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1

Znaczenie sztucznej inteligencji we wspomaganiu procesu beztlenowej fermentacji odpadów kuchennych zawierających bioplastiki

Arendt Ryszard, Kopczyński Andrzej, Hupka Jan, Grabowiec Aleksandra

Przemysł Chemiczny

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2024

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T. 103, nr 6

711--719

PL

Przebiegu procesu fermentacji anaerobowej nie można w pełni sformalizować. W tym odniesieniu pożądane jest wykorzystanie metod sztucznej inteligencji (AI) i uczenia maszynowego do monitoringu i sterowania procesami i operacjami jednostkowymi w celu uzyskania bardziej wydajnych metod prowadzenia procesu i ilości produktów końcowych. Akwizycja danych odbywa się przez automatyczny monitoring oraz poprzez badania analityczne. Wiedzę opisującą prowadzenie procesu fermentacji anaerobowej zestawiono w postaci reguł: IF (przesłanka) THEN (konkluzja). Zestawiony zbiór reguł tworzy bazę wiedzy systemu ekspertowego prowadzenia procesu wraz ze wskazówkami dla operatora. Reguły wiedzy są aktualizowane i rozwijane w trakcie prowadzenia procesu, zaś zastosowanie AI zapewnia zachowanie wiedzy operatorów przy zmianach personelu obsługi reaktorów. Przedstawiono budowę laboratoryjnego stanowiska fermentacji anaerobowej odpadów kuchennych i żywnościowych, stosowane urządzenia techniczne, strukturę systemu AI oraz wybrane reguły wiedzy.

EN

Artificial intelligence (AI) and machine learning were used to obtain more effective methods for conducting the digestion process and achieving final products. Data acquisition was carried out by an automatic monitoring and anal. research. The knowledge describing the anaerobic digestion process was summarized in the form of rules: IF (premise) THEN (conclusion). The compiled set of rules created a knowledge base of the expert system, which was used to run the anaerobic digestion process and provided instructions to the operator. Knowledge rules were updated and developed during the process. The construction of a mobile laboratory system for the anaerobic digestion of kitchen and food waste, the tech. devices, the structure of the AI system, and selected knowledge rules were presented.

2

Koncepcja zintegrowanego systemu fermentacji beztlenowej i kompostowania z wykorzystaniem odpadowego tlenu pochodzącego z procesu elektrolizy

Jurczyk Michał, Ochmann Jakub, Gholizadeh Towhid, Skorek-Osikowska Anna

Rynek Energii

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2023

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Nr 5

59--63

PL

W artykule przedstawiono koncepcję systemu fermentacji beztlenowej i kompostowania wraz z wykorzystaniem odpadowego tlenu, pochodzącego z procesu elektrolizy wody. Elektrolizer, oprócz wodoru, generuje także duże ilości tlenu, który można sprzedać jako dodatkowy produkt z instalacji lub wykorzystać w innym procesie przemysłowym. Wykorzystanie tlenu z procesu rozpadu wody zachodzącego w obrębie generatorów wodoru pozwala pominąć konieczność zabudowy kosztownej jednostki separacji powietrza ASU (ang. Air separation unit) w analizowanym systemie. Tlen potrzebny w procesach zgazowania lub w procesie spalania tlenowego może pochodzić z procesu elektrolizy. W rozważanym systemie do pozyskiwania paliw zaproponowano wykorzystanie elektrolizerów wysokotemperaturowych typu SOE (ang. Solid Oxide Electrolyzers). Głównym celem badań laboratoryjnych jest określenie wpływu utleniacza (tlenu) na skład oraz parametry otrzymanego w procesie kompostowania gazu.

EN

The article presents the concept of an anaerobic digestion and composting system with the use of waste oxygen from the water electrolysis process. Apart from hydrogen, the electrolyser generates large amounts of oxygen, which can be sold as an additional product from the installation or used. The use of oxygen ﬁom the water decomposition process taking place within the hydrogen generators makes it possible to omit the need to use a costly air separation unit (ASU) in the analyzed system. The oxygen needed in the gasiﬁcation or oxycombustion processes can come from the electrolysis process. In the considered system for obtaining fuels, the use of high- temperature electrolysers of the SOE type (Solid Oxide Electrolyzers) was proposed. The main purpose of laboratory tests is to determine the inﬂuence of the oxidant (oxygen) on the composition and parameters of the gas obtained in the composting process.

