Anaerobic Biodigestion Research Articles

Investigation of solid waste generation rate and biogas production

Anaerobic Digestion (AD) of organic waste is one of the most promising processes and is the ideal solution for the disposal of organic waste (OW) and at the same time, the production of methane gas which may be used as a sustainable energy resource. An anaerobic biodigester with a volume of (20) liters has been used to digest organic waste and to trace the changes that occur during the AD process. Operating parameters such as temperature, pH, total solids, and volatile solids (TS, VS) have been measured which have a significant impact on the rate and quality of biogas production. Experiments on anaerobic biodegradation of OW-SS were monitored under mesophilic conditions (temperature 37 °C, retention time 30–31 days). The pH value varied between (4.2–5.8) for OW-SS. During 30 days of the detection period, the maximum methane production (corrected) occurred on day 21 which was equal to 254.3-ml. The cumulative volume of the produced methane was recorded as (3409 ml), OW-SS, and these results were corrected to the standard conditions, where after correction, it became (2929 ml). The highest rate of methane concentration was estimated at (52 %) for OW-SS, while the rate of decrease in the TS and VS was (54 %, and 45 %), respectively. It is recommended to examine the changes that occur if a larger digester is used than the one used in the current study, such as 50 L, 100 L …. Etc. To compare the data obtained in this study with the results of larger digestions to allow for the opportunity to build anaerobic digesters at the plant level with the benefit of renewable energy production. It is also recommended to investigate the impact of some types of pretreatments on biogas production such as the use of alkali, enzymatic, ultrasonic treatment or acid ton the solid waste feed.

Experimental Analysis of Anaerobic Co-digestion: Potential of Fruit Wastes

This study focuses on converting fruit waste into usable clean energy by an innovative, cost-effective anaerobic biodigester. The biodigester is designed to anaerobically digest various fruit wastes and starter inoculums of cow dung that are locally obtained. A batch vertical digester of 1000 liters capacity built of fiber with a phonematic agitator positioned in the center is used to improve mixing. The retention time is 30 days with a substrate of banana peels co-digested with mango and papaya peels individually in the ratio of 50:50. The combined wastes generated the biogas and the total quantity of biogas generated for all combined wastes over 21 days varies between 530L/day and 480L/day respectively. In this work, banana and mango peel (waste/water) split 50:50 gives a peak yield of 530L/day. The average ambient temperatures are kept in the range of 25°C to 35°C (i.e., mesophilic range). The pH range of 6.4 to 7.8 is consistently maintained and seems to be stable. Therefore, this proposed anaerobic digester would reduce the disposal of solid waste, and it is cost-effective. After cleaning, it is observed that the combined peels of bananas and papaya contained 91.95% of the estimated biogas and methane, which can be used to solve energy issues such as electricity production and cooking purposes.

Characterization and Performance Evaluation of Anaerobic Night Soil Biodegrading Inoculum

The efficiency of anaerobic night soil (human excreta) biodegradation depends on the characteristics of the inoculum used. This anaerobic microbial inoculum (AMI) contains a microbial consortium, including rate-limiting methanogens whose growth depends on various physicochemical and biological parameters necessitating the inoculum characterisation essential for optimum night soil (NS) biodegradation. The inoculum contained 24.567 g/L (±0.07) total solid, 5.022 (±0.57) g/L total dissolved solid, 18.148 (±0.0.058) g/L volatile solid (VS), and 7.0±0.2 pH. The Gas chromatography analysis confirmed the presence of a small amount of volatile fatty acid (VFA), (≤ 4 mM except propionate) showing rapid conversion of VFA to methane, and 55% methane. Further, the presence of methanosaetaceae group of methanogens was detected through Taqman probe-based real-time PCR. The inoculum performance was evaluated for NS biodegradation in semicontinuous mode of feeding in four 2 L anaerobic biodigesters (2D HRT, 4D HRT, 5D HRT, and 10D HRT) with varying hydraulic retention time (HRT) (2, 5, 8, and 10 days, respectively) at mesophilic temperature (35°C). After 5 HRT, VS reduction for 2D HRT and 5D HRT was <40% while for 8D HRT and 10D HRT was >45-50% and >45-60%, respectively. The methane content was <20% in biogas for 2 and 5 days HRT while for 8 and 10 days >45-50% and 50-65% methane, respectively. The % VS reduction and methane content showed the overfeeding of NS in biodigesters 2D HRT and 5D HRT while 8D HRT showed towards optimum and 10D HRT optimum with improved VS reduction and methane content.

