Waste Biochar Research Articles

Improvement of Brown Coal Quality through Variation of Acacia Wood Waste Biochar Composition in Producing Alternative Solid Fuel

Improvement of Brown Coal Quality through Variation of Acacia Wood Waste Biochar Composition in Producing Alternative Solid Fuel

Chemical and Physical Properties of Selected Biochar Types and a Few Application Methods in Agriculture

Biochar, a carbon-rich by-product of organic matter pyrolysis, has a variety of physiochemical properties beside a variety of applications. This review highlights some physical and chemical characteristics of herbaceous, woody, and sewage waste biochar under different pyrolysis conditions, as well as soil and foliar applications of biochar. The controlling role of pyrolysis temperature was the reason for selecting the discussed biochar types in the study. This review concludes that increasing pyrolysis temperature mainly raised the values of some chemical properties of the biochar, such as pH, electrical conductivity (EC), ash content, total phosphorus (TP), and a few values of physical properties like porosity and specific surface area (SSA). On the other hand, yield and total nitrogen (TN) decreased with rising pyrolysis temperature. Among biochar application methods to soil, mixing biochar with soil before planting is one of the best methods of application, and in most cases, biochar reapplication improved soil properties, while foliar application of biochar has positive effects on plant growth and yield parameters, ranging from low rates to the highest ones.

A quantitative review of the effects of biochar application on the reduction of Cu concentration in plant: a meta-analysis.

Contamination and toxicity of copper (Cu) in soils are global issues, particularly in regions where Cu-based fungicides are utilized. Elevated Cu concentrations can lead to soil contamination and pose significant risks to the ecosystem, including plant life, wildlife, and human health. The application of biochar has been proposed as a viable strategy to mitigate Cu accumulation in plants. However, there is no quantitative and data-based consensus on the impact of biochar on plant Cu accumulation. In this meta-analysis, 624 data records from 65 published literature were collected and the effects of various factors, including biochar properties, experimental conditions, and soil properties on Cu accumulation in plants, were examined through meta-subgroup analysis and meta-regression models. The results obtained indicate a significant dose-dependent effect of biochar in decreasing Cu concentration in plants by an average of 23.45%. Soils with acidic pH values and medium textures were more conducive for biochar to mitigate Cu accumulation in plant tissues. In addition, manure biochar and green waste biochar were found to be more successful in decreasing Cu concentrations in plants compared to other biochar types. Biochar types with pyrolysis temperatures of > 600°C and pH values of ≥ 10 resulted in greater decreases in plant Cu concentration. Regarding biochar application, biochar minimum range of 1% in potting experiments and 20 t/ha in field experiments have been recommended to effectively decrease Cu concentration in plants. Overall, these findings provide valuable insights into Cu transfer mitigation through food chain to human bodies and for policymakers to take preventive measures.

Performance Assessment of a Novel Green Concrete Using Coffee Grounds Biochar Waste

An actual scientific problem in current concrete science is poor knowledge of the problem of modifying concrete with plant waste. At the same time, plant waste benefits from other types of waste because it is a recycled raw material. A promising technological approach to modifying concrete with plant waste is the introduction of components based on the processing of coffee production waste into concrete. This study aims to investigate the use of biochar additives from spent coffee grounds (biochar spent coffee grounds—BSCG) in the technology of cement composites and to identify rational formulations. A biochar-modifying additive was produced from waste coffee grounds by heat treatment of these wastes and additional mechanical grinding after pyrolysis. The phase composition of the manufactured BSCG additive was determined, which is characterized by the presence of phases such as quartz, cristobalite, and amorphous carbon. The results showed that the use of BSCG increases the water demand for cement pastes and reduces the cone slump of concrete mixtures. Rational dosages of BSCG have been determined to improve the properties of cement pastes and concrete. As a result of the tests, it was determined that the ideal situation is for the BSCG ratio to be at a maximum of 8% in the concrete and not to exceed this rate. For cement pastes, the most effective BSCG content was 3% for concrete (3%–4%). The compressive and flexural strengths of the cement pastes were 6.06% and 6.32%, respectively. Concrete’s compressive strength increased by 5.85%, and water absorption decreased by 6.58%. The obtained results prove the feasibility of using BSCG in cement composite technology to reduce cement consumption and solve the environmental problem of recycling plant waste.

