Agricultural Waste Products Research Articles

Utilizing Pistachio Shell Biochar to Replace Carbon Black in Natural Rubber Composites

Biochar is a promising source of renewable carbon that potentially can serve the same purpose as carbon black (sourced from fossil fuels) to reinforce rubber composites. Pistachio shells are a prolific agricultural waste product that is a suitable feedstock for biochar. Unlike many other agricultural residues, pistachio shells are a feedstock that yields biochar with a high concentration of carbon (>80%) and low concentration of ash (<5%), which is necessary to replace carbon black without detrimental effects to the final composite. Filler blends of pistachio shell biochar and carbon black were explored to see how much carbon black could be replaced before composite properties were affected. Pistachio shell biochar was able to replace up to 40% of the carbon black while improving the tensile strength, elongation, and toughness of the rubber composites, but a reduction in modulus was observed. Based on the results obtained, pistachio shell biochar would be suitable for partially replacing carbon black in applications like hoses, seals, belts, and gloves, thereby enabling a new application for this sustainable, agricultural waste product that will help reduce dependence on fossil fuels.

Optimization of Manure-Based Substrate Preparation to Reduce Nutrients Losses and Improve Quality for Growth of Agaricus bisporus

With the growing world population, food demand has also increased, resulting in increased agricultural waste and livestock manure production. Wheat straw and cow dung are rich nutrient sources and, if not utilized properly, may lead to environmental pollution. Keeping in view the cultivation of Agaricus bisporus on straw/manure-based substrate, the current study aimed to optimize the conventional manure preparation technique to reduce nutrient losses and keep the quality of manure at its best. The treatments were considered as traditional and optimized schemes for mushroom substrate preparation. The results achieved herein indicated that the nutrient losses were low in the optimum scheme. For carbon (C), the loss was 43.55% at the substrate stage in the traditional scheme and reduced to 37.75% in the optimum scheme. In the case of nitrogen (N), the loss was 22.01% in the traditional scheme and was lower (18.49%) in the optimum scheme. The nutrient concentration in Agaricus bisporus was higher with the optimum scheme compared with the traditional scheme. It was 1.74% for C, 7.17% for N, 3.58% for phosphorus (P), and 4.92% for potassium (K). The optimum scheme also improved the Agaricus bisporus yield per unit area (84.55%) and the total yield (28.92%). The net income of the optimum scheme was 102.95% higher compared to the traditional scheme. The economic analysis also revealed that the benefit–cost ratio of the optimum scheme was high (48.86%) compared with the traditional scheme. This study concludes that the use of the optimum scheme can better utilize the wheat straw and cow manure waste for substrate preparation and reducing nutrient losses. In addition, the final mushroom residue can also be used as a leftover substrate for further utilization.

A preliminary investigation of banana pseudo-stem (Musa cavendish) for pulp and paper production: morphology, chemical composition, FTIR, XRD and thermogravimetric analysis

Abstract In today’s world, the use of paper and cardboard increasing but the availability of raw materials and the environmental impact on the paper industry is a big concern. To address these concerns, researchers are exploring the potential of agricultural waste products as raw materials for pulp production. This study uses morphological, chemical composition, FTIR, XRD, and thermogravimetric analysis to examine the potential of banana pseudo-stem as a raw material for paper pulp to address environmental concerns and raw material shortages in the paper industry. The study reveals favorable characteristics for papermaking, including long fiber length (1750 μm), thin cell wall thickness (9.7 μm), and large lumen diameter (22.15 μm). The chemical composition of banana pseudo-stem contains cellulose (44.93 %), hemicellulose (23.7 %), and Klason lignin (11.1) showing its suitability for pulp production. FTIR analysis highlights the functional groups present on the banana pseudo-stem. The XRD analysis shows that it has a similar cellulosic peak and crystallinity index with common raw materials used in pulp production. The thermogravimetric analysis shows that the banana pseudo-stem has high thermal stability. The findings demonstrate that banana pseudo-stem, both by itself and in combination with other raw materials, might be a potential raw material for the pulp production.

