High Phosphorus Content Research Articles

The Effect of Harvest Time and Plantation Age on the Yield, Chemical Composition, and Calorific Value of Reed Canary Grass (Phalaris arundinacea L.) Intended for Energy Purposes

Based on our own research conducted on a purpose-built plantation, the production capacity of reed canary grass (Phalaris arundinacea L.) was assessed depending on the age of the plantation and the date of the biomass harvest. The aim of this study was to assess the influence of the harvest date and plantation age on the yield, chemical composition, and calorific value of reed canary grass intended for energy purposes. The biomass on the plantation was cut twice during the growing season (summer/winter). The obtained biomass was analyzed for its ash content and selected elements, i.e., nitrogen, phosphorus, potassium, calcium, magnesium, sodium, sulfur, and chlorine. The total moisture, calorific value in working condition, and combustion heat were also assessed. The two-cut harvest system allowed us to obtain 3.85 t∙ha−1 of biomass from reed canary grass in the first year of cultivation. The highest biomass yields were obtained in the third and sixth years of cultivation and amounted to 8.50 and 8.75 t∙ha−1, respectively. Regardless of the age of the plantation, the biomass yield harvested in the summer period was always higher than the yield obtained from the winter harvest. The contents of some elements in the biomass also depended on the age of the plantation and the harvest date. The biomass of reed canary grass obtained from the summer harvest of the annual plantation was characterized by a high content of nitrogen (1.97% d.m.), potassium (2.35% d.m.), and phosphorus (0.31% d.m.) compared to the content of these elements in the biomass obtained from the three- and six-year plantations. In the case of sodium, the highest content (0.072% d.m.) was found in the biomass obtained from the summer harvest of the three-year plantation, and the lowest was obtained from the winter harvest of the six-year plantation (0.037% d.m.). The average sulfur content was the highest in the biomass obtained from the annual plantation, regardless of the harvest date (0.20% d.m.—summer harvest and 0.21% d.m.—winter harvest). On the other hand, the lowest amount of sulfur was contained in the biomass obtained from the winter harvest of the six-year plantation (0.12% d.m.). Only the magnesium content (from 0.09% d.m. to 0.14% d.m.) in the biomass remained at a similar level, regardless of the age of the plantation or the harvest date. The calcium content was the highest in the biomass obtained from the winter harvest of the annual plantation (0.35% d.m.), and the lowest was obtained from the six-year-old plantation, also from the winter harvest. In addition, the moisture and ash content of the obtained biomass depended on the age of the plantation and the harvest date. The highest moisture content (12.50%) was characteristic of the biomass harvested in the summer period from the one-year plantation. On the other hand, the lowest moisture content was found for the biomass harvested in the winter period from the six-year plantation. The highest ash content was obtained from biomass harvested in the summer period from the one-year plantation (75 g∙kg−1 d.m.) and the three-year plantation (69 g∙kg−1 d.m.). The lowest ash content was obtained from the winter harvest from the six-year plantation (45 g∙kg−1 d.m.). The highest calorific value of 16.0–16.2 MJ∙kg−1 d.m. was obtained for biomass harvested in the sixth year of the study (irrespective of the harvest date). The value of the combustion heat was also dependent on the age of the plantation and the date of the biomass harvest. The highest value for the combustion heat of 17.5 MJ∙kg−1 d.m. was obtained for biomass harvested in the winter period from the six-year plantation

Evaluating Black Soldier FLY (Hermetia illucens) Frass and Larval Sheddings in the Production of a Quality Compost