Food waste biochar for sustainable agricultural use: Effects on soil enzymes, microbial community, lettuce, and earthworms

This study investigates the effects of food waste biochar (FWB) on the biological properties of soil, including the microbial community structure, enzyme activities, lettuce growth, and earthworm ecotoxicity. This holistic assessment of various soil organisms was used to assess the potential of FWB as a soil amendment strategy. Pot experiments were carried out over a 28-d period using various FWB concentrations in soil (0–3% w/w). The presence of FWB enhanced the activity of alkaline phosphatase and beta-glucosidase in proportion to the FWB concentration. Similarly, the dehydrogenase activity after 28 d was positively correlated with the FWB concentration. Notably, the application of FWB improved the bacterial diversity in the soil, particularly among hydrocarbonoclastic bacteria, while also prompting a shift in the fungal community structure at the class level. Measures of lettuce growth, including total fresh weight, shoot length, and leaf number, also generally improved with the addition of FWB, particularly at higher concentrations. Importantly, FWB did not adversely affect the survival or weight of earthworms. Collectively, these findings suggest that FWB can enhance soil microbial enzyme activity and support plant growth-promoting rhizobacteria, potentially leading to increased crop yields. This highlights the potential of FWB as an eco-friendly soil amendment strategy.

Application of oil palm and cacao waste biochar to improve the chemical properties of an Ultisol of Langsa, Aceh

Ultisols, including those of Langsa, Aceh, are known to have low fertility due to low pH, low available nutrients, low base saturation, high pH and exchangeable Al, and low cation exchange capacity. These problems can be alleviated by applying organic amendments to the soil. One of the soil amendments is biochar. This study aimed to elucidate the potential of oil palm and cacao waste biochar for improving the chemical properties of an Ultisol of Langsa, Aceh. Biochars generated from oil palm kernel shell (PKS), oil palm empty fruit bunch (PEFB), and cacao pod husk (CPH) were applied to the soil and incubated in the laboratory for 16 weeks. At 4, 8, 12, and 16 weeks after incubation, the changes in soil chemical properties were measured. The results showed that applying different types of biochar significantly improved the chemical properties of the Ultisol of Langsa. Specifically, PEFB biochar caused significant increases in soil pH (H2O and KCl), total phosphorus, available phosphorus, organic C, and cation exchange capacity. These increases became more pronounced with longer incubation times. In addition, using PEFB biochar resulted in the lowest levels of exchangeable Al and Fe in the soil. These levels decreased further with longer incubation times. In general, PEFB biochar produced at a pyrolysis temperature of 450oC for 4 hours is the most effective biochar for improving the chemical properties of the Ultisol of Langsa.

Synthesis and application of biomass-based graphene oxide using microwave-assisted pyrolysis method

Graphene and related materials have excellent potential to revolutionise many emerging fields, but the large quantity synthesis using environmentally sustainable methods is still challenging. This work studies the synthesis of graphene oxide from food waste biochar with negatively charged properties, which is initially produced using microwave pyrolysis. The synthesised graphene oxide achieved 64.53 % carbon content, 345.79 m2/g surface area, 0.074 cm3/g micropore volume, large reactive surface area, and ribbon/banded organisation. The performance of carbon-based material is evaluated in the fabrication of a modified screen-printed carbon electrode (SPCE) for selective dopamine (DA) detection in the coexistence of ascorbic acid (AA) and uric acid (UA). The electrostatic interactions between the negatively charged biochar-based graphene oxide (BBGO) on the surface SPCE and opposite-charged dopamine assisted the oxidation potential with interfering species by electrostatic repulsion of AA and UA. This manuscript substantiates the resource recovery from organic materials and sustainable graphene oxide synthesis, underscoring their application in detecting positively charged species.