3

Dezintegracja ultradźwiękowa jako skuteczna metoda intensyfikacji procesu stabilizacji beztlenowej osadów ściekowych

Tytła Malwina

Laboratorium - Przegląd Ogólnopolski

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2023

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nr 2

36--42

PL

Biologiczna stabilizacja beztlenowa, zwana inaczej fermentacją beztlenową, jest jednym z najważniejszych procesów przeróbki osadów stasowanych w oczyszczalniach ścieków. Proces ten umożliwia redukcję masy osadów przeznaczonych do zagospodarowania, zmniejsza udział patogenów oraz eliminuje odory. W procesie tym powstaje biogaz, który stanowi cenne źródło energii odnawialnej. Celem stabilizacji beztlenowej jest generowanie bezpiecznego dla środowiska odpadu, który może być wykorzystany, np. do celów rolniczych lub do rekultywacji. Stabilizacji beztlenowej poddawane są głównie osady nadmierne. Niestety stosowanie nowoczesnych technologii oczyszczania ścieków oraz zagęszczanie osadów z dodatkiem polielektrolitu powodują, że znaczna część materii organicznej zawartej w tych osadach staje się niedostępna i trudno biodegradowalna w procesie fermentacji metanowej, co wpływa negatywnie na przebieg fazy hydrolitycznej limitującej szybkość stabilizacji. W związku z powyższym konieczne jest stosowanie metod mających na celu wstępną obróbkę osadów nadmiernych przed procesem stabilizacji beztlenowej, która pozwoli na przyspieszenie fazy hydrolitycznej oraz poprawi uzyskiwane w procesie efekty. Jedną z takich metod jest dezintegracja ultradźwiękowa.

EN

Anaerobic biological stabilization, known as anaerobic digestion, is one of the most important sewage sludge treatment processes used in wastewater treatments plants. This process enables reducing the mass of sludge intended for management, reduces the share of pathogens and eliminates odours. In this process, a biogas is produced, which is a valuable source of renewable energy. The purpose of anaerobic stabilization is to generate environmentally safe waste that can be used, for example, for agricultural purposes or for reclamation. Excess sludge is mainly subjected to anaerobic stabilization. Unfortunately, the use of advanced wastewater treatment technologies and sludge thickening with the addition of polyelectrolyte makes a significant part of the organic matter contained in the sludge unavailable and difficult to biodegrade in the process of methane fermentation, which negatively affects the course of the hydrolytic phase, limiting the rate of stabilization. Therefore, it is necessary to use methods aimed at the pre-treatment of excess sludge before the anaerobic stabilization, which will allow for the acceleration of the hydrolytic phase and improve the effects obtained in the process. One of such methods is ultrasonic disintegration.

4

The effect of silage additive on the kinetics of biogas production from lignocellulosic perennial crops

Kupryś-Caruk Marta, Lisowski Aleksander, Chomontowski Chrystian

Journal of Water and Land Development

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2023

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no. 56

58--66

EN

The aim of the study was to assess the effect of silage additive containing heterofermentative lactic acid bacteria (LAB) strain of Lactobacillus buchneri species on ensiling quality, as well as methane yield and the kinetics of biogas production from ensiled perennial energy grasses: Miscanthus × giganteus (miscanthus), Spartina pectinata (cordgrass), Panicum virgatum (switchgrass) and Andropogon gerardii (big bluestem). The listed plants are not commonly used for biogas production, their susceptibility to ensiling is also little known, hence the need to investigate their suitability for these processes. Effective methods for increasing the biogas yield from biomass are still demand, hence the research on the use of LAB for this purpose. After harvesting the grasses were cut and ensiled in barrels with and without (controls) the usage of commercial silage inoculant containing Lactobacillus buchneri LN40177. After 90 days of ensiling obtained silages were analysed in order to compare their chemical composition: organic acids content, the loss of dry matter, the differences in particular fibres composition. The silages were then subjected to methane fermentation using OxiTop® sensors and exposed to air in order to check their aerobic stability. The silages prepared with LAB additive had higher concentration of acetic acid than the control silages prepared without LAB addition, which contributed to increased aerobic stability but had no effect on the methane yield of miscanthus, switchgrass and big bluestem. Using the microbial inoculant during ensiling had beneficial effect in terms of reducing the duration of biogas production process from obtained silages: lag phase was shortened, daily biogas production rate was increased and 90% of biogas was produced in a shorter period of time compared to the control silages from investigated grasses. The modified Gompertz model well reflected the kinetics of biogas production process.