Anaerobic sludge from a full-scale biodigester: physico-chemical and organic characterization, and principal component analysis (PCA)

The biological transformation of the organic fraction of municipal solid waste into bioenergy yields a solid digested material known as anaerobic sludge, comprising a mixture of organic and inorganic substances. This sludge holds significant potential as a renewable resource for agricultural reuse. However, there is also the potential risk of contamination from this material in receiving environments. Therefore, it is crucial to assess the characteristics of this material to ensure compliance with local regulations regarding its soil application, aiming to avoid adverse environmental impacts and ensure proper and viable disposal. In this study, conducted to explore the characteristics of bottom sludge collected from a pilot-scale anaerobic biodigester, various parameters were analyzed. The biodigester in question had a capacity of 1300 liters and a useful volume of 1000 liters, digesting food waste and water hyacinth (Eichhornia crassipes) in a ratio of 20% in terms of volatile solids from the macrophyte to the volatile solids of the food waste. A multivariate analysis was conducted on the following parameters: metals (Al, Ba, Cd, Cr, Cu, Fe, Mn, Mo, Pb, Se, V, Zn, Na, and K); total, fixed, and volatile solids; alkalinity; volatile fatty acids; ammonia; Kjeldahl nitrogen (NTK); and organic, inorganic, and total carbon (COT), to observe possible correlations among these parameters. Additionally, the sludge underwent nuclear magnetic resonance (NMR) analysis for detection and characterization of organic compounds. This approach provided a deeper understanding of the properties of anaerobic sludge produced strictly under the aforementioned conditions, contributing to further research in the field.

Isolation and Characterization of Microorganisms Involved in Biogas Production from Agricultural Waste

The study aimed to investigate the microbial composition involved in the biogas production process using a diverse range of substrates, including Spinacia oleracea (vegetable), banana peel, plant extract, watermelon residue, wheat straw and paddy straw, sourced from multiple locations in Jaunpur. Over a period of five weeks (30 days), the research employed established microbiological methodologies and customized anaerobic bio-digesters for the comprehensive analysis of the isolates and substrates to assess biogas generation. The evaluation revealed dynamic fluctuations in the digester temperature within the range of 30°C to 36°C, accompanied by initial pH levels ranging from 4.2 to 8.3, which subsequently decreased to pH 5-6 during and after the anaerobic digestion process. The identified anaerobic bacterial species encompassed Staphylococcus sp., Micrococcus, Enterobacter, Escherichia, Citrobacter, Bacillus sp., and Pseudomonas aeruginosa. Furthermore, the findings demonstrated a hierarchy in the percentage of biogas yield from the substrates, with the following ranking: synergistic mixture > plant extract > banana > wheat straw > spinach > watermelon. Notable disparity in the volume of biogas produced was observed across different substrate treatments and digestion periods. The research underscored the pivotal role of methanogens and other auxiliary bacteria in the overall biogas production process. Additionally, the average pH levels were determined to range between 6.3 - 7.2 before and 5.0 - 6.2 during and after anaerobic digestion. The observed decline in pH during the anaerobic digestion process was associated with the production of metabolites such as acetate, hydrogen gas, carbon dioxide and other volatile fatty acids, exerting significant influence on the substrates within the digesters.

