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Abstract In order to identify the key antioxidant defense systems used to cope with high-temperature stress in rice leaf chloroplasts following biochar supplementation, the present study compared the expression levels of chloroplast proteins related to antioxidant defense in high-temperature stressed rice leaves between without (C0) and with biochar supplementation (C40; 40 g biochar kg–1 soil). A total of sixteen differentially expressed antioxidant chloroplastic proteins were identified. Among them, three antioxidant enzyme proteins and eight thioredoxin proteins were 62–123% and 37–225% higher under the C40 treatment compared to C0, respectively. These results suggest that both antioxidant enzymes and the thioredoxin system are central to the biochar-mediated protection of rice leaves exposed to high-temperature stress.

In this research, a pesticide-fertilizer combination (PFC) was fabricated using chlorantraniliprole and biochar. The PFC had a spherical shape, smooth surface, uniform particles, relatively dense structure and good compression resistance. The adsorption propertie of biochar to chlorantraniliprole was investigated. During the preparation of pelleted granules, the types and concentrations of core fillers and adhesives were screened and optimized. Besides, the safety to maize and effectiveness against fall armyworms of PFC had been investigated. Meanwhile, The PFC could promoted growth of maize significantly and control fall armyworm effectively. This work provides a promising approach to slow the release of chlorantraniliprole, which has a potential application to enhance the pesticides efficiency.

Abstract Biochar, with its potential to enhance soil fertility, sequester carbon, boost crop yields and reduce greenhouse gas emissions, offers a solution. Addressing the challenges posed by climate change is crucial for food security and agriculture. However, its widespread adoption in agriculture remains in its infancy. This study assessed the effects of rice hull biochar on cabbage production and greenhouse gas emissions, especially nitrous oxide (N2O). A trial, employing a randomized block design in triplicate was conducted from September 13 to November 23, 2022, where "Cheongomabi" cabbage was cultivated with N-P2O5-K2O fertilization at 32 $$-$$ - 7.8 $$-$$ - 19.8 kg 10a−1. Additional fertilizer was applied twice post-sowing. The Biochar application rates were control = 0 ton ha−1, B1 = 1 ton ha−1, B3 = 3 ton ha−1, and B5 = 5 ton ha−1. The aboveground biomass of autumn cabbage harvested 82 days after sowing was 2.40–2.70 kg plant−1 in the control and biochar treatments (B1, B3, and B5), with no significant differences (p > 0.05). Cumulative CO2 emissions during cultivation varied across treatment groups, with initial and cumulative emissions of 10.40–17.94 g m−2 day−1 and 3.63–4.43 ton ha−1, respectively. N2O emissions decreased with higher biochar application: reductions of 2.9%, 25.4%, and 41.1% in the B1, B3, and B5 treatments, respectively, compared to the control. The biochar application had no significant impact on yield but curbed soil emissions, Net ecosystem carbon balance during cabbage cultivation ranged from 0.42 to 3.41 ton ha−1 for the B1, B3, and B5 treatments, respectively, compared to control. Overall, the study underscores biochar’s role in mitigating emissions and boosting soil carbon during cabbage cultivation in fall.

The co-pyrolysis (at 300°C and 600°C) of municipal sewage sludge (SS) with zero-valent iron (Fe0: 1.5% and 3%) was investigated to reduce the toxicity of arsenic (As) and zinc (Zn) in SS. The BCR sequential extraction method, desorption kinetic analysis, and material characterization techniques (Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, X-ray diffraction) were used to evaluate the effects of the treatments on Zn and As behavior. The results showed that co-pyrolysis significantly reduced the acid-soluble fraction (18–43% for Zn; 83–95% for As) and mobility factor (45–85% for Zn; 86–96% for As) of Zn and As compared to untreated SS. Desorption experiments indicated a significant reduction in Zn and As release in treated samples, particularly in the co-pyrolysis sample at 600°C and Fe0 3% (67% for Zn; 88% for As) in comparison with untreated SS. Co-pyrolysis of Fe0 and SS led to the formation of new functional groups (Si–O, aromatic), a more porous surface morphology, and highly stable chemical crystals (ferric arsenate, zinc arsenide), which played a crucial role in Zn and As stabilization. The findings of this study suggest that co-pyrolysis is a promising approach for mitigating As and Zn toxicity in SS. However, additional field testing with plant-based systems is necessary for confirmation.

Organic dyes constitute an integral part of industrial effluents. Advanced oxidation processes are efficient methods for the degradation of organic pollutants, one of the most promising of which is sonocatalysis. In this study, we aimed to immobilize MoS2 nanopetals on honeycomb-like biochar through a one-step hydrothermal method and evaluate its sonocatalytic performance in the degradation of acid blue 7 (AB7). The MoS2-Biochar composite demonstrated enhanced sonocatalytic activity, approved by its larger specific surface area (5.0 m2/g) and narrower bandgap (1.25 eV) compared with those of pure MoS2. Application of 1.5 g/L MoS2-Biochar (10:1) led to a 95 % decolorization of AB7 (20 mg/L) within 40 min of reaction time. Moreover, considerable degradation efficiencies were achieved for various organic pollutants, including hydroxychloroquine (96 %), levofloxacin (81 %), phenazopyridine (80 %), and tilmicosin (67 %) with initial concentration of 20 mg/L within 120 min of treatment. The synergy factor and degradation turnover value of the sonocatalytic process for decolorization of AB7 were calculated to be 4.88 and 27.37 µmol/h.gcat, respectively. Trapping experiments were conducted to determine the roles of various reactive species in the sonocatalytic degradation process, and holes were found to be the dominant species. Furthermore, the generated intermediates were identified using gas chromatography–mass spectrometry (GC–MS) analysis, which suggested a possible mechanism for the degradation process. A stable structure and acceptable reusability with a 16 % reduction in the decolorization efficiency after four consecutive sonocatalytic runs were observed for the 10:1 composite, suggesting a promising perspective for the application of the studied system in the efficient treatment of organic pollutants.

Contamination of water bodies due to pharmaceutical pollutants including antibiotics is growing day by day due to enhanced consumption of these molecules. Biochar is a competent material for wastewater treatment due to ease of preparation as well as high adsorption capability towards desired pollutants. Cassia fistula biochar (CFB) was prepared by torrefaction process in an inert atmosphere. Owing to a large surface area of 672.3 m2/g, the purpose of this work is to carry out adsorption studies of three antibiotics, namely, ciprofloxacin (CFX), levofloxacin (LVX) and diclofenac sodium (DFC) in aqueous phase as well as for the sequestration of carbon dioxide in gaseous phase. The batch adsorption studies were carried and effects of various operational conditions were studied. The maximum adsorption capacities for CFX, LVX, and DFC were found to be 607.86 mg/g, 68.27 mg/g and 160.51 mg/g respectively under the optimum pH 6.0 for all the three adsorbates, contact time of 60 minutes for CFX, LVX and 20 minutes for DFC at room temperature condition of 298 K. Various operational parameters were optimized using Response Surface Methodology (RSM). Isotherm and kinetics studies for the adsorption of all three drugs followed Langmuir model (R2 >0.99) and pseudo-second order kinetics (R2 >0.95). Thermodynamic studies show the adsorption of all three drugs were enthalpy driven spontaneous processes. Fixed bed studies were performed showing the applicability of CFB for larger sample volumes. DFT calculations showed strong attractive interaction of CFB with all the three drug molecules. The same material has been applied for capture of carbon dioxide at different temperatures. The CO2 capture studies showed maximum adsorption capacity of 64.78 cc/g at 273 K owing to activation of CFB with high CO2 selectivity of 14.29 with respect to nitrogen. Hence, a multipurpose adsorbent has been thoroughly studied with environmental sustainability factor of 0.03.

