Organic Waste Resources Research Articles

Crude Oil Extraction Technology from Organic Waste Resources: A Review

Crude Oil Extraction Technology from Organic Waste Resources: A Review

Establishment of an inspection standard for decomposition and methane production rates of organic waste co-digestion facilities in Korea

Domestic organic waste resources have increased over the past decade and treatment of this waste via co-digested biogasification facilities is increasing annually. However, inspection standards for such facilities are not well-established. Herein, we aimed to derive calculation formulas and factors related to organic matter decomposition efficiency and methane production rate in accordance with waste treatment facility inspection standards. We also aimed to determine the optimum waste mixing ratio. Sample (field) surveys of 18 treatment facilities and complete enumeration of 110 facilities were conducted. Calculation formulas and factors were derived using the survey data and biochemical methane potential (BMP) test. The calculated coefficients derived through the BMP test were 0.512 m3 CH4/kgVSin for food waste, 0.601 m3 CH4/kgVSin for livestock manure, and 0.382 m3 CH4/kgVSin for sewage sludge. The final derived calculation factors were 65.0% for food waste, 36.0% for livestock manure, and 20.0% for sewage sludge for organic matter decomposition efficiency, and 0.380 m3 CH4/kgVSin for food waste, 0.27 m3 CH4/kgVSin for livestock manure, and 0.140 m3 CH4/kgVSin for sewage sludge for methane production rates. The derived effective capacity calculation factors can be utilized in future waste treatment facility inspection methods by aiding in the establishment of appropriate inspection standards for co-digested biogasification facilities other than single food waste treatment facilities. In addition, the optimum mixing ratio can be used as design data for co-digested biogasification facilities.

The new strategy of using humic acid loaded biochar to enhance the anaerobic digestion of cow manure for methane production

Anaerobic digestion is a beneficial way to convert organic waste resources, such as cow manure, into clean energy through microbial actions. However, when biochar was used as an additive to promote the efficiency of anaerobic digestion, there was a problem that the number of oxygen-containing functional groups was small, resulting in a limited effect on improving the electronic transport efficiency of the anaerobic digestion system. In this study, a high oxygen functional group containing humic acid biochar was prepared using ball milling technology to enhance reactivity and improve the anaerobic digestion performance of cow manure. The results showed that humic acid biochar had a more excellent performance in improving the gas production efficiency of cow manure AD. The addition of humic acid biochar did not significantly affect methane content. The humic acid biochar with a milling time of 8 h showed the best promotion effect in the anaerobic digestion system, and the methane yield reached 110.49 mL/gVS, which was 43.16% higher than that of the control group. The addition of humic acid biochar stimulated the secretion of extracellular polymers and enhanced interspecific electron transfer, leading to increased activity of key enzymes, including coenzyme F420. As a result, hydrogen-producing methanogens were enriched, methanogenic pathways were enhanced, and methane production was ultimately increased. Therefore, it improves intermediate product yield and utilization efficiency, thereby increasing methane production, and has great potential in the treatment of refractory organic waste.

SCREENING AND CHARACTERIZATION OF POTENTIAL ETHANOL OXIDIZING YEAST ISOLATES FROM SUGAR-RICH ORGANIC WASTE RESOURCES USING SCHIFF’S-BASE REACTION

