Search Results (13)

Spent mushroom compost (SMC) is a waste byproduct generated by the mushroom industry, with the current disposal methods involving landfills or incineration, causing environmental problems. This study introduces a cascading valorization based on circular economy. A water-washing pretreatment is suggested to reduce the ash content and improve the calorific value. Furthermore, an oxidative torrefaction is proposed to enhance the physicochemical properties and evaluate the residence time, temperature, and initial weight effects. The investigation revealed that the calorific value increased by 49.46% in the best water washing scenario and the SMC contains laccase. During SMC torrefaction, mass and energy yields exceeded 80%, and the calorific value was improved. Finally, torrefaction in situ CO₂ capture was achieved by forming CaCO₃, with a mass fraction increase of up to 7.4%. The study describes the cascading innovation use of this residue on a TRL4 higher than previously reported studies, thereby contributing to gaining an understanding of sustainable industrial mushroom production. Full article

Research into alternative vineyard practices is essential to maintain long-term viticulture sustainability. Organic mulching on the vine row improves vine cultivation properties, such as increasing soil water retention and nutrient availability. This study overviewed the effects of three organic mulches (spent mushroom compost (SMC), straw (STR), and grapevine pruning debris (GPD)) and two conventional soil practices (herbicide application (HERB) and tillage (TILL)) on grapevine physiology, agronomy, and grape quality parameters over three years. SMC mulch enhanced soil moisture and nutrient concentration. However, its mineral composition increased soil electrical conductivity (0.78 dS m⁻¹) and induced grapevine water stress due to osmotic effects without significantly affecting yield plant development. Only minor differences in leaf physiological parameters were observed during the growing season. However, straw (STR) mulch reduced water stress and increased photosynthetic capacity, resulting in higher pruning weights. Organic mulches, particularly SMC and STR, increased grape pH, potassium, malic acid, and tartaric acid levels, while reducing yeast assimilable nitrogen. The effect of organic mulching on grapevine development depends mainly on soil and mulch properties, soil water availability, and environmental conditions. This research highlights the importance of previous soil and organic mulch analysis to detect vineyard requirements and select the most appropriate soil management treatment. Full article

This study focuses on applying ash reduction treatments in order to explore the potential for industrial-scale thermochemical utilization of Spent Mushroom Compost (SMC). SMC is a waste byproduct generated by the mushroom industry. Typically, for every kilogram of produced mushrooms, five kilograms of SMC are discarded, with current disposal methods involving landfills or incineration, causing environmental problems. Utilizing SMC effectively presents challenges due to the inherent properties of this biomass type, characterized by high moisture and ash content, low fixed carbon content, and material heterogeneity. These attributes create difficulties when employing a thermochemical valorization route due to the low carbon content and mineral treatments involved. The results have unveiled the heterogeneous nature of the material and its individual components when physically separated. Among the three identified fractions (agglomerated, woody, and fines), the woody fraction showed the highest potential for thermochemical utilization. Notably, when subjected to washing with distilled water and citric acid treatments, it resulted in up to 66% ash reduction, a significant outcome. Other fractions of the material may find potential applications in agriculture. The effective utilization of such high-volume waste biomasses demands diverse and innovative approaches, underlining the urgency and complexity of the problem and the need to employ the principles of a circular economy. Full article

The addition of soil amendments and plants in heavy metal-contaminated soil can result in a significant impact on physicochemical properties, microbial communities and heavy metal distribution, but the specific mechanisms remain to be explored. In this study, Koelreuteria paniculata was used as a test plant, spent mushroom compost (SMC) and attapulgite (ATP) were used as amendments, and manganese slag was used as a substrate. CK (100% slag), M0 (90% slag + 5% SMC + 5% ATP) and M1 (90% slag + 5% SMC + 5% ATP, planting K. paniculata) groups were assessed in a pilot-scale experiment to explore their different impacts on phytoremediation. The results indicated that adding the amendments significantly improved the pH of the manganese slag, enhancing and maintaining its fertility and water retention. Adding the amendments and planting K. paniculata (M1) significantly reduced the bioavailability and migration of heavy metals (HMs). The loss of Mn, Pb and Zn via runoff decreased by 15.7%, 8.4% and 10.2%, respectively, compared to CK. K. paniculata recruited and enriched beneficial fungi, inhibited pathogenic fungi, and a more stable fungal community was built. This significantly improved the soil quality, promoted plant growth and mitigated heavy metal toxicity. In conclusion, this study demonstrated that the addition of SMC-ATP and planting K. paniculata showed a good phytostabilization effect in the manganese slag and further revealed the response process of the fungal community in phytoremediation. Full article