TECNOLOGÍAS DEL BENEFICIADO DE CAFÉ Y TRATAMIENTO DE EFLUENTES LÍQUIDOS

<p><strong>Background.</strong> The coffee processing process generates polluting solid and liquid waste. It is possible to reduce its effects through treatments that allow its use. <strong>Objective.</strong> To analyze the alternatives for the management of the effluents and residues generated in the coffee processing process to reduce its effects and to show treatments that have had positive results. <strong>Methodology.</strong> To obtain the information, specialized search engines were used in databases such as: RESEARCHGATE, GOOGLE SCHOLAR, CIRAD, CATIE, IICA, ELSEVIER, SCIENCIE DIRECT, REDALYC, SCOPUS. An exploration and analysis of 100 documents related to the following topics was carried out: 1) history of the use of effluent treatment systems in coffee processing, 2) types of treatments for the management of liquid and solid waste, 3) operation of these technologies, capacity, place where the research was carried out, variables measured, as well as the capacity of these systems. The search period was planned from 1980 to 2023. The history of the beginning of the systems for the treatment of waste generated in coffee processing was also investigated. The key words used for the search were: wet processing, wastewater, solid and liquid waste, coffee by-products, treatment systems, chemical oxygen demand, biological oxygen demand, total solids, turbidity, anaerobic treatments, and aerobic treatments. Approximately 100 documents were reviewed for the writing of the paper. <strong>Main findings.</strong> Research has been reported since 1980. Colombia and Mexico have focused on the development of machinery to mechanize processing operations to reduce water use, as well as anaerobic treatment systems, biodigesters and wetlands. <strong>Implications.</strong> It is necessary to know the main methods of wastewater treatment in the coffee processing process to determine the most suitable in coffee growing regions. <strong>Conclusions.</strong> Anaerobic biodigestion technology is the most used for the treatment of liquid effluents and with the best results. For the solid effluent, different alternatives are used for substrate such as the extraction of substances for industry, composting and biomaterials, among others.</p>

Mathematical modelling of biodigestion in an Indian biodigester and its stability analysis via Lyapunov technique

Biodigesters are vessels in which a microbiological consortium converts an organic residue into biogas and biofertilizer. This bioprocess, anaerobic biodigestion, plays an important environmental role since the residue at the end of the reaction has a reduced organic load, in addition to lower toxicity, and can therefore be disposed of with less impact on the environment. Moreover, biodigestion produces biogas, which is of great interest in view of the current shortage of fossil fuels. In this sense, this work proposes a nonlinear mathematical model based on the mass flux balance of an Indian biodigester and it also analyses its properties, in particular the Lyapunov stability of its equilibrium solutions, and verifies the non-negativity of its solutions to be consistent with the biology of the issue. The proposed model represents an important tool to describe anaerobic biodigestion in an Indian biodigester, providing information for further planning, scenario prediction and control of the bioprocess. Simulations of the model in different scenarios showed that lower initial bacteria/substrate concentration ratios (≈0.14) can promote better biogas production performance.

The Advantage of Citrus Residues as Feedstock for Biogas Production: A Two-Stage Anaerobic Digestion System

Anaerobic digestion (AD) is an important step in waste recovery. In Colombia, the production of citrus food significantly contributes to environmental impact via waste generation. In 2021, the waste produced, specifically citrus rind, amounted to 725,035 tons/year. During degradation, wastes generate leachate and greenhouse gases (GHGs), which negatively impact water sources (leachate), soil, and human and animal health. This article describes the design of a two-phase biodigestion system for the degradation of organic matter and biogas production. The system uses citrus waste to produce biogas with neutral emissions. The biodigestion process begins with the stabilization of the methanogenesis reactor (UASB), which takes approximately 19 days. During this period, the biogas produced contains approximately 60% methane by volume. Subsequently, the packed bed reactor operates for 7 days, where hydrolytic and acetogenic bacteria decompose the citrus waste, leading to the production and accumulation of volatile fatty acids. The final step involves combining the two phases for 5 days, resulting in a daily biogas production ranging from 700 to 1100 mL. Of this biogas, 54.90% is methane (CH4) with a yield of 0.51 LCH4gSV−1. This study assesses the methane production capacity of citrus waste, with the process benefiting from the pH value of the leachate, enhancing its degradability. Consequently, this approach leads to a notable 27.30% reduction in solids within the digestion system. The two-phase anaerobic biodigestion system described in this article demonstrates a promising method to mitigate the environmental impact of citrus waste while concurrently producing a renewable source of energy.