Alcohol dehydrogenase is an oxidoreductase enzyme that carries both alcohol oxidation and aldehyde/ketone reduction activity. Alcohol dehydrogenase (ADH) activity of yeast cells were essential for industrial applications. Sugar-rich organic waste resources including spoiled fruits, fruit peel waste, spoiled vegetables, raw and composed sludge from the dairy industry, and cane molasses spill from the sugar industry, provide a favorable habitat for ethanol-oxidizing microorganisms with ADH activity. The total ethanol oxidizing microbial population of organic waste resources differs considerably from the overall microbial community. Yeast from the natural habitats has a great potential for developing novel enzymes for industrial uses. Under this backdrop, the present study was focused on screening and characterization of potential ethanol oxidizing yeast strains from sugar-rich organic waste resources. Totally seventeen ethanol oxidizing yeast strains belongs to Pichia sp. (9 strains), Candida sp. (2 strains) and Debaryomyces sp. (2 strains), Hanseniaspora sp, Lachancea sp, Torulaspora sp, and Magnusiomyces sp. have been identified. The ability of strains to oxidize ethanol into acetaldehyde was verified by the Schiff’s-base reaction through p-rosaniline assay. The selected five potential ethanol oxidizing strains were identified by 18S rRNA gene sequence as Pichia kluyveri FYES5, Pichia kudriavzevii FYES6, Pichia kudriavzevii VYES2, Candida mengyuniae CSYES1, and Magnusiomyces capitatus CSYES2 with the p-r index of 2.64±0.40, 3.79±0.54, 3.73±0.69, 2.28±0.24, and 2.87±0.58 respectively at 28°C. This is the first report to identify ethanol oxidizing yeast strains from sugar-rich organic waste resources and by this study found that the strain Candida mengyuniae has a better ability to oxidize ethanol.

Transformation characteristics of organic matter and phosphorus in composting processes of agricultural organic waste: Research trends

Agricultural waste is rich in organic matter and an important secondary source of phosphorus, which can be converted into valuable products through various technologies. Composting is an effective way to treat agricultural waste and further produce organic fertilizer, achieving waste minimization and stabilization. This paper reviews the current situation of agricultural waste pollution and composting technology, introduces the parameters that influence of the composting process and the optimal conditions, and presents the indicators for evaluating the decay of compost products and the evaluation criteria as well. In the composting process, small-molecule organic acids produced by the degradation of easily degradable organic matter such as sugars and lipids and various enzymes produced by microorganisms (phytase, phosphatase, etc.) can mineralize organic phosphorus such as phytate and phospholipids, promote phosphorus activation and provide phosphorus sources for microorganisms, so the conversion of organic matter and phosphorus is related to the fertilizer effect of composted products. Therefore, the clarification of the characteristics of organic matter and phosphorus transformation in the composting process is an important prerequisite for the resource utilization of agricultural organic waste. This paper provides theoretical support for the sustainable utilization of agricultural organic waste resources.

Analysis on the Utilization of Renewable Energy for Carbon Neutralization in Sewage Treatment Facilities

Domestic wastewater treatment facilities(WTF) in Korea consume a lot of energy and generate greenhouse gases in the process of treating contaminated sewage. In response to climate change and the government's carbon neutrality, measures for energy reduction in WTF is an important issue along with water quality management, and simultaneously, diversification of renewable energy based on treatment facilities is essential. The energy independence and renewable energy utilization by facility capacity were analyzed based on sewage statistics (2019) and operation data of the National Sewage Information System. The amount of energy consumed by WTF was analyzed to be 83.6 million TOE, and the renewable energy produced was 10.8 million TOE. In consequence of analysis, the energy independence of domestic WTF in Korea was 12.9%. Among renewable energy, the contribution of biogas was the highest at 83.6%, but the current status of energy independence is somewhat insufficient to energy independence plan of WTF, requiring support for alternatives and policies to produce and secure additional renewable energy. In order to increase and diversify the use of renewable energy, the integrated digestion biogas of organic waste resources, the use of cooling and heating energy based on sewage heat, and the development of salinity gradient power generation were reviewed. Based on this, it was intended to contribute to the preparation of measures to achieve carbon neutrality in sewage treatment facilities.