Spent mushroom compost (SMC) substrates are commonly used as growth media for greenhouse crops and horticulture production. This study aimed to investigate the responses of physiochemical soil properties, enzyme activities, and microbial community compositions to different cultivation durations and SMC soil treatments on tomatoes. The experiment included the following treatments: SMC substrate and the surrounding soil after planting at 1, 3, and 7 years and comparing control treatments including non-planting SMC substrates and continuous mono-cropping soil. The results revealed that the SMC substrates had higher contents of total N P and organic C nutrients than the surrounding soil treatments. The physicochemical soil properties and soil enzyme activities of the SMC substrates were significantly decreased with longer cultivation duration. Microbial alpha diversity was higher in the SMC substrates regardless of cultivation duration than in the control treatments. It was observed that many beneficial microbes, such as bacteria of the Deinococcus-Thermus, Halanaerobiaeota, and Nitrospirae phyla, and the fungi of the Basidiomycota, Mortierellomycota, and Chytridiomycota phyla were enriched in the SMC substrates. The SMC substrate and surrounding soil had enriched several potentially beneficial microorganism genera such as the bacterial Saccharimonadales, Gaiella, Bacillus, and the fungal Thermomyces, Kernia, and Mortierella. Therefore, the agro-based SMC substrate grooved cultivation system is recommended as an environmentally compatible practice for tomato growth in the greenhouse. Full article

The most common approaches for the in-situ bioremediation of contaminated sites worldwide are bioaugmentation and biostimulation. Biostimulation has often proved more effective for chronically contaminated sites. This study examined the effectiveness of optimized water hyacinth compost in comparison with other organic and inorganic amendments for the remediation of crude oil-polluted soils. Water hyacinth was found to be rich in nutrients necessary to stimulate microbial growth and activity. An organic geochemical analysis revealed that all amendments in this study increased total petroleum hydrocarbon (TPH) biodegradation by ≥75% within 56 days, with the greatest biodegradation (93%) occurring in sterilized soil inoculated with optimized water hyacinth compost. This was followed by polluted soil amended with a combination of spent mushroom and water hyacinth composts (SMC + WH), which recorded a TPH biodegradation of 89%. Soil amendment using the inorganic fertilizer NPK (20:10:10) resulted in 86% TPH biodegradation. On the other hand, control samples (natural attenuation) recorded only 4% degradation. A molecular analysis of residual polycyclic aromatic hydrocarbons (PAHs) showed that the 16 PAHs designated by the US EPA as priority pollutants were either completely or highly degraded in the combined treatment (SMC + WH), indicating the potential of this amendment for the environmental remediation of soils contaminated with recalcitrant organic pollutants. Full article

The edible mushroom industry has grown significantly in recent years due to the dietary change and the demand for heathy food. However, the spent mushroom compost (SMC) will be produced in large quantities after the harvest, thus forming an agricultural waste requiring proper management other than dumping or burning. In this work, two types of SMCs with the cultivation of shiitake fungus (SF) and black fungus (BF) were converted into porous biochar products (a series of SMC-SF-BC and SMC-BF-BC) at higher pyrolysis temperatures (i.e., 400, 600 and 800 °C) based on their thermochemical characteristics, using thermogravimetric analysis (TGA). The pore and chemical properties of the resulting products, including surface area, pore volume, average pore size, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier Transform infrared spectroscopy (FTIR), were studied to correlate them with the most important process parameter. The results showed that the pore properties of the biochar products indicated a significant increase with the increase in the pyrolysis temperature from 400 to 600 °C. The data on the maximal Brunauer-Emmett-Teller (BET) surface area for the biochar products produced at 800 °C (i.e., SMC-SF-BC-800 and SMC-BF-BC-800) were found to be 312.5 and 280.9 m²/g, respectively. Based on the EDS and FTIR, plenty of oxygen-containing functional groups were found on the surface of the resulting biochar products. Full article

The public is already aware that nitrate pollution caused by nutrient runoff from farms is harmful to aquatic life and human health, and there is an urgent need for a product/technology to solve this problem. A biochar adsorbent was synthesized and used to remove nitrate ions from aqueous media based on spent mushroom compost (SMC), pre-treated with iron (III) chloride hexahydrate and pyrolyzed at 600 °C. The surface properties and morphology of SMCB/Fe were investigated using Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The effect of main parameters such as the adsorbent dosages, pH of the solutions, contact times, and ion concentrations on the efficiency of nitrate removal was investigated. The validity of the experimental method was examined by the isothermal adsorption and kinetic adsorption models. The nitrate sorption kinetics were found to follow the pseudo-second-order model, with a higher determination coefficient (0.99) than the pseudo-first-order (0.86). The results showed that the maximum percentage of nitrate adsorption was achieved at equilibrium pH 5–7, after 120 min of contact time, and with an adsorbent dose of 2 g L⁻¹. The highest nitrate adsorption capacity of the modified adsorbent was 19.88 mg g⁻¹. Full article

Spent mushroom composts (SMCs) are waste products of mushroom cultivation. The handling of large amounts of SMCs has become an important environmental issue. Phthalates are plasticizers which are widely distributed in the environment and urban wastewater, and cannot be effectively removed by conventional wastewater treatment methods. In this study, SMCs are tested for their ability to remove phthalates, including benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), and diethyl phthalate (DEP). Batch experiments reveal that BBP, DBP, and DEP can be degraded by the SMC enzyme extracts of four edible mushrooms: Pleurotus eryngii, Pleurotus djamor, Pleurotus ostreatus, and Auricularia polytricha. Potential fungus enzymes associated with BBP, DBP, and DEP degradation in SMCs (i.e., esterases, oxygenases, and oxidases/dehydrogenases) are uncovered by metaproteomic analysis using mass spectrometry. Bioreactor experiments indicate that the direct application of SMCs can remove BBP, DBP, and DEP from wastewater, through adsorption and biodegradation. The results of this study extend the application of white-rot fungi without laccases (e.g., Auricularia sp.) for the removal of organic pollutants which are not degraded by laccases. The application of SMCs for phthalate removal can be developed into a mycoremediation-based green and sustainable technology. Full article

Many reclaimed opencast coal-lands in Wales are now seriously degraded. This study explores the 10-year growth of native trees planted on compacted coal spoil. It compares the relative benefits of planting with spent mushroom compost (SMC) or well-rotted farmyard manure (FYM), both with and without supplementary fertilizer. Four main tree species—Common Alder, Oak, Scots Pine and Silver Birch—are considered. The survival of SMC-planted trees (77%) was significantly higher than for FYM-planted (72%). In Year 10, SMC-planted trees were significantly taller than those planted with FYM (4.75 vs. 4.57 m, respectively). Similarly, basal diameter (measured above the root collar) was larger among the SMC-planted trees. Discriminant analysis showed that the key discriminating variable between SMC-planted and FYM-planted trees was the type of fertilizer applied during planting. Adding slow-release fertilizer (SRF) and SRF plus superphosphate (SRF + P₂O₅) was beneficial to FYM-planted trees. Fertilizer supplements often favor the growth of FYM-planted trees in the early years, but later SMC-planted trees take the lead. The only species that benefited long term from FYM or fertilizer supplements was Alder. Overall, SMC-planted trees perform better than FYM-planted trees, but some of the difference can be mitigated by supplementary fertilization. Overall, SMC-planted trees perform better than FYM-planted trees. Full article

Organic UV filters in sunscreen products are released to aquatic ecosystems through human recreational activities and urban wastewater treatment plant effluents. The biodegradation of three organic UV filters, 2-ethylhexyl salicylate (EHS), homosalate (HMS) and ethylhexyl methoxycinnamate (EHMC), which cannot be effectively removed by conventional wastewater treatment plants, was investigated in this study. Spent mushroom compost (SMC), a waste product of the mushroom industry, which contains white-rot fungus extracellular enzymes, was tested for its ability to remove the three organic UV filters. The results of batch experiments revealed that the SMC enzyme extract of Pleurotus djamor exhibited the highest ability for EHS and HMS removal. The results of bioreactor experiments indicated that direct application of SMCs may be a feasible solution to remove EHS and HMS from urban wastewater. The application of SMCs for the removal of organic UV filters can be developed into a green and sustainable technology. Full article

A greenhouse pot trial was conducted to investigate the effect of organic amendments combined with triple superphosphate on the bioavailability of heavy metals (HMs), Amorpha fruticosa growth and metal uptake from Pb-Zn mine tailings. Cattle manure compost (CMC), spent mushroom compost (SMC) and agricultural field soil (AFS) were applied to tailings at 5%, 10%, 20% and 30% w/w ratio, whereas sewage sludge (SS) and wood biochar (WB) were mixed at 2.5%, 5%, 10% and 20% w/w ratio. Triple superphosphate (TSP) was added to all the treatments at 4:1 (molar ratio). Amendments efficiently decreased DTPA-extracted Pb, Zn, Cd and Cu in treatments. Chlorophyll contents and shoot and root dry biomass significantly (p < 0.05) increased in the treatments of CMC (except T4 for chlorophyll b) and SMC, whereas treatments of SS (except T1 for chlorophyll a and b), WB and AFS (except T4 for chlorophyll a and b) did not show positive effects as compared to CK1. Bioconcentration factor (BCF) and translocation factor (TF) values in plant tissues were below 1 for most treatments. In amended treatments, soluble protein content increased, phenylalanine ammonialyase (PAL) and polyphenol oxidase (PPO) decreased, and catalase (CAT) activity showed varied results as compared to CK1 and CK2. Results suggested that A. fruticosa can be a potential metal phytostabilizer and use of CMC or SMC in combination with TSP are more effective than other combinations for the in situ stabilization of Pb-Zn mine tailings. Full article

When using food and green waste composts as peat-free plant growing media, there is a challenge that nutrient immobilisation and high pH and salts content limit plant growth. The present study explored the use of spent mushroom compost (SMC) of Agaricus subrufescens in a sustainable plant growing system where only vermicompost from digested food waste and composted green wastes were used, even for the seedling stage. However, negative effects of high compost inclusion were offset by adding SMC. Significantly higher plant yield was obtained in several of the SMC amended treatments in four out of five lettuce experiments and in one tomato experiment. In addition, an experiment with cucumbers showed that nutrients were not available to the plant when the mushroom mycelium was actively growing, but became available if the mushroom mycelium had been inactivated first by pasteurisation. A significant effect from SMC was not observed under full fertigation. This study demonstrated that the addition of pasteurised Agaricus mycelium colonised compost can successfully offset negative effects from high pH and EC as well as limited nutrient supply (and nitrogen immobilisation) in peat-free, compost-based growing media. Full article