Black Soldier Fly (Hermetia illucens) is well-known for having a high protein and lipid content during its larval stage and is cultivated for animal feed. Rearing Black Soldier Fly larvae (BSFL) produces byproducts known as frass and larval sheddings in large volumes with limited applications. Therefore, there is a need to identify viable sustainable management strategies to prevent potential environmental issues associated with their accumulation. Accordingly, the purpose of this study was to evaluate BSFL frass and larval sheddings as viable ingredients in composts that utilize additional nitrogen feedstocks. Four experimental compost piles (22.7 m3) with different ratios of BSFL frass and sheddings were developed based on previous research; two piles included 25% frass, whereas the other two included 30% frass. Across these piles, the inclusion of wood chips, food waste, and livestock manure varied to determine the best proportions for compost. The compost piles were maintained for five months, including a curing phase. After curing, samples from each pile were collected to analyze their pH, macro- and micro-nutrients, particle size, stability, and maturity. The findings indicated that the pH levels (7.1–8.1) and carbon-to-nitrogen ratios (10.40–13.20) were within the optimal ranges for all piles. The phosphorus levels (0.75–1.30%) of each pile exceeded typical ranges, likely due to the high phosphorus content of the frass itself. The moisture content varied widely (24.5–51.7%), with some piles falling below optimal levels. Stability and maturity tests yielded mixed results, with some piles demonstrating continued decomposition activity. Overall, the findings indicated that inclusion rates of 25–30% of BSFL frass and sheddings produced compost with generally favorable characteristics when high nitrogen feedstocks were also incorporated into the compost piles. These findings align with those from previous research and highlight both the potential and challenges of incorporating BSFL frass into compost production.

Atmospheric air pollution from the Ermakovskoe fluorite-beryllium deposit development waste

Relevance. Negative impact of waste from mining enterprises on the ecological state of the surrounding areas. Aim. To determine the migration ability of toxic chemical elements from waste storage sites of the Ermakovskoe beryllium deposit in the air. Object. Ermakovskoe fluorite-bertrandite-phenacite deposit and the surrounding area. Methods. Inductively coupled plasma mass spectrometry, laser diffraction, inductively coupled plasma atomic emission spectrometry. Results and conclusions. The paper introduces the experimental studies of surface atmospheric pollution by mining waste from the Ermakovskoe fluorite-bertrandite-phenakite deposit are presented using an installation for collecting aerosols above the sand surface. It was established that toxic components formed during the decomposition of residual sulfide mineralization and products of the interaction of acidic waters with rocks move from the sand thickness to the surface along with water vapor. The moisture condensed over the sand contains high contents of aluminum, iron, manganese, zinc, and phosphorus. These elements form a halo of air pollution over mining waste and are then dispersed by air currents into the surrounding area. In winter, due to wind dispersion of aerosols, the snow cover becomes contaminated over a vast area. Among the toxic elements found were beryllium, lead, cadmium, and molybdenum, which belong to the second hazard class. The solid residue of the snow cover contains a fine fraction of dust, the size of which is less than 10 microns. The halo of snow contamination with toxic chemical elements and dust extends several kilometers away from the disturbed lands.

Study of temperature dynamics and influencing factors during composting process

Abstract This study investigated the most influential composting parameters (temperature, pH, humidity, C/N ratio, and CO2 emissions) on final compost quality. Composting bags (turned daily) containing prunings, lignocellulose material, cattle manure, and household organic waste were monitored for eight weeks across three batches. All the temperature data registered daily were statistically analyzed with one-way ANOVA to verify the consistency between batches. This study employs a first-order kinetic model to quantify the decomposition of organic matter in composting, revealing the influence of temperature on the decomposition rate. Principal component analysis was conducted for these factors and their interactions with respect to the final compost quality. Finished compost showed a significantly high nitrogen, phosphorus, and potassium content compared with that in the feedstock of the initial compost mixture, while there was constant organic carbon content. In addition to the control of key parameters, a linear regression analysis allowed us to identify the factors that most influenced temperature. We identified two key models: one including pH, humidity, C/N ratio, and CO2 emissions, and another focusing only on CO2. This study emphasized the importance of monitoring and controlling the crucial parameters of the composting process in order to obtain quality compost suitable for application in soil use. Moreover, high temperatures possibly attained in the process of aerobic decomposition destroy the pathogens, making the end products safer for uses in agriculture.