Production and characterization of biogas obtained from biomass of aquatic plants

The present work describes an experimental investigation concerning the production and characterization of biogas, obtained from biomass of Eichhornia crassipes and biomass of aquatic plants mixture (Eichhornia crassipes; Eichhornia azurea; Pistia stratiotes and Salvinia). The biogas was obtained in anaerobic biodigestion process. The biogas obtained has considerable tenors of methane, in way to make possible its use

Characterization of four digestates from different types of substrates used in biogas production in Northern Peru

Background Biol is one of the best-known digestates, which occurs during anaerobic digestion in biodigesters to generate biogas, using animal manure and vegetable waste. This digestate type is used in organic agriculture due to its easy application, contributing simultaneously to the circular economy and food security. Methods The objective of this study was to characterize four types of biol, generated in four anaerobic biodigesters for biogas production implemented in northern Peru fed with manure: i) pig manure; ii) cattle manure; iii) horse manure; iv) cattle manure with coffee processing water. All the biodigesters implemented had the same design but worked under different environmental conditions. Descriptive and multivalent statistics were applied to the data obtained for the parameters evaluated. Results The biols obtained had different nutritional compositions, depending on the type of substrate used. The biol from pig manure was characterized by high concentrations of bacteria, the one from cattle manure had low concentrations of nutrients in general, the one from horse manure was rich in salts, and the one from cattle manure with coffee processing water was rich in organic matter. Conclusions These results showed that all the biols obtained can be used for organic agriculture. However, their selection will depend on the nutritional requirements of the type of crop and soil where the biols are to be applied.

Virulence profile of Candida spp. isolated from an anaerobic biodigester supplied with dairy cattle waste

Anaerobic biodigesters play a crucial role in enhancing animal waste management. However, the presence of pathogens in the biodigestion process poses a significant concern. Candida spp., a widespread fungus known for its opportunistic nature and adaptability to diverse environmental conditions, including reciprocal transmission between humans and animals, is one such pathogen of concern. Therefore, it is imperative to assess the virulence profile of Candida spp. originating from anaerobic biodigestion processes. Here we demonstrate that strains isolated from the biodigestion process of dairy cattle waste exhibit noteworthy virulence mechanisms, surpassing the virulence of clinical control strains. After we identified strains from affluent, effluent, and biofertilizer, we observed that all analyzed isolates produced biofilm. Additionally, a substantial proportion of these isolates demonstrated phospholipase production, while only a few strains exhibited protease production. Furthermore, all strains exhibited resistance or dose-dependent responses to amphotericin B and itraconazole, with the majority displaying resistance to fluconazole. In the in vivo test, we observed a significant correlation (p < 0.05) between the LT50 and biofilm formation as well as hyphae/pseudohyphae production. Additionally, some isolates demonstrated a quicker nematode-killing capacity compared to clinical controls. Our findings underscore the considerable pathogenic potential of certain Candida species present in the dynamics of anaerobic biodigestion. Importantly, the anaerobic biodigester system did not eliminate Candida strains from dairy cattle waste, highlighting the need for caution in utilizing biodigester products. We advocate for further studies to explore the virulence of other microorganisms in various animal production contexts. Furthermore, our results emphasize the urgency of enhancing waste treatment methods to effectively eliminate pathogens and curb their potential dissemination.