A Study on the change of nitrogen removal characteristics in the applications of external carbon sources using organic waste resources

Waste water emitted from industrial facilities is increasing in relative inorganic content along with a decrease in the amount of organic matter every year, making it difficult to remove nutrients caused by high concentrations of organic matter in the early stages of wastewater treatment. In the wastewater treatment process, the denitrification process for nitrogen removal requires organic carbon as an electronic donor, so the addition of external carbon sources is necessary, but there is a concern of increased cost, obstruction of nitrification of residual organic carbon sources. The external carbon sources used for denitrification can include methanol, ethanol, and wastewater, which have been studied in various ways. However, failure to properly use these sources of external carbon can lead to a decrease in denitrification efficiency, which can lead to increased COD(Chemical Oxygen Demand), resulting in deterioration of water quality as well as a decrease in nitric oxide efficiency. Therefore, the purpose of this study was to investigate the nitrogen removal characteristics of wastewater when applying wastewater, methanol, and antibiotic-announced wastewater used as an external carbon source. This study was conducted in a biological diffuse reaction tank, and the KNO3 reagent was injected to 1.4 mg/L within the reaction tank to see the denitrification efficiency, and methanol, A negative wastewater, B negative waste water, and antibiotic fermented waste were injected in the same amount. Methanol, primary treated water, and antibiotic fermented waste reduced the total solids concentration of sludge in bioreactors by 5.2%, 17.4% and 3.4%, respectively, but the total solids concentration of A food wastewater and H food wastewater was increased by 9.1% and 8.3%, respectively. In addition, the concentration of T-N(Total Nitrogen) in bio-reactor treated water decreased by 15.6% and 0.97% and 0.85%, respectively, when methanol, primary treatment water and antibiotic fermented waste liquid were injected, but T-N in A food wastewater and H food wastewater negative waste water increased by 6.7% and 2.9%, respectively. The concentration of NO3--N in methanol, primary treated water, antibiotic fermented waste solution, A negative wastewater, and H negative wastewater was reduced by 56.4%, 9.95%, 0.85%, 11.8% and 18.3%, respectively. If organic waste resources are applied as external carbon sources in the wastewater treatment process, it is possible to supply insufficient carbon sources during the denitrification process, but the nitrogen concentration of organic waste resources can rather increase the concentration of T-N. Further research on the possibility of decomposition of nitrogen sources contained in drinking water and antibiotic fermented waste liquid in the wastewater treatment process will be conducted through continuous experiments by type of organic waste resources.

Advanced technologies on the sustainable approaches for conversion of organic waste to valuable bioproducts: Emerging circular bioeconomy perspective

Rapid population growth and other human activities have generated massive waste from various sectors in recent decades. Studies revealed that by 2050, global solid waste generation is expected to reach 70% to 3.4 billion metric tons. Thus, the authorities urgently need to provide a low-cost, efficient technology for treating waste disposal. However, it is evident that only 20% of waste is recycled, and the remaining is still being considered for landfilling. In developing countries, the generated waste is simply disposed of in an open area, which causes a severe threat to humans, animals, and the environment. To date, organic waste and fourth-generation biomass have been investigated for multiple targeted products. Thus, the present review article highlights the emerging problems in organic waste generation, management, and converting them into various value-added bioproducts. This review also deals with the conversion of multiple biofuels such as liquid, solid, gaseous, and bioelectricity from organic waste resources. Besides, the latest approaches in organic waste are also detailly addressed for the production of value-added bioproducts such as bioplastic, bio-compost, and organic acids. Furthermore, the techno-economic analysis (TEA) and life cycle assessment (LCA) of organic waste is also explored. The transformation of organic waste to value-added bioproducts enhances the circular bioeconomy approach by reducing waste, increasing energy production, and other healthcare products. Finally, it is concluded that the utilization of organic waste to value-added bioproducts and biofuels production will be helpful in achieving high energy security, environmental protection, as well as enhancing the bioeconomy perspective.

Recent Trends and Prospects of Microbial Fuel Cell Technology for Energy Positive Wastewater Treatment Plants Treating Organic Waste Resources

Microbial fuel cell (MFC) technology is receiving a lot of attention recently as a promising technology for generating electricity by treating organic waste resources. Over the past 20 years, the MFC technology has made rapid progress: various research on system architectures, electrochemistry, materials, and microbiology has been conducted for developing practical ideas and fundamental principles. Recently, a lot of research on scaled-up systems for practical application is being conducted in the MFC field. In this review, materials, electrochemistry, system development and scale-up systems of MFCs studied so far are reviewed, and future prospects and directions of MFC technology are presented.

