Production of Highly Porous Biochar Materials from Spent Mushroom Composts

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.

Biosorption of Copper(II) and Iron(II) using Spent Mushroom Compost as Biosorbent

The application of the biosorption process and agricultural waste to treat heavy metals has drawn much attention. This method seems to be a more economical, environmentally friendly, and simple way for removing heavy metals from effluents. The study was conducted to explore the efficiency of the biosorption process utilizing spent mushroom compost to remove copper (II) and iron (II) from synthetic wastewater. Biosorption studies at different operating parameters, such as biosorbent dosage (1.0 – 5.0 g), pH (pH 4 – 8), contact time (1 - 30 minutes), and initial heavy metal concentration (10 - 100 mg/L), were conducted in batch experiments. The highest performance for copper (II) and iron (II) biosorption was found at 5.0 g biosorbent dosage of spent mushroom compost, unadjusted pH 6, 10 minutes of contact time, and 10 mg/L of initial concentration. The study was well fitted to the Langmuir isotherm model (R2 > 0.95) for copper (II) and iron (II) biosorption, which are much greater compared to the Freundlich model. The study is also very well suited to the pseudo-second-order (R2 > 0.999) than the pseudo-first-order kinetic models. In conclusion, the spent mushroom compost has the potential to be an effective biosorbent for removing copper (II) and iron (II) from synthetic wastewater.

Application of Modified Spent Mushroom Compost Biochar (SMCB/Fe) for Nitrate Removal from Aqueous Solution

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.

Easy and effective analytical method of carbendazim, dimethomorph, and fenoxanil from Protaetia brevitarsis seulensis using LC-MS/MS

Traditionally in Korea, Protaetia brevitarsis seulensis (white-spotted flower chafer) has been used as a medicine, and recently has attracted increased attention due to its antithrombotic efficacy. Some of spent mushroom compost or fermented oak sawdust, a feedstock for P. brevitarsis, were contaminated with three fungicides, carbendazim, dimethomorph, and fenoxanil, which could be transferred to the insect. This study was aimed to optimize a simple extraction method combined with liquid chromatography tandem mass spectrometry and apply it to the real samples. After the pulverized samples (5 g) were extracted with acetonitrile (10 mL) and formic acid (100 μL), fat and lipids in the samples were slowly precipitated at -20°C for 24 hours. After eight different clean-up methods were investigated, the mixture of 150 mg MgSO4/25 mg PSA/25 mg C18 was selected due to optimal recovery of the target compounds. Recovery (77.9%‒80.8% for carbendazim, 111.2%‒116.7% for dimethomorph, and 111.9%‒112.5% for fenoxanil) was achieved with reasonable relative standard deviation (<5.5%) The analytical method developed in this study was used to analyze three compounds in the 24 insect samples donated by the insect farm owners but no target compounds were detected. These results can provide important data for establishing the pesticide safety standards for P. brevitarsis before the medical applications.

ALTERNATIVE SUBSTRATE USE IN SAGE TRANSPLANTS PRODUCTION (SALVIA OFFICINALIS L.)

Mushroom production has become more popular in our environment. The most common cultivated mushroom is Agaricus bisporus. After mushrooms are harvested a large amount of used compost remains. This compost is a good material and producers used it as alternative substrate in plant production. The benefits of this compost are numerous like high content of organic matter and the rich mineral composition. The aim of this study was to determine the effectiveness of the use of spent mushroom compost (as alternative substrate) on growth and development of roots and above-ground parts of sage transplants (Salvia officinalis L.). Measurements of morphological parameters of plants (plant height, number of leaves, number of branches and plant diameter) were performed, as well as determination of fresh and dry weight of roots and above-ground parts of transplants. Application of spent mushroom substrate in the production of sage Salvia officinalis L. positively influenced growth and development as well as fresh and dry weight of roots and above-ground parts of treated plants compared to nontreated plants during transplanting growing stage. Plant height (+104%), number of leaves (+65%), number of branches (+143%), plant diameter (89%), were significantly increased by the spent mushroom compost application compared to the control - commercial substrate.

Weed Occurrence in a Young Apple Orchard Mulched With Two Different Organic Materials

In this study, conducted at the Research Station of the Wrocław University of Environmental and Life Sciences, Poland, we sought to determine the communities of weed species and their temporal occurrence in a young apple orchard mulched with spent mushroom compost or Miscanthus straw applied to tree rows. A herbicide fallow treatment was used as a control. During the first year of application, both organic mulches protected against the germination of weed seeds stored within the soil. In subsequent years, however, annual weeds occurred in the mulched tree rows, the most aggressive of which was Chenopodium album L. Annual increases in population densities were noted over the 4 subsequent years of research, particularly in the rows receiving spent mushroom compost. Perennial species in the family Poaceae and genus Malva were present in soil receiving both organic mulches. Trifolium repens L. was the perennial weed most often noted in the Miscanthus mulch, whereas Taraxacum officinale Web. was more characteristic of the spent mushroom compost. Commencing from the spring of the third year following apple tree planting, weed infestation associated with the spent mushroom compost was similar to that observed in the herbicide fallow, thus necessitating three annual applications of herbicide to further maintain the orchard. The insufficient weed suppression obtained with this mulch precludes its recommendation as an effective weed management system. Although Miscanthus straw provided extended tree row protection from weed infestation, herbicide intervention was also required. Notably, however, despite the fact that Miscanthus straw provided conditions more favorable to tree growth, apple tree yields and fruit quality tended to be similar under the three investigated orchard soil management systems.

Reclaiming Open Coal Spoils by Mixed Woodland: Varteg (Wales), 10 Year Results

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.