Insights into potential of banana leaf powder as a mud soil stabilizer

This study proposes a novel method for managing surplus soil in urban construction projects by investigating the use of banana leaf powder (BLP) as an eco-friendly and efficient mud-soil stabilizer. This study is pioneering in its focus on the use of an agricultural waste product, BLP, as an alternative to conventional methods that frequently rely on cement or lime, which pose environmental concerns owing to their high alkalinity and carbon emissions. BLP, derived from dried and pulverized banana leaves, traditionally used in various industries, was evaluated for its suitability as a stabilizer against orange peel biopolymer (OBP) and fly ash (FA). The findings of this study are groundbreaking. BLP's water absorption capacity, Wab, although lower than that of OBP, was significantly higher than that of FA, demonstrating its potential as a mud soil stabilizer. BLP increased the compaction and strength of the treated clay, whereas OBP made it more challenging to compact the clay owing to gelatinization. The ease of compaction with BLP is attributed to the absorption of free water into the pores of the particles. These results suggest that differences in the stabilizer's water absorption mechanism affect the effectiveness of the post-treatment compaction process on the treated soil. An analysis of the impact of water absorption capacity on the cone index, qc, revealed a material-independent relationship between the parameter β (=Wab × A, where A denotes stabilizer addition content) and qc for BLP and FA. This is because, in contrast to OBP, BLP and FA did not gelatinize the free water that was not absorbed by the stabilizer and remained in the same form within the treated clay. This indicates that understanding the water absorption capacity and mechanism of organic- or inorganic-based stabilizers is important for predicting the strength of treated soil. The same relationship between β and qc holds true for the hybrid-treated clay using both BLP and FA, with β considered to be the sum of β for both BLP and FA. Furthermore, this study innovatively addresses the concern of BLP decay in treated soil by creating a hybrid stabilizer with FA and conducting experiments to accelerate BLP decay using fungal mycelia. These experiments revealed that the hybrid-treated clay exhibited a more gradual decrease in carbon content and stabilized pH levels, implying that FA could inhibit decay by fungal mycelia, improving the BLP-treated soil's long-term durability. These findings suggest that agricultural wastes with high organic content can be effectively used for soil stabilization and ground improvement in civil engineering construction and maintenance projects by combining inorganic materials and taking advantage of their properties, such as high water absorbency. This can address the issues (such as high alkalinity and high carbon dioxide emissions) associated with cement- and lime-based stabilizers, which were previously widely used.

Application of Pyroligneous Acid as a Plant Growth Stimulant Can Improve the Nutritional Value of Soybean Seed

Farmers today are using biochemical treatments to improve their crop yields. Commercialized organic biostimulants exist in the form of pyroligneous acid generated by burning agricultural waste products. During the 2023 growing season, we demonstrated that soil treatment with a commercial pyroligneous acid product, Coriphol™, manufactured by Corigin Solutions, Inc., stimulated plant growth and significantly improved yield with an optimal treatment dose of 2 gal. acre−1. In the present work, we examined the effect of this treatment on soybean nutritional content using seed harvested from the 2023 season. Total mean seed protein content for untreated control plants was 32.26 ± 0.49% of dry mass and increased 10.8% to 35.64 ± 0.64% with treatment. This increase resulted in a net reduction in total free amino acid content, although levels of the essential dietary amino acid, lysine, were boosted 6-fold. Total lipid content was unaffected by treatment with mean levels of 21.61 ± 0.70% of dry mass noted. Treatment, however, reduced saturated fatty acid content by roughly 40%, and reduced the polyunsaturated content of linoleic acid in favor of the monounsaturated fatty acid, oleic acid. Finally, Coriphol™ treatment did not impact seed content of eight essential micronutrients including Na, Mg, K, Ca, Fe, Ni, Cu, and Mo, but did significantly boost Zn and Mn levels. Altogether, these results demonstrate that soil treatment with the growth stimulant Coriphol™ has the potential to improve the dietary nutritional value of soybean.