A comprehensive decision-making approach for the application of biochar in agriculture to enhance water security: A GIS-AHP based approach

In the context of climate change, biochar application is a promising approach to mitigate the adverse effects of climate change on agriculture. However, the selection of suitable biochar produced from food waste and optimization of loading rates to improve soil quality remains a significant challenge. This study explores the potential impact of biochar application using an integrated analytical hierarchy process (AHP) and geographical information system (GIS) approach. The study first aims to develop an AHP model to prioritize the appropriate biochar source and dosage for soil amendment. The different biochar sources considered are: peas pod shell, pistachio shell, and mixed vegetable waste. The AHP design evaluated the weight percentage of different types of biochar amendments ranging from 0 % to 8 % based on soil quality, nutrient analysis and water retention capacity. Furthermore, an integrated spatial analysis case study was conducted for fodder farms across Qatar using GIS mapping with seasonal variation to evaluate the impact of biochar on water management. According to the AHP decision making, 2 % mixed vegetable waste biochar achieved the goal with the highest priority score, with a value of 0.29, followed by 2 % pistachio shell biochar with a score of 0.22. This is attributed to the high water retention rate determined from the experimental study. The 2% biochar amendment retained 20 % more water compared to the 0 % biochar. Results from the GIS mapping identified priority areas for improving water retention and soil quality. The evapotranspiration maps for winter and summer generated using GIS provide valuable insights into the spatial disributio of biochar application across Qatar fodder farms. The outcomes may encourage policymakers and stakeholders to consider valorizing food waste into biochar.

Photocatalytic removal of rhodamine B using a novel g–C3N4–organic solid waste biochar composite: Pathway, key factors, and mechanism

Over the past decades, water pollution caused by organic dyes has attracted extensive attention. The development of efficient, environmental friendly photocatalysts is a promising route for wastewater purification. Herein, a novel wild jujube shell derived biochar/g-C3N4 (BC/CN) composite has been prepared via a one-step calcination route. Although the specific surface area (9.37 m2/g) and pore size (14.57) of the BC/CN composite are smaller than those of g-C3N4, it exhibits enhanced photocatalytic activity. Especially, the 0.25-BC/CN composite (sour jujube shell powder/melamine ratio = 0.25) displays excellent photocatalytic activity, and can degrade ∼97.1 % of RhB under 40 min light irradiation, which is ∼46.51 times to that of pure g-C3N4. The actives species of h+, ·OH, ·O2− and 1O2 active species play the important roles in the photocatalytic system of the BC/CN composite. The results mechanistic study demonstrates that the enhanced photocatalytic activity of the BC/CN composite can be mainly attributed to the improved light absorption and charge separation efficiency of the catalyst. This work provides a simple method for preparing of novel highly efficient g–C3N4–based photocatalyts for wastewater purification, and provides a new idea for the recycling, and high-value utilization of the organic solid waste from traditional Chinese medicine.

Development of sustainable and high-performance polymer composite rebar using vegetable waste biochar and areca fiber as reinforcement materials for green construction

Development of sustainable and high-performance polymer composite rebar using vegetable waste biochar and areca fiber as reinforcement materials for green construction

Characteristics of composite briquettes produced from carbonized banana peels and waste glass

Briquettes made from carbonized agricultural residues present sustainable material alternatives to wood charcoal and firewood for commercial and industrial applications. However, these briquettes are plagued by property weaknesses including low drop strength and thermal efficiency. Therefore, this study focuses on enhancing the physical, mechanical and thermal properties of composite briquettes produced from carbonized banana peels and waste glass. Composite briquettes comprised of banana peels biochar and waste glass powder (0%, 5%, 10%, 20%, 30%, 40%, and 50%) were developed, characterized, and evaluated using thermo-gravimetric analysis and bomb calorimetry to determine thermo-physical properties and higher heating values, respectively. The thermal efficiency and emissions (CO, CO2, and PM2.5) were assessed using the water boiling test and an emissions monitoring system. Proximate analysis revealed that moisture content, volatile matter, fixed carbon, and ash content of the developed briquettes ranged from 2.5 to 9.7%, 19.2 to 37.2%, 28.7 to 55.6%, and 7.2 to 44.9%, respectively. Drop strength for the briquettes was 84% without waste glass in the composite, increasing to 94–98% with waste glass included in the composite matrix. Higher heating values ranged from 20.1 to 35.8 MJ/kg. Thermal efficiency rose from 22% with no waste glass powder to 40% with 50% waste glass powder addition, while CO and CO2 emissions decreased from 41 to 11 ppm; and 50 to 15 ppm, respectively. PM2.5 remained constant across all banana peel biochar waste glass composites. Notably, even a modest 10% waste glass composition significantly improved drop strength and thermal efficiency, but higher waste glass percentages correlated with elevated ash values and reduced higher heating values. Therefore, the developed composite briquettes can be used in commercial and industrial applications including in some industrial boilers.