5

Reduction of Greenhouse Gas Emissions by Replacing Fertilizers with Digestate

Kowalczyk-Juśko Alina, Pochwatka Patrycja, Mazurkiewicz Jakub, Pulka Jakub, Kępowicz Barbara, Janczak Damian, Dach Jacek

Journal of Ecological Engineering

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2023

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Vol. 24, nr 4

312--319

EN

Digestate from a biogas plant can be a valuable organic and mineral fertilizer. Quantitative proportions of cosubstrates used in three agricultural biogas plants in Poland were analyzed. The composition of digestates was examined and large differences in the content of macronutrients were found, especially N and K. On the basis of the factors used to calculate emissions from the production and use of artificial fertilizers, the greenhouse gas (GHG) reduction resulting from replacing mineral fertilizers with digestate was calculated. In terms of 1 Mg of fresh digestate, this reduction may not seem large, as it amounts to 27.9–61.6 kg of CO2 eq, but it should be taken into account that digestate contains little dry matter. The annual amount of digestate used on an area of 1 ha allows avoiding GHG emissions of 25.8–44.5 Mg CO2 eq.

6

Effect of Biological Pretreatment on Anaerobic Sewage Sludge Digestion: Using Growth Media for Methanogenic Bacteria and Kinetic Studies for Biogas Yield

Lihi Khadija, Auajjar Nabila, Hamdi Inass, Echchayeb Kaouatar, Attarassi Benaissa

Journal of Ecological Engineering

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2023

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Vol. 24, nr 12

178--186

EN

The valorization of sewage sludge, a by-product of wastewater treatment by anaerobic digestion (AD), is getting more attention as a result of the advantages it provides for the environment and economy. The current investigation is an experiment performed in a lab setting using a batch-operated anaerobic digestion reactor with a mesophilic temperature of 35°C. This study examined the generation of experimental biogas and biodegradability .The effect of pretreatment by methanogenic bacteria growth medium on anaerobic digestion of sewage sludge was studied on three different concentrations of growth media, a control, and a low, medium and high concentration of culture medium, with cumulative biogas production of 610N ml /gVS added, 750 N ml /gVS added, 900 N ml /gVS added, 10 N ml /gVS added, respectively, with biodegradability rate of 52.16%, 56.5%, 74.04%, 28.70% respectively. Biogas production was enhanced at a medium concentration of culture medium and inhibited at a high concentration during anaerobic digestion of sewage sludge. Additionally, a theoretical biogas estimate was evaluated using four kinetic models (Logistic function, Modified Gompertz, Transference function, and First order); which were utilized to match the experimental biogas generation process involving the anaerobic digestion of untreated and pretreated sewage sludge by various concentrations of growth media of methanogenic bacteria . The kinetic findings demonstrated that both models, Modified Gompertz and Logistic function, were useful for predicting biogas output and matched experimental biogas production.