Developing greener concretes from spent bleaching earth and sugarcane bagasse ash

Concrete is by far the most widely utilized construction material due to its excellent mechanical and durability properties. However, the concrete industries are notorious for their anthropogenic activities that contribute to climate change. Cement production alone consumes immense amounts of energy and trails a significant CO2 footprint. One solution that researchers have deemed promising over the last couple of decades is the substitution of cement with agricultural waste products, which subsequently serves to alleviate waste disposal problems. This study investigates the suitability of spent bleaching earth (SBE) and sugarcane bagasse ash (SCBA) as partial replacement of ordinary Portland cement (OPC) in increments of 0, 5, 10 and 15% by mass. Tests were conducted in accordance to British Standards to assess the consistence, compressive strength, split tensile strength and drying shrinkage strain of SBE and SCBA based concretes. Results indicated that while these concretes displayed similar degrees of consistency, the SCBA concretes exhibited superior compressive and tensile strengths. Optimum SCBA dosages were revealed to be about 5-10%, yielding a 7-12% and 3-8% increase in compressive and tensile strengths, respectively, as compared to OPC concrete. Drying shrinkage behavior was also improved in the SCBA concretes. Further, comparisons of the mechanical and durability performances of the concretes with British and American codes suggest that up to 10% replacement of cement with SCBA may be a viable approach to developing sustainable materials for the concrete industry.

Laboratory assessment of the effect of rice husk, groundnut shells and RHA on the shear, permeability and consolidation of clayey sands

Utilizing waste materials to improve soil properties can result in cost savings and environmental benefits. This study aims to determine the effect of adding agricultural wastes like rice husk ash (RHA), rice husk (RH), and groundnut shells (GS) to clayey sands from Mysore district, India. The study focused on the undrained strength, permeability and volume change behaviour of soils mixed with RHA, RH and GS. The soil samples were mixed with varying amounts of RHA (5%, 10%, 15%, and 20%) and RH-GS (1%, 2%, 3%, 4%, and 5%) and cured for 1, 7, 14 and 21 days. These blended specimens were then used to determine the maximum dry density (MDD), optimum moisture content (OMC) and unconfined compressive strength (UCS). The soil mixture containing 5% RHA and 4% (RH + GS) yielded optimal results in the UCS test. Further tests, including unconsolidated undrained (UU) triaxial, permeability and consolidation tests, were conducted on the parent soil and the soil composite with 5% RHA and 4% (RH + GS). From the undrained test, the strength increased for the soil admixture, with a reduction in the cohesion and an increment in the friction angle, compared to that of the parent soil. The experimental results also showed improvement in the permeability and consolidation characteristics of the blended soil. As RH, GS, and RHA are abundant and considered to be agricultural waste products, using them represents an innovative, sustainable, and cost-effective solution with promising potential for soil improvement.

Novel Fungicide from Waste Oil Palm Fruit Bunch for Sustainable Management of Tomato Wilt Disease Caused by Fusarium oxysporum - experimental and in silico studies