Control system and process optimization for electroless nickel plating

A novel method based on mid-frequency vibration is proposed to eliminate coating defects such as bubbles during electroless nickel plating. An automated control system for the plating, enabling precise and stable measurements and adjustments of critical parameters such as plating solution temperature, pH, and nickel ion concentration, is also established, which significantly improves process efficiency and coating quality. Experimental results indicate that the system is capable of realizing stable operation over extended periods. A nonporous nickel–phosphorus coating with a thickness greater than 200 μm is successfully obtained, with high phosphorus content, robust adhesion, and superior machinability.

Cultivation viability of Allium tuberosum L. in the Western Ghats: insights into crop dynamics, yield and quality.

Allium tuberosum, commonly known as garlic chives, is an underutilized Allium species despite its significant culinary value for its mild garlic flavor and therapeutic potential due to the presence of sulphur-containing compounds with antimicrobial, anti-inflammatory, and antioxidant properties. This study assessed the cultivation potential of A. tuberosum in the non-traditional agro-climatic region of the Western Ghats, focusing on the effects of cultivars and seasonal variations on growth, yield, and quality in two-year field trials. Among the accessions tested, A. tuberosum Kazakhstan CGN-1587 demonstrated the highest yield, producing 157.01 tons of green foliage per hectare. Bright sunshine seasons positively influenced both yield and quality, while the monsoon season induced morphological changes such as increased stem length, reduced leaf width, and decreased stem girth, traits generally considered inferior for market quality. The monsoon also led to increased waste generation, highlighting the need for careful management during this period. Nutritional analysis revealed high concentrations of potassium (5355 mg/kg), phosphorus (691 mg/kg), and sulphur (2484 mg/kg), while biochemical profiling identified bioactive compounds such as flavonoids (3.19 mg/g) and organosulfur compounds, including Allyl Methyl Thiosulfinate (269.00 mg/kg), which contribute to the plant's notable health benefits. These findings support the suitability of A. tuberosum for year-round cultivation in the Western Ghats and its potential for commercialization, especially in regions with similar climatic conditions.

Sludge from Arapaima Gigas Culture as an Alternative Culture Medium for Lipid Production in Nannochloropsis Sp

Objective: The objective of this work was to evaluate the use of sludge generated during the culture of Arapaima gigas as an alternative medium for Nannochloropsis sp. Theoretical Framework: Microalgae are photosynthetic micro-organisms with the ability to transform organic waste or effluents into valuable biomass. They are currently of great interest for their use in the food and pharmaceutical industry. Nannochloropsis sp. is a valuable microalga due to its excellent lipid profile. Method: The sludge used was collected from A. gigas culture ponds at the CITE Acuícola Pesquero Ahuashiyacu (Tarapoto-Peru). An aqueous extract of sludge (EAL) was obtained from the sample by a thermal procedure, which was dosed into the cultures at concentrations of 100, 150 and 200 mL/L. The experimental units followed the traditional batch culture arrangement under laboratory conditions. Guillard F/2 medium was used as control treatment. The characterisation of metals in the medium was performed by coupled plasma induction (ICP) and the determination of ammonium and nitrite by colorimetric tests. In addition, population density, productivity and total lipid content were estimated. Results and Discussion: Chemical analyses revealed high concentrations of calcium, sodium, magnesium, iron, potassium, phosphorus, ammonium and nitrite (655, 648, 283, 67, 32, 17, 1.5, and 10 ppm, respectively). Likewise, the best growth (3590.00 ± 91.24 x 104 cells/mL) and productivity (0.69 ± 0.01 g/L) was obtained with 200 mL/L of EAL, presenting significant statistical differences (p < 0.05) with respect to the other treatments. In contrast, the highest lipid production (29.67 ± 1.53 %) was observed in the control treatment, far exceeding the EAL cultures; however, no significant statistical difference was observed between EAL treatments. Research Implications: These results demonstrate the feasibility of using EAL as an alternative medium for the production of Nannochloropsis sp. with a positive environmental and economic impact on the production of A. gigas. Originality/Value: The use of sludge generated in fish culture, in particular A. Gigas, has not been reported previously. In this study, we demonstrate for the first time the feasibility of using this sludge in the culture of the microalga Nannochloropsis sp. which also has a high potential for use in fish larviculture.

