Urban Organic Waste Research Articles

Multi-stage anoxic/oxic sequencing batch reactor realizes shortcut nitrogen removal for anaerobically co-digested liquor of municipal sludge and urban organic wastes

Multi-stage anoxic/oxic sequencing batch reactor realizes shortcut nitrogen removal for anaerobically co-digested liquor of municipal sludge and urban organic wastes

Identifying leverage points using material flow analysis to circularise resources from urban wastewater and organic waste

Anthropogenic systems are synonymous with linear economies that cause widespread resource waste and environmental degradation. Urban areas are hotspots for this behaviour due to their high population density and resource consumption. Changing this situation is limited by the lack of a holistic but sufficiently detailed understanding of system units where resource waste occurs. The objectives of this study were: (1) to develop and apply a model of the material and substance (nitrogen, phosphorus, and carbon) flows of organic waste and wastewater systems at a local scale, taking Christchurch, New Zealand, as a study case, and (2) to identify leverage points within the system to achieve resource circularisation. Results show that groundwater, infiltrated water, and industrial wastewater are the predominant material flows into the system. Nitrogen and phosphorus inputs predominantly come from food products, detergents, green waste, and industrial wastewater. The Christchurch wastewater system is a prime example of a linear economy, where ∼66 % of the nitrogen and ∼63 % of the phosphorus entering the wastewater system is discharged to the ocean. Leakage from the water supply system reduces water resource efficiency, while water infiltration into the wastewater network inflates the quantity of wastewater treated at the centralised treatment plant, limiting nutrient recovery. In the compost facility, 86 % of the waste is composted, with 33% of the nitrogen and all the phosphorus exiting as compost, while ∼66 % of the nitrogen treated exits through volatilisation. The remaining 14 % of the organic waste entering the treatment plant is deemed unsuitable for composting and is landfilled. The material and substance flow analysis allowed the identification of flows with leverage points in the system where there are opportunities to reduce, reuse, or recover materials and substances to encourage circularisation. These flows include food products, detergents, unsuitable materials for composting, domestic water supply leakages, wastewater network infiltration, and wastewater treatment plant's nutrient recovery.

Occurrence of 40 sanitary indicators in French digestates derived from different anaerobic digestion processes and raw organic wastes from agricultural and urban origin.

This study investigated the sanitary quality of digestates resulting from the mesophilic anaerobic digestion (AD) of urban and agricultural organic wastes (OWs). 40 sanitary indicators, including pathogenic bacteria, antimicrobial resistance genes, virulence factor genes, and mobile genetic elements were evaluated using real-time PCR and/or droplet digital PCR. 13 polycyclic aromatic hydrocarbons (PAHs) and 13 pharmaceutical products (PHPs) were also measured. We assessed agricultural OWs from three treatment plants to study the effect of different AD processes (feeding mode, number of stages, pH), and used three laboratory-scale reactors to study the effect of different feed-supplies (inputs). The lab-scale reactors included: Lab1 fed with 97% activated sludge (urban waste) and 3% cow manure; Lab2 fed with 85% sludge-manure mixture supplemented with 15% wheat straw (WS); and Lab3 fed with 81% sludge-manure mixture, 15% WS, and 4% zeolite powder. Activated sludge favored the survival of the food-borne pathogens Clostridium perfringens and Bacillus cereus, carrying the toxin-encoding genes cpe and ces, respectively. Globally, the reactors fed with fecal matter supplemented with straw (Lab2) or with straw and zeolite (Lab3) had a higher hygienization efficiency than the reactor fed uniquely with fecal matter (Lab1). Three pathogenic bacteria (Enterococcus faecalis, Enterococcus faecium, and Mycobacterium tuberculosis complex), a beta-lactam resistance gene (bla TEM), and three mobile genetic elements (intI1, intI2, and IS26) were significantly decreased in Lab2 and Lab3. Moreover, the concentrations of 11 PAHs and 11 PHPs were significantly lower in Lab2 and Lab3 samples than in Lab1 samples. The high concentrations of micropollutants, such as triclosan, found in Lab1, could explain the lower hygienization efficiency of this reactor. Furthermore, the batch-fed reactor had a more efficient hygienization effect than the semi-continuous reactors, with complete removal of the ybtA gene, which is involved in the production of the siderophore yersiniabactin, and significant reduction of intI2 and tetO. These data suggest that it is essential to control the level of chemical pollutants in raw OWs to optimize the sanitary quality of digestates, and that adding co-substrate, such as WS, may overcome the harmful effect of pollutants.