7

Biogas Production from Manure of Camel and Sheep Using Tomato and Rumen as Co-Substrate

Alharbi Mariam, Alseroury Fathiya, Alkthami Boshra

Journal of Ecological Engineering

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2023

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Vol. 24, nr 11

54--61

EN

Rumen accumulation in slaughterhouses produced by sheep is a significant issue that endangers human life and the ecosystem. Use of rumen appears to improve biogas production due to a high rate of hydrolytic bacteria. Hydrolytic bacteria are required for the breakdown of organic matter and biogas. This study proposes that combined camel and sheep manure with tomatoes and Rumen be co-digested under mesophilic conditions by anaerobically fermenting in a batch system to produce biogas. In the cross-sectional area of the study at the same operating conditions, biogas volume was measured for a period of 14 days, and on the last day, methane concentrations were measured. The study found that the rumen sample had the highest methane concentration, measuring 69.30%. Conversely, the control mixture without any additional co-substance had the lowest percentage of methane. Additionally, the tomato sample showed a slightly higher methane concentration of 0.1% compared to the control mixture. The study results show that efficient biogas production increased with rumen and tomatoes addition to manure compared to the control bio-digester sample. This demonstrates how waste can be transformed into wealth, which can be used to reduce costs for the community.

8

Methane Production from Farmed Rainbow Trout Byproducts by Anaerobic Digestion in Morocco

Essalhi Fatima, Bengueddour Rachid

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 2

45--54

EN

Fish are a staple in human nutrition because of their great nutritional and dietetic value. The processing stages of these fish before being sold generates an important quantity of byproducts (head, viscera, skeleton, fins, scales, tail, and skin). This study aims to determine the methane production, methanogenic potential and the percentage of volatile solids removed by the anaerobic digestion process. The experiment was carried out at mesophilic conditions in a Continuous Stirred-Tank Reactor (CSTR) with a discontinuous feeding mode (batch). The results obtained showed that the byproducts of farmed rainbow trout have a maximum methane production 1176 Nml whose methanogenic potential is 206.68 Nml/gVS with a biodegradability equal to 57.95%. For the kinetic modeling, four models were applied for an adequate fit of the experimental results (first order, MGompertz, transfererence function, and logistic function). The production of methane closest to the experimental results is that estimated by the logistic function with a methanogenic potential of 212.21 Nml/gVS whose correlation coefficient R2= 0.9870 and a very low percentage of error (1.18%), also the MGompertz model presented results adapted to those of the experiment with a methanogenic potential equal to 223.61 Nml/gVS (R2= 0.9889 and %error = 2.95); This confirms that these two kinetic models are the most suitable for this type of substrate.

9

Kinetic Modeling of Methane Production from the Anaerobic Digestion of Wastewater Sludge from a Treatment Plant in Kenitra, Morocco

Lihi Khadija, Auajjar Nabila, Nizar Youness, Attarassi Benaissa

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 1

165--174

EN

It is necessary to understand the process of anaerobic digestion (AD) of sewage sludge and to find an adequate strategy to improve the efficiency of methane production. In this work, the production of methane and detailed properties of sludge are determined. The physico-chemical parameters of the digester 1 'D1' and the digester 2 'D2' remain in the optimal range of AD stability with a median value of pH (7.82; 7.93); Temperature (36.70; 37.10°C); alkalinity (3.52; 3.58 g/L); and volatile fatty acids (0.47; 0.52 g/L), respectively. This paper focuses on the performance optimization of the methane production by kinetic models of two continuous digesters in a wastewater treatment plant in Kenitra City, Morocco. Mathematical models used in anaerobic digestion are: Modified Gompertz, transference functions, and logistics functions. These kinetic models have benefitted experimental methane production for both digesters. Results show that all the models used are appropriate to optimize the kinetic parameters for producing methane, showing that the transference function is the most suitable model for predicting kinetic results.

10

Energetic Potential of Coffee Waste from Anaerobic Digestion and Combustion

Ait Lhaj Lahcen Samira, Ibn Ahmed Said, Lahboubi Nabila, El Bari Hassan

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 2

138--145

EN

Coffee is present in every street in the world and is without a doubt one of the most consumed beverages. Moreover, it is the third most consumed drink in the world. Recent estimations from the International Coffee Organization put. The world coffee production at about 6 million tons per year. Its uncontrolled disposal can cause environmental problems, but if handled properly, it can be processed into pellets, and used as an energy source. In the present study, the production of energy from coffee waste (CW) is an interesting alternative to traditional production lines. The objective of this study is to calculate the energetic potential (Ep), which can be generated by anaerobic digestion (AD) and thermochemical conversion (TC), of the organic fraction of CW in the city of Kenitra, Morocco. An elementary analysis allows us to estimate the calorific value by the TC. The lower and higher calorific values were estimated to be: 18.71 and 20.28 MJ/Kg, respectively. Ep results by AD and CT were 0.25 and 1.3 MWh/t, respectively.