Improving phosphorus availability in sewage sludge ash through a novel microwave‐based technology

AbstractThis work is connected with the increasing demand for fertilizers and the associated supply risks and market volatility in the European Union (EU). It highlights the reliance on phosphorus from Moroccan phosphate rocks and the environmental issues stemming from the overuse of phosphate‐based fertilizers. The paper suggests a shift in perspective, viewing waste as a valuable resource. Specifically, it explores the potential of recycling phosphorus from sewage sludge ash, which contains a high phosphorus concentration. The focus is on comparing two methods of phosphorus extraction from sewage sludge ashes: classical wet‐chemical extraction and a new microwave‐based technology. There is an increase in phosphorus bioavailability with the microwave treatment, making it a promising approach for waste management. An initial economic evaluation suggests that the microwave method is highly competitive, especially when compared with wet‐chemical extraction technologies. The resulting material from the microwave treatment is classified as a straight solid inorganic macronutrient fertilizer according to EU regulations.

Revealing the flame inhibition effect of phytic acid (PA) by PIV measurements and detailed chemical kinetic modeling of counterflow CH4/PA/air flames

As industrialization continues to deepen, polymers have become ubiquitous in daily life. However, their flammable characteristics pose significant safety risks. Therefore, supporting the global goal of sustainable development necessitates the development of high-performance, environmentally friendly flame retardants. Biomass phytic acid (PA) has emerged as a promising option because of its high phosphorus content and excellent biocompatibility. However, its combustion behaviors and chemical kinetic mechanisms remain unclear. In this study, quantum chemical calculation methods were used to construct a detailed PA chemical reaction kinetic model. A series of experiments were conducted to validate the model and evaluate PA's flame suppression effect. Utilizing a counterflow flame burner and particle image velocimetry (PIV), the inhibitory effect of various PA concentrations was examined based on the laminar flame speed of CH4/PA/Air mixture. The results revealed that a merely 0.2 % addition of PA could reduce the laminar flame speed by 38.9 %, demonstrating its significant flame suppression effect. Building on the foundational GRI-Mech 3.0 and integrating PA's pyrolysis and reaction mechanism, this study developed for the first time a detailed chemical model of CH4/PA/Air combustion. This model integrated PA's thermal decomposition module and thermodynamic data via ab-initio quantum chemical calculations, thereby accurately predicting global kinetic indicators such as laminar flame speed. Results suggested that the key reactions, such as PO2+H + M→HOPO + M, HOPO2+H→PO2+H2O, and HOPO + OH→PO2+H2O primarily influenced the laminar flame speed. Moreover, the CFD simulation elucidated the complex interaction between PA and flame structures. A detailed analysis of the spatial distribution of key parameters such as temperature, combustion radicals, and effective inhibition radicals unveiled the PA's flame suppression mechanism in support of the practical application of this eco-friendly flame retardant.

Drivers of greenhouse gas emissions in agricultural soils: the effect of residue management and soil type

