Types Of Biowaste Research Articles

Effect of substrate moisture content during cultivation of Hericium erinaceus and subsequent vermicomposting of spent mushroom substrate in a continuous feeding system

Cultivation of Hericium erinaceus depends on various factors, one of which is water content in the substrate. This parameter influences not only the growth rate of the mushroom but also enzymatic activity, which is important for substrate decomposition and for the later usage of spent mushroom substrate (SMS). This study compared parameters, such as mycelial growth, pH and enzymatic activity in substrates with different initial water content. During cultivation, the water content and pH decreased in all variants, but the activity of hydrolytic enzymes increased with time and was higher in variants with higher water content (70% and 75%); however, the activity of ligninolytic enzymes decreased during cultivation. The production of 1 kg of mushrooms generates about 5 kg of SMS. Vermicomposting is a natural method for processing SMS, as it involves a combination of earthworms, microorganisms and enzymatic activity; thus, we compared the differences between variants with and without earthworms using continuous feeding vermicomposters. The C:N ratio in the variant with earthworms radically decreased from 153.7:1 to 16.5:1. The ratio of bacteria to fungi in both variants was highest in the oldest compost layer in the vermicomposters. The variant without earthworms exhibited the highest enzymatic activity of β-D-glucosidase and Mn-peroxidase, but the highest activity of cellobiohydrolase and laccase occurred in the variant with earthworms. The vermicomposting process is ideal for this type of biowaste, as it produces a fertilizer rich in beneficial microorganisms and enzymatic activity.

The Nutritional Value of Biowaste Bovine Slaughterhouse Meals for Monogastric Species Feeding: The Guinea Pig as an Animal Model.

Biowaste from slaughterhouses can be recovered to benefit food security and reduce contamination potential. More than 3 billion heads of livestock are consumed worldwide, which will increase by 17% by 2028, generating more biowaste, increasing infectious agents, and causing economic losses due to circular economy principles not being applied. This work evaluated the nutritional quality of four types of biowaste from bovine slaughter which were transformed into a meal for guinea pigs (rumen content (RCM), ears (EaM), blood (BM), and cheeks (CM)) according to their chemical composition, digestible components, energy contribution, and voluntary consumption. For the animal model, adult male guinea pigs were arranged in metabolic cages for feces collection without urinary contamination. Nine guinea pigs were used in each digestibility test. First, a direct digestibility test was conducted using a meal of barley as a reference diet (RD), the indigestibility coefficient of which allowed for the estimation of the digestibility of biowaste meals through indirect calculations; for this, diets composed of 80% of the RD and 20% of the corresponding biowaste meals were evaluated. The difference method was suitable for determining the digestibility of beef biowaste using the indigestibility coefficients of the reference diet to calculate the digestibility of ingredients which could not be offered as 100% of the meal but were incorporated as 20%. The digestible protein and metabolizable energy contents of RCM, EaM, BM, and CM were 10.2% and 2853 kcal/kg, 44.5% and 3325 kcal/kg, 70.7% and 2583 kcal/kg, and 80.8% and 3386 kcal/kg, respectively. The CM and BM feeds had the highest contributions of digestible protein due to their higher nitrogen content, and the CM and EaM feeds had the highest ME contents due to their higher fat contents. The biowaste meal consumption in descending order was CM > RCM > EaM > BM, which were consumed without problems. These results are indicative that these components can be part of guinea pigs' diets, and it is recommended to continue studies into guinea pig growth and fattening diets with different levels of these biowaste meals.

Physicochemical properties and fatty acid profile of oil extracted from black soldier fly larvae (Hermetia illucens)

Background and Aim: Hermetia illucens, a black soldier fly, is widely recognized for sustainable recycling of organic waste. Black soldier fly larvae (BSFLs) can consume various types of biowastes and convert them into nutrient-rich biomass, including proteins, lipids, chitin, and minerals. This study investigated the best extraction method by comparing the fatty acid profiles, percentage yield, and antioxidant properties of BSFL oil extracted using different extraction methods. Materials and Methods: The physicochemical properties, fatty acid profile, and free radical scavenging ability of BSFL oil were analyzed using six extraction methods. Results: Ultrasonic extraction with hexane resulted in the highest yields compared with different extraction methods. Lauric acid (28%–37%) was the most abundant fatty acid in all extracts, followed by palmitic acid, myristic acid, oleic acid, and linoleic acid. Compared with other methods, aqueous extraction showed the highest lauric acid composition and free radical scavenging activities. In addition, high-temperature aqueous extraction resulted in higher oil yield and free radical scavenging activities than low-temperature extraction. Conclusion: High-temperature aqueous extraction is the best extraction method because it is rich in lauric acid, has antioxidant ability, and can be further developed to produce novel sustainable biomaterials for humans and animals. Keywords: black soldier fly, extraction method, fatty acid, Hermetia illucens.

New insights into vermiremediation of sewage sludge: The effect of earthworms on micropollutants and vice versa

Vermicomposting represents an environmentally friendly method for the treatment of various types of biowastes, including sewage sludge (SS), as documented in numerous studies. However, there are few papers providing insights into the mechanisms and toxicity effects involved in SS vermicomposting to present a comprehensive overview of the process. In this work, the vermiremediation of SS containing various micropollutants, including pharmaceuticals, personal care products, endocrine disruptors, and per/polyfluoroalkyl substances, was studied. Two SSs originating from different wastewater treatment plants (WWTP1 and WWTP2) were mixed with a bulking agent, moistened straw, at ratios of 0, 25, 50, and 75% SS. Eisenia andrei earthworms were introduced into the mixtures, and after six weeks, the resulting materials were subjected to various types of chemical and toxicological analyses, including conventional assays (mortality, weight) as well as tissue- and cell-level assays, such as malondialdehyde production, cytotoxicity tests and gene expression assays. Through the vermiremediation process significant removal of diclofenac (90%), metoprolol (88%), telmisartan (62%), and triclosan (81%) was achieved. Although the concentrations of micropollutants were substantially different in the original SS samples, the micropollutants vermiaccumulated to a similar extent over the incubation period. The earthworms substantially eliminated the present bacterial populations, especially in the 75% SS treatments, in which the average declines were 90 and 79% for WWTP1 and WWTP2, respectively. To the best of our knowledge, this is the first study to investigate the vermiremediation of such a large group of micropollutants in real SS samples and provide a thorough evaluation of the effect of SS on earthworms at tissue and cellular level.

Enhancing the Durability of Green Concrete through the Utilization of Nano-sized Palm Oil Fuel Ash and Nano-sized Eggshell Powder

Concrete is often regarded as a material representing robustness and long-lasting properties in contemporary society. The manufacture and utilization of cement are responsible for environmental contamination. Green concrete, often known as GC, has been increasingly recognized as a key material in the global concrete industry. Palm Oil Ash (POA) is a significant Lightweight Aggregate (LA) used in GC. Palm Oil (PO) processing generates POA as a by-product, which is thrown out in open areas and landfills without treatment, leading to environmental degradation. The pozzolanic activity is enhanced by grinding POA to nanoparticles, known as NPOA. Egg Shells (ES) are a type of biowaste that originates from eateries. They are deposited in landfills, producing toxic gases and inflicting environmental harm. Nano-sized ES Powder (NESP) contains a significant quantity of calcium oxide, which is crucial for hydration in concrete formation. Also, POA can serve as a fractional replacement for cement in concrete. This paper offers a study that utilized NPOA to improve the subpar performance of LA for GC produced with POA aggregate. The study involved replacing a portion of the cement with NPOA at 5%, 10%, and 15% ratios. Additionally, NESP was used as an admixture at a ratio of 1.5% to produce green concrete in cubes and cylinders. The concrete samples (in the shape of cubes and cylinders) are exposed to a curing process for 7, 14, and 28 days, respectively. Afterward, these samples are examined to evaluate their performance and measure their strength. The Conventional concrete is produced using an M20 grade mix. It is then compared to GC, both with and without NPOA concrete, using cube and cylinder models.

The results of the study of obtaining alternative fuels from biowaste in the experimental pyrolysis device

The research presents the thermal processing of agricultural biowaste based on the pyrolysis device and the process of obtaining energy fuels. These energy fuels can be effectively used in the energy system of households, industry and greenhouses. The resulting fuels are considered environmentally friendly and help to solve problems such as environmental pollution, CO2 emissions, and dependence on oil and natural resources. In the study, the results of pyrolysis of different types of biowaste at a temperature of up to 400 0C were obtained. The quantity, characteristics and factors affecting gas, bio-oil, and bio-coal fuel released from biomass were carried out on the basis of scientific and theoretical analyses.

A Simple Methodology for Estimating the Potential Biomethane Production in a Region: Application in a Case Study

Biomethane is an example of a biofuel that is currently gaining interest due to its possible use as a substitute for natural gas and due to its generation in a “power to gas” production scheme. It can be injected into the gas network under certain purity requirements. It can also act as a source for the production of “green hydrogen”. This paper proposes a simple methodology to estimate the potential to obtain biomethane through the anaerobic digestion of biowaste in a delimited region. The mentioned methodology consists of the following main steps: (i) estimation of the potential biowaste from different sources in the region; (ii) characterization of each type of biowaste production; (iii) estimation of biogas production for each type of biowaste according to the selected anaerobic digestion process; and (iv) estimation of potential biomethane production through the purification of the biogas produced. The different types of biowaste that this methodology considers are the organic fraction of municipal solid waste, agroindustrial solid biowaste (biowaste from the food industry and livestock), and sewage sludge (urban and industrial). Energy crops are not considered because they are not treated as biowaste. After defining the proposed methodology, it is applied to a Spanish case study, in which the potential to obtain biomethane in Spain in 2019 is estimated. The results show that in Spain, around 4499 ktoe could be obtained if all biowaste was destined to produce biomethane, which would allow 31.6% of the final demand for natural gas to be satisfied in a sustainable way. In that sense, a double effect on climate change mitigation can be obtained, reducing use of fossil fuels and minimizing the final biowaste disposal into landfills.

PM 3/66 (3) Guidelines for the management of plant health risks of biowaste of plant origin

<scp>PM</scp> 3/66 (3) Guidelines for the management of plant health risks of biowaste of plant origin

Green Template-Mediated Synthesis of Biowaste Nano-Hydroxyapatite: A Systematic Literature Review.

Hydroxyapatite (HA) is a well-known calcium phosphate ingredient comparable to human bone tissue. HA has exciting applications in many fields, especially biomedical applications, such as drug delivery, osteogenesis, and dental implants. Unfortunately, hydroxyapatite-based nanomaterials are synthesized by conventional methods using reagents that are not environmentally friendly and are expensive. Therefore, extensive efforts have been made to establish a simple, efficient, and green method to form nano-hydroxyapatite (NHA) biofunctional materials with significant biocompatibility, bioactivity, and mechanical strength. Several types of biowaste have proven to be a source of calcium in forming HA, including using chicken eggshells, fish bones, and beef bones. This systematic literature review discusses the possibility of replacing synthetic chemical reagents, synthetic pathways, and toxic capping agents with a green template to synthesize NHA. This review also shed insight on the simple green manufacture of NHA with controlled shape and size.

Preparation of Boron/Sulfur-Codoped Porous Carbon Derived from Biological Wastes and Its Application in a Supercapacitor.

Abundant biomass resources are a good choice for preparing electrode materials for supercapacitors, but developing a versatile and simple synthetic method to convert them into electrode materials remains a challenge. In the present research, our team reports a promising strategy and cost-efficient method to fabricate boron/sulfur-codoped porous carbon from biomass sources, mainly utilizing four biomass materials. Detailed material characterization showed that the samples produced by this approach possess rich B and S doping. Additionally, the original biomass materials treated by activation produce abundant pores. Therefore, owing to the synergetic effect of abundant atomic doping and microporous/mesoporous distribution, the obtained carbon as electrode material manifested excellent specific capacitances of 290 F g−1 at a 0.5 A g−1 current density. Moreover, the specific energy of the prepared samples of the as-assembled symmetric supercapacitor is as high as 16.65 Wh kg−1 in 1 M Na2SO4, with a brilliant cyclical performance of only a 2.91% capacitance decay over 10,000 cycles. In addition, it has been verified universally that three other types of bio-wastes can also prepare electrode material using this method. This paper represents a significant attempt to turn waste biomass into treasure while also providing ideas for the design and preparation of supercapacitor electrode materials.

Sustainable Slow-Pyrolysis Simulation of 12 Lignocellulosic Bio-wastes: CO2 Emission, Energy, and Water Consumption

The development and increase of the agro-industrial activity generate bio-waste that represents significant quantities and causes environmental impacts, as residual effluents and solid wastes. These bio-wastes can be converted into different products through the pyrolysis processes (biochar, bio-oil, and gas). In this work, the pyrolysis at 673, 773, and 873 K of 12 types of bio-waste characterized by their elemental composition was assessed through the simulation process. Cape Open to Cape Open Simulator (COCO) free software was used in simulations. Thus, the biochar, bio-oil, and gas yields were predicted. Also, the energy, water consumption, and CO2 emission were calculated for each type of bio-waste. The marc and the stalk of white grape presented the highest biochar and bio-oil yields (30.7 and 53.1 %wt) at 673 K. The pistachio green shell presented the highest gas yield, 53.7 %wt at 873 K. The maximum energy consumption and CO2 emissions founded were 13.72 kWh and 3.72 kg/h for the stalk of white grape at 873 K respectively, while the lowest energy consumption and CO2 emission were 9.22 kWh and 2.31 kg/h for plum pits at 773 K respectively. The highest water consumption was 25.86 kg/h for the stalk of red grape at 773 K, while the lowest value was 14.30 kg/h for plum pits at 773 K.

The Transition to Energy Efficient Biomass Torrefaction Technology

Torrefaction or low-temperature pyrolysis makes it possible to obtain high-quality solid biofuel from various types of biomass (peat, wood and agricultural waste, various types of biowaste) for the needs of distributed energy. The creation of energy supply systems based on local fuel and energy resources is a priority task for Russian Federation. The article presents the results of research on the development of a new method for energy utilization of biomass by torrefaction.

Environmental assessment of a waste-to-energy practice: The pyrolysis of agro-industrial biomass residues

The bio-wastes pyrolysis is a waste to energy strategy that converts bio-wastes into valuable products (bio-char, bio-oil) with wide use in the agri-food sector. However, limited efforts are paid to the investigation of its environmental sustainability: in this context, the study contributes the need towards the assessment of a wide range of environmental impacts for the pyrolysis process of different types of bio-wastes under different operating conditions. The study estimates the potential environmental impacts related to bio-char production from the pyrolysis of several different agro-industrial residues and different temperatures and identifies the process “hot spots”. The analysis is carried out through the life cycle assessment methodology. The functional unit for the analysis is 1 MJ of thermal energy potentially released during the complete combustion of bio-char obtained from the pyrolysis process.

Recognize and assessment of key host humic-reducing microorganisms of antibiotic resistance genes in different biowastes composts

Humic-reducing microorganisms (HRMs) can utilize humic substance as terminal electron mediator promoting the bioremediation of contaminate, which is ubiquitous in composts. However, the impacts of HRMs on antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) in composts and different HRMs community composition following the types of biowastes effected the spread of ARGs have not been investigated. Herein, the dynamics and mobility of ARGs and HRMs during protein-, lignocellulose- and lignin-rich composting were investigated. Result show that ARGs change significantly at the thermophilic phase, and the relative abundance of most ARGs increase during composting. Seven groups of HRMs communities are classified as primary host HRMs of ARGs, and most host HRMs groups from protein-rich composts. Conclusively, regulating methods for inhibiting ARGs spread for different composts are proposed. HRMs show a higher ARGs dissemination capacity in protein-rich composts than lignocellulose- and lignin-rich composts, but the spread of ARGs can be inhibited by regulate physicochemical parameters in protein-rich composts. In contrary, most HRMs have inhibitory effects on ARGs spread in lignocellulose- and lignin-rich composts, and those HRMs can be used as a new agent that inhibits the spread of ARGs. Our results can help in understanding the potential risk spread of ARGs by inoculating functional bacteria derived from different biowastes composts for environmental remediation, given their expected importance to developing a classification-oriented approach for composting different biowastes.

An enhanced composting process with bioaugmentation: Mathematical modelling and process optimization

In this paper, two different types of biowaste composting processes were carried out - composting without and with bioaugmentation. All experiments were performed in an adiabatic reactor for 14 days. Composting enhanced with bioaugmentation was the better choice because the thermophilic phase was achieved earlier, making the composting time shorter. Additionally, a higher conversion of substrate (amount of substrate consumed) was also noticed in the process enhanced by bioaugmentation. A mathematical model was developed and process parameters were estimated in order to optimize the composting process. Based on good agreement between experimental data and the mathematical model simulation results, a three-level-four-factor Box-Behnken experimental design was employed to define the optimal process conditions for further studies. It was found that the air flow rate and the mass fraction of the substrate have the most significant effect on the composting process. An improvement of the composting process was achieved after altering the mentioned variables, resulting in shorter composting time and higher conversion of the substrate.

Dilution rate of compost leachate from different biowaste for the fertigation of vegetables

Compost leachate (CL) is often treated as sewage. Limited studies have characterised the use of CL for agriculture application due to the variation of nutrient range, potential pollutants and need for pretreatment before use. This paper reviewed the characteristics of CL in terms of its nutrients and physical characteristics from three types of biowastes, i.e. the organic portion of municipal solid waste (OP-MSW), animal manure and green waste. The nutrient range characterised are used to develop the dilution rate of the CL as fertigation water for three types of vegetables. The dilution rate of CL developed is based on the fertigation standards set by the Food and Agriculture Organization of the United Nations and Malaysia Standards. The results show that all CL contain high organic content and micronutrients, which exceeded the upper limits. For the fertigation of vegetables using the CL, based on the requirement of COD and micronutrients (Fe, Mn, Zn, Cu, Pb, Ni, Cd, Cr) of the vegetables, the CL from green waste required the lowest dilution rate (8–45 fold), followed by animal waste (33–65 fold) and the OP-MSW (193–1770 fold). The novel dilution range developed is vital to balance the essential nutrients in the CL while avoiding phototoxicity on plant and soil pollution. The dilution strategy developed is essential to support the conversion of CL as an organic liquid fertiliser for agricultural application.

Total organic carbon as a proxy for metal release from biostabilized wastes.

In this study, we introduce a simple screening method to predict the metal release from biostabilized wastes as a function of the total organic carbon (TOC) content of the sample. The method relies on a model that simulates the release of dissolved organic carbon (DOC) as a function of the applied liquid to solid (L/S) ratio. The metal release is then estimated using generic empirical DOC to metal correlation coefficients (KDOC,Me) extrapolated from the literature. Specifically, the results of leaching tests carried out on different types of biowastes and biostabilized wastes were used to calculate the upper and lower KDOC,Me values that can be expected for common metals of concern (Al, Ba, Cr, Cu, Mo, Ni, Pb, V, and Zn). The statistical analysis of the estimated empirical coefficients highlighted that for most of the investigated metals, the adoption of generic DOC to metal correlation coefficients introduces relatively low uncertainties. The quartiles ratio (QR calculated as the ratio of third and first quartile) of the KDOC,Me coefficients extrapolated from the literature was indeed below 3 for Cu, Ni, and Zn and below 5 for Al, Ba, Cr, Pb, and V. Only for Mo, the QR was around 10 indicating that for this element, DOC can be a poor indicator of the release expected as a function of the applied L/S. Furthermore, by performing a sensitivity analysis, we found that the experimental conditions only slightly influence the metals release predicted by the model. Based on this evidence, simple nomograms that estimate the cumulative metal release in percolation column tests as a function of the applied L/S are provided. Furthermore, a simple equation that predicts the cumulative metal release expected at L/S of 10L/kg is presented. The application of the latter to the results of percolation column tests carried out on 8 mechanical biological treatment (MBT) waste samples highlighted that the predicted metals release was close to the measured values with deviations within a factor of 5 for all the investigated metals.

Mechanical separation of impurities in biowaste: Comparison of four different pretreatment systems

Impurities in biowaste, such as plastics, glass, metals and inert material, negatively impact the operation of anaerobic digestion plants and compost quality, and have to be removed prior to the anaerobic digestion process. Different mechanical pretreatments are available for this purpose. However, data on the removal efficiencies of pretreatment systems for different types of biowaste and for different kinds of impurities are still scarce. This study aims to determine the efficiencies for impurity removal of four biowaste pretreatment plants (BTPs) at real scale – (1) drum-screen + shredder + piston press; (2) shredder + piston press + screw press; (3) separation-mill; and (4) pulper + drum-screen. BTP 1 treats mixed food and garden wastes, while BTP 2, 3 and 4 treat mostly food waste. The efficiency of the pretreatment systems was influenced by the type of pretreated biowaste. The recovery of organics by the press was more efficient when pretreating food waste (BTP 2, 93%) than for treating mixed food and garden wastes (BTP 1, 77%). BTP 3 presented the highest recovery of biogas (up to 98%), but also the highest transfer of inert particles to the substrate. On the contrary, BTP 4 was the most efficient for the removal of inert particles; however, this system also presented 18% loss of biogas potential.

Pyrolytic conversion of biowaste-derived hydrochar: Decomposition mechanism of specific components

Hydrothermal carbonization (HTC) coupled with subsequent downstream conversion is a new concept for the utilization of industrial biowastes for energy production. In this work, three representative biowastes (i.e., lignocellulosic, non-lignocellulosic and ash-rich samples) were selected for HTC pretreatment, and the subsequent pyrolysis of the derived hydrochars was evaluated using multiple kinetic models and combined instrumental analyses. Results showed that the thermal weight loss peak for each biowaste was progressively shifted to a higher temperature after HTC pretreatment, while the maximum value of weight loss was reduced compared to that of the original feedstock. This change was shown to be caused by the shift in biowaste compositions to a more stable one in the hydrothermal stage, but the dissimilarity of evolution pathways among specific components affected the rate and degree of pyrolysis of the hydrochars to different extent. In addition, fewer volatile compounds were released during the pyrolysis of the hydrochars, and the composition of pyrolytic volatiles was found to be mainly dependent on the types of biowaste and HTC conditions. These findings not only provide essential information on the pyrolytic capability of HTC-derived hydrochars, but can also help in designing, optimizing and scaling up the thermochemical conversion of industrial biowastes.

Towards the circular nitrogen economy – A global meta-analysis of composting technologies reveals much potential for mitigating nitrogen losses

Composting is an important technology to treat biowastes and recycle nutrients, but incurs nitrogen (N) losses that lower the value of the final products and cause pollution. Technologies aimed at reducing N losses during composting have inconsistent outcomes. To deepen insight into mitigation options, we conducted a global meta-analysis based on 932 observations from 121 peer-reviewed published studies. Overall, N losses averaged 31.4% total N (TN), 17.2% NH3-N, and 1.4% N2O-N, with NH3-N accounting for 55% of TN losses. The primary drivers affecting N losses were composting method, type of biowaste, and duration of composting. N losses were significantly impacted by the carbon-to-nitrogen (C/N) ratio of the input materials (feedstock of nutrient dense biowastes and C-rich bulking agents), moisture content and pH. Our analysis revealed N-conserving optima with C/N ratios of 25–30, 60–65% moisture content and pH 6.5–7.0. In situ mitigation technologies that control feedstock and processing conditions reduced average N losses by 31.4% (TN), 35.4% (NH3-N) and 35.8% (N2O-N). Biochar and magnesium-phosphate salts emerged as the most effective N-conserving strategies, curbing losses of TN by 30.2 and 60.6%, NH3 by 52.6 and 69.4%, and N2O by 66.2 and 35.4% respectively. We conclude that existing technologies could preserve ~0.6 Tg of biowaste-N globally, which equates to 16% of the chemical N-fertilizer used in African croplands, or 39% of the annual global increases of 1.58 Tg fertilizer-N. However, the adoption of N-conserving technologies is constrained by a lack of knowledge of best practice, suitable infrastructure, policies and receptive markets. To realize an N-conserving composting industry that supports sustainable practices and the circular nitrogen economy, stakeholders have to act collectively. Benefits will include lowering direct and indirect greenhouse gas emissions associated with agriculture, and facilitating the recarbonization of soils.