11

Influence of Mesophilic Bacteria Inoculation with Chicken Manure for Biogas Production Enhancement in Anaerobic Digestion (AD) Process

Alkarimiah Rosnani

Civil and Environmental Engineering Reports

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2023

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Vol. 33, no. 3

33--49

EN

The objective of this study is to investigate biogas production by anaerobic digestion using mesophilic bacteria mixed with Palm Oil Mill Effluent (POME). This project aims to determine the volume of biogas generation and volatile fatty acid (VFA) production from chicken manure via the anaerobic digestion process. Anaerobic digestion (AD) of chicken manure (CM) often faces obstacles, including high total ammonia nitrogen (TAN) concentration, inorganic soil particles, and wood chips. The digestion process was carried under batch mode conditions in Scott bottles of 1.0 L active volume. The bottles were immersed in a water bath to control their temperature at 37℃. The characteristics of total solid, volatile solid of mass fraction, pH, and temperature on the amount of biogas produced were studied. The investigation showed that biogas production can be enhanced by inoculation of another material. The optimum biogas composition in the AD system was recorded by Inoculum I, which was achieved on Day 2 at 560 mL/L. The highest cumulative methane yield was observed in the leachate with Inoculum (I), which was 8976 mL/gVS, while the CML produced 4 mL/g VS. The anaerobic digestion (AD) process augmented with inoculum demonstrated heightened efficacy in biogas generation and VFA concentration reduction during the acidogenic phase, surpassing the observed performance in chicken manure leachate.

12

Anaerobic digestion and composting as methods of bio-waste management

Czekała Wojciech, Nowak Mateusz, Bojarski Wiktor

Agricultural Engineering

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2023

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Vol. 27, No. 1

173--186

EN

The management of biodegradable waste from various sectors of economy is an essential element in terms of environmental protection. The paper discusses issues related to the possibility of bio-waste treatment using anaerobic digestion technologies and composting processes, highlighting the conditions for the processes and their advantages and disadvantages. The challenges of overproduction of bio-waste faced by highly developed countries around the world are also presented. Research showed that the anaerobic digestion of this waste combines both biofuel production and a circular economy. The popularity of this method is linked, among others to a low cost of raw materials and wide range of possible uses for biogas (i.e. electricity, heat, or biomethane). In addition, an alternative bio-waste management option, compost production, was discussed. The study aimed to compare anaerobic and aerobic bio-waste management processes.

PL

Zagospodarowanie odpadów biodegradowalnych pochodzących z różnych gałęzi gospodarki jest niezbędnym elementem w aspekcie ochrony środowiska. W artykule omówione zostały zagadnienia związane z możliwością przetwarzania bioodpadów wykorzystując technologie fermentacji metanowej i procesu kompostowania, z podkreśleniem warunków prowadzenia procesów oraz ich wad i zalet. Przedstawione zostały także wyzwania związane z nadmierną produkcją bioodpadów, przed którymi stoją państwa wysokorozwinięte na całym świecie. Prowadzone badania pokazują, że fermentacja beztlenowa omawianych odpadów łączy zarówno produkcję biopaliw oraz gospodarkę obiegu zamkniętego. Popularność omawianej metody jest związana m.in. z niskim kosztem surowców oraz szeroką możliwością wykorzystania produktu jakim jest biogaz (tj. elektryczność, ciepło lub biometan). Ponadto omówiona została tematyka związana z alternatywną możliwością zagospodarowania bioodpadów jaką jest produkcja kompostu. Celem pracy było porównanie procesów beztlenowego i tlenowego zagospodarowania bioodpadów.