Investigating the efficacy of biochar produced from agro-waste for basic fuchsin dye removal: Kinetics, isotherm, and thermodynamic studies

The present article investigates the efficacy of biochar (BC) derived from agricultural waste for treating cationic dyes. Various biomass, including sycamore leaf (SL), cotton waste (CW), groundnut shell (GS), rice husk (RH), coconut shell (CS), banana pith (BP), and coconut husk (CH) were used to prepare biochar at 400, 600, and 800 °C. The highest removal of basic fuchsin (BF) dye was observed onto the BC prepared at 800 °C, with the removal efficiency as follows: cotton waste biochar (CWB) 88.12 %, groundnut shell biochar (GSB) 88.73 %, rice husk biochar (RHB) 89.37 %, coconut shell biochar (CSB) 90.4 %, coconut husk biochar (CHB) 91.24 %, banana pith biochar (BPB) 96.7 %, and sycamore leaf biochar (SLB) 100 %, respectively. The dye concentration, BC dose, reaction time, temperature, and pH were optimized. Optimal conditions for higher BF dye sorption (174.5 mg g−1) were found at the dye concentration of 3500 mg L−1, SLB dose of 0.2 g, time 45 min, temperature 40 ± 2 °C, and pH 9 ± 0.2. The sorption kinetic data best fit a pseudo-second-order model, while isotherm data followed the Freundlich model, suggesting chemisorption with a multilayer sorption process. Thermodynamic data implied that the sorption process was endothermic and spontaneous. The present research revealed the hidden potential of widely and easily available waste biomass to competently remove the cationic dye.

Synergetic effect of heating rate, temperature, and residence time of modified agro-industrial waste biochars on phosphate adsorption

Synergetic effect of heating rate, temperature, and residence time of modified agro-industrial waste biochars on phosphate adsorption

Microwave-assisted magnetic biochar for removal of hexavalent chromium from aqueous solution

ABSTRACT In this study, biochars were prepared by pyrolysis of tea waste and rice husk and hexavalent chromium (Cr(VI) sorption was obtained after post-modification of biochars with magnetic iron nano/micro-particles. The maximum sorption of Cr(VI) by magnetic tea waste biochar (MTWB) was 99.9% followed by 97.36% for magnetic rice husk biochar (MTRHB) at pH 5.2. Among studied competing ions, sulfate ions (SO4 2-) considerably reduced the sorption of Cr(VI) up to ~66.5% for both biochars. The surface functional groups such as – OH, C-H, Fe-O and porous biochars structure loaded with iron nanoparticles helped in Cr(VI) adsorption by ion exchange and electrostatic interactions as indicated by FTIR, XPS and SEM-EDS data. Both Cr(III) and Cr(VI) species were observed on biochars surface confirming the Cr(VI) removal process by reduction and direct adsorption of Cr(VI) ions. Hence, this study provides an excellent option for the application of magnetic biochars to treat Cr(VI) containing wastewater.

Mitigation of drought stress in chili plants (Capsicum annuum L.) using mango fruit waste biochar, fulvic acid and cobalt

