Search Results (2,449)

Miniaturized near-infrared (NIR) spectrometers are revolutionizing the agri-food industry thanks to their compact size and ultra-fast analysis capabilities. This work compares the analytical performance of a handheld NIR spectrometer and a benchtop FT-NIR for the determination of several parameters, namely, pH, electrical conductivity (EC₂₅), C/N ratio, and organic matter as LOI (loss-on-ignition) in compost. Samples were collected at different stages of maturity from a full-scale facility that processes olive mill semi-solid residue together with olive tree pruning residue and animal manure. Using an FT-NIR spectrometer, satisfactory predictions (RPD > 2.0) were obtained with both partial least squares (PLS) and support vector machine (SVM) regression, SVM clearly being superior in the case of pH (RMSEP = 0.26; RPD = 3.8). The superior performance of the FT-NIR spectrometer in comparison with the handheld spectrometer was essentially due to the extended spectral range, especially for pH. In general, when analyzing intact samples with the miniaturized spectrometer, sample rotation decreased RMSEP values (~20%). Nevertheless, a fast and simple assessment of compost quality with reasonable prediction performance can also be achieved on intact samples by averaging static measurements acquired at different sample positions. Full article

Agricultural activities generate substantial quantities of waste, which are often relegated to landfills or incineration. However, these residues can be effectively valorized through composting, which transforms them into valuable organic fertilizers (OF). Composting agricultural waste (AW) mitigates environmental impacts and offers significant benefits in enhancing soil fertility and productivity. This practice is particularly beneficial in regions with low soil fertility and degraded land, where compost can improve soil health and productivity. This review provides a comprehensive analysis of the literature on the valorization of AW through composting, focusing on its environmental, agricultural, and economic impacts on soil health, especially in Morocco’s agricultural ecosystems. It synthesizes findings from studies published over the past two decades to offer critical insights and recommendations for optimizing composting practices. By systematically evaluating, this review highlights composting as a pivotal strategy for enhancing soil health, reducing environmental impact, and promoting sustainable AW management. Future research is essential to explore opportunities for optimizing the composting process, including content enhancement and processing duration. In summary, the composting process can be seen as an effective and sustainable solution that fits within the principles of circular economy (CE) and that requires careful evaluation and ongoing monitoring. Full article

Basic inventory is required for proper understanding and utilization of Earth’s natural resources, especially with increasing soil degradation and species loss. Soil carbon is newly refined at >30,000 Gt C (gigatonnes C), ten times above prior totals. Soil organic carbon (SOC) is up to 24,000 Gt C, plus plant stocks at ~2400 Gt C, both above- and below-ground, hold >99% of Earth’s biomass. On a topographic surface area of 25 Gha with mean 21 m depth, Soil has more organic carbon than all trees, seas, fossil fuels, or the Atmosphere combined. Soils are both the greatest biotic carbon store and the most active CO₂ source. Values are raised considerably. Disparity is due to lack of full soil depth survey, neglect of terrain, and other omissions. Herein, totals for mineral soils, Permafrost, and Peat (of all forms and ages), are determined to full depth (easily doubling shallow values), then raised for terrain that is ignored in all terrestrial models (doubling most values again), plus SOC in recalcitrant glomalin (+25%) and friable saprock (+26%). Additional factors include soil inorganic carbon (SIC some of biotic origin), aquatic sediments (SeOC), and dissolved fractions (DIC/DOC). Soil biota (e.g., forests, fungi, bacteria, and earthworms) are similarly upgraded. Primary productivity is confirmed at >220 Gt C/yr on land supported by Barrow’s “bounce” flux, C/O isotopes, glomalin, and Rubisco. Priority issues of species extinction, humic topsoil loss, and atmospheric CO₂ are remedied by SOC restoration and biomass recycling via (vermi-)compost for 100% organic husbandry under Permaculture principals, based upon the Scientific observation of Nature. Full article