Digestão anaeróbica em duas fases de águas residuais de mandioca com adição de glicerol residual para produção de hidrogênio e metano

Abstract Biogas production through co-digestion of two or more waste products has garnered increasing attention from researchers seeking to optimize this process. Biogas and methane production increase with the addition of glycerol to agro-industrial wastes during anaerobic biodigestion. However, the utilization of a two-phase process focused on hydrogen production has not been widely explored. This work aims to evaluate two-phase anaerobic biodigestion of cassava wastewater by adding residual glycerol and swine wastewater to enhance hydrogen and methane production. A pilot-scale biodigester was used during the acidogenic phase at 38.5°C, containing 4% glycerol. The effluent was submitted to methanogenic treatment, and the influence of temperature (36.0 to 39.0°C) and sodium bicarbonate concentration (2.0 to 6.0 g L-1) were evaluated. The results indicated that the optimum conditions during the methanogenic phase were 39.0°C with a sodium bicarbonate concentration of 5.0 g L-1. The two-phase biodigestion produced 30.8 mL of (H2) RCOD-1 and 104.5 mL of (CH4) RCOD-1. Thus, the substrates and inoculum used were adequate for the anaerobic biodigestion process, increasing the energetic efficiency of the process due to hydrogen production.

Anaerobic biodigester as a community-based food waste processor (case study: Canteen area of PT PLN Nusantara Power UP Muara Karang)

In 2022, DKI Jakarta disposed of ± 8,000 tons/day of waste to the Integrated Waste Processing Site (TPST) Bantar Gebang. Among them, 3,761.90 tons/day of organic waste were generated from domestic activities. Considering the amount of organic waste, the potential to convert it into biogas through anaerobic biodigester was feasible. As the organic waste decomposes, it produces methane (CH4) gas, which holds value as a renewable alternative energy source. Processing food waste into biogas is not only perceived as an effective way to reduce CH4 hazards but also provides economic benefits for the community. PT PLN Nusantara Power UP Muara Karang, located in Pluit - North Jakarta, attempted to make a breakthrough in waste management, especially in the Pluit Sub-district, through a methane capture and processing facility. Employing quantitative methods with primary data, this research was conducted from May to August 2023 and focused on the canteen area whose tenants came from the Pluit neighborhood. The anaerobic biodigester facility has a design capacity of up to 5 m3 or 800 kg of food waste. In its initial operation (May to August 2023), the food waste processed 363.5 kg and produced 40.7 m3 of methane gas, or 1.4009 GJ, and was used by canteen tenants for their daily operations. Annually, based on its initial condition, the activity conducted in this research can reduce greenhouse gases by 690 kg CO2e and provide economic benefits of Rp 16,000,000.

OPTIMIZATION OF CASSAVA EFFLUENT BIOMETHANIZATION WITH ASH AS COSUBSTRATE

The main objective of this study is to determine the optimal conditions for anaerobic biodigestion of cassava effluents with the ash of cassava peels as co-substrate. To do this, three (03) digesters were used in which were put effluent + ash for digester 1, effluent + ash + cow dung for digester 2 and effluent + ash + urine for digester 3. The physico-chemical parameters (temperature, pH), biochemical parameters (COD and TKN) and the volume of biogas produced were quantified. In each of the reaction media a decrease in values was observed in pH (digester 1: 7.15 to 6.92 digester 2: 7.20 to 5.38 digester 3: 7.00 to 5.28), COD (digester 1: 1.66g/l to 1.16g/l digester 2: 1.81g/l to 1.44g/l digester 3: 1.46g/l to 0.99g/l) and NTK (digester 1: 0.27 g/l to 0.24 g/l digester 2: 0.29 g/l to 0.22 g/l digester 3: 0.25 g/l 0.16 g/l). ¨For the temperature of the media, the recorded values are in the range of mesophilic fermentation (digester 1: 26.66°C, digester 2: 27.97°C and digester 3: 27°C). Regarding gas production, the digesters produced gas from day 1 with 37.463 m3, 37.463 m3 and 69.272 m3 respectively. A significant improvement in the biogas production rate was observed in all digesters. Thus, the ash could be used as a replacement for human urine for pH adjustment of cassava effluents.