Drought stress can have negative impacts on crop productivity. It triggers the accumulation of reactive oxygen species, which causes oxidative stress. Limited water and nutrient uptake under drought stress also decreases plant growth. Using cobalt and fulvic acid with biochar in such scenarios can effectively promote plant growth. Cobalt (Co) is a component of various enzymes and co-enzymes. It can increase the concentration of flavonoids, total phenols, antioxidant enzymes (peroxidase, catalase, and polyphenol oxidase) and proline. Fulvic acid (FA), a constituent of soil organic matter, increases the accessibility of nutrients to plants. Biochar (BC) can enhance soil moisture retention, nutrient uptake, and plant productivity during drought stress. That’s why the current study explored the influence of Co, FA and BC on chili plants under drought stress. This study involved 8 treatments, i.e., control, 4 g/L fulvic acid (4FA), 20 mg/L cobalt sulfate (20CoSO4), 4FA + 20CoSO4, 0.50%MFWBC (0.50 MFWBC), 4FA + 0.50MFWBC, 20CoSO4 + 0.50MFWBC, 4FA + 20CoSO4 + 0.50MFWBC. Results showed that 4 g/L FA + 20CoSO4 with 0.50MFWBC caused an increase in chili plant height (23.29%), plant dry weight (28.85%), fruit length (20.17%), fruit girth (21.41%) and fruit yield (25.13%) compared to control. The effectiveness of 4 g/L FA + 20CoSO4 with 0.50MFWBC was also confirmed by a significant increase in total chlorophyll contents, as well as nitrogen (N), phosphorus (P), and potassium (K) in leaves over control. In conclusion4g/L, FA + 20CoSO4 with 0.50MFWBC can potentially improve the growth of chili cultivated in drought stress. It is suggested that 4 g/L FA + 20CoSO4 with 0.50MFWBC be used to alleviate drought stress in chili plants.

Effectiveness of feeding different biochars on growth, digestibility, body composition, hematology and mineral status of the Nile tilapia, Oreochromis niloticus

Oreochromis niloticus fingerlings (5.15 ± 0.02 g; n = 315) were fed with different types of biochar (BC)-supplemented sunflower meal-based (SFM) diet to investigate the effects of various BC inclusions on their nutritional digestibility, body composition, hematology and mineral status for 60 days. Seven different diets were formulated based on the SFM based diet: one was a control (TD-I, CON) and the other six diets were supplemented with 2% BC derived from different sources. These BCs were derived from the following: cotton stick (CSBC, TD-II), wheat straw (WSBC, TD-III), corn cob (CCBC, TD-IV), house waste (HWBC, TD-V), grass waste (GWBC, TD-VI), and green waste (GwBC, TD-VII) biochar. There were three replicates for each test diet. Each tank had fifteen tilapia fingerlings, and they were fed with 5% of their live wet weight and twice daily. The outcomes showed that the supplementation of CCBC significantly elevated the growth, nutrient absorption, and body composition of the O. niloticus fingerlings (p < 0.05); with concomitant lowering of the quantity of nutrients released into the water bodies whereas HWBC gave negative impacts. The maximal mineral absorption efficiency (Ca, Na, K, Cu, Fe, P, and Zn) was achieved by the supplementation of 2% CCBC. All hematological parameters showed positive improvements (p < 0.05) with CCBC. Interestingly, CCBC significantly improved the growth, digestibility, body composition, hematology, and mineral status of O. niloticus.

Lanthanum and cerium functionalised forestry waste biochar for phosphate removal: Mechanisms and real-world applications

Phosphorus as a diminishing finite resource, yet is an essential element for the growth of biota. However, elevated concentrations in water can imbalance ecosystems and cause eutrophication. To address both problems, two highly efficient biochars, namely La-OB and CeLa-OB were synthesised by lanthanum and cerium doping. The performance of La-OB and CeLa-OB were evaluated in both batch and dynamic regimes with synthetic phosphate (PO43--P) solutions and eutrophic lake water. PO43--P adsorption mechanisms were investigated in terms of pH, kinetics, isotherms, activation energy, thermodynamics and using in-depth characterisation (XPS, FTIR, XRD, BET, pHpzc and SEM-EDX). The feasibility of using such biochar in ‘real life’ situations was studied with column filtration of lake water with low and high PO43--P concentrations. Reusability/desorption and toxicity in the water environment was also considered. The mechanistic study showed that both biochars predominantly had inner-sphere complexes with La and Ce ligands (as a monolayer), while outer-sphere complexation was less common. The exothermic adsorption process followed the Elovich kinetic and Langmuir isotherm models, with a maximum adsorption capacity of 112 mg/g for La-OB and 40 mg/g for CeLa-OB. In column filtration trials the adsorption capacity reached 78 mg/g, while low metal leaching (0.08 mg/L) and low toxicity to Lepidium sativum germination were detected. The results indicated that these biochars, especially La-OB, could be used in circular economy-based water treatment.