In the present work, the impact of three new bacterial strains and their consortium on composting was evaluated using textile waste as a main substrate mixed with paper, cardboard and green waste, The effectiveness of these micro-organisms in accelerating organic matter degradation was tested. For bioaugmentation of composting, three concentrations (4%, 6% and 8%) were applied. Among the three strains tested, one strain and the consortium demonstrated high organic matter degradation potential, achieving a total organic carbon concentration between 19–21%, total Kjeldahl nitrogen between 1.29–1.56%, a C/N ratio between 13–16%, and a temperature exceeding 55 °C. In the current study, mature compost was attained in 10 weeks, instead of the 44 weeks required for conventional composting and the 12 weeks achieved with other strains previously used. Identification of the strains by 16S rRNA sequencing revealed that they belonged to Bacillus sp., Paenibacillus sp., and Enterobacter aerogenes, respectively. These strains are recognized for their remarkable potential to breakdown a broad variety of organic matter, including lignocellulosic molecules. Furthermore, incorporation of bacteria into the waste mixture (either separately or as a consortium) extended the thermophilic phase by 2 weeks in this study, especially Bacillus sp., Paenibacillus sp. and consortium, leading to a significant reduction in compost production time. It is noteworthy that the efficacy of these strains was considerably greater compared with the three previous strains (i.e., Streptomyces cellulosae, Achromobacter xylosoxidans and Serratia liquefaciens), which were isolated from compost and used for bioaugmentation in a previous study. Our results demonstrate that bioaugmentation by endogenous microbial strains and/or their consortium significantly accelerates the composting process. Full article

According to the Bureau of National Statistics of the Republic of Kazakhstan, by the end of 2023, approximately 120 million tons of municipal solid waste (MSW) had been generated across over 3200 landfills in the country. About 4.5 million tons are generated annually, of which only about 15% are recycled. The accumulation of both unsorted and sorted waste poses significant environmental risks, primarily through the generation of methane, a greenhouse gas that is 28 times more dangerous than carbon dioxide in contributing to the planet’s greenhouse effect over a century and 84 times more effective over a 20-year timeframe. The objective of this research is to examine the physicochemical composition, as well as the physical and thermal-chemical properties, of municipal solid waste from six cities in Kazakhstan: Astana, Almaty, Shymkent, Aktobe, Karaganda, and Ust-Kamenogorsk. Unlike existing studies, this study has a uniform waste sample, which includes the complete emptying of dozens of containers from different areas of the cities under consideration. Thus, the average composition of solid waste across the cities was maintained. Analysis of the physicochemical composition was conducted for both unsorted and sorted municipal solid waste from all cities, determining the total and analytical moisture content, ash content, and volatile matter, as well as the higher and lower calorific values. The calorific value of unsorted waste by city was as follows, in kJ/kg: Astana,8850.37; Almaty, 9244.57; Atobe, 9596.41; Shymkent, 9425.48; Karaganda, 8902.8; Ust-Kamenogorsk, 9669.07. The calorific value of sorted waste was as follows, in kJ/kg: Astana, 11,922.79; Almaty, 11,692.31; Atobe, 11,913.13; Shymkent, 12,494.38; Karaganda, 11,671.92; Ust-Kamenogorsk, 12,462.52. The efficiency of sorting was estimated as the first stage of MSW processing. The efficiency factor of the manual sorting process in practice was 0.4–0.8. The results obtained enable the evaluation of technologies for the effective management of municipal solid waste and facilitate experimental investigations into semi-industrial pyrolysis, combustion, plasma processing, and composting facilities. Full article

The increasing presence of compostable bioplastics as substitutes for conventional fossil-based plastics necessitates a deeper understanding of their environmental impacts, particularly in marine ecosystems, where they often accumulate. This study examines the leaching potential of different phthalic acid esters (PAEs) from commercial biodegradable plastic bags into natural seawater over a three-month period. Degradation experiments were conducted to investigate the release of PAEs under direct solar radiation exposure and in shielded conditions. ¹H-NMR analysis of the seawater confirmed the release of phthalates, with higher concentrations observed in the samples exposed to sunlight. The leaching rate ranged from 264–342 microgram/g plastic under light exposure to 20–167 microgram/g in dark conditions. These results indicate that the accumulation of compostable plastic waste in coastal marine environments leads to the release of phthalic acid esters, with potential implications for marine ecosystem health and human exposure to these emerging contaminants. Full article