To explore how chemical, physical and biological process impact the adsorption capacity of biochar for cations and anions, five kinds of spent mushroom substrate biochars including PB (carbonized Auricularia auricula substrate at 600 °C for 6 h), NB (Aged PB at 25 °C and 40 % moisture for 12 mon), AB (PB treated with 20 % mixed acid solution at 70 °C for 6 h), FB (PB subjected to 16 freeze–thaw cycles between − 20 °C and 25 °C) and MB (PB incubated with microbes from contaminated soil for 15 cycles) were prepared under simulated conditions, the internal mechanisms were revealed. Results showed that all aging processes caused a variation in crystal quantity and structure on different biochar. AB, NB and MB had higher hydrophilicity and polarity, and more positive charges than PB. Moreover, AB and MB had a higher cation exchange capacity (CEC) (70.7 and 75.3 cmol/kg) and more oxygen-containing functional groups than PB. MB has the maximum adsorption capacity for Cd(II) (24.2 mg/g), followed by PB (23.5 mg/g), FB (22.7 mg/g), NB (22.2 mg/g), and AB (22.0 mg/g). Langmuir model better described the Cd(II) adsorption onto NB, FB, and PB, while Freundlich better described AB and MB. As for Cr(VI), the maximum adsorption capacity followed the order: MB (24.1 mg/g) > AB (23.7 mg/g) > FB (23.5 mg/g) > PB (23.0 mg/g) > NB (22.7 mg/g). Langmuir model was better for Cr(VI) adsorption onto FB and PB, while Freundlich was better for AB, NB and MB. The pseudo-first-order kinetic model fits for Cd adsorption by FB，while the pseudo-second-order kinetic model fit for the adsorption of Cd and Cr by other biochars. The adsorption of Cr by all biochars was significantly related to the content of lactone group. Acidification and organic acids from microorganisms increased the pHPZC values of AB and MB, which was not conducive to the adsorption of Cd. The surface fragmentation of FB caused by the freezing and thawing process promoted its adsorption of Cd.

Biochar is an rich source of carbon formed through biomas’s thermal decomposition. There is a lot of scope of interest in developing biochar derived from biomass in various disciplines to address the most significant ecological challenges. In the present study herbal waste collected from herbal processing industry (Bangalore, India). So, this biomass will be no use after the extraction process. Hence, present work mainly concentrates the conversion this herbal waste to biochar (BC). Research highlights the BC was prepared from herbal industry waste using pyrolysis method. The obtained BC used as adsorbent for adsorption of Cr (VI) from aqueous solution. A characterization of BC was performed using XRD, SEM-EDS and FT-IR which confirms the material. The adsorption experiments were carried out using batch and fixed bed column. The experimental studies were carried out at room temperature with initial Cr (VI) concentrations (IC) of 10–120 ppm using an adsorbent dosage (AD) of 0.05–0.55 g, agitation speed of 150 rpm for contact time (CT) 15–165 min and temperature (20–40 °C). Then various parameters for column study like bed height, flow rate and IC were also studied. The maximum removal of Cr (VI) was 88 % found at a pH 2, AD 0.55g, CT 90 min, and IC 100 ppm at 30 °C. For column study: higher removal of Cr (VI) achieved by bed height (BH) of 6 cm and at lower flow rate (FR), of 3 mL/min.

Solid hydrolysate and biochar 2:1 are synthetic humus from hydrothermal carbonization of chicken feather waste and contain humin that can be isolated by IHSS method. The recalcitrant humin is obtained in solid form. The yield of isolated humin from biochar 2:1 was 44.5%, and humin from solid hydrolysate was 12.7%. Analysis of humin by FTIR indicated the characteristics of complex functional groups. Based on the XRD and TEM tests, humin is formed from amorphous crystals with

The stalks left after harvesting corn, tomatoes, and tobacco have no further use and are usually burned on agricultural land. In our work samples of this waste were collected and pyrolyzed at 400 ℃ for 30 min in a nitrogen atmosphere. The solid residue (biochar) obtained by pyrolysis was analyzed, and the results were compared with widely used solid fuels such as wood, coal, coke and charcoal. The heat values of biochar from tomato, tobacco, corn ZP 6263, and corn BC 398 stalks were 24.12, 23.09, 26.24 and 25.78 MJ kg-1, respectively. These values are significantly higher than the heat value of wood, which is about 12.50 MJ kg-1. The ash content of biochar was 12–20 %, which is consistent with the ash content of solid fuels. No heavy metals were found in biochar samples. The results show that biochar obtained from the pyrolysis of agricultural waste, such as tomatoes, tobacco and corn stalks, has good potential for use as a solid fuel.

This work showcases a novel application of biochar for analytical sample treatment. The carbonaceous material, obtained by pyrolysis of orange peel waste (550°C) without any post-synthesis treatment or functionalization, was thoroughly characterized and easily immobilized on the inner wall of sampling tubes in order to perform a sort of “in-vial” solid-phase extraction (SPE). The as-obtained device was tested for the extraction of seven sexual steroids, as probe water pollutants, from tap, lake, river water and wastewater treatment plant effluent samples spiked with 0.2-5 µg L−1 of each compound. The sorption kinetics profiles showed quantitative uptake from the sample (25 mL) in 20 min contact time, followed by complete elution in pure ethanol (2 mL, 15 min), thanks to the proper balance between sorption affinity and ease of elution. Under the selected conditions, recovery was in the range 60-123 %, with good inter-day precision (RSD 10-18 %, n=3). As evidence of the excellent reproducibility, an overall RSD below 15 % was observed from inter-day inter-batch recovery tests on three individually prepared sampling tubes. The procedure, carried out on a roller mixer, allows 10 samples to be extracted simultaneously, improving the sample throughput. Moreover, reusability tests showed that the same device maintains its efficiency for 10 consecutive sorption/desorption cycles. The greenness assessment, carried out by two dedicated software, further supported the sustainability of this biochar-based sample preparation as an alternative SPE.

This research reveals the adsorption of cadmium (Cd2+) and zinc (Zn+2) from water using sewage sludge-derived biochar pyrolysed at 700 °C (SSB). The morphology and particle characteristics of SSB were characterised through scanning electron microscopy (SEM), particle size distribution (PSD), fourier transform infrared (FTIR), X-ray diffraction (XRD), and X-ray fluorescence (XRF). The adsorption study showed that the optimum contact times for removing Zn2+ and Cd2+ were 80 and 140 minutes, respectively. 95.51% Zn2+ and 97.54% Cd2+ could be removed from spiked solutions featuring 50 mg/L of Zn2+ and 50 mg/L Cd2+, each treated with 25 g/L biochar. The optimum pH of the solutions was 8–9 at a temperature of 40°C, indicating some precipitation of the metal ions at an alkaline pH. The highest adsorption capacity of SSB for Cd2+ and Zn2+ was found to be 3.02 and 2.51 mg/g, respectively, which compares favourably with other adsorbents. The isotherm studies confirmed experimental data to closely follow the Langmuir isotherm model at an R2 value of 0.9846 and 0.9816 for Cd2+ and Zn2+, respectively. The kinetic study confirmed the physical interaction between the adsorbents and the adsorbate. The spontaneous and exothermic nature of the process was confirmed by negative values of change in Gibbs free energy (ΔG) and enthalpy (ΔH). SSB could be regenerated for 6 cycles. Overall, this study explores sustainability, recycling, and waste management by offering SSB as a potentially cost-effective and environment-friendly solution to remove Cd2+ and Zn2+ from water.

