solid conditions. Even in solid conditions, 169.3 mL/g volatile solids of chicken manure (VS-CM) was produced, despite the accumulation of ammonia (4.2 g NH3-N/kg CM). To the best of our knowledge, this is the highest methane production from CM alone, without pretreatment, in solid conditions (20%). Comparing MS to Ozouh sludge (excess activated sewage sludge) (OS), using OS under semi-solid conditions resulted in higher methane production, while using MS resulted in more ammonia tolerance (301 mL/gVS-CM at 8.58 g NH3-N/kg). Production optimization was carried out via a response surface methodology (RDM) model involving four independent variables (inoculum ratio, total solid content, NaCl concentration, and incubation time). Optimized methane production (324.36 mL/gVS-CM) was at a CM:MS ratio of 1:2.5 with no NaCl supplementation, 10% total solid content, and an incubation time of 45 days.