Using Deficit Irrigation Strategies and Adding Sugarcane Waste Biochar as a Sustainable Material to Sandy Soils for Improving Yield and Water Productivity of Cucumber

This study investigates the potential of biochar to mitigate drought stress in crops. Biochar amendments are increasingly recognized for their ability to enhance soil properties that promote water retention and plant resilience during dry periods. In a study conducted in Egypt, impacts of the application of sugarcane biochar on cucumber production, water productivity, and quality characteristics under deficient irrigation conditions were evaluated. Increasing the biochar application rate under arid region conditions resulted in significant improvements in cucumber yield, water productivity, vitamin C, soluble sugar content, and total soluble solids. The activated sugarcane biochar exhibited desirable properties, including a large surface area (250 m2g−1) and pore size (0.28 cm3g−1), with a microporous nature. The positive effects observed can be attributed to reduced water volume leaving the root zone, enhanced nutrient absorption, increased water holding capacity, and augmented nutrient availability. Based on the results, it is recommended to implement under-irrigation at 75% of full irrigation and apply a biochar rate of 10 tons per hectare to mitigate the environmental impacts of water scarcity and support the development of sustainable agricultural systems. In conclusion, biochar emerges as a valuable soil amendment for bolstering cucumber production and water use efficiency (WUE) under limited irrigation scenarios. Its potential lies in promoting improved soil moisture retention, enhancing nutrient availability for cucumber plants, and potentially mitigating plant stress.

Iron ore reduction using agricultural waste biochar with different carbon to oxygen ratios

BackgroundDuring iron production ferric oxide is reduced to iron, with carbon used as the reducing agent. Traditionally, coke was used as the carbon component, which became a crucial raw material in the iron and steel industry after the industrial revolution. However, coke is the most significant contributor to CO2 emissions due to the source of heat and reducing agent. Thus, shifting to low carbon energy systems, such as those based on biomass, is challenging. Therefore, in this study, we employed the mushroom cultivation residue char (MCRC) as a reducing agent to investigate the feasibility of replacing coke in the production of metallic iron. MethodsAfter carbonization at different temperatures (500 °C, 700 °C and 900 °C), mushroom cultivation residue char (MCRC), were used as a reducing agent in the production of metallic iron. To create the composite pellets, the MCRCs were individually mixed with iron ore at different carbon to oxygen ratios (C/O) (0.7, 0.8 and 0.9) and 1 % of bentonite. The reduction process was undergoing in the electric muffle furnace at different high temperatures (1,000 °C, 1,200 °C and 1,300 °C) to investigate the biomass C/O ratios required for efficient iron production. Significant findingsThe results show that 0.8 was selected as the optimal C/O ratio for mushroom cultivation residue char (MCRC) to be used as a reducing agent. Its metallization rate can reach 31.99 %. The results also indicate that the carbon and volatiles in MCRC play a key role in iron making production using such biochar pellets. In conclusion, MCRC can be used as a reducing agent to increase the sustainability of iron production and reduce agricultural waste.

DEVELOPMENT OF WATER SOFTENING METHOD BY USING NATURAL ADSORBENT: TEMPLE WASTE

Nowadays, Heavy metals are the prime concern due to their adverse effects on the environment and human beings. It is discharged from various industries such as mining, metal finishing, electroplating, glass, textiles, ceramics, and storage batteries. Copper is the metal used in many electronic devices and involved in other production processes. On the other hand, the amount of floral waste generated from temples and festivals/celebrations are increasing day by day, its impact on the solid waste management process is huge and it creates a fouling smell when it is disposed of improperly. Therefore, the present aim of the project is to utilize the waste flowers for the development of Biochar where it is used in the removal of heavy metal i.e., copper from synthetic wastewater. The other advantage of floral Biochar is the increase in soil organic matter (SOM) which can influence the soil microclimate, microbial community structure, biomass turnover, and mineralization of nutrients. The preparation, physicochemical properties, and adsorption mechanisms of floral waste Biochar in removing copper metal from synthetic wastewater have been discussed in this study. Key Words: optics, photonics, light, lasers, templates, journals