Tomato wilt, a widespread and persistent disease caused by the fungus Fusarium oxysporum, can be effectively controlled through biological approaches, promoting ecosystem sustainability and enhancing agricultural productivity and quality. This study explored the use of empty oil palm fruit bunch (EOPFB) waste as a natural fungicide to control tomato Fusarium wilt disease through in vitro, pilot scale, and molecular docking experiments. EOPFB aqueous extract showed the highest mycelium growth inhibition of 68.3 %, with the commercial fungicide Mancozeb exhibiting a moderate 42.30 % inhibition, and sterile distilled water having a negligible effect of 0.24 %. The inhibition rate varied with concentration, peaking at 72.63 % at 0.15 g/mL and dropping to 54.80 % at 0.01 g/mL. In terms of wilt disease incidence and severity, EOPFB performed best, recording the lowest incidence of 47.20 % and severity of 15.58 %. Mancozeb followed closely, with an incidence of 46.30 % and severity of 26.23 %. Sterile distilled water, on the other hand, showed the highest incidence of 76.28 % and severity of 56.17 %. Molecular docking simulations corroborated the experimental results, validating the potency of EOPFB as an inhibitor of trypsin from F. oxysporum, and identifying 2-amino-5,6-dimethyl-3 H-pyrimidine-4-one as the primary active compound responsible for the fungicidal activity. This phytochemical, abundant in the crude ethanolic extract of EOPFB, was found to have a higher binding affinity (6.1 kcal/mol) than Mancozeb (4.8 kcal/mol), at the trypsin target. These findings demonstrate the potential of EOPFB, an agricultural waste product, as a sustainable and eco-friendly solution for managing tomato Fusarium wilt disease, contributing to increased tomato production. It also highlights the potential of 2-amino-5,6-dimethyl-3 H-pyrimidine-4-one as a lead compound for the development of novel, natural fungicides, and underscores the value of EOPFB as a rich source of bioactive compounds with agricultural and biotechnological applications.

Exploring eco-friendly pseudo stem fiber from the agricultural byproducts of the Alpinia purpurata plant

This study explored the potential of Alpinia purpurata pseudostems, an agricultural waste product, as a sustainable and eco-friendly source of natural fibers for the textile industry. The aim was to characterize the properties of natural cellulose fibers from the pseudostems of the Alpinia purpurata plant. The research employed water retting to extract the fibers, and the intrinsic fiber properties obtained were evaluated for their suitability in textile applications. The average length of an Alpinia purpurata fiber was 67.80 cm with a fineness value of 7.61 Tex. A bundle of Alpinia purpurata fibers was comprised of many elementary fibers. Alpinia purpurata had an irregular cross-section, with the lumen having a varied oval shape. The fibers exhibited tenacity and elongation values of 2.49 g/denier and 5.72 %, respectively, and a coefficient of friction value of 0.49. Additionally, Alpinia purpurata fibers were hygroscopic, with a moisture regain value of 11.97 %. The findings revealed that the fibers possessed notable tensile strength, moderate elongation, and high moisture regain, making them suitable for non-apparel textile products requiring durability and moisture management. While not the strongest among natural fibers, their sufficient strength and other advantageous properties demonstrated their viability for various applications. This work addressed a significant gap in the literature on the utilization of agricultural by-products, proposing Alpinia purpurata pseudostems as a sustainable alternative that aligned with environmentally responsible manufacturing practices and supported the circular economy. Future research was recommended to optimize processing techniques and explore broader applications.

Impact of Spent Mushroom Substrate Combined with Hydroponic Leafy Vegetable Roots on Pleurotus citrinopileatus Productivity and Fruit Bodies Biological Properties.