A Critical Overview of the State-of-the-Art Methods for Biogas Purification and Utilization Processes

Biogas is one of the most attractive renewable resources due to its ability to convert waste into energy. Biogas is produced during an anaerobic digestion process from different organic waste resources with a combination of mainly CH4 (~50 mol/mol), CO2 (~15 mol/mol), and some trace gasses. The percentage of these trace gases is related to operating conditions and feedstocks. Due to the impurities of the trace gases, raw biogas has to be cleaned before use for many applications. Therefore, the cleaning, upgrading, and utilization of biogas has become an important topic that has been widely studied in recent years. In this review, raw biogas components are investigated in relation to feedstock resources. Then, using recent developments, it describes the cleaning methods that have been used to eliminate unwanted components in biogas. Additionally, the upgrading processes are systematically reviewed according to their technology, recovery range, and state of the art methods in this area, regarding obtaining biomethane from biogas. Furthermore, these upgrading methods have been comprehensively reviewed and compared with each other in terms of electricity consumption and methane losses. This comparison revealed that amine scrubbing is one the most promising methods in terms of methane losses and the energy demand of the system. In the section on biogas utilization, raw biogas and biomethane have been assessed with recently available data from the literature according to their usage areas and methods. It seems that biogas can be used as a biofuel to produce energy via CHP and fuel cells with high efficiency. Moreover, it is able to be utilized in an internal combustion engine which reduces exhaust emissions by using biofuels. Lastly, chemical production such as biomethanol, bioethanol, and higher alcohols are in the development stage for utilization of biogas and are discussed in depth. This review reveals that most biogas utilization approaches are in their early stages. The gaps that require further investigations in the field have been identified and highlighted for future research.

Creating Revenue Out Of Green Waste: New Perspectives For Municipal Organic Waste Harvesting In Geelong, Australia

The diversion and recovery of organic waste are one of the most significant opportunities and challenges for reducing the environmental impacts of waste disposal internationally, as recognised by the United Nations’ SDG 12 that seeks to “ensure sustainable consumption and production patterns”. This issue is particularly pertinent to developed countries, like Australia, who have a high propensity for waste removal arising from their industrial and domestic use of products, materials and organic consumables. Through the use of GIS technology, using modelling software developed by the Global Methane Initiative, a series of simulations were undertaken to determine the viability of an anaerobic digester for the City of Greater Geelong (COGG), located in the State of Victoria (Australia), where organic materials constitute over 25% of all waste land-filled. Using only municipal organic waste, the modelling concluded that the COGG would generate between AU$6M-AU$11M/annum from the sale of biogas/methane. In addition to this revenue stream, COGG would have an Annual Projected Net Emissions Reductions of 3797 Mt. This paper further considers the development of a geospatial database to identify and locate concentrated organic waste resources in COGG, the design and development of a software tool to help quantify the production of food waste, and the development of an economic model to value the organic waste stream of COGG arising from the implementation of this proposal.

Bioconversion of Plant Hydrolysate Biomass into Biofuels Using an Engineered Bacillus subtilis and Escherichia coli Mixed-whole Cell Biotransformation