Optimization of anaerobic digestion through automatic control with neural networks: a bibliometric analysis

The present work was carried out with the objective of presenting the current importance of work related to the optimization of anaerobic digesters using artificial neural networks. A scientometric methodological approach was used for a systematic review of the publications indexed in Scopus until 2023. The H index was used to evaluate the visibility and impact of the journals, authors, countries, and institutions with the highest levels of production and recognition in the field of study. This review also allowed us to analyze the interaction between groups and knowledge networks with the authors and institutions identified in the classification. The results show a significant increase in the number of publications between the years 1973 and 2023, which allow us to characterize on a scale the main dimensions of research, development and innovation related to the study of optimization methods of anaerobic biodigesters for the production of biogas from different waste such as that from the palm oil extraction process. The results show a significant increase in the number of publications between 2016 and 2023, a total of 2847 documents were found, where 95.64% are in English. The country that presents the most publications on the topic is China with a contribution of 19.28%, followed by the United States with 9.8%, India with 7.2% and Spain with 6.2% among others.

Future pathways for decarbonization and energy efficiency of ports: Modelling and optimization as sustainable energy hubs

The increasing energy demand in harbour areas, coupled with the need to reduce pollutant emissions, has led to the development of renewable energy-based polygeneration systems to face the carbon footprint of ports and ships at berth. In this way, in the coming years, ports can be converted into modern energy hubs.From this point of view, this paper presents a new dynamic simulation model for assessing and optimizing the energy and economic impact of ports. Here, energy systems and renewable sources can be designed to be connected to national electricity and natural gas grids and can include also alternative fuels (hydrogen, biomethane, etc.) and thermal energy networks, as well as different biomass fluxes (to be exploited for energy aims). Energy availability/demands of near towns and port buildings/infrastructures, as well as on-shore power supply are also included in the dynamic assessments. Hourly weather data and different prices for all the considered energy carriers are taken into account hour by hour. A multi-objective optimization approach is also implemented in the model considering energy and economic indexes to be optimized. The whole model is implemented in a computer tool written in MATLAB.For showing the capability of the developed model, a novel case study referred to the port of Naples (South-Italy) is presented. Here, several renewable energy sources are considered, including an anaerobic biodigester for producing biogas from the organic waste of docked cruise ships. A combined heat and power system (fed by biogas) is implemented in the port energy hub also for supplying absorption chillers. PV panels, and marine power generators are also included. In the conducted analysis, optimization targets are the maximization of system self-consumption and self-sufficiency as well as the minimum simple payback period. The proposed system can effectively contribute to the decarbonization of the port energy demand and reduce harmful pollutant emissions. Results showed that very high rate of renewable energy produced on-site can be exploited (up to 84%) by the considered port facilities, ensuring increasing independency from utility power grid (self-sufficiency index up to 40%). By the obtained results and through the developed simulation/optimization tool, novel design and operating criteria can be achieved for future port energy hubs featured by renewables and bi-directional energy exchange between ships and port.

The Potential of Recycling Used Engine Oil for Biogas Generation by Co-Digestion with Animals’ Manure: Experimental and Kinetic Study