Agricultural activities produce large quantities of organic byproducts and waste rich in lignocellulosic materials, which are not sufficiently utilized. In this study, alternative agricultural waste products, namely, spent mushroom substrate (SMS) from the cultivation of edible Pleurotus ostreatus mushrooms and the roots of leafy vegetables from hydroponic cultivation (HRL), were evaluated for their potential to be used as substrates for the cultivation of Pleurotus citrinopileatus and their effects on the quality, the nutritional value, the chemical properties (lipid, protein, carbohydrate, ash, fatty acid and carbohydrate composition) and the bioactive content (total phenolic compounds and antioxidant activity) of produced mushrooms. SMS and HRL (in different ratios with and without additives) and wheat straw with additives (WS-control) were used. During incubation, the linear growth rate of the mycelium (Kr, mm/day) was measured and used for screening. Mushroom cultivation took place in bags, where several characteristics were examined: earliness (duration between the day of substrate inoculation and the day of first harvest) and biological efficiency (B.E. %, the ratio of the weight of fresh mushrooms produced per dry weight of the substrate × 100). Furthermore, this study aimed to investigate the effect of the protein extract (PE) and carbohydrate extract (CE) of P. citrinopileatus after in vitro digestion (fraction less than 3kDa: PE-DP-3; digestate fraction: CE-D, respectively) on the expression of antioxidant-related genes in the THP-1 cell line. The results showed that mushrooms grown on SMS 50%-HRL 40% had the fastest growth (6.1 mm/d) and the highest protein and lipid contents (34.7% d.w.; 5.1% d.w.). The highest B.E. (73.5%), total carbohydrate (65.7%) and total phenolic compound (60.2 mg GAE/g d.w.) values were recorded on the control substrate. Antioxidant activity was observed in all extracts; the total flavonoid content was low in the samples, and the maximum total triterpene value was detected in SMS 80%-HRL 20% (9.8 mg UA/g d.w.). In all mushrooms, linoleic acid (C18:2) was the main fatty acid (above 60%), and fructose was the dominant individual saccharide. In the investigation of the regulation pathway, NFE2L2 gene expression was upregulated only in the SMS 60%-HRL 40% intervention during incubation with CE-D samples. Additionally, the transcription levels of antioxidant-related genes, SOD1, CAT, HMOX1 and GSR, were increased in the SMS 60-30% intervention. Compared to WS, the alternative substrates are observed to trigger a pathway concerning CE that may resist oxidative stress. This study supports the utilization of agricultural byproducts through sustainable and environmentally friendly practices while simultaneously producing high-value-added products such as mushrooms. Therefore, alternative substrates, particularly those containing HRL, could serve as natural sources of antioxidant potential.

Torrefaction of durian peel in air and N2 atmospheres: Impact on chemical properties and optimization of energy yield using multilevel factorial design

This study investigated the torrefaction of durian peel using air and nitrogen as carrier gases. A multilevel factorial design coupled with response surface methodology (RSM) and ANOVA analysis was employed to analyze the impact of torrefaction parameters on chemical properties and energy yield. Durian peel, an agricultural waste product, was torrefied at temperatures ranging from 200 to 320 °C for residence times between 0 and 30 min. Results showed that air torrefaction significantly enhanced thermal decomposition, reducing mass yield from 94.65 % to 30.63 % as the temperature increased from 200 °C to 300 °C with a 30-min holding time. Air torrefaction also increased the higher heating value (HHV) from 19.02 MJ/kg to 35.26 MJ/kg at 300 °C, compared to nitrogen, which achieved a maximum HHV of 32.49 MJ/kg. ANOVA analysis revealed that torrefaction temperature and carrier gas significantly affect energy yield and chemical properties. Air torrefaction positively affected HHV while reducing mass yield compared to nitrogen. Low-temperature air torrefaction showed enhanced energy yield improvement. These findings provided insights for optimizing torrefaction processes enhancing utilization wasted durian peel as a sustainable bioenergy resource.

Antibacterial Application of Copper Nanoparticles Biosynthesized by Water Caltrop Pod.

This study investigates the utilization of water caltrop pod, an abundant agricultural waste product, as a green extract for the optimized biosynthesis of copper nanoparticles (CuNPs). To comprehensively characterize the water caltrop pod and the biosynthesized CuNPs by water caltrop pod a sophisticated techniques were employed, including U.V-Vis spectrophotometry for probing their preliminary analysis of copper nanoparticles, FT-IR spectroscopy for elucidating the functional groups present in water caltrop pod, Scanning Electron Microscopy (SEM) for visualizing the morphology, Energy Dispersive X-ray (EDX) for elemental analysis while Energy-Dispersive X-ray (XRD) to determine crystalline structure of copper nanoparticles. Furthermore, the antibacterial application of these biogenic copper nanoparticles was explored. The antibacterial activity of copper nanoparticles (CuNPs) was investigated against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, revealing their efficacy in combating microbial growth employing a Well Diffusion method. Copper nanoparticles showed greater antibacterial treatment against Gram (+ve) bacteria i.e. Staphylococcus aureus as compared to Gram (-ve) bacteria i.e. Escherichia coli. This research paves the way for the sustainable production of bio-functional CuNPs from waste biomass, offering promising application in antibacterial therapies.

Biochar Prepared from Steam-Exploded Bitter Melon Vine for the Adsorption of Methylene Blue from Aqueous Solution: Kinetics, Isotherm, Thermodynamics and Mechanism

Bitter melon vine (an agricultural waste product with high fiber content) is difficult to treat and has caused problems in the environment. This research aims to produce biochar through low-temperature pyrolysis assisted by non-polluting steam explosion. The physical and chemical properties of the biochar were characterized using scanning electron microscopy (SEM) images, specific surface area measurements (BET), X-ray diffraction patters (XRD), elemental analysis (EA), and Fourier transform infrared spectroscopy (FTIR). Next, the adsorption mechanism of methylene blue (MB) on the steam-exploded bitter melon vine biochar pyrolyzed at 200 °C (qBC200) and the effects of adsorption time, pH, initial concentration, adsorption temperature, and adsorbent dosage on the adsorption effect were investigated. Steam explosion destroyed the dense structure of the plant, increased the number of oxygen-containing surface functional groups, and improved the adsorption performance of the material. Therefore, qBC200 more effectively adsorbed MB than untreated biochar, reaching a saturated adsorption capacity of 267.72 mg/g. The MB adsorption kinetics and isothermal adsorption process of qBC200 align with the pseudo-second-order kinetic model and Langmuir isothermal equation (monolayer adsorption), respectively. The thermodynamic results show that MB adsorbs via a spontaneous, entropy-increasing exothermic reaction. The adsorption mechanism involves electrostatic attraction, hydrogen bonding, and π–π interactions. The prepared biomass with high fiber content is a promising new material for wastewater treatment.

Experimental Investigation on Concrete with Zeolite Powder, Silica Fume and Cashew Nut Shell Ash

Abstract: This experimental investigation explores the impact of incorporating zeolite powder as a partial replacement for fine aggregate, along with silica fume and cashew nut shell ash (CNSA) as partial replacements for cement in concrete. Zeolite, a natural aluminosilicate mineral, is known for its pozzolanic properties, which can enhance the mechanical and durability characteristics of concrete. Silica fume, a byproduct of silicon and ferrosilicon alloy production, is renowned for its high silica content and fineness, contributing to the strength and density of concrete. Cashew nut shell ash, an agricultural waste product, offers a sustainable alternative to traditional cementitious materials, potentially reducing the environmental footprint of concrete production. This experimental study investigated the effects of partially replacing fine aggregate with zeolite powder (5%,10% and 15%) and cement with silica fume (3%,6%,9%,12% and 15%) and cashew nut shell ash (5%,7.5%,10%,12.5%,15% and 17.5%) on the properties of concrete. This study underscores the viability of using zeolite powder, silica fume, and CNSA in sustainable concrete production, contributing to the development of more environmentally friendly construction materials. Further research is recommended to explore the long-term performance and environmental benefits of these alternative materials in concrete applications.

Effects of Palm Kernel Shells (PKS) on Mechanical and Physical Properties of Fine Lateritic Soils Developed on Basalt in Bangangté (West Cameroon): Significance for Pavement Application

The utilization of an agricultural waste product known as palm kernel shells (PKS) combined with fine laterites (from basalt in Bangangté, West Cameroon) to produce low-cost and innovative materials with good bearing capacities for road pavement was investigated. Fine laterites from two soil profiles (BL31 and BL32) and made up of kaolinite, hematite, goethite, gibbsite, anatase, ilmenite and magnetite minerals were partially replaced with PKS at 15%, 25%, 35%, and 45% by weight. Physical and mechanical tests, including particle size distribution, Atterberg limits, unsoaked and soaked California Bearing Ratio (UCBR and SCBR), unconfined compressive strength (UCS), and tensile strength (Rt), were performed on the different mixtures. After the addition of PKS, a decrease in fine particle content (77 to 38%), liquidity limit (LL: 72 to 61%), plasticity index (PI: 30 to 19%), maximum dry density (MDD: 1.685 to 1.29 t/m3), and optimum moisture content (OMC: 27.5 to 24.0%) was noticed. Additionally, there was an increase in UCBR (16–72%), SCBR (14–66%), UCS (1.07–7.67 MPa), and Rt (2.24–9.71 MPa). This allows new materials suitable for the construction of base layers for low trafficked roads (T1–T2), as well as sub-base and base layers for high trafficked roads (T3), to be obtained. This newly formed material can be recommended locally for road construction works, though more in-depth studies are required.

Allelopathic Effects of Sugarcane Leaves: Optimal Extraction Solvent, Partial Separation of Allelopathic Active Fractions, and Herbicidal Activities.

The inhibitory potential of allelopathic plants is the subject of increasing research attention for their application in weed management. The sugarcane leaf is an agricultural waste product that has been reported to have allelopathic potential. Therefore, the present study determined the optimal organic solvent system and fractionation procedure to enhance the quantity of this extract and its allelopathic efficiency. Sugarcane leaves were extracted using five ethanol/water solvent ratios (v/v): 00:100, 25:75, 50:50, 75:25, and 100:00. Their allelopathic effects on seed germination and seedling growth were assayed in two major weeds, Echinochloa crus-galli (L.) Beauv. and Amaranthus viridis L. The results showed that the extract concentration, solvent ratio, and their interaction significantly inhibited the growth parameters in A. viridis. Consequently, a crude ethanol/water ratio of 00:100 was used to separate the active fraction via acid-base solvent partitioning. The acidic fraction (AE) exerted the greatest inhibitory effect and completely (100%) inhibited A. viridis at all concentrations, followed by the original crude fraction, neutral fraction, and aqueous fraction. Moreover, all of the fractions had selective effects, inhibiting A. viridis much more than E. crus-galli in the laboratory tests. The chemical analysis using gas chromatography/mass spectrometry indicated that the AE fraction contained 20 different compounds. The five major compounds included alkaloids, organic acids, and phenols. Therefore, the AE fraction was selected for formulation in a concentrated suspension and tested for its herbicidal characteristics. The formulation exhibited early post-emergence activities and had a stronger effect on A. viridis compared to E. crus-galli. The physiological mechanism of the formulation was tested against A. viridis. The thiobarbituric acid reactive substances and H2O2 occurred in the A. viridis leaf, which suggests lipid peroxidation and cell disruption.

Sustainable ground improvement of soft clay using eggshell lime and rice husk ash

Stabilization of clay using lime or cement is conventionally accepted practice. Although it is effective, they impose several implications on the environment. Hence, it is high time that an alternate sustainable binder needs to be investigated. Eggshell, a waste from food industry, is an alternate source for calcite and can be considered to produce eggshell lime (EL). Also, rice husk ash (RHA), an agricultural waste product, is a silica rich source which is a pozzolanic material. In the current study, the efficiency of both the materials in stabilizing the soft soil is investigated and the results suggests that the plasticity and the strength characteristics of soft clay can be significantly improved by the addition of EL. After adding optimum concentration of 3 % EL, the liquid limit decreased from 74 % to 53 %, plastic limit increased from 27 % to 46 % and shrinkage limit increased from 8 % to 44 %. On increasing the EL content, the swelling got reduced from 88 % of virgin clay to 17 % in case of 3 % EL and finally to zero with 5 % of EL. Also, the addition of combination of EL and RHA to the soft clay has improved the strength characteristics significantly. As the curing days increased, slight variation was only seen in the plasticity characteristics which may be due to rapidity of cation exchange. But strength characteristics increased suggesting the occurrence of pozzolanic reactions and formation of gel. The 28th day strength of the clay treated with 3 % EL increased to as high as 757 kPa. The strength characteristics showed that as we increase the percentages of EL and RHA combination, the strength would increase tremendously much better than the treatment with eggshell lime alone. This is because of the supply of CaO and SiO2 sources. For 5 % of EL and 15 % of RHA, the 1 day curing strength was near to 500 kPa. With less concentration of eggshell lime and RHA, the treated soil was appearing to be more porous in SEM while when the binder concentration was increased, the pores were filled and presence of C-S-H gel was also detected. XRD test results also showed the presence of C-S-H gel.

GIS mapping of agricultural plastic waste in southern Europe

The escalating use of plastics in agriculture, driven by global population growth and increasing food demand, has concurrently led to a rise in Agricultural Plastic Waste (APW) production. Effective waste management is imperative, prompting this study to address the initial step of management, that is the quantification and localization of waste generated from different production systems in diverse regions. Focused on four Southern European countries (Italy, Spain, Greece, and Portugal) at the regional level, the study uses Geographic Information System (GIS), land use maps, indices tailored to each specific agricultural application and each crop type for plastic waste mapping. Furthermore, after the data was employed, it was validated by relevant stakeholders of the mentioned countries.The study revealed Spain, particularly the Andalusia region, as the highest contributor to APW equal to 324,000 tons per year, while Portugal's Azores region had the lowest estimate equal to 428 tons per year. Significantly, this research stands out as one of the first to comprehensively consider various plastic applications and detailed crop cultivations within the production systems, representing a pioneering effort in addressing plastic waste management in Southern Europe. This can lead further on to the management of waste in this area and the transfer of the scientific proposition to other countries.

Determining and Mapping Biomass Energy Potential from Agricultural Residues in Syria

Syria faces a problem of restricted access to fossil fuels due to limited resources. In this paper, the potential of biomass and the total heat value produced from agricultural residues for 32 agricultural crops has been studied. Data from the Syrian Ministry of Agriculture for the year 2016 were utilized to determine the total annual potential of field and orchard agricultural residues using the residue-to-product ratio. The study also examined the distribution of regions with the highest production of agricultural waste in the country. The research found that approximately 1.93 million tons of agricultural residues were produced, with 0.698 and 1.213 million tons for field and orchard crops, respectively. The most significant agricultural residues came from olive trees, wheat plants, and orange trees, accounting for 35%, 11%, and 10%, respectively. The possible heat value from field and orchard crops was 23,972 and 44,932 Btu, respectively. This quantity provides 17.6% of Syria's energy consumption. The provinces with the highest production of agricultural residues were Aleppo, Lattakia , and Tartus, with values of 12.35, 11.8, and 8.04 PJ, respectively. According to the study, agricultural residues in Syria have the potential to be a sustainable source for biomass.

Enhanced Adsorption of Aqueous Pb(II) by Acidic Group-Modified Biochar Derived from Peanut Shells

Using peanut shells, a sustainable agricultural waste product, as its raw material, the acid group-modified biochar (AMBC) was prepared through phosphoric acid activation, partial carbonization, and concentrated sulfuric acid sulfonation for efficient removal of lead ion from aqueous solutions. Characterization techniques such as N2 isothermal adsorption–desorption, SEM, XRD, FT-IR, TG-DTA, and acid–base titration were utilized to fully understand the properties of the AMBC. It was found that there were high densities of acidic oxygen-containing functional groups (-SO3H, -COOH, Ph-OH) on the surface of the AMBC. The optimal adsorption performance of the AMBC for Pb(II) in water occurred when the initial concentration of Pb(II) was 100 mg/L, the pH was 5, the dosage of the adsorbent was 0.5 g/L, and the contact time was 120 min. Under the optimal conditions, the removal ratio of Pb(II) was 76.0%, with an adsorption capacity of 148.6 mg/g. This performance far surpassed that of its activated carbon precursor, which achieved a removal ratio of 39.7% and an adsorption capacity of 83.1 mg/g. The superior adsorption performance of AMBC can be caused by the high content of acidic oxygen-containing functional groups on its surface. These functional groups facilitate the strong binding between AMBC and Pb(II), enabling effective removal from water solutions.