Developing successful mitigation strategies for greenhouse gases (GHGs) from crop residue returned to the soil can be difficult due to an incomplete understanding of factors controlling their magnitude and direction. Therefore, this study investigates the effects of varying levels of wheat residue (WR) and nutrient management on GHGs emissions (CO2, N2O, and CH4) across three soil types: Alfisol, Vertisol, and Inceptisol. A combination of laboratory-based measurements and a variety of data analysis techniques was used to assess the GHG responses under four levels of WR inputs (0, 5, 10, and 15 Mg/ha; WR0, WR5, WR10, and WR15) and three levels of nutrient (NP0: no nutrient, NP1: nutrients (N and P) were added to balance the residue C/nutrient stoichiometry of C/N/P= 100: 8.3: 2.0 to achieve 30% stabilization of added residue C input at 5 Mg/ha (R5), and NP2: 3 × NP1). The results of this study clearly showed that averaged across residue and nutrient input, Inceptisol showed negative N2O flux, suggesting consumption which was supported by its high legacy phosphorus (19.7 mg kg⁻1), elevated pH (8.49), and lower clay content (13%), which reduced microbial activity, as indicated by lower microbial biomass carbon (MBC) and alkaline phosphatase (Alk-P) levels. N2O emissions were more responsive to nutrient inputs, particularly in Vertisol under high WR (15 Mg/ha) input, while CH4 fluxes were significantly reduced under high residue inputs, especially in Vertisol and Inceptisol. Alfisol exhibited the highest total carbon mineralization and GWP, with cumulative GWP being 1.2 times higher than Vertisol and 1.4 times higher than Inceptisol across residue and nutrient input. The partial least square (PLS) regression revealed that anthropogenic factors significantly influenced CO2 and N2O fluxes more than CH4. The anthropogenic drivers contributed 62% and 44% of the variance explained for N2O and CH4 responses. Our study proves that different biogeochemical mechanisms operate simultaneously depending on the stoichiometry of residue C and nutrients influencing soil GHG responses. Our findings provide insight into the relative contribution of anthropogenic and natural drivers to agricultural GHG emissions, which are relevant for developing process-based models and addressing the broader challenge of climate change mitigation through crop residue management.

The Influence of Fluoride Ions on the Forms of Lanthanide Migration in Natural and Polluted Waters of the Lovozero Massif (The Kola Peninsula)

A comprehensive study (monitoring, thermodynamic modeling) of natural and anthropogenically polluted waters of the Lovozero Massif has been carried out. A thermodynamic study of the weathering of the Lovozero Massif within the “water-rock-atmosphere” system at a temperature of 5 °C showed that the elements contained in the rocks of the studied massif influence the formation of the chemical composition of natural waters. It has been established that an increase in the degree of “water-rock” interaction leads to an increase in the concentrations of F−, Cl−, SO42−, and HCO3− in the solution. This affects the mobility of lanthanum, cerium, and other elements due to the formation of complex compounds with them. The relatively high content of fluorine, phosphorus, and HCO3− (weak and medium acids) in the solution promotes the dissolution of silicates while Si, Al, and P are released into the solution. Monitoring of water from a flooded mine in which there is an increase in the degree of interaction of water with rock showed higher pH values for the concentrations of Na, HCO3−, F−, P, Al, Si, V, U, La, and Ce. The conclusions are relevant in the context of the use of groundwater for drinking water supply purposes. The obtained information is useful to evaluate the health of the population of the region under study.

A novel bio-based ferric flame retardant effectively improving the flame retardancy and mechanical properties of polylactic acid

PTDF is prepared by a convenient ionic reaction of phytic acid, terephthalic dihydrazide and iron salts in water. It is a new type of high efficiency flame retardant. PTDF has high phosphorus and nitrogen content and good thermal stability, which can effectively improve the flame retardancy of PLA. PTFE is an anti-drip agent and is often used to improve the flame retardancy of PLA together with flame retardants. The addition of 4 wt% PTDF and 0.1 wt% PTFE made PLA reach V-0 flame retardant grade from non-flame retardant, and the oxygen index increased from 19.5 % to 24.5 %. With the increase of PTDF content, the performance of PLA improved significantly. The peak heat release rate (PHRR) and THR of PLA/6PTDF composites decrease by 27.4 % and 16.2 %, respectively, and the flame retardant index FRI increase by 232 %, showing excellent flame retardant efficiency. 6 wt% PTDF can increase the crystallinity of PLA by 25.9 %, tensile strength, maximum force required for impact fracture and notch impact strength by 12 %, 37 % and 129 %, respectively, and effectively improve the mechanical properties and toughness of the composite. The bio-based flame-retardant PLA/PTDF composites reported in this paper can be applied to office equipment.

A novel phosphate detection sensor: From FTIR to EC-QCL

Excessive discharges of industrial and domestic sewage containing high concentrations of phosphorus are causing damage to the environment, so the detection of these pollutants in bodies of water is extremely critical. External cavity quantum cascade laser (EC-QCL) spectroscopy is a novel measurement technology that surpasses conventional infrared spectroscopy techniques. In this research, we propose a transmission detection system with a long optical path based on an EC-QCL for the detection of phosphate concentration in water bodies. Linear regression models were established based on this detection system, with all determination coefficients higher than 0.98 and a minimum detection limit smaller than 5.1 ppm. Additionally, the high-power spectral density of the EC-QCL permits the construction of a model using the raw radiation intensity data, as opposed to the conventional technique which depends on a reference background. The results show that the overall performance of the model based on the raw radiation intensity is similar to that of the model based on absorbance data. The EC-QCL detection system proposed in this study can ensure accuracy in the detection of pollutants, and the advantage of miniaturization provides a novel idea for the following development of portable phosphate in-situ sewage detection sensors.

Performance of carbon felt as cathodes in magnesium corrosion method to recover phosphate from swine wastewater

With the large-scale development of the livestock and poultry breeding industries, swine wastewater with high nitrogen and phosphorus concentrations has become an urgent problem. Given the continuous demand for phosphorus resources in industrial production, the study of phosphate recovery in phosphorus-rich wastewater is of great value for the sustainable utilization of phosphorus resources and for alleviating the eutrophication of aquatic ecosystems. In this study, a magnesium metal corrosion method was used to recover phosphorus resources from swine wastewater using carbon felt as the cathode instead of traditional cathode materials such as graphite and titanium plates. The effects of different cathode materials on the corrosion potential of magnesium metal plates were compared, and the effects of carbon felt as a cathode plate on the removal rate and pH of phosphate from wastewater were discussed. Additionally, the economic feasibility of phosphate recovery from swine wastewater was evaluated. The experimental results showed that the effect of carbon felt on the corrosion potential of the magnesium metal plate was more evident than that of the graphite and titanium plates (Ecorr = −1.74676). When carbon felt was used as the cathode plate, the most energy-saving reaction conditions were as follows: reaction time T = 30 min, ratio of wastewater volume to plate area V: S = 500 cm3:50 cm2, aeration rate Re = 8 L/min, stirring rate r = 400 rpm, phosphate recovery rate = 92.3%, and pH = 8.83. The economic feasibility assessment shows that the proposed method is $2.047 g-1 PO4-P without considering the reuse of carbon felt. Carbon felt has good stability and can be recycled eight times or more, and the proposed method achieves a more efficient phosphate recovery rate at a relatively low cost.

Corn stover waste preparation cerium-modified biochar for phosphate removal from pig farm wastewater: Adsorption performance and mechanism

The high phosphorus content in livestock and poultry wastewater is a significant factor contributing to water eutrophication. It is imperative to seek an economically efficient method for phosphate recovery. This study employed cerium-modified biochar to recover phosphate from pig farm wastewater. An investigation was conducted to examine the adsorption performance and removal mechanism of phosphate. Among the different samples, 0.1CeB-500℃ was selected for subsequent experiments. It exhibited a phosphate adsorption capacity of 9.58 mg/g and a removal efficiency of 95.75 %. The results showed that the phosphate adsorption process followed not only the pseudo-second-order kinetic model, but also the Langmuir isotherm model. It suggested that the adsorption of phosphate onto the biochar occurred in a monolayer chemical manner, with a maximum adsorption capacity of 10.86 mg/g. Phosphate adsorption was minimally affected within the pH range of 2–9, with Cl- having negligible impact, NO3- slightly inhibiting, and HCO3- and CO32- significantly hindering phosphate adsorption. A series of characterization results indicated that phosphate removal occurred through surface precipitation forming CePO4, ligand exchange between carbonate and phosphate, inner-sphere complexation, and electrostatic attraction. The phosphate removal efficiency from pig farm wastewater was 43.25 %, demonstrating promising potential for practical application.

A two-step approach to recycling hydroponics waste nutrient solutions using fertiliser drawn forward osmosis and chemical precipitation

Hydroponic waste nutrient solutions (HWNS) present significant environmental and economic challenges due to their high phosphorus content and potential for eutrophication. Addressing these issues requires innovative approaches that mitigate environmental impacts and recover valuable resources. This study introduces a novel two-step approach that combines Fertiliser Drawn Forward Osmosis (FDFO) and chemical precipitation to recycle HWNS effectively.In the first phase, FDFO was employed to concentrate HWNS using a commercial hydroponic fertiliser as the draw solution. This process resulted in a diluted fertiliser solution (potentially suitable for reuse in hydroponics irrigation) and a concentrated HWNS rich in phosphorus. The concentrated HWNS was then subjected to chemical precipitation in the second phase, where phosphorus was recovered as calcium phosphate by adding sodium hydroxide at an optimised pH of 9.5.Bench-scale experiments demonstrated a 93% water recovery rate using FDFO and an impressive 99.5% phosphorus removal efficiency through chemical precipitation. These results indicate that the combined FDFO and chemical precipitation processes effectively recover water and phosphorus from HWNS and reduce reliance on synthetic fertilisers and freshwater in hydroponic systems.The findings of this study demonstrate that the two-step approach not only enhances water and phosphorus recovery but also improves the efficiency of the chemical precipitation process by achieving higher recovery rates resulting in more sustainable hydroponic systems.

Landfill mining: A step forward to reducing CH4 emissions and enhancing CO2 sequestration from landfill

Landfill management is a major challenge for sustainable development in terms of climate change and resource scarcity. Landfill leachate contains high concentrations of nitrogen (N) and phosphorus (P), which cause eutrophication if discharged improperly. However, the nutrients can be recovered and reused as fertilizers for agriculture, contributing to resource recovery, circular economy, food security, and net zero emissions. Recent advances in landfill management have transformed landfills into resource recovery facilities that can produce nutrient-energy-material (NEM) products for applications through biological or physico-chemical process. Through a literature survey, this article reviews NEM recovery from landfills such as biogas production and composting. This work also discusses the benefits and challenges of NEM recovery for sustainability transition towards net zero emissions, while analyzes knowledge gaps and future research directions for landfill management and NEM recovery. It was conclusive from 193 articles published between 1993 and 2024 that landfill mining presents a promising solution for mitigating CH4 emissions and enhancing CO2 sequestration, both critical in reducing the overall greenhouse gas footprint of waste management. From landfill leachate and/or landfill gas, engineers can recover and recycle nutrients (for fertilizer), materials (for chemistry), and biogas (for electricity). Through landfill management, roadmaps towards decarbonization can be cost-effective and sustainable so that a maximum value of the waste can be extracted before it is discarded. Key findings reveal that CH4 emissions can be reduced by uncovering buried waste, while soil and residual organic material enhance CO2 sequestration through microbial activity. Additionally, this review highlights the economic and environmental benefits of material recovery from landfills, including metals and plastics. Overall, this work emphasizes landfill mining as a sustainable strategy for improving waste management practices, while contributing to climate change mitigation.

Assessing the nutrient removal performance from rice-crayfish paddy fields by an ecological ditch-wetland system