This study investigates the potential of biogas recovery from used engine oil (UEO) by co-digestion with animals’ manure, including cow dung (CD), poultry manure (PM), and cattle manure (CM). The experimental work was carried out in anaerobic biodigesters at mesophilic conditions (37°C). Two groups of biodigesters were prepared. Each group consisted of 4 digesters. UEO was the main component in the first group of biodigesters with and without inoculum, whereby a mix of UEO and petroleum refinery oily sludge (ROS) was the component in the second group of biodigesters. The results revealed that for UEO-based biodigesters, maximum biogas production was 0.98, 1.23, 1.93, and 0 ml/g VS from UEO±CD, UEO±CM, UEO±PM, and UEO, respectively, whereby, for the UEO=ROS-based biodigesters, maximum biogas production was 3.49, 2.47, 3.64 and 2.44 ml/g VS from UEO+ROS±CD, UEO+ROS±CM, UEO+ROS±PM, and UEO+ROS, respectively. These results indicated that UEO was not feasible and efficient for biogas recovery since biogas production was very low in the first group of biodigesters compared to its recovery in the second group. A modified Gompertz model was applied to study the kinetics of the bio-digestion process. Measured and predicted values of biogas generation were fitted well with determination coefficients higher than 0.92.

Swine meat production integrated with energy cogeneration: challenges and opportunities in using anaerobic biodigestion

As environmental concerns and regulatory requirements increase over time, new alternatives for swine manure disposal emerge. Among them, anaerobic biodigestion is a relevant technology because it reduces the organic load of wastewater before its final disposal and provides economic benefits to farmers with biogas and biofertilizer production. Efficiently managing the anaerobic biodigestion process remains a challenge in developing countries, mainly due to the lack of information from swine meat producers to deal with the complexity of this system. A risk analysis can represent a promising tool for farm assistance because it provides a process overview. Hence, this study reports the results of a process mapping in a swine meat production farm in Minas Gerais, Brazil. This mapping was performed while monitoring biodigestion operational parameters and allowed the identification of the primary causes of process failures and potential environmental impacts. The results showed that anaerobic digestion promotes a relevant environmental gain. However, the need for improved process monitoring, investments in environmental assessment equipment, and technical training for producers also stood out as an improvement opportunity.

SISTEM MONITORING BIODIGESTER BERBASIS ARDUINO NANO

Biogas is a renewable energy source that is now a trend among the wider community because biogas fermented from feces or organic waste is relatively easy to do by ordinary people. Biogas can be a solution to overcome rising fuel prices due to depletion of petroleum. the price of fuel that rises due to depletion of petroleum. the utilization of biogas is currently felt to be less than optimal because the control system is still manual and less effective. Biodigester is a gas collection system for methane, carbon dioxide and other mixed gases obtained from the decomposition of organic materials such as cow dung by bacteria that cause methanogens in an anaerobic biodigester. With the Smart Biodigester Control System we can see waste data and can make the system more optimal, namely with the automatic biogas control system in the biodigester. In a tank that is 40 cm high we can see the waste data in the tank and the AC motor in the tank will stop when at a height of 35 cm. Strobe is not active if the pressure value does not exceed 0.4 Bar. The DC valve is active from the pH data value exceeding 7.5. The success rate is 98%, the remaining 2% is further research.

Optimizing food waste biodigestion: pre-selection of microbial groups and isolated enzymes using the plackett-burman experimental design

This study investigated the use of anaerobic biodigestion as an ecological technique for treating organic waste in urban solid waste. Biogas production is carried out through the action of microorganisms, and the use of enzymatic hydrolysis can increase biogas production, although it presents economic challenges. The aim of the study was to pre-select microbiological groups and enzymes to optimize the process and increase biogas production using statistical tools. Organic waste from a restaurant and sludge from a sewage treatment plant in Brazil were used, and three bacterial strains and 12 groups of microorganisms, as well as commercial enzymes, were evaluated. The study was divided into four stages to reduce the number of independent variables and increase the accuracy of methane and biogas production results. The results indicated that careful selection of microbial groups had a significant positive impact on biogas and methane production. The interaction between pre-selected groups of microorganisms and enzymes resulted in significant positive effects on cumulative biogas and biometane production. The study concluded that careful selection of microbial groups is essential to maximize biogas production and the efficiency of the anaerobic digestion process. Further, a more detailed identification of microorganisms and their interactions is needed to further optimize biogas production. In general, the appropriate choice of microbial groups is fundamental to the success of anaerobic digestion and biogas production.