Non-asbestos and non-copper polybenzoxazine friction composites were developed with varying mass ratios of synthetic graphite (SG)/carbonized hemp hurd (CHH). Mechanical, thermal, and tribological properties of the polybenzoxazine friction composites were studied. The wear simulation of the polybenzoxazine friction composites has been performed with commercial ANSYS finite element analysis software. The strength and modulus under flexure mode, glass transition temperature of the polybenzoxazine friction composite samples were observed to be improved with increasing CHH content. It appears that the incorporation of the CHH into the polybenzoxazine friction composites not only enhanced the coefficient of friction (COF) but also improved the overall wear resistance of the units. The wear resistance and wear pattern obtained by the wear simulation also showed a good correlation with the experimental results. Based on the findings in this study, it is evident that the carbonized hemp hurd possesses a great potential to be used in green brake pad application.

The present research work reports the preparation of Hyphaene thebaica derived-biochar (HTBC) and its applicability as eco-friendly and low-cost adsorbent for the removal of methyl orange (MO) dye. The main physicochemical characteristics of HTBC including its morphology, crystallinity and chemical function groups were determined through scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results showed that HTBC adsorbent was found to be constituted by heterogeneous surface with mesoporous having a surface area of 33.38 m2/g and pore diameter of 23.53 nm, and carboxylic and amine functional groups. Adsorption experiments were conducted using batch mode, by varying key adsorption parameters such as contact time, solution pH, adsorbent dosage and concentration. Adsorption isotherm modelling revealed that the Langmuir model (higher R2 and lower χ2) provided a better fit for MO adsorption onto HTBC, while the adsorption kinetics followed a pseudo-second-order kinetic model. Under optimized conditions (pH 2, HTBC dose of 0.03 g, initial dye concentration of 100 mg/L, 313 K, 270 rpm), the maximum Langmuir monolayer adsorption capacity for MO adsorption onto HTBC was found to be 264.922 mg/g. According the thermodynamic parameters, it can be deduced that MO adsorption on HTBC was exothermic and spontaneous. Adsorption mechanism can be attributed to various interactions, including electrostatic attraction, H-bonding, and π-π interaction. In light of these findings, biochar from Hyphaene thebaica shells can be considered a cost-effective and biodegradable adsorbent with significant potential for the treatment of water contaminated with anionic dyes.

Abstract Efficient energy storage systems are crucial for the optimal utilization of renewable energy. Sodium‐ion batteries (SIBs) are considered potential substitutes for next‐generation low‐cost energy storage systems due to the low cost and abundance of sodium resources. However, the industrialization of SIBs faces a great challenge in terms of the anode. Hard carbon could be a promising anode material due to its high capacity and low cost which originates from biomass. This study used pre‐treatment and template carbonization methods to extract a hard carbon material from a large amount of discarded biomass in bamboo powder waste. This material has a good initial Coulombic efficiency of 78.6 % and good cycling stability when applied to sodium ion batteries.Typically, the optimal hard carbon material is used as the anode to prepare sodium ion battery prototypes to demonstrate their potential applications. The anode exhibited excellent sodium storage performance with a reversible capacity of 303 mAh ⋅ g−1 at 1 C rate and good cycling performance, retaining 92.0 % of its capacity after 100 cycles. These results demonstrate that BPPHC is a promising candidate for anode material in sodium‐ion batteries. This work suggests that bamboo powder could be a low‐cost anode material for SIBs.

Land degradation and climate change, two intricately intertwined phenomena, demand appropriate management solutions to effectively tackle the escalating issues of food and nutritional security. In this context, the realm of agriculture confronts formidable challenges in its pursuit of soil resource reclamation, improving water quality, mitigating climate change, and maintaining soil and natural resources for posterity. Central to these aspirations is the preservation of an optimum organic matter, serving as a linchpin threshold is crucial for protecting the physical, chemical, and biological integrity of the soil, while simultaneously sustaining agricultural productivity. To address these multifaceted challenges, the introduction of diverse organic amendments has emerged as a crucial strategy. Noteworthy among these is the application of biochar, which functions as a soil conditioner capable of bolstering soil health, mitigating the impact of climate change, and securing global food security. Biochar is a carbon-enriched substance produced through pyrolysis of assorted biomass waste. It has a larger surface area, higher cation exchange capacity, and an extended carbon storage capability. The strategic integration of biochar production and subsequent soil application engenders an array of benefits, encompassing the amelioration of soil physical properties, augmented retention and the availability of nutrients, and the enhancement of biological activity, resulting in higher agricultural yields and societal benefits through the curtailment of soil to atmosphere greenhouse gas emissions. Additionally, biochar demonstrates its efficacy in the realm of environmental restoration by serving as a medium for extraction and elimination of heavy metals, which often pervade aquatic ecosystems and soil matrices. This review addressed the need for biochar production, characterization, soil health, the possibility for environmental restoration, and crop yield fluctuations owing to climate change.

Sandy soils are characterized by low soil moisture content and nutrient retention due to high permeability, limiting crop productivity and threatening food security in arid and semi-arid regions worldwide. Various reclamation technologies have been developed to address these challenges, but their effectiveness has not been comprehensively evaluated. This systematic review evaluated the performance of 42 sandy soil reclamation technologies reported in 144 studies from 27 countries that met specified selection criteria. Performance was evaluated based on response ratio (RR) of aboveground biomass and grain yield, as indicators of productivity, and soil moisture content and soil organic carbon (SOC), as indicators of soil health. The 42 technologies employed four main soil amendments: biochar, organic amendments, organic amendments combined with biochar, and soft rock. Overall, all technologies increased productivity and improved soil health. Biochar application was found to be the most effective technology, increasing grain yield by 51.6%, aboveground biomass by 67.4%, soil moisture content by 17.3%, and SOC by 74.2%. Soft rock application increased grain yield by 20.3%, aboveground biomass by 27.6%, soil moisture content by 54.5%, and SOC by 12.8%. Organic amendments increased grain yield by 48.7%, aboveground biomass by 45.6%, soil moisture content by 20.8%, and SOC by 36.7%. However, the combination of biochar and organic amendments showed lower improvements, with increases of 25.4%, 15.6%, 1.3%, and 25.4% for grain yield, aboveground biomass, soil moisture content, and SOC, respectively. Our conclusion is that the findings provide strong evidence that sandy soil reclamation technologies can significantly improve crop productivity and food security. Considering the variability in technologies responses across continents, there is need for further research to determine the optimal technology for specific locations, crops, and management practices.