The growing awareness of the depletion of fossil fuels and numerous environmental issues have led to increased interest in finding natural components that can be used to produce various types of fuels. In this study, composts made from the organic fraction of agri-food waste (i.e., two composts produced in a bioreactor and one obtained from a Municipal Waste Disposal Facility) were evaluated for the first time as potential sources of additives for fuel production. The presence of fatty acid methyl esters was determined using gas chromatography–mass spectrometry (GC-MS/SIM), while the calorific value and heat of combustion of the samples were measured in accordance with the PN-EN ISO 1928:2002 standard using a calorimeter. Chromatographic studies identified the presence of 33 compounds, predominantly unsaturated esters. The highest ester content was noted in the compost obtained from the company, while the lowest content was found in the compost containing grass, buckwheat husk, and apple pomace. Of the studied raw materials, the highest calorific value and heat of combustion on a dry matter basis were observed for the compost containing grass, buckwheat husk, and apple pomace, while the lowest values were recorded for the compost obtained from the company. Based on the obtained results, it can be concluded that composts could serve as biocomponents of fuels. Full article

The aim of this work was to analyze the influence of thermal conditions and the presence of biomass in the chamber on the composting process. The work analyzed the process of the aerobic decomposition of grass, the inoculating fraction and the structure-forming fraction. The analysis covered the batch composting process using veterinary biomass in the treatment chamber. Observations of the process included the following: determining the rate of mineralization, process temperatures, pH, process gas concentrations, chemical composition, physical properties of the compost, and the maturity of the compost. In all analyzed samples, the composting process works correctly in terms of thermal parameters; the obtained fresh compost, after the thermophilic phase has ended, requires action be taken with reference to the values of the seed generation index and the respiration activity (AT4) parameter. After the thermophilic phase, after 60 days of composting, it was noted that for P1 (Probe 1) and P2 (Probe 2) mixtures, the seed germination level decreased below 10%. The AT4 parameter for the P1 and P2 compost samples was between 29.8 and 26.2 mg O₂∙g⁻¹. The improvement of the germination level to values in the 30% to 40% range for the maturing compost samples was caused by the thermal conversion of biomass with the regulation of air and water conditions. The phytotoxicity of the compost was overcome, while an improvement in the value of the AT4 index was achieved. Full article

To evaluate the effects of the type and proportion of bulking agents on compost maturity, chicken manure feedstock (J) was selected as the main raw material for aerobic composting, and wood chips (M), straw (S), and cornmeal (Y) were used as bulking agents. The ratios of chicken manure feedstock to the three bulking agents were set at 1:3, 1:1, and 3:1, respectively. The compost mixture composed of wood chips (M) and feedstock (J) in a 1:1 ratio exhibited the highest temperature (75 °C). The treatment with a bulking-agent-to-feedstock ratio of 3:1 exhibited the lowest temperature (52 °C) and the longest high-temperature period (about 10 days). Moreover, the compost mixture composed of wood chips (M) and feedstock (J) in a 3:1 ratio exhibited the highest seed germination index (1.32), while the GI values for all cornmeal treatments did not meet the standard requirements (0.4). The predominant microorganisms in all three treatments included Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria. The total carbon transformation-related microorganism abundance in MJ31, SJ31, and YJ31 was 1.65%, 10.69%, and 3%, respectively. Further analysis showed that the bioavailability of feedstock was strongly correlated with compost maturity. The treatment with a bulking-agent-to-feedstock ratio of 3:1, with the highest GI, also exhibited the highest bioavailability. These results can guide the selection of the appropriate bulking agent and the optimal bulking-agent-to-feedstock ratio, offering a new direction for the optimization of the composting process. Full article

Biochar undergoes significant transformations in soil as a result of chemical, physical, and biological processes. These alterations can impact its initial properties, influencing both its agronomic effectiveness and its capacity for carbon sequestration. Long-term observations of biochar-aging effects in soil are limited but highly relevant, as they provide a more realistic picture of the agronomic and societal benefits of biochar than short-term studies with relatively “fresh” biochar. This study aimed to describe the aging effects of biochar and their impact on a range of soil properties at a long-term biochar experiment in Bayreuth, Germany. For this purpose, soil and biochar samples were taken 13 years after application (two variants: 1. co-composted and 2. pristine biochar) and compared with a fresh variant in which the same unaged biochar was freshly mixed with the control soil. The soil quality parameters, pH and electrical conductivity, decreased significantly (p < 0.05) during biochar aging. Specifically, the pH dropped from 7.4 in freshly biochar-amended soil to 6.8 in the pristine aged biochar variant and 6.9 in the co-composted aged biochar variant. Electrical conductivity decreased from 217.0 µS cm⁻¹ in the freshly amended soil to 81.1 µS cm⁻¹ in the pristine aged variant and 87.6 µS cm⁻¹ in the co-composted aged variant. Nitrogen retention was enhanced in the soil amended with co-composted aged biochar compared to the pristine aged biochar soil. Total nitrogen (TN) was higher at 1.94 g kg⁻¹ versus 1.57 g kg⁻¹ (p < 0.05), and ammonium-N (NH₄⁺-N) was slightly elevated at 35.7 mg kg⁻¹ versus 33.0 mg kg⁻¹, although the difference was not statistically significant. The nitrate-N (NO₃⁻-N) content was significantly lower in all biochar-amended soil variants compared to the control soil. Total carbon (TC) levels decreased during biochar aging in all soil variants. However, the reduction was significantly lower in the co-composted aged biochar soil (25.0 g kg⁻¹) compared to the pristine aged biochar soil (20.5 g kg⁻¹, p < 0.05). This study identified multiple aging effects on biochar following 13 years of exposure in loamy soil. Importantly, the results showed that compared to the amendment of pristine biochar, co-composting did not diminish the TC of the treated soil, and more N could be retained, 13 years after amendment. In fact, co-composting prior to soil application is recommended to fully realize the potential agronomic benefits. Full article

Kazakhstan is embarking on a fresh approach to managing waste, aiming to recycle and repurpose solid household waste while integrating innovative, eco-friendly technologies for its treatment and disposal. The main goal is to reduce the amount of waste sent to landfills and instead convert it into more stable forms, lessening its harmful impact on the environment. This effort requires a comprehensive strategy, especially as existing landfills still need to be managed and rehabilitated when they reach capacity. It is essential to use municipal solid waste as a resource for producing various goods, which not only helps in landfill management but also aligns with principles of sustainability. This approach aligns with circular economic principles and helps to reduce the technological impact of landfills on the surrounding environment. The main types of waste in the Aktas landfill were identified as a result of this research: it is glass, of which only 3% is recycled. In our results, the setup allowed for the extraction of valuable components from the fine fraction, which can then be recycled. This enriches the organic material ready for composting (organo-mineral raw material mixture) with food waste. Full article

Soilborne plant pathogens significantly impact agroecosystem productivity, emphasizing the need for effective control methods to ensure sustainable agriculture. Soil fungistasis, the soil’s ability to inhibit fungal spore germination under optimal conditions, is pivotal for biological control. This study explores soil fungistasis variability across land-use intensities, spanning deciduous and evergreen forests, grasslands, shrublands, and horticultural cultivations in both open fields and greenhouses. Soil characterization encompassed organic matter, pH, total nitrogen, C/N ratio, key cations (Ca²⁺, Mg²⁺, K⁺, Na⁺), enzymatic activities, microbial biomass, and soil microbiota analyzed through high-throughput sequencing of 16s rRNA genes. Fungistasis was evaluated against the pathogenic fungi Botrytis cinerea and the beneficial microbe Trichoderma harzianum. Fungistasis exhibited similar trends across the two fungi. Specifically, the application of glucose to soil temporarily annulled soil fungistasis for both B. cinerea and T. harzianum. In fact, a substantial fungal growth, i.e., fungistasis relief, was observed immediately (48 h) after the pulse application with glucose. In all cases, the fungistasis relief was proportional to the glucose application rate, i.e., fungal growth was higher when the concentration of glucose was higher. However, the intensity of fungistasis relief largely varied across soil types. Our principal component analysis (PCA) demonstrated that the growth of both Trichoderma and Botrytis fungi was positively and significantly correlated with organic carbon content, total nitrogen, iron, magnesium, calcium, and sodium while negatively correlated with fluorescein diacetate (FDA) hydrolysis. Additionally, bacterial diversity and composition across different ecosystems exhibited a positive correlation with FDA hydrolysis and a negative correlation with phosphoric anhydride and soil pH. Analysis of bacterial microbiomes revealed significant differences along the land use intensity gradient, with higher fungistasis in soils dominated by Pseudoarthrobacter. Soils under intensive horticultural cultivation exhibited a prevalence of Acidobacteria and Cyanobacteria, along with reduced fungistasis. This study sheds light on soil fungistasis variability in diverse ecosystems, underscoring the roles of soil texture rather than soil organic matter and microbial biomass to explain the variability of fungistasis across landscapes. Full article

Existing studies have demonstrated the positive effects of nano-sized iron oxide on compost maturity, yet the impact of nano-sized iron oxide on phosphorus speciation and bacterial communities during the composting process remains unclear. In this study, pig manure and straw were used as raw materials, with biochar-supported nano-sized iron oxide (BC-Fe₃O₄NPs) as an additive and calcium peroxide (CaO₂) as a co-agent, to conduct an aerobic composting experiment with pig manure. Four treatments were tested: CK (control), F1 (1% BC-Fe₃O₄NPs), F2 (5% BC-Fe₃O₄NPs), and F3 (5% BC-Fe₃O₄NPs + 5% CaO₂). Key findings include the following. (1) BC-Fe₃O₄NPs increased compost temperatures, with F3 reaching 61℃; F1 showed optimal maturity (C/N ratio: 12.90). (2) BC-Fe₃O₄NPs promoted stable phosphorus forms; Residual-P proportions were higher in F1, F2, and F3 (25.81%, 51.16%, 51.68%) than CK (19.32%). (3) Bacterial phyla Firmicutes, Actinobacteria, and Proteobacteria dominated. BC-Fe₃O₄NPs altered community composition, especially on day 7. Firmicutes dominated CK, F1, and F3; Proteobacteria dominated F2. At the genus level, day 7 showed Corynebacterium (CK), Clostridum (F1, F3), and Caldibacillus (F2) as predominant. (4) Pearson correlation analysis revealed shifted correlations between phosphorus forms and bacterial phyla after BC-Fe₃O₄NPs addition. Firmicutes positively correlated with NaOH-OP in F1 during the thermophilic phase, facilitating phosphate release and adsorption by BC-Fe₃O₄NPs. The significance of correlations diminished with increasing additive concentration; in F3, all phyla positively correlated with various phosphorus forms. Full article

Sustainable management of organic waste, such as food waste (FW) and livestock manure (LS), is essential for reducing pollution and promoting resource recycling. This study investigated the effects of Bacillus sp. inoculation and biochar addition on composting efficiency, microbial dynamics, and physicochemical properties. Bacillus sp. accelerated the breakdown of cellulose and lignin, reduced moisture content, stabilized pH, and mitigated ammonia volatilization. Biochar reduced ammonia emissions by 17.04%, increasing to 28.89% with Bacillus sp. Next-generation sequencing revealed Bacillus sp. enhanced microbial diversity, suppressed pathogens, and promoted beneficial microbial interactions. LS treatments retained Firmicutes dominance (up to 95.17%), improving nitrogen retention, while FW treatments transitioned to Proteobacteria and Bacteroidota, driving plant material decomposition. By day 35, Bacillus sp. increased late-stage microbial taxa (Deinococcota, Myxococcota), linked to cellulose degradation and pathogen suppression. In FW biochar compost (FWBC), Planococcaceae and Bacillaceae synergistically decomposed complex organic matter. LS biochar compost (LSBC) reduced anaerobic families like Clostridiaceae and Peptostreptococcaceae, lowering methane and hydrogen sulfide emissions. Microbial network analysis highlighted improved cooperation under Bacillus sp., with LSBC sustaining positive interactions at higher dosages. These results demonstrate that microbial inoculants and biochar enhance composting efficiency, nutrient cycling, and environmental sustainability. Full article

Dog and cat faeces are a globally neglected issue that demands proper management. The poor handling of pet waste not only impacts environmental health but also contributes to community conflicts due to insufficient waste management practices. The objectives were to investigate the properties of pet wastes compared to livestock wastes (pigs, hens, and cattle) with the intention of formulating an efficient compost product suitable for agricultural applications. Faeces from dogs and cats were collected from the community, while faeces from livestock (pigs, cattle, and hens) were collected from farms. Faeces were mixed with probiotics, rice bran, and rice husk to make compost and used to grow sweet corn plants. The nutrient content was compared between fresh and composted faeces. Composted manure from different animal sources was compared for its effectiveness in promoting sweet corn growth. The results showed that fresh and composted dog and cat manures contained higher levels of nutrients (p < 0.05) compared to livestock manures. Additionally, composted pet manure accelerated (p < 0.05) the growth of the plants compared to composted livestock manures and control groups. This is the first study to conclude that composted pet faeces surpass livestock manure in their higher nutrients and enhance plant growth. The findings could help reduce pet waste and transform it into a valuable recycled resource. However, the safety of composted manure, especially concerning toxoplasmosis from cat faeces, remains a significant concern and requires further investigation. Full article