13

Water Lettuce (Pistia stratiotes L.) as a Potential Material for Biogas Production

Cong Nguyen Van, Thanh Tran Van, Kha Le Thi Mong, Hoang Nguyen Xuan

Journal of Ecological Engineering

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2022

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Vol. 23, nr 6

182--188

EN

This study evaluated the biogas production potential of water lettuce (Pistia stratiotes L.) by batch anaerobic digestion under in-vitro conditions. Twenty-one litre-plastic jars were used to conduct 4 replications over 75 days. The results showed that solution temperature, pH and Eh were suitable for biogas production. More than 50% of the obtained CH4 was formed within 17–42 days after incubation. The maximum daily CH4 production was 0.052 L/gVS, whilst the daily H2S concentration was low, with a maximum value of 28 ppm within 14–21 d after incubation. Moreover, the peak of daily biogas production was seen at day 16 with production of 0.12 L/gVS. The results highlight that water lettuce biomass can be potentially used to produce high quality biogas in anaerobic incubation.

14

Recent Challenges of Biogas Production and its Conversion to Electrical Energy

Syahri Siti Noor Khaleeda Mhd, Abu Hasan Hassimi, Abdullah Siti Rozaimah Sheikh, Othman Ahmad Razi, Abdul Peer Mohamed, Azmy Raja Farzarul Hanim Raja, Muhamad Mohd Hafizuddin

Journal of Ecological Engineering

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2022

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Vol. 23, nr 3

251--269

EN

A pressing concern of issues such as climate change has drawn main attention in the world. The burning of fossil fuels by human due to increasing energy demand in various sectors is one of the main factors that influence the climate change. This has resulted in the introduction of many renewable energy sources as alternatives to fossil fuels. Biogas is one type of renewable energy that has numerous advantages. The present review covers the recent challenges of biogas production and its conversion to electrical energy. This includes the substrates used, the operating parameters, and the pre-treatment used, which can be implemented to maximise the biogas yield. The challenges and potential of the generation of electricity from biogas were also discussed in this review. The results obtained in this review emphasise that biogas is a good renewable energy, as it solves multiple problems and at the same brings benefits to human beings in many ways.

15

Process Performance of Thermophilic Anaerobic Co-Digestion of Municipal Sewage Sludge and Orange Peel

Szaja Aleksandra, Golianek Paweł, Kamiński Marek

Journal of Ecological Engineering

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2022

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Vol. 23, nr 8

66--76

EN

In the present study, the process performance of anaerobic co-digestion of municipal sewage sludge and orange peel (OP) was evaluated. The experiment was conducted in batch mode under thermophilic conditions (55 °C). It involved adding 1.5 and 3.0 g of OP to reactors R2 and R3, respectively. In R1 (control reactor), the mono-digestion of sewage sludge was conducted. The obtained results indicated that the application of OP led to deterioration of process efficiency. Decreased methane and biogas productions were noticed at both doses of OP. The average values of methane production were 518.9, 416.8 and 458.6 mLCH4·g-1 VS in R1, R2 and R3, respectively. The declining tendency on the biogas and methane rates was also observed. The application of OP resulted in degradation of the stability parameters. The negative effect of OP application was related with the presence of inhibitors such as ammonia nitrogen, volatile fatty acids, limonene and phenol, importantly theirs increased contents were observed in R2 and R3. Moreover, the thermophilic conditions are not recommended for the anaerobic co-digestion of those substrates, because they might accelerate the inhibition phenomenon.

16

Impact of Nanoparticles on Biogas Production from Anaerobic Digestion of Sewage Sludge

Heikal Ghada, Shakroum Mohamed, Vranayova Zuzana, Abdo Ahmed

Journal of Ecological Engineering

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2022

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Vol. 23, nr 8

222--240

EN

Since anaerobic digestion (AD) is the preferred procedure for sludge treatment and disposal, it is constrained by the hydrolysis and acidogenesis stages. Nanomaterials have an impact on the AD process due to their unique properties (large specific surface areas, solubility, adsorption reduction of heavy metals, degradation of organic matter, reduction of hydrogen supplied and catalytic nature) which make them advantageous in many applications due to their effectiveness in improving the AD efficiency. Magnetic Nanoparticles (MNPs) were used in the present study to improve the biogas production. The experiments were divided into two stages to evaluate the effect of adding MNPs to two types of sewage sludge (SS): attached growth process (AG) and activated sludge (AS). The first stage consists of 15 tests divided into three experiments (A, B, and C). Doses of MNPs (20, 50, 100, 200) mg/l were added to all digesters in the same experiment except for one digester (the control). Experiments A, B and C achieved the highest biogas production when 100 mg/l of MNPs was added. They were 1.9, 1.93 and 2.07 times higher than the control for A, B and C respectively. The second stage consists of 12 tests with a pretreatment for some of SS. It was divided into two experiments (D, E), where the chemical pretreatment was applied to experiment D and the thermal pretreatment was applied to experiment E except for the control. For digester D4, which had 100 mg/l of MNPs after a chemical pretreatment at pH = 12, the biogas production increased by 2.2 times higher than the control (D0) and 1.5 times higher than the untreated sludge with the addition of 100 mg/l MNPs (DN). Thermal pretreatment at 100 °C with addition of 100 mg/l MNPs (E4) achieved a biogas yield 2 times higher than the control (E0), and 1.39 times higher than untreated sludge with 100 mg/l MNPs (EN). The previous results indicate that the integration of magnetite can serve as the conductive materials, promoting inherent indirect electron transfer (IET) and direct interspecies electron transfer (DIET) between methanogens and fermentative bacteria which lead to a more energy-efficient route for interspecies electron transfer and methane productivity. This study demonstrated the positive effect of magnetite on organic biodegradation, process stability and methane productivity.

17

Mikroorganizmy jako producenci biowodoru: Od badań podstawowych do prac rozwojowych z dziedziny biotechnologii

Sikora Anna, Detman Anna

Gaz, Woda i Technika Sanitarna

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2022

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Nr 12

16--23

PL

Biowodór powstaje w wyniku aktywności metabolicznej mikroorganizmów w warunkach beztlenowych. W artykule omówiono szlaki metaboliczne produkcji biowodoru: biofotolizę, fotofermentację i ciemne fermentacje. Szczególny nacisk położono na procesy produkcji biowodoru na etapie kwasogenezy beztlenowego rozkładu biomasy (ciemna fermentacja i konwersja mleczanu i octanu do maślanu) jako obiecującą metodę produkcji biowodoru. Produkcja biowodoru taką metodą charakteryzuje się niską wydajnością i wymaga ograniczenia procesów konkurencyjnych, głównie innych typów fermentacji kwaśnych. Produkcja biowodoru na etapie kwasogenezy jest możliwa w instalacjach dwu - lub wieloetapowych, w których etap kwasogenezy jest oddzielony czasowo i przestrzennie od etapów acetogenezy i metanogenezy. Przedstawiono prace nad tego typu technologią na przykładzie dwuetapowej instalacji produkcji biowodoru i biometanu na drodze beztlenowego rozkładu produktów ubocznych przemysłu cukrowniczego opracowanej w jednostce naukowej i rozwijanej przez partnera przemysłowego. Omówiono wyzwania i ograniczenia produkcji biowodoru, zwłaszcza na etapie kwasogenezy. Zdefiniowano powody niedojrzałości technologii produkcji biowodoru i pozostawanie ich ciągle na etapie badawczo-rozwojowym w porównaniu do zaawansowanych, wdrażanych rozwiązań produkcji biogazu.

EN

Biohydrogen is produced by the metabolic activity of microorganisms under anaerobic conditions. The article discusses the metabolic pathways of biohydrogen production: biophotolysis, photo-fermentation, and dark fermentations. Special emphasis was put on biohydrogen production processes at the acidogenesis stage of anaerobic digestion (dark fermentation and conversion of lactate and acetate to butyrate) as a promising method of biohydrogen production. The production of biohydrogen by such a method has low yields and requires the reduction of competing processes, mainly other types of acid fermentation. Production of biohydrogen at the acidogenesis stage is possible in two-stage or multi-stage systems, in which the acidogenesis stage is separated in time and space from the acetogenesis and methanogenesis stages. The work on such a technology is presented using the example of a two-stage installation for the production of biohydrogen and biomethane by anaerobic digestion of sugar industry by-products developed at a research unit and being developed by an industrial partner. Challenges and limitations of biohydrogen production were discussed, especially at the acidogenesis stage. Reasons for the immaturity of biohydrogen production technologies and their still remaining in the research and development stage compared to advanced, implemented biogas production solutions were discussed.

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Effect of Thermal Pretreatment on the Kinetic Parameters of Anaerobic Digestion from Recycled Pulp and Paper Sludge

Habchi Sanae, Lahboubi Nabila, Karouach Fadoua, Naim Ikram, Lahlou Yahya, Bakraoui Mohammed, Sallek Brahim, El Bari Hassan

Ecological Engineering & Environmental Technology

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2022

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Vol. 23, iss. 1

192--201

EN

This paper investigates the influence of thermal pretreatment on kinetic parameters based on four kinetic models: Modified Gompertz, transference and logistic functions and first order equation. The kinetic modeling was applied on experimental results of previous study on producing methane from anaerobic digestion of Recycled Pulp and Paper Sludge (RPPS) under mesophilic conditions. We observed that the thermal pretreatment improve considerably improved the kinetic parameters mainly the methane production rate and the lag phase. Indeed, it can be noted that methane production rate μ increases significantly from a value of 4.72 to 16.27 ml/h using logistic function for 1 g VS/L added load. Then the lag phase parameter λ has dramatically decreased from 5.46 to 1.04 h using logistic function for 1.5 g VS/L added load. This means that the thermal pretreatment of RPPS accelerates the methane production process and saves time.

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Application of response surface methodology to improve methane production from jerusalem artichoke straw

Meng Yan, Li Yi, Chen Laisheng, Han Rui

Archives of Environmental Protection

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2022

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Vol. 48, no. 3

70--79

EN

Anaerobic digestion (AD) converts organic matter and biomass waste into biogas, making it an environmentally friendly technology to improve energy resources for a wide range of applications. Jerusalem artichoke straw (JAS) has an enriched content of cellulose and exhibits a high potential for methane production. AD-based production of methane can eff ectively utilize waste JAS. This study investigated the AD performance of JAS to explore the enhancement of methane yields by employing a Box-Behnken experimental design (BBD) of response surface methodology (RSM). The overall goal was to identify the optimal levels of pretreatment factors, including HCl concentration, pretreatment time, and pretreatment temperature, for producing optimal biomethane yields from JAS. The highest value of methane production achieved was 256.33 mL g-1VS by using an optimal concentration of HCl as 0.25 M, a pretreatment time of 10 h, and a pretreatment temperature of 25°C. These results inform the future application of JAS in enhanced methane production.

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Full-Scale Application of Up-flow High Rate Anaerobic Reactor with Substrate Modification and Effluent Recirculation for Sugarcane Vinasse Degradation and Biogas Generation

Harihastuti Nani, Yuliasni Rustiana, Djayanti Silvy, Handayani Novarina Irnaning, Rame Rame, Prasetio Adi, Kadier Abudukeremu

Journal of Ecological Engineering

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2021

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Vol. 22, nr 4

314--324

EN

This study was aimed at studying the potential of biogas (methane) production from vinasse wastewater in real full-scale application using a two-stage sequencing Up-flow High Rate Anaerobic Reactor (UHRAR), with effluent recirculation and substrate modification. A batch experiment was initially conducted prior to the full-scale application experiment. The batch experiment was done with experimental condition variable: undiluted sample (pH 6) and diluted samples (pH: 5; 6 and 7), while pH and methane production were observed for 50 days. Full-scale application was carried out in two-stage UHRAR reactors with volume 60 m3, HRT 40 d and OLR 60.1–104 kg COD/m3•d. The observation lasted for 32 d. The result from the batch experiment showed that the diluted samples achieved higher COD degradation and methane generation than the undiluted sample. The optimum condition occurred at pH 7, with theoretical methane yield of 7.5–10.64 L CH4 per kg COD. In turn, in full scale application, at day 32, COD removal was 71% (69.1 kg COD/d removed), with methane production was 36.72 m3 CH4/d. Methane production per COD removed was 0.53 m3 CH4/kg COD•d. Substrate modification and effluent recirculation could improve the substrate biodegradability, maintain microbial diversity and enrich nutrients in the reactor.