Agricultural drainage from catchments significantly impacts aquatic ecosystems due to high nitrogen and phosphorus concentrations in runoff. While original ecological ditches and wetlands have demonstrated effectiveness in nutrient load removal, the overall impact of an ecological ditch-wetland system (EDWS) on agricultural nutrient removal has received limited attention. This study conducted a field experiment to investigate the physicochemical conditions and nutrient removal efficiency of an EDWS for purifying nutrient discharge from rice-crayfish paddy fields. Variations in water temperature (WT), dissolved oxygen (DO), pH, and total suspended solids (TSS) within the EDWS were assessed. Nutrient concentrations—including total nitrogen (TN), ammonium nitrogen (NH4-N), nitrate nitrogen (NO3-N), total phosphorus (TP), and soluble reactive phosphorus (SRP)—were monitored from the tillering to the ripening stage of the rice growth cycle. The evaluation of nutrient removal efficiencies in the EDWS revealed that ecological ditches exhibited higher removal efficiencies compared to wetlands. The average total removal efficiencies for TN, NH4-N, NO3-N, TP, and SRP were 37.50 %, 39.38 %, 38.62 %, 37.94 %, and 39.51 %, respectively, with peak removal efficiencies observed at specific growth stages of the rice crop. Furthermore, the study explored the influence of hydraulic retention time on nutrient removal efficiency in the EDWS, indicating higher nutrient discharge removal efficiencies under low water discharge rates. Linear regression analysis identified water discharge, influent nutrient loads, and TSS as significant factors affecting nutrient removal efficiency in the EDWS. This study provides valuable insights into the effectiveness of EDWS in purifying nutrient discharge from rice-crayfish paddy fields, highlighting their potential as sustainable solutions for nutrient management in agricultural landscapes.

Characterization of Oils and Solid Residues Obtained from <i>Bauhinia variegata L.</i> and <i>Pachira glabra pasq.</i> Seeds Through the Solvent Extraction Method

Vegetable oils derived from non-edible seeds are excellent sources for producing biodiesel which serves as an alternative to fossil fuels. In this study, products viz vegetable oils and solid residues obtained from solvent extraction method of <i>Bauhinia variegata</i> and <i>Pachira glabra</i> seeds were characterized according to standard norms to evaluate their energy potential. The oils obtained have a free fatty acid content of 2.31 wt% and 13.6 wt%, a kinematic viscosity of 12.45 and 3.24 mm²/s, an iodine value of 17.26 and 12.37 (g of I<sub>2</sub>/100g of oil), a saponification value of 207.57 and 183.03 (mg of KOH/g of oil), a peroxide value of 10 and 8.06 (meq O<sub>2</sub>/kg of oil), and a calorific value of 40.66 and 65.08 MJ/kg, respectively. Furthermore, the physicochemical analysis of the oils revealed that they are excellent choice for biodiesel production. In addition, the proximate analysis of the solid residues of <i>Bauhinia variegata</i> and <i>Pachira glabra</i> showed high level of protein, fiber, and total carbohydrates with respective values of 34.79 and 30.41 wt%, 10.44 and 15.16 wt%, and 47.50 and 52.92 wt%. Mineral analysis indicated a high concentration of minerals, particularly potassium, sodium, calcium, and phosphorus. The solid residues exhibit anti-nutritional properties, making it suitable for various applications such as bioconversion by black soldier fly larvae, bioelectricity, biogas production, and biofuels among others.

Formation of the quality of champignons using organic additives and biologically active substances

This article provides a summary of the results of research using various additives to improve the yield of mushrooms. To improve the quality of mushrooms mushrooms studies were carried out to increase the yield of mushrooms using organic additives and biologically active substances grown on substrates of soybean seeds, meat and bone meal, powder from buckwheat seeds and millet. Conducted a comparative characterization of the impact of mushrooms mushrooms on quality indicators. In carrying out the study different objectives, such as increasing the composition, the quality of agricultural products, as well as the volume of production, the impact on growth. The article presents current methodological and agro-technical problems of mushroom growing technology. However, they are not enough, in our opinion, studied the effect of organic additives and biologically active products on the formation of not only the yield but also the quality of mushrooms. Vitamins, macro - and microelements and energy value of mushrooms champignons presented in the results of the study. Cultivation of mushrooms is provided to meet the needs of humans and the environment on the basis of increasing their biological value, for therapeutic treatment of various cancers and use as a food, pesticide product, in everyday life for the human body, health, normal daily diet as a product with many benefits from high quality and simple mushrooms. In the study, vitamins C,PP showed higher values than other vitamins, And in the amount of 100 g of macro and trace elements can be noticed high content of potassium and phosphorus. It is worth noting that the calorie content of mushrooms is only 27 kilocalories per one hundred grams of product. The nutritional value of mushrooms is one of the factors affecting their population.