A corrigendum for article: Characterization of urban organic solid waste compost from six districts of the Leoncio Prado province, Peru

Ríos-Velasquez, E.A.; Florida-Rofner, N.; Lama-Isminio, D.A. 2023. Caracterización de compost de residuos sólidos orgánicos urbanos de seis distritos de la provincia Leoncio Prado, Perú. Rev. U.D.C.A Act. & Div. Cient. 26(1):e2371. http://doi.org/10.31910/rudca.v26.n1.2023.2371. Cuando se publicó el artículo señalado arriba, el autor de correspondencia Nelino Florida Rofner incluyó a Demetrio Angelo Lama Isminio. Sin embargo, Demetrio Lama solicitó a la Revista U.D.C.A Actualidad & Divulgación Científica su retiro de la publicación por no participar activamente en el desarrollo del trabajo y no ser su campo de experticia. La solicitud fue atendida por la revista y consultada con Nelino Florida Rofner, quien estuvo de acuerdo con el retiro de Demetrio Angelo Lama Ismino de la publicación. El cuerpo editorial de la revista aclara que, con base en la evaluación de los pares y el proceso editorial, se considera que los datos presentados en el artículo no pierden validez con esta acción. Además del retiro de Demetrio Angelo Lama Isminio del documento, se cambió el apartado de contribución de los autores que inicialmente se publicó de la siguiente manera: Contribución autores: Emilio Anthony Ríos-Velásquez y Demetrio Angelo Lama-Isminio realizaron los trabajos de campo, obtención y análisis formal de los datos para la escritura del borrador del manuscrito. Nelino Florida Rofner contribuyó con la asesoría de la investigación, la contextualización, la metodología, revisión y redacción del manuscrito. Todos los autores participaron en la redacción, revisión, edición del manuscrito y aprueban la versión final. Nelino Florida Rofner y el cuerpo editorial de la Revista U.D.C.A Actualidad & Divulgación Científica piden disculpas por este error.

Using organic amendments in disturbed soil to enhance soil organic matter, nutrient content and turfgrass establishment

Disturbed soils, including manufactured topsoils, often lack physical and chemical properties conducive to vegetation establishment. As a result, efforts to stabilize disturbed soils with vegetation are susceptible to failure. Urban organic waste products such as wood mulch, composted leaf and yard waste, and biosolids are widely distributed as organic amendments that enhance sustainability and plant establishment. Correct use can be determined by examining soil properties such as pH; the concentration of soluble salts (SS); and plant available nutrients — particularly N, C and P; as well as root and shoot growth. This research examined the effects of three typical organic amendments on fertility, establishment, and nutrient loss. A manufactured topsoil was used as the base soil for all treatments, including a control unamended soil (CUT), and soil amended with either mulch (MAT), composted leaf and yard waste (LAT), or biosolids (BAT). A 2 % organic matter concentration increase was sought but not achieved due to difficulty in reproducing lab results at a larger scale. Results showed that LAT improved soil fertility, particularly N-P-K concentrations while maintaining a good C:N ratio, pH, and SS concentration. BAT was the most effective at enhancing shoot growth but results suggest that improved growth rates could result in increased maintenance. Additionally, biosolids were an excellent source of nutrients, especially N-P-K and S, but diminished root growth and N leachate losses indicate that N was applied in excess of turfgrass requirements. Therefore, biosolids could be used as fertilizer, subject to recommended rates for turfgrass establishment to prevent poor root growth and waterborne N pollution. To ensure establishment efforts are successful, MAT is not recommended without a supplemental source of soluble N. Altogether, study results and conclusions could inform others seeking to improve specifications for disturbed soil where turfgrass establishment is needed to stabilize soil.

Effects of Fly Ash on the Efficiency and Bacterial Community Structure of Urban Multi-source Organic Solid Waste

To achieve efficient resource utilization of fly ash and multi-source organic waste, a composting experiment was carried out to investigate the effects of fly ash on co-aerobic composting using kitchens, chicken manure, and sawdust (15:5:2). The effects of different application doses (5 % and 10 %, calculated in total wet weight of organic solid waste) of fly ash on physical and chemical properties, nutrient elements, and bacterial community structure during co-composting were evaluated. The results showed that the addition dose of 5 % and 10 % fly ash significantly increased the highest temperature (56.6 ℃ and 56.9 ℃) and extended the thermophilic period to nine days. Compared with that in the control, the total nutrient content of compost products in the treatments of 5 % FA and 10 % FA was increased by 4.09 % and 13.55 %, respectively. The bacterial community structure changed greatly throughout the composting, and the bacterial diversity of all treatments increased obviously. In the initial stage of composting, Proteobacteria was the dominant phylum of bacteria, with a relative abundance ranging from 35.26 % to 39.40 %. In the thermophilic period, Firmicutes dominated; its relative abundance peaked at 52.46 % in the 5 % FA treatment and 67.72 % in the 10 % FA treatment. Bacillus and Thermobifida were the predominant groups in the thermophilic period of composting. The relative abundance of Bacillus and Thermobifida in the 5 % FA and 10 % FA treatments were 33.41 % and 62.89 %(Bacillus) and 33.06 % and 12.23 %(Thermobifida), respectively. The results of the redundancy analysis (RDA) revealed that different physicochemical indicators had varying degrees of influence on bacteria, with organic matter, pH, available phosphorus, and available potassium being the main environmental factors influencing bacterial community structure. In summary, the addition of fly ash promoted the harmlessness and maturation of co- aerobic composting of urban multi-source organic waste, while optimizing microbial community structure and improving the quality and efficiency of composting.

A new scheme for low-carbon recycling of urban and rural organic waste based on carbon footprint assessment: A case study in China

Organic waste treatment is a major driver of global carbon emissions, thus its low-carbon utilization is essential yet unclear. Through a life cycle assessment of organic waste data from 34 provincial-level regions in China, we have determined that the synergistic and integrated utilization scheme (URIRP) with organic fertilizer and biochar as the primary products can reduce the annual life cycle carbon emissions from 6.9 Mt CO2e to 2.83 Mt CO2e. This reduction can offset 6% of the carbon emissions from the electricity industry mainly through carbon sequestration by application of biochar-based fertilizer, and fossil fuel displacement by bio-energy. Moreover, URIRP can promote the recycling of N and P, reduce annual emission of air pollutants by 866 Mt, and increase topsoil organic matter content by 0.25‰ and economic efficiency by 135%. These findings indicate that URIRP could realize sustainable management of UROSW with significant environmental and economic benefits, and contribute to the realization of China’s carbon neutrality goal.

Wild black soldier flies, Hermetia illucens (Diptera: Stratiomyidae): Seasonal availability and life history traits in two common organic streams in Bangladesh

The black soldier fly (BSF) Hermetia illucens (L.) (Diptera: Stratiomyidae) is a “crown jewel” in waste management because it rapidly bioconverts organic streams into nutrient-rich biomass. Bangladesh's inefficient waste management has caused serious environmental issues due to the massive amounts of organic waste, mainly livestock manures and municipal organic waste, generated daily. We need reliable BSF to maximize our organic resources. To establish a long-term, stable BSF colony, we closely examined the seasonal abundance and life cycle features of BSF raised on municipal garbage and poultry manure in a regional natural environment in the lab. This investigation lasted two years (2019–2020). Season and raising substrates affected wild BSF egg clutches and life cycles. Organic waste dumps captured the most egg clutches in rainy seasons and the fewest in cooler months. Municipal rubbish dumps consistently produced wilder BSF egg clutches than poultry manure dumpsites. The BSF larvae grew slower in winter and faster in the rainy season, independent of substrate. Winter was optimal for adult BSF longevity in all organic streams. Winter cultivated wild BSF on two organic streams exhibited fewer egg clutches per female, shorter and lighter prepupae, and lower adult ecolosion rates than wetter months. While BSF given municipal organic wastes had the highest adult ecolosion rates, BSF fed poultry manure had more variation in prepupae length and weight, adult lifespan, and egg clutches. Larval development was faster with poultry manure BSF than with municipal organic waste. The protein and ash content of prepupae rearing on poultry manure exceeded those of prepupae on urban organic waste, although fat content was equivalent. These findings indicate that both types of organic streams may be suitable substrates for BSF larvae for trash treatment.

Urban food waste for soil amendment? Analysis and characterisation of waste-based compost for soil fertility management in agroecological horticultural production systems in the city of Rosario, Argentina

Urban and peri-urban lands can be an important source of food production for localised and sustainable food systems, however, their soils can be of poor quality, degraded or damaged by anthropic activities, and little is known about their suitability or safety. This paper aims to contribute to this knowledge gap by assessing the soil remediation capacity and qualities of different types of compost made from urban and peri-urban organic wastes for agroecological food production. Prepared over the course of 2021, and used in 2022 for food growing, five different composts were observed and analysed, in two different farms in the city of Rosario, Argentina. Four raw materials generated largely by local industries were used to make the composts: chicken manure, rumen (cow’s stomachs), brewer’s bagasse (byproducts of the beer industry) and urban leaves collected from the municipality waste collection. These were mixed in different proportions (all reaching the 20–30 C/N ratio, typical of quality compost) to produce viable growing substrates where radishes and lettuces were grown. The aim of the study was to assess the possibility, quality and limitations to use locally available organic inputs for soil fertility management in agroecological farming, in the context of urbanisation and to assess pathways to develop closed-cycle agroecological agriculture at metropolitan level. Natural manure substrates (raw and composted) were analysed, as well as crops grown and fertilised with each of the substrates. The attributes and limiting factors of each substrate and their response to local soil conditions were compared and physicochemical, biochemical, and microbiological analyses were performed, including among others, the study of microbial biomass, biological activity, biophytotoxicity, pH, aerobic heterotrophs, nitrogen fixation, and the presence of antibiotics, agrochemicals and heavy metals. The results of the analyses show that all the composted materials improved the physical, chemical and biological properties. However, in some cases, pollutants were present even after composting. Analysis carried out on the vegetables generally indicate undetectable levels or levels below the admissible limits, demonstrating the filtering capacity of the different composts and the soil.

A novel strategy for urban and rural organic waste utilization with outstanding integrated benefits: based on study in China's Taihu Lake region

Typical organic waste in urban and rural regions (TWUR) is big in volume and poor in resource utilization, and there is currently a lack of integrated evaluation studies on the optimal pattern of TWUR resource utilization. Based on a representative case study of China's circum-Taihu Lake region, this study integrated material flow, life cycle assessment and comprehensive evaluation methods to explore the optimal scenario pattern for TWUR disposal and utilization under multi-scenario settings from multiple perspectives, including cost-benefit-technology-resource depletion. The synergistic coupled aerobic fermentation scenario in Scenario S2, which has a high level of technological maturity and can maximize nutrient recycling while minimizing environmental impacts, is the optimal scenario for using TWUR, according to the results of the entropy weight-TOPSIS integrated evaluation. Following the implementation of Scenario S2, 20% of the chemical fertilizers utilized in the study region will be substituted with organic fertilizers, resulting in a $16.19 billion reduction in organic waste disposal expenses and $228.64 billion in economic benefits. Additionally, China's carbon emissions will drop by 94.316 million tons as a result. This study validates that the optimal configuration pathway to achieve TWUR resource usage is synergistic coupled aerobic fermentation, in contrast to the majority of prior studies. In addition to being a valuable reference for TWUR's resource use transition and future market planning, this environmental technology analysis will help China in achieving its carbon emission reduction targets.

Consumer Perception and Marketing Strategies for Promoting Bio-degradable Polymers in Transition Towards Circular Economy

Bio-degradable polymer base plastics represent an innovative solution over synthetic non-biodegradable plastic derived from fossil fuels, non-renewable energy, and feedstock that has the potential to provide considerable environmental benefits. The prefix "bio" indicates that biopolymers are biodegradable. The word "biodegradable" means that materials can be decomposed by bacteria, fungi, and yeast to the final products of biomass under anaerobic conditions—hydrocarbons and methane. Bioplastics are eco-friendly products that are not only highly bio-gradable and compostable, but also have robust rheological properties compared to fossil-based plastic products.The demand for biodegradable polymers is growing, owing to rising oil prices, which is the primary feedstock for plastic made from petroleum, as well as the difficulty of removing waste plastics from the environment. Biodegradable polymers have several advantages over synthetic polymers, including the ability to breakdown into non-hazardous chemicals in the environment. A new epoch of biodegradable polymers made from urban organic waste is now theoretically conceivable. This research is one of the novel approaches to examine what might lead to commercial acceptability of this biodegradable polymer from the perspective of customers rather than manufacturers. Conceptual model is developed to uncover psychological motivations that may cause customers to migrate from a linear to a circular economy, with the goal of better understanding what motivates customers to switch to bio-degradable plastic made from municipal organic waste. We discovered that having a green self-identity has a beneficial impact on perceived value, which leads to a shift in buying behavior intention. Self-congruity also helps to control the relationship.

Compost promotes biocrust and plant growth in greenhouse cocultures for dryland restoration

Biocrusts and plants are the main ground cover and provide multiple ecosystem functions in arid and semiarid areas. As land degradation worsens and waste management is ever more pressing, the use of composted waste appears as a sustainable restoration practice to enhance vegetation reestablishment, but its effects on biocrusts still remain largely understudied. Moreover, developing appropriate methods for the co‐introduction of plants and biocrusts can be an emerging approach to reconstruct the biocrust/plant interaction and their associated functions. We evaluated the effect of different compost types on biocrust and plant cocultivations. We performed a greenhouse mesocosm experiment using urban organic solid waste and sewage sludge composts to grow a moss‐dominated biocrust and seedlings of two pioneer shrubs (Senecio filaginoides and Acaena splendens) in the Patagonian steppe. Both compost types successfully enhanced biocrust cover and chlorophyll a development, with cultured biocrusts being compositionally similar to the natural inoculum. Only the addition of composted sewage sludge enhanced seedling growth, and biocrusts had significant but opposite effects (positive/negative) on the two plant species we used for experimentation. This difference in the biocrust/plant interaction outcome was likely mediated by the significant influence of biocrusts on the relative availability of ammonium and nitrate and possible plant species‐specific preferences for different inorganic nitrogen forms. We conclude that the application of sewage sludge compost effectively improves the success of biocrust and plant cocultures, but species‐specific differences in the performance of seedlings growing in biocrusted soils impose limits on attempts to promote biocrust and plant joint restoration.

Sustainable Recovery of Urban Organic Waste: A Case Study of Composting Waste from the Mfidi Market in Kinshasa, Democratic Republic of the Congo

Aims: This study aimed to evaluate the methods of solid waste management in the Mfidi market in order to detect the various problems and propose strategies to fight against insalubrity.
 Study Design: This research consists of four parts, an introduction with literature review, a description of the study environment, the methods used and finally the results obtained.
 Location and Duration of the Study: This study took place in the Mfidi market in Kinshasa from January 20 to May 15, 2023.
 Methodology: The methodological approach was based on observation and experimentation. The quantification consisted in characterizing the waste, recovering the biodegradable organic fraction by the technique of composting. Then test the effectiveness of this compost in its application in the field.
 Results: This study showed that the quantity of waste at the Mfidi market varies daily between 1,580 and 4,827 kg, with an average of 3,543.8 kg. With regard to the characteristics of the waste, we note that plants and others are the most important with an average proportion of 59.5%, followed respectively by cardboard and paper (16.6%), plastics (14.6 %), metals (5.4%), textiles (2.1%) and glass (1.9%). The organic fraction was recycled into compost, whose contribution to soil fertility was justified by the growth of the species Amaranthus hubridus sp.
 Conclusion: The establishment of an integrated solid waste management system within the Mfidi market can guarantee sanitation conditions in this market.

Effects of adding micro- and nano-sized biomass fly ash on two-stage biohythane production from the urban organic solid waste

In this work, the effect of ash particle size on the sequential production of bioH2 and bioCH4 for biohythane recovery from the organic fraction of municipal solid waste (OFMSW) was investigated for the first time using micro- and nano-sized biomass fly ash (FA). In the first hydrogenogenic stage, the highest bioH2 yield of 215 mL/g VSadded was noticed in the reactor added with micro-sized FA. On the contrary, in the second methanogenic stage, the maximum bioCH4 yield of 676 mL/g VSadded was witnessed in the reactor fed with acidogenic effluent containing nano-sized FA. In the integrated two-stage process, the addition of FA with nano-sized particles showed superiority over micro-sized FA supplementation and led to an increase of about 582 and 595% in organic matter conversion and energy yield, respectively, compared to the control test, as well as achieving biohythane with an optimal hydrogen content of 15% v/v.

Nitrogen, potassium and sulphur availability from residue-based fertilisers produced in Denmark applied singly or combined

In organic farming systems, nutrients taken up by crops should be replenished by the recycling of agricultural and urban organic waste to close nutrient cycles. However, the availability of organic wastes permitted for application in organic farming is limited, and organic farmers usually have to apply manure from conventional farms, which is considered to be contentious. Alternative nutrient sources acceptable for application in organic farming are therefore needed to supply available nutrients to maintain or increase organic food production. In this study, we investigated the ability of manure, digested manure, manure co-digested with the organic fraction of municipal solid waste, Fertigro® (a by-product from heparin production), and ash from straw to supply N, K and S to ryegrass grown in pots. We sought to establish whether the use of complex mixtures to obtain more suitable nutrient ratios can benefit plant growth. Digested manure and manure co-digested with the organic fraction of municipal solid waste gave on average 50% greater plant growth and 63% higher N recovery than manure, while no significant differences were observed in terms of K recovery. Fertigro® showed similar plant growth and nutrient uptake to the mineral S and N positive controls, while the addition of straw ash demonstrated similar K recovery as that observed for the mineral K positive control. The mixture of Fertigro® with manure co-digested with the organic fraction of municipal solid waste and ash was outstanding among the waste-based fertilisers in terms of amount of N, K and S supplied for plant uptake. However, further efforts are needed to confirm these benefits under field conditions.

Effect of size and additives on the decomposition process and nutrient content of urban organic waste compost

To participate in overcoming the problem of 500 tons of organic waste per day in Makassar City, in 2017-2019 Environment and Forestry Research and Development Institute of Macassar conducted research activities to develop community-based organic waste management models for pollution control and urban farming development. One of the activities is making compost from urban litter using a shredding machine to speed up the decomposition process, and mixing household waste rich in N, P, K and micro nutrients to increase the nutrient content of the compost. Observations showed that the litter mincing process significantly accelerated the decomposition process. Furthermore, the addition of nutrient-rich material from household waste into compost material has increased the nutrient content of compost which is higher than the SNI standard, thereby increasing the competitive value of compost against factory-made chemical fertilizers. These two activities have an impact on increasing public interest in managing urban organic waste to reduce pollution while developing urban farming.

Utilization of urban waste as liquid organic fertilizer for vegetable crops in urban farming system

Converting vegetable, fruit, food, fish offal and slaughterhouse waste that become a problem for the community in the urban areas into useful plant fertilizer is the solution. This study aims to determine (1) the potential of urban organic waste into liquid organic fertilizer and (2) the effectiveness of liquid organic fertilizer (LOF) in increasing the growth and yield of vegetable crops in urban farming systems. The study used Randomized Block Design (RBD) with some treatments P0 (control) and P1 (LOF with 6 types of waste) consisting of P2 (vegetable waste), P3 (fruit waste), P4 (sprouts waste), P5 (food waste), P6 (catfish waste) and P7 (blood waste). The treatment was repeated 3 times for a total of 28 experimental units. The three vegetable plants; eggplant, Bok Choy and mustard, were used in the experiment. The study found that liquid organic fertilizers from vegetables, fruit, sprout, food, fish, blood waste and mixed waste all contain organic matter, varying amounts of nitrogen (N), phosphorus (P), potassium (K), carbon (C), magnesium (Mg), calcium (Ca), copper (Cu), zinc (Zn), iron (Fe) and humic acid. All liquid organic fertilizer treatments increased eggplant and Bok Choy vegetable growth and yield; however, the type of organic waste used as a raw material for LOF did not affect growth but eggplant and Bok Choy yield. LOF from blood waste (P7) and fish waste (P6) has higher measured nutrients and yield from eggplant, Bok Choy and mustard vegetables than other treatments.

ТЕХНОЛОГИЧЕСКИЕ ОСОБЕННОСТИ ПЕРЕРАБОТКИ ОРГАНИЧЕСКИХ ОТХОДОВ ДЛЯ ПОЛУЧЕНИЯ БИОГУМУСА

This article highlights the technology of processing organic waste in order to obtain biohumus. The varietal composition of urban organic waste has been studied. The technology of preparation of raw materials for obtaining a high-quality substrate for further processing, which provides for the purification of the total mass of organic waste from particles of plastic, glass metal, etc., is considered. An experiment was carried out to determine the optimal composition of the substrate for «California» worms (E. Andrei), which have a high productivity. The optimal parameters of humidity and ambient temperature for the vital activity of worms are considered. In the experiment, three experimental groups were formed, which differed in the composition of organic waste. All three groups contained 40% food waste; 10% – branches, wood cuttings, grass; 10% – tea bags, coffee waste, paper and cardboard; 10% soil and 30% animal waste. In each group, animal waste was different: cattle manure, bird droppings and horse manure. The effectiveness of the varietal composition of the substrate was assessed by the increase in the productivity of «California» worms. The highest results were shown by the substrate in which cattle manure was introduced, the growth of worms in which increased by 6.5 times, the lowest results were in a mixture with the addition of bird droppings – by 5.1.

Integrated vermicomposting and green roof techniques for food production in urban and rural areas

Thousands of tons of biodegradable organic waste generates in urban and rural areas every day, creating disposal problems. Urban organic waste can be converted into valuable output products (vermicompost, vermin-liquid, and earthworms) by applying a vermicomposting technique that had different. Implementing green roofs via soilless culture systems as micro-scale farms led to increasing natural resource use efficiencies as well as producing fresh food. The integration of both techniques will create not just reduce pollution and climate change impacts but also for increasing food production and security in urban, enhance the lifestyle and increase public awareness of environmental issues. This process is profitable at any scale of operation.

A novel biomethane (BMP) and composting (CMP) potential framework for determining biogas and composting potential of urban organic waste

ABSTRACT Without treatment, urban market-generated organic waste is discarded in landfills. This could cause environmental contamination due to leachate. This study aims to develop a novel bio-methane and composting potential framework for evaluating the biogas and compostability of organic waste from the Bantama market in Kumasi. Using novel dashboards, the bio-methane and composting potentials were evaluated, and the Theoretical Biomethane Potential (TBMP) was reported to be between 331.52 and 457.93 l CH4/kg VS for carrot leaves and banana peels, respectively, assuming a biodegradability of 80% for the substrates. Only one of the four conditions for compostability was met by the substrates, indicating that they are not suitable for direct composting. In order to optimize the potential of the waste, an integrated system of anaerobic digestion (AD) and composting was utilized. The proposed plant was profitable since the payback period was less than two years, the Net Present Value (NPV) was greater than one, and the Benefit Cost Ratio (BCR) was greater than one. The anaerobic digester and composting plant are capable of producing 12269392 kWh of electricity and 19585 kg of compost per year, respectively. Lastly, the AD and composting technologies at the Bantama market are cost-effective. The government and municipalities may therefore assist private investors in constructing a waste processing plant.