Bioconversion of organic biomass such as plant hydrolysate and organic waste into valuable biochemicals is very challenging. In this study, carbohydrate-rich watermelon rinds and protein-rich okara (soybean waste) were converted into biofuels of ethanol, isobutanol, and methylbutanols using an engineered Escherichia coli and Bacillus subtilis mixed-whole cell biotransformation. The engineered E. coli expressed the genes alsS, kivD, ilvC, ilvD, and yqhD, and the engineered B. subtilis expressed the genes leuDH, kivD, and yqhD. The growth inhibition of the B. subtilis strain, which was reduced by 50% with addition of 1 mM furfural, was restored by the addition of 1 g/mL of activated carbon. The ratio of the E. coil and B. subtilis was optimized depending on carbohydrate and protein composition of the hydrolysate. When the carbohydrate levels were high, a 4:1 ratio of engineered E. coli to B. subtilis led to the highest overall biofuel (1.1 g/L) and isobutanol (80%) production. Viability analysis of the engineered E. coli to B. subtilis strains showed that the E. coli strain had higher activity at the beginning of the biotransformation period, while the B. subtilis strain exhibited higher activity in the later stages. The results of the present study provide important information for future biochemical production research, particularly regarding the diversification of organic waste resources.

Enhanced hydrogen gas production from mixture of beer spent grains (BSG) and distiller's grains (DG) with glycerol by Escherichia coli

Escherichia coli perform mixed acid fermentation and produce hydrogen gas (H2) as one of the fermentation end products. E. coli can ferment sugars like glucose, xylose and alcohols like glycerol. It has been shown that E. coli has the ability to utilize pretreated organic waste (BSG or DG) or mixtures of it with glycerol and H2 can be produced. H2 evolution was maximum when the concentration of BSG was 4% and DG - 10% yielding 1.4 mmol L−1 H2. H2 evolution was prolonged to ~24–120 h when mixtures of glycerol and DG or BSG wastes were applied. Moreover, in hycE (lacking large subunit of Hyd-3) or hyfG (lacking large subunit of Hyd-4) single mutants H2 production was absent compared to wild type suggesting that Hyd-3 and Hyd-4 are responsible for H2 generation. In addition, multiple mutant enhanced cumulative H2 production ~3–4 fold. Taken together it can be proposed that BSG or DG wastes either together or in mixture with glycerol can be applied to obtain E. coli biomass and produce bio-H2. The novel data can be used to further control effectively the application of organic waste resources as a feedstock for developing bio-H2 production technology.

Enhanced polyunsaturated fatty acid production using food wastes and biofuels byproducts by an evolved strain of Phaeodactylum tricornutum

This study investigates the prospective of utilizing kitchen wastewater and food wastes, biofuels industry byproducts as alternative water and carbon sources. Kitchen wastewater did not impede cellular growth rate of the evolved Phaeodactylum strain E70, which indicates its potential as an alternative to freshwater resources. Among the organic wastes assessed, food waste hydrolysate significantly increased cell growth. Supplement of crude glycerol in cultivation medium enhances the total fatty acid content. Mixed food waste hydrolysate and crude glycerol remarkably increased both the cell density and total fatty acid content. Also, the supplement of butylated hydroxytoluene alleviated the oxidative stress induced by impurities in organic wastes and concomitantly increased microalgal total fatty acids and polyunsaturated fatty acids content. The experimental results reported in this study show that a waste-based biorefinery could lead to utilization of organic waste resources for the efficient production of value-added products.

Improving methane yield and quality via co-digestion of cow dung mixed with food waste

Methane (CH4) production and quality were enhanced by the co-digestion of cow dung and food waste (FW) mixed with organic fraction of municipal solid waste (OFMSW) under optimized conditions in bench and semi continuous-scale mode for a period of 30 days. A bacterium capable of high yield of CH4 was enriched and isolated by employing activated sewage sludge as the inoculums. The thirteen bacterial isolates were identified through morphological and biochemical tests. Gas chromatography was used to analyze the chemical compositions of the generated biogas. CH4 yields were significantly higher during co-digestion of Run II (7.59 L) than Run I (3.7 L). Therefore, the co-digestion of FW with OFMSW and Run II was observed to be a competent method for biogas conversion from organic waste resources.

Study on the effect of textile effluent on the growth and fecundity of Eudrilus euginiae

Eudrilus euginiae is one among the well studied species of earthworms involved in the conversion of organic waste resources into value added products (vermicompost). Efforts were taken to understand the impact of textile effluent on the population of earthworms mimicking the condition prevalent in textile belt of Tamil Nadu, India where effluents are drained into the cultivable land through the water stream. Categories of earthworms were maintained and drained with calculated amounts of raw, chemically and biologically treated effluents for a period of eight weeks in which fecundity and growth were recorded. There was significantly high fecundity in the soil treated with raw effluent than that of control and the treated effluents suggesting us to use of these worms for bioremediation of textile effluent polluted soil.

Fertilization effects of organic waste resources and bottom wood ash: results from a pot experiment

We conducted a pot experiment to study the fertilization effects of four N- and P-rich organic waste resources alone and in combination with K-rich bottom wood ash at two application rates (150 kg N ha–1 + 120 kg K ha–1, 300 kg N ha-1 + 240 kg K ha–1). Plant-available N was the growth-limiting factor. 48–73% of N applied with meat and bone meal (MBM) and composted fish sludge (CFS) was taken up in aboveground biomass, resulting in mineral fertilizer equivalents (MFE%) of 53–81% for N uptake and 61–104% for yield. MFE% of MBM and CFS decreased for increasing application rates. Two industrial composts had weak N fertilization effects and are to be considered soil conditioners rather than fertilizers. Possible P and K fertilization effects of waste resources were masked by the soil’s ability to supply plant-available P and K, but effects on plant-available P and K contents in soil suggest that the waste resources may have positive effects under more nutrient-deficient conditions.

Production of earthworm Allolobophora parva (Eisen) in cattle dung

Vermicomposting potential of Allolobophora parva is well proven in recent experiments but little is known about its growth and reproduction performance. Efforts were made in this study to assess the biological productivity of A. parva in cattle waste solids under laboratory conditions. The growth and reproduction performance of A. parva was monitored up to its termination state in experimental beddings. A. parva was weighed weekly and cocoons produced during the interval were also counted. The maximum individual biomass and maximum growth rate (wt. mg worm −1 week −1) was 190.9 ± 0.07 mg (after 13 weeks) and 2.66 (after 12th week), respectively. A. parva showed the maximum values of cocoon number (within a week) and reproduction rate: 26 ± 1.12 and 0.74 ± 0.05 cocoon worm −1 week −1, respectively, during the 8th week of vermiculture. Cocoon production in earthworms was terminated after the 17th week of culture. Data suggested that A. parva may acts as a potential candidate to convert negligible organic waste resources into worm biomass for sustainable environmental management.

Utilization of earthworms in organic waste management

Vermicomposting is an ecofriendly, socially sound and economically viable technology to manage the organic waste resources. It is popular particularly in India, because it is the cheapest solution to overcome the dangerous effects of modernized agriculture. Vermicomposting is the application of earthworm in producing vermifertilizer which helps in maintenance of better environment and results in sustainable agriculture. The aim of the present study was to evaluate the efficiency and the nutritional status of vermicompost processed by two earthworm species, Eisenia fetida and Eudrilus eugeniae from leaf litter and sugarcane trash.Chemical analysis of the vermicompost obtained from leaf litter wastes showed that the quantity of organic carbon was reduced from 38.65 to 28.89 and 28.0% by E. fetida and E. eugeniae respectively. The level of nitrogen (1.30%), phosphorus (0.38%), potassium (0.57%) and calcium ((0.70%) was maximum in leaf litter vermicompost processed by E. eugeniae than E. fetida. At the end of 45 days of composting, E. eugeniae has tremendously decreased the C/N ratio from 45.47, 60.19 to 22.40 and 29.19 in the composts of leaf litter and sugarcane trash respectively. Similarly, E. eugeniae processed leaf litter compost treated with plant, Abelmoschus esculentus showed maximum height (61.4cm), number of leaves (16 per plant), leaf area (365 cm²), fruit length (15.8cm), fruit weight (17.9gm) and total chlorophyll content (3.76 mg/g.fresh wt) than those treated with sugarcane trash.

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Abstracts of Nippon Dojo-Hiryogaku Zasshi