Abstract Biochar, widely recognized for its capacity to counteract climate change impacts, has demonstrated substantial benefits in agricultural ecosystems. Nevertheless, empirical studies exploring its efficacy during climatic aberrations such as heavy rainfall are limited. This study investigated the effects of compost and biochar addition on corn growth attributes, yield, and soil CO2 and N2O fluxes under heavy rain (exceeding 5-yr average) and waterlogging conditions. Here, treatments included compost (CP, 7.6 t ha−1); rice husk biochar (RB, 7.6 t ha−1); wood biochar (WB, 7.6 t ha−1); and control (Cn). Under high rainfall and waterlogging, the CP treatment manifested a pronounced enhancement in corn biomass and productivity, exceeding biomass and productivity of Cn treatment by 12.6 and 32.2%, RB treatment by 120 and 195%, and WB treatment by 86.1 and 111%, respectively. Corn yield increased in the order: CP > Cn > WB > RB. Intriguingly, negligible disparity occurred between the RB and WB treatments in straw yield, grain yield, grain index, and corn productivity but both treatments recorded distinctively lower values than CP treatment. Also, the CO2 and N2O fluxes remained largely similar for two biochar treatments but lower than CP treatment. Overall, CP increased corn yield, straw, and grain yield whereas biochars reduced N2O flux during waterlogging. Although derived from a short-term experimental window, these pivotal findings furnish invaluable insights for devising soil amendments for yield and environmental benefits in contexts of extreme climatic perturbations. Our findings offer a robust foundation for refining nutrient management strategies confronted with waterlogging challenges, but long-term studies are necessary for definitive conclusions.

The purpose of this study was to evaluate the feasibility of using residues from cooking oil production to produce alternative biochar fuels along with optimizing the pyrolysis process. The work consisted of carrying out the pyrolysis process at varying temperatures and holding times at the final temperature, and then evaluating the energy potential of the materials studied. Taking into account aspects of environmental emissions, the content of selected oxides in the flue gases generated during the combustion of cakes and the biochar obtained from them was evaluated. Plant biomass derived from a variety of oilseeds, i.e., fennel flower (Nigella sativa L.), rapeseed (Brassica napus L. var. Napus), flax (Linum usitatissimum L.), evening primrose (Oenothera biennis L.), milk thistle (Silybum marianum L. Gaertn.) and hemp (Cannabis sativa L.), was used to produce biochar. The experimental data have shown that the obtained biochar can have a calorific value of nearly 27 MJ kg−1. The use of pyrolysis allowed for a maximum increase in the calorific value of nearly 41% compared to non-thermally processed cakes and a several-fold decrease in carbon monoxide, nitrogen oxides and sulfur dioxide emissions. According to these results, it can be concluded that the pyrolysis process can be an attractive method for using residues from the production of various cooking oils to produce alternative biofuels, developing the potential of the circular economy.

The disposal and treatment of antibiotic residues is a recognized challenge due to the huge production, high moisture content, high processing costs, and residual antibiotics, which caused environmental pollution. Antibiotic residues contained valuable components and could be recycled. Using a one-step controllable pyrolysis technique in a tubular furnace, biochar (OSOBs) was produced without the preliminary carbonization step, which was innovative and time- and cost-saving compared to traditional methods. The main aim of this study was to explore the adsorption and removal efficiency of tetracycline (TC) in water using porous biochar prepared from oxytetracycline fermentation residues in one step. A series of characterizations were conducted on the prepared biochar materials, and the effects of biochar dosage, initial tetracycline concentration, reaction time, and reaction temperature on the adsorption capacity were studied. The experimental results showed that at 298 K, the maximum adsorption capacity of OSOB-3-700 calculated by the Langmuir model reached 1096.871 mg/g. The adsorption kinetics fitting results indicated that the adsorption of tetracycline on biochar was more consistent with the pseudo-second-order kinetic model, which was a chemical adsorption. The adsorption isotherm fitting results showed that the Langmuir model better described the adsorption process of tetracycline on biochar, indicating that tetracycline was adsorbed in a monolayer on specific homogeneous active sites through chemical adsorption, consistent with the kinetic conclusions. The adsorption process occurred on the surface of the biochar containing rich active sites, and the chemical actions such as electron exchange promoted the adsorption process.

Green roofs (GRs) are a well-established green infrastructure (GI) strategy that have been extensively studied for decades to address a growing array of social and environmental challenges. Research efforts have been continuously made to contribute to the awareness of benefits of GRs and towards their widespread application. The substrate, which is one of the crucial layers of a GR system, plays a major role in the serviceability of GRs. Thus, several studies have been undertaken to alter the substrate characteristics by applying innovative substrate additives. Biochar, a carbon-rich material with a highly porous structure and large specific surface area, has been found advantageous in several areas such as agriculture, water filtration, environmental remediation, construction, and so on. However, the application of biochar in GRs has been insufficiently studied, partially because biochar amendment in GRs is a relatively recent innovation. Furthermore, a comprehensive review of the performance of biochar-amended GR substrates is lacking. This review paper aims to summarize the past performance of GRs enhanced with biochar by considering the various benefits that biochar offers. The results indicate that most of the reviewed studies observed increased retention of runoff and nutrients when utilizing biochar. Additionally, the capabilities of biochar in improving thermal insulation, plant performance, and microbial diversity, as well as its effectiveness in sequestrating carbon and controlling soil erosion, were mostly agreed upon. Notwithstanding, a definitive conclusion cannot yet be confidently made due to the limited research information from biochar–GR systems and the uneven research focus observed in the studies reviewed. The influence of biochar-related variables (including amendment rates, application methods, processed forms, and particle size) on the effectiveness of biochar was also discussed. Opportunities for future research were suggested to fill the research gaps and address challenges restricting the application of biochar in GRs. Detailed information from past research findings could serve as a foundation for further investigations into the large-scale implementation of biochar in GRs.

This paper contains guidelines and provides a basic understanding of how to do experiments in dye adsorption using carbon. This paper presents a step-by-step experimental procedure from carbon preparation (as biochar) from agricultural waste to concentration measurement using UV-Vis Spectroscopy. We used agricultural waste as a model due to its high cellulose and organic content, making it easily converted into carbon. Furthermore, carbon is used as a model bioadsorbent for water treatment by the adsorption method. Here, the wastewater model used in this study is water containing organic dyes. As for the dye source model, curcumin was used in this study. This paper can be used as a guide for researchers and students in the fabrication of carbon from agricultural waste biomass easily and inexpensively for its application as an adsorbent in the batch adsorption process. This paper also supports the current issues in Sustainable Development Goals (SDGs). [ABSTRACT FROM AUTHOR]

Biochar (BC) is widely used in the remediation of soil and wastewater polluted by heavy metals, but there are few reports on the characteristics of biochar derived via pyrolysis from different traditional Chinese medicine residues (TCMRs). In this study, biochars were prepared by slow pyrolysis of five common Chinese medicine residues, namely, Salvia miltiorrhiza (DNS), Ligusticum striatum (CX), Angelica sinensis (DG), Codonopsis pilosula (DGS), and Astragalus membranaceus (HQ). The biochars were systematically investigated by determining their physicochemical properties and using common characterization techniques. The Spearman correlation matrix between factors was used to examine relationships between properties of different biochars. Batch adsorption experiments were carried out to investigate the adsorption characteristics of biochar on Pb(II) and the mechanisms involved. The results showed that the physicochemical properties and adsorption performance of biochar were related to the type of its pharmaceutical residue. Biochar produced from materials with higher lignin content showed a better adsorption of the heavy metal Pb(II). All biochars were alkaline, with yields ranging from 29.30 to 38.65 %, and the main structure comprised of mesopores and macropores. The FT-IR and Boehm experiments revealed that the various TCMR biochars contained comparable functional groups, but their content varied. XRD and TEM results show that all biochar is amorphous with a crystalline structure, with the surface dominated by cellulose crystals and graphitic carbon. The O/C ratio ( 0.99), and their isotherms were consistent with the Langmuir model (R2 > 0.99), indicating a monolayer chemisorption process. The biochar samples exhibited varying adsorption capacities for Pb(II), with the highest capacity observed for BDNS (36.42 mg/g). The adsorption mechanism mainly involved precipitation, complexation with oxygen-containing functional groups, and ion exchange. This study indicates that biochars from herbal residues exhibit promising potential for adsorbing heavy metal Pb(II), suggesting biochar production as a viable method for recycling herbal residues.

The world is currently facing significant challenges in reducing the concentration of atmospheric carbon dioxide (CO2) through scientific methods, primarily by sequestering the CO2 in the soil. Biochar is a kind of charcoal that is primarily composed of carbon, hydrogen, and oxygen. Due to its aromatic content, biochar can persist in the environment for an extended period and absorb greenhouse gases (GHG). Each year, biochar effectively captures an estimated amount of CO2 ranging from 1 to 35 gigatons (GtCO2) and 78 to 477 GtCO2 over this century. Biochar helps mitigate climate change by sequestering carbon in the soil for extended periods and consequently reducing GHG emissions. This enhances soil fertility, water retention capacity, and nutrient circulation, which promote higher crop yields. Biochar's by-products of biochar can be harvested and used as a renewable energy source. Besides, biochar integration can be effective in waste management strategies that mitigate the challenges of organic waste disposal. Biochar is also an efficient water purification element that favors climate action. Through the application of biochar alteration can be employed to establish carbon credits, and its methods can effectively reduce carbon emissions to an acceptable level. Biochar's unique properties, wide-spread applicability, cost-effectiveness, and trustworthy development prospects demonstrate great potential towards the Sustainable Development Goals (SDG). This review discusses the properties, diverse applications, and social and technical impacts of biochar in the global carbon cycle towards sustainable development goals.

In this study, iron oxide biochar nanocomposites made from khat leftover (KL) and coffee husk (CH) are investigated as possibly useful adsorbents for the removal of Cr (VI) from water. Biochar-based iron oxide nanocomposites were synthesized by pretreating 25 g of biomass with a 1:1 M ratio of FeS to FeCl3 and pyrolyzing at 300 °C for 1 h. Pristine biochar, synthesized through biomass pyrolysis of CH and KL at 300 °C, removed 74.98% and 84.78% of Cr (VI) from aqueous solutions containing 20 mg L−1, respectively. The corresponding nanocomposites showed a maximum removal efficiency for Cr (VI) of 99.83% with the iron oxide-coffee husk biochar nanocomposite (Fe3O4–CHBNC) and 99.86% with the iron oxide-khat leftover biochar nanocomposite (Fe3O4-KLBNC). A pseudo-second-order model and the Langmuir isotherm are both well-fitted by the adsorption process, suggesting advantageous monolayer adsorption. The Fe3O4–CHBNC and Fe3O4-KLBNC demonstrated satisfactory removal efficiencies even up to six cycles, indicating their potential effectiveness for large-scale use for treating wastewater contaminated by Cr (VI).

Okara biochar was obtained through the pyrolysis process and continued by encapsulation into beads form to ensure biochar does not leach into the environment. The utilization of okara biochar beads (OBB) as an adsorbent of eosin yellow (EY) dye was developed due to its porosity and high surface area properties. The adsorption kinetics of EY by OBB follows the pseudo second order (PSO) model while the adsorption isotherms follow the Freundlich isotherm model with reaction rate constants of 19.71 g mg−1 min−1 and KF = 12.12 L mol−1. The results show that OBB is easily separated from water and has an adsorption percentage up to 80%.

Abstract Ammonium ions (NH4 +) are commonly found in contaminated water and are a contributing factor to water eutrophication. Carbonized rice husk, derived from various biomass sources, possesses a porous structure, and its characteristics are influenced by the feedstock and pyrolysis conditions. Hence, this study aimed to investigate the applicability of carbonized rice husk as an absorbent for NH4 + removal. The adsorption kinetics were analyzed using the Pseudo-first-order and Pseudo-second-order models, while the adsorption characteristics were assessed using the Langmuir and Freundlich isotherms. The adsorption rate of NH4 + by carbonized rice husk increased until 240 min and then gradually approached equilibrium state. Notably, the highest NH4 + adsorption rate was observed in pH 7.1 carbonized rice husk 36.045 mg/g∙min. Moreover, the NH4 + adsorption capacity exhibited an increase with increasing concentration and quantity of the solution. The pH of the carbonized rice husk was found to influence the NH4 + adsorption process, with higher pH values corresponding to increased NH4 + adsorption rates. The NH4 + sorption rate carbonized rice husk was higher in pH 11.0 at 31.440 mg/g compared to pH 6.1 (7.642 mg/g) and pH 7.1 (10.761 mg/g). These findings highlight the impact of pyrolysis conditions on the adsorption characteristics of carbonized rice husk.

Microplastics (MPs) are prevalent emerging pollutants in soil environments, acting as carriers for other contaminants and facilitating combined pollution along with toxic metals like cadmium (Cd). This interaction increases toxic effects and poses substantial threats to ecosystems and human health. The objective of this study was to investigate the hydrodynamic adsorption of Cd by conducting experiments where polystyrene microplastics (PS) and biochar (BC) coexisted across various particle sizes (10 µm, 20 µm, and 30 µm). Then, soil incubation experiments were set up under conditions of combined pollution, involving various concentrations (0.5 g·kg−1, 5 g·kg−1, 50 g·kg−1) and particle sizes of PS and BC to assess their synergistic effects on the soil environment. The results suggest that the pseudo-second-order kinetic model (R2 = 0.8642) provides a better description of the adsorption dynamics of Cd by PS and BC compared to the pseudo-first-order kinetic model (R2 = 0.7711), with an adsorption saturation time of 400 min. The Cd adsorption process in the presence of PS and BC is more accurately modeled using the Freundlich isotherm (R2 > 0.98), indicating the predominance of multilayer physical adsorption. The coexistence of 10 µm and 20 µm PS particles with BC enhanced Cd absorption, while 30 µm PS particles had an inhibitory effect. In soil incubation experiments, variations in PS particle size increased the exchangeable Cd speciation by 99.52% and decreased the residual speciation by 18.59%. The addition of microplastics notably impacted the exchangeable Cd speciation (p < 0.05), with smaller PS particles leading to more significant increases in the exchangeable content—showing respective increments of 45.90%, 106.96%, and 145.69%. This study contributes to a deeper understanding of the mitigation mechanisms of biochar in the face of combined pollution from microplastics and heavy metals, offering theoretical support and valuable insights for managing such contamination scenarios.

Pollution caused by antibiotics has brought significant challenges to the ecological environment. To improve the efficiency of the removal of tetracycline (TC) from aqueous solutions, a composite material consisting of TiO2 and phosphoric acid-treated peanut shell biochar (p-BC) has been successfully synthesized in the present study by the sol-gel method. In addition, the composite material was characterized using various techniques, including scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) spectroscopy, X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectroscopy, and ultraviolet–visible diffuse reflectance spectroscopy (UV-vis DRS). The XPS and FTIR analyses revealed the formation of a new Ti–O–C bond, while the XRD analysis confirmed the presence of TiO2 (with an anatase phase) in the composite material. Also, the PL analyses showed a notable decrease in the recombination efficiency of electrons and holes, which was due to the formation of a composite. This was further supported by the UV-vis DRS analyses, which revealed a decrease in bandgap (to 2.73 eV) of the composite material and led to enhanced light utilization and improved photocatalytic activity. Furthermore, the effects of pH, composite dosage, and initial concentration on the removal of TC were thoroughly examined, which resulted in a maximum removal efficiency of 95.3% under optimal conditions. Additionally, five consecutive cycle tests demonstrated an exceptional reusability and stability of the composite material. As a result of the experiments, the active species verified that ·O2− played a key role in the photodegradation of TC. Four possible degradation pathways of TC were then proposed. As a general conclusion, the TiO2/p–BC composite can be used as an efficient photocatalyst in the removal of TC from aqueous solutions.

Due to a large number of harmful chemicals flowing into the water source in production and life, the water quality deteriorates, and the use value of water is reduced or lost. Biochar has a strong physical adsorption effect, but it can only separate pollutants from water and cannot eliminate pollutants fundamentally. Photocatalytic degradation technology using photocatalysts uses chemical methods to degrade or mineralize organic pollutants, but it is difficult to recover and reuse. Woody biomass has the advantages of huge reserves, convenient access and a low price. Processing woody biomass into biochar and then combining it with photocatalysts has played a complementary role. In this paper, the shortcomings of a photocatalyst and biochar in water treatment are introduced, respectively, and the advantages of a woody biochar-based photocatalyst made by combining them are summarized. The preparation and assembly methods of the woody biochar-based photocatalyst starting from the preparation of biochar are listed, and the water treatment efficiency of the woody biochar-based photocatalyst using different photocatalysts is listed. Finally, the future development of the woody biochar-based photocatalyst is summarized and prospected.

Sandy areas occupy a huge amount of land worldwide, but due to their characteristics, they are mostly low in fertility and low in organic matter. Sandy soils have coarse texture, high saturated hydraulic conductivity, low soil organic carbon, and poor aggregate stability and water retention capacity; therefore, it is necessary to add organic additives to them. The objective of this study was to assess the effect of particle size and application rate of biochar (BC) produced under different pyrolysis temperatures on the porosity P, available water content for plants AWC, saturated hydraulic conductivity Ks, and contact angle CA of sandy soil. The results show that an application of BC to sandy soil significantly increased AWC by 76–168%, CA by 252–489%, P by 6–11%, and significantly reduced Ks by 37–90%. Statistical analysis of the effect of three examined factors (BC application rate, particle size, and pyrolysis temperature) revealed that P, AWC, and Ks were affected by all three factors, while CA was affected only by BC application rate and particle size. The statistically significant interaction between the two factors was found for P (temperature × rate and size × rate), AWC (temperature × size), and Ks (size × rate). Statistically significant interaction among the three factors was not found for any hydrophysical parameter. The application of BC to amend sandy soils can be seen as a strategy to mitigate drought conditions and to reduce the amount of irrigation, saving water. Further investigations are needed with regard to the BC application under climate conditions with long hot and dry periods, which may promote soil water repellency.

The increasing industrial waste was caused problems for the environment. Bagasse is a solid waste produced from the sugar industry. Vinasse is bioethanol industry liquid waste from molasses which contains much nutrients. The vinasse and bagasse in this study was developed into biochar. This study aimed to determine the effect of vinasse addition on biochar characteristics. The yield and characteristics of the biochar were then compared. Based on gravimetric, pH, and SEM-EDX analysis, the result indicated that adding vinasse to the biochar was increasing yield, water content and ash content, lowering pH, and tend to increase nutrient levels (carbon, nitrogen, and potassium). The biochar produced from bagasse and vinasse by pyrolysis had a yield of 6.682-9.406%; water content of 7.0-8.2%; ash content of 4.8-13.6%; at pH 8.4-88; carbon content (C) of 65.07-80.88%; nitrogen (N) content of 2.06-8.66%; and potassium (K) levels of 0.00-2.15%, while phosphorus (P) levels were not detected in SEM-EDX analysis. Based on the consideration of the highest levels of nitrogen and potassium elements needed by plants, the optimum biochar was obtained from bagasse with a vinasse of 7.5%.

Palm oil is a product of major economic importance worldwide however, palm tree cultivation generates large quantities of palm fronds as waste. In this work, the sorption of Eu3+ from aqueous solutions by oxidized biochar derived from palm tree fronds was studied at pH 3 by batch type experiments under ambient conditions. Following biochar production, the sample was oxidized using HNO3 to increase the oxygen-containing moieties on its surface. The oxidized biochar was characterized through surface and spectroscopic techniques. As indicated by the coefficient of determination value of 0.99, Eu3+ adsorption was best described by the Langmuir isotherm model. The optimum adsorption capacity was determined at qmax= 0.81 mol kg−1. Adsorption was an entropy-driven process and followed the 2nd order kinetics, reaching a plateau value of 50% relative adsorption within 60 min. Furthermore, Fourier Transform InfraRed spectroscopic data and the effect of ionic strength indicated that adsorption proceeded via the development of inner-sphere complexes between Eu3+ and the carboxylic groups on the biochar surface.

A heterogeneous acid catalyst was synthesized by anchoring 12–tungstophosphoric acid (HPW) onto biochar derived from Brazil nut shells (Bertholletia excelsa). This catalyst was used for the synthesis of vanillin from isoeugenol, employing hydrogen peroxide in acetonitrile solvent. The HPW-functionalized biocatalyst was prepared using a sonication method, which avoids the need for toxic and corrosive solvents, effectively incorporating tungsten at a mass proportion of 25%. Characterization of the catalysts utilized various techniques, including X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, and ultraviolet–visible spectroscopy. 30HPW/CC(200–2) exhibited high selectivity for vanillin (55%) with a significant conversion rate (69%). Over four cycles, selectivity and conversion remained consistently above 56% and 45%, respectively. The results presented in this study have the potential to promote a more sustainable vanillin production process, a valuable additive in the food and perfume industries, renowned for its high economic value.

Carbon materials displaying electrical double layer capacitance are widely used in the electrochemical energy storage devices. To enhance the electrochemical performance, compositing carbon with transition metal oxides and conducting polymers have been very much appreciated. A novel and effective approach to prepare a high energy density and high specific capacitance composite electrode material from a biomass is presented in the work. Pyrolysis of biomass at 500 °C in the nitrogen atmosphere yielded a biochar (BC) with well-developed porosity, surface functionality and suitable morphological characteristics. Anchoring ZnO nanoparticles on BC and subsequently coating it with a conducting polymeric material, polyaniline (PANI) obtained the hierarchical BC-ZnO/PANI composite. Both BC-ZnO and BC-ZnO/PANI composites have been characterized by FTIR, UV–Visible, XRD, SEM and TEM studies. The characteristic signals at 2θ values 18.5°, 28.4°, 24.0° and 31.4° in XRD correspond to wurtzite structure of ZnO nanoparticles. ZnO rod like structural morphology was confirmed by SEM analysis. The maximum specific capacitance was found to be 110.0 F/g for BC-ZnO and 198.0 F/g for BC-ZnO/PANI. The ternary composite displayed low solution resistance and charge transfer resistance as evident from the Nyquist plots. The results proved that PANI coating is a promising methodology in the fabrication of electrode materials for energy storage applications.

The rapid growth of various industries has led to a significant, alarming increase in recalcitrant pollutants in the environment. Hazardous dyes, heavy metals, pesticides, pharmaceutical products, and other associated polycyclic aromatic hydrocarbons (such as acenaphthene, fluorene, fluoranthene, phenanthrene, and pyrene) have posed a significant threat to the surroundings due to their refractory nature. Although activated carbon has been reported to be an adsorbent for removing contaminants from wastewater, it has its limitations. Hence, this review provides an elaborate account of converting agricultural waste into biochar with nanotextured surfaces that can serve as low-cost adsorbents with promising pollutant-removing properties. A detailed mechanism rationalized that this strategy involves the conversion of agrowaste to promising adsorbents that can be reduced, reused, and recycled. The potential of biowaste-derived biochar can be exploited for developing biofuel for renewable energy and also for improving soil fertility. This strategy can provide a solution to control greenhouse gas emissions by preventing the open burning of agricultural residues in fields. Furthermore, this serves a dual purpose for environmental remediation as well as effective management of agricultural waste rich in both organic and inorganic components that are generated during various agricultural operations. In this manner, this review provides recent advances in the use of agrowaste-generated biochar for cleaning the environment.

Interleukin-6 (IL-6) plays a crucial role in autoimmunity and chronic inflammation. This study aims to develop a low-cost, simple-to-manufacture, and user-friendly label-free electrochemical point-of-care device for the rapid detection of IL-6 in patients with psoriasis. Precisely, a sandwich-based format immunosensor was developed using two primary antibodies (mAb-IL6 clone-5 and clone-7) and screen-printed electrodes modified with an inexpensive recycling electrochemical enhancing material, called biochar. mAb-IL6 clone-5 was used as a covalently immobilized capture bioreceptor on modified electrodes, and mAb-IL6 clone-7 was used to recognize the immunocomplex (Anti-IL6 clone-5 and IL-6) and form the sandwich. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to conduct electrochemical characterization of the layer-by-layer assembly of the immunosensor, while square wave voltammetry (SWV) was used to perform the sensing. The developed immunosensor demonstrated robust analytical performance in buffer solution, with a wide linear range (LR) by varying from 2 to 250 pg/mL, a good limit of detection (LOD) of 0.78 pg/mL and reproducibility (RSD

Objectives: Indian agricultural wastes such as Juglans regia shells get attention frequently because they can be used as adsorbents. This study aimed to prepare magnetically modified iron oxide immobilized biochar adsorbent using Juglans regia shells and investigate its adsorption capacity for Cu2+ and Ni2+ removal from synthetic wastewater contaminated with metals. Methods: As part of the investigation of the properties of the prepared material and its role in the adsorption process, it was characterized with FTIR, FESEM, EDX, XRD, BET, and VSM techniques. A batch adsorption method was examined by varying pH (2–12), adsorbate concentration (10–100 mg/L), contact time (5–240 min), and temperature (288–308 K). Results: A pH of 6 and an initial concentration of 50 mg/L, as well as equilibrium times of 120 and 150 min, resulted in 98.30 % copper removal and 98.10 % nickel removal, respectively. It was found that both Cu2+ and Ni2+ adsorption was governed by Langmuir's isotherm and obeyed the pseudo-second-order kinetic model. In terms of thermodynamic parameters, it appears that the adsorption of Cu2+ and Ni2+ took place in an endothermic and physical manner. The thermodynamic study determined that the activation energy (KJ/Mol) for Cu was 117.27 and for nickel was 100.24. Using Box-Behnken response surface methodology, the experiments were statistically optimized. Based on the cost estimation study, the prepared adsorbent can be used in metal-contaminated water at a cost-effective rate. Conclusion: Therefore, the prepared magnetic biochar will be useful for the adsorptive removal of Cu2+ and Ni2+ from electroplating wastewater.

The global annual production of rice is over 750 million tons, and generates a huge amount of biomass waste, such as straw, husk, and bran, making rice waste an ideal feedstock for biomass conversion industries. This review focuses on the current progress in the transformation of rice waste into valuable products, including biochar, (liquid and gaseous) biofuels, valuable chemicals (sugars, furan derivatives, organic acids, and aromatic hydrocarbons), and carbon/silicon-based catalysts and catalyst supports. The challenges and future prospectives are highlighted to guide future studies in rice waste valorization for sustainable production of fuels and chemicals.

In the present investigation the adsorption behavior of methylene blue (MB) dye from aqueous solution onto untreated chinar leaves powder (CLP) and chinar leaves biochar (CLB) has been studied. To find out optimum conditions, adsorption process was carried out by varying different parameters such as contact time, adsorbent dose, concentration, temperature, salts, and pH. The equilibrium adsorption data were subjected to different popular isotherms (Langmuir, Freundlich, and Temkin) and kinetic models (pseudo-first order, pseudo-second order and intra-particle diffusion model). The thermodynamic study was also done on the adsorption process. The maximum monolayer adsorption capacities for MB dye onto given adsorbents are 1.53 mg/g (CLP) and 1.02 mg/g (CLB). Also the values of RL and n suggest favourable adsorption process of MB dye onto CLP and CLB adsorbents. The pseudo-second order kinetic model is best obeyed by both the mentioned adsorbents for MB dye adsorption with R2 value equal to 1. Thermodynamic study reveals that the adsorption process of MB dye is spontaneous, endothermic (CLB) and exothermic (CLP). At an equilibrium time of 20 min the uptake efficiency (> 99%) was recorded for both the low cost adsorbents (CLP and CLB) thus proved them fast and effective adsorbents for the removal of MB dye.

Dyes induce acute to chronic illnesses in humans and aquatic animals. This study tested dolomite-modified rice husk biochar (DRHB) to eliminate anionic reactive dyes Remazol Brilliant Blue (RBB) and Reactive Black 5 (RB-5) from simulated wastewater solutions. DRHB was produced by pretreating rice husk biomass with the natural mineral dolomite (CaMg(CO3)2) solution following pyrolysis step at 700 °C for 4 h at 8 °C min−1. Pristine rice husk biochar (PRHB) was made by pyrolyzing rice husk for 4 h at 700 °C. The DRHB and PRHB were characterized via different techniques including, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and Scanning electron microscopy (SEM). Afterwards, DRHB was used to get rid of the dyes in the wastewater solutions, and the effects of dose, pH, and contact duration were studied. Both RBB and RB-5 exhibited maximal adsorption capacities of 52.07 and 35.518 mg/g at 50 °C, respectively, and the findings matched well with the Langmuir model, demonstrating monolayer adsorption. For this system, the pseudo-second-order fit is optimal, pointing to chemisorption of both substances. The outcomes presented higher adsorption for RBB (95.63%) compared to RB-5 (85.20%) at 70 mg/L concentration, pH 6, 4 hr. contact time, and 0.3 mg of DRHB dosage. The primary mechanism to remove of both dyes was chemisorption via π-π bond and hydrogen bond. These findings provide insights to build an economical, and sustainable anionic dyes removal technique especially for the third world nations.

Layered double hydroxide (LDH) of Ni/Al was synthesized by coprecipitation method at pH 10 followed by the formation of composite with carbon-based material i.e., biochar (B) and graphite (G) to form Ni/Al-B and Ni/Al-G. Materials were characterized by XRD powder, FTIR, BET surface area, thermal analyses, and SEM analysis. The regeneration process and adsorption evaluated the performance of materials toward iron(II) [Fe(II)] from an aqueous solution. The results showed that the surface area of Ni/Al-B (428.94 m2/g) was increased mainly up to twenty-nine-fold than Ni/Al LDH (15.11 m2/g), while Ni/Al-G (21.59 m2/g) had slightly increased than pristine LDH. Composite of Ni/Al-B had reusability properties for Fe(II) adsorption up to five cycles and showed higher structural stability. The adsorption capacity of Ni/Al-B was 104.167 mg/g and can be a potential adsorbent to remove Fe(II) from an aqueous solution.

Soil amendments play a crucial role in modern agriculture, as they effectively enhance the planting environment. This study innovatively proposes the use of gel as a crosslinking agent to embed biochar and hydroxyapatite (HAP), thereby preparing a novel soil amendment. Furthermore, this study investigates the soil improvement effects of this amendment as well as its influence on plant growth. This study employed a hydrothermal method to combine corn stalk (CB) or sludge (SB) biochar with HAP at different ratios (0–20%). Subsequently, sodium alginate gel (SA) was utilized to encapsulate the biochar and minerals, successfully forming a ternary composite gel material (corn stalk biochar/sludge biochar–sodium alginate gel-hydroxyapatite: CB/SB-SA-HAP). Finally, the practical effectiveness of this amendment was verified through potted soil experiments. The results indicate that the CB/SB-SA-HAP composite materials exhibited a micrometre-scale spherical structure with well-developed micropores and possess the functional groups of CB/SB, SA, and HAP, along with unique mineral properties. Through pot experiments, it was verified that the composite material effectively enhances multiple soil properties. After 21 days of cultivation, the soil pH values stabilized within the neutral range (pH = 7 ± 0.3) across all treatment groups. Except for the CB0 (CB:HAP = 1:0) and CB2.0 (CB:HAP = 1:2) treatments, the remaining treatments significantly reduced the soil EC values by 3.27% to 47.92%. All treatments significantly increased the contents of alkali-hydrolysable nitrogen (AHN) (34.89~57.91%), available phosphorus (AP) (35.93~56.55%), and available potassium (AK) (36.41~56.80%) in the soil. In comparison, although the SB treatment was more effective in regulating the pH and electrical conductivity (EC) of saline–alkali soil than the CB treatment, it was less effective in promoting plant growth in the short term. Through correlation analysis and redundancy analysis, a significant positive correlation was found between soil pH and ryegrass germination rate and plant height, particularly with the most pronounced impact on soil pH observed in the CB1.0 and SB0 (SB:HAP = 1:0) treatments. This study underscores the potential of CB/SB-SA-HAP composite materials in soil improvement and plant growth promotion, providing valuable insights for soil remediation, enhancement, and plant cultivation advancements in the agricultural sector.

Biochar (BC) and hydrochar (HC) have attracted considerable attention owing to their versatile characteristics and proven effectiveness in diverse technical fields. Solid BC is generated as a result of the dry carbonisation process of pyrolysis, in contrast to the slurry HC, which is produced during the hydrothermal carbonisation process. In this study, we evaluated the adsorption potential of two hydrochar samples (HCs) and three biochar samples (BCs) produced from sugar cane bagasse. The adsorption capacity of these samples was tested for ammonium, nitrate, and phosphate ions under various conditions. The BCs and HCs were subjected to characterisation using a CHNS/O analyser, the zeta potential, and Fourier transform infrared (FTIR). Elevating the pyrolysis temperature of the biochar resulted in changes in the fixed carbon and ash contents, while the volatile matter and H/C and O/C atomic ratios decreased. As the residence time increased, the H/C ratio and volatile matter content of the hydrochars (HCs) decreased. However, the fixed carbon content, ash content, and O/C and C/N ratios exhibited an increase. Thermodynamics, adsorption isotherms, and pH were also taken into consideration. The FTIR spectra analysis indicated that the carboxyl and ester functional groups present in both the BCs and HCs displayed reduced peak intensities subsequent to the adsorption of the three ions. While the adsorption was exothermic, we noticed that the adsorption capacity increased with temperature. The results indicate that sorption was homogenous across all binding sites, as evidenced by the optimal fit to the Langmuir isotherm. The research findings indicate that the adsorption capacity of various BC and HC adsorbents is significantly influenced by the surface area of the adsorbents in the case of nitrate and phosphate, but in the case of ammonia, adsorption is dictated by the functional polar groups present on the adsorbent surface.

Biochar, the solid sub-product of biomass pyrolysis, is widely considered an effective water retention material thanks to its porous microstructure and high specific surface area. This study investigates the possibility of improving both mechanical and rheological properties of cement pastes on a micro-scale. The results show that using biochar as a reinforcement at low percentages (1% to 5% by weight of cement) results in an increase in compressive strength of 13% and the flexural strength of 30%. A high fracture energy was demonstrated by the tortuous crack path of the sample at an early age of curing. A preliminary study on the rheological properties has indicated that the yield stress value is in line with that of self-compacting concrete.

In this work, a closed-loop strategy for the management and valorization of winery waste was proposed. The exhausted pomace and grape stalks that are typically obtained from white wine industries were used as a source of simple sugars, namely, glucose and fructose, and of lignocellulosic feedstock for the preparation of selective catalysts for the 5-hydroxymethylfurfural (5-HMF) production from fructose. A novel synthetic procedure was developed for the synthesis of iron-sulfonated magnetic biochar catalysts (Fe-SMBCs). Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), BET surface area, porous structure analysis and determination of total amount of acid sites were performed in order to characterize the physico-chemical properties of the synthesized systems. Then, these heterogeneous catalysts were successfully tested via the dehydration of simple sugars into 5-HMF by using methyl isobutyl ketone (MIBK) and gamma valerolactone (GVL) as co-solvents. The optimum 5-HMF yield of 40.9 ± 1.1%mol with a selectivity of 59.8 ± 2.6%mol was achieved by adopting the following optimized conditions: 0.1 g of catalyst, volume ratio of GVL to H2O = 2 to 1, 403 K, 6 h. In addition, the catalyst was easily recycled using an external magnetic field and used for at least five reaction cycles without significant loss of catalytic activity.

Mg/Fe layered bimetallic oxide mulberry rod biochar composites (MFBCs) were prepared from mulberry rods and characterized using electron microscopy scanning (SEM), X-ray diffraction (XRD), Fourier infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). We investigated the adsorption properties of MFBCs for phosphorus, which was recovered via crystallization using calcium chloride as a precipitant. According to the findings, the MFBC is a layered bimetallic oxide with a specific surface area of 70.93 m2·g−1. Its point of zero charge values, or pHzpc, was 7.66. The removal of phosphorus usingMFBCs gradually decreased with increasing pH, and the optimum pH for phosphorus removal was 4.0. The maximum phosphorus adsorption by MFBCs at 298 K was 29.682 mg·g−1 for MFBCs. The adsorption process of phosphorus onto MFBCs is a heat absorption process, and the adsorption isothermal data of phosphorus onto MFBCs fit with the Langmuir adsorption isothermal model. Phosphorus recovery is achieved when calcium chloride is added to the phosphate-enriched desorption solution at a Ca/P molar ratio of 2.2. The phosphorus product obtained from this process is very pure hydroxyphospapatite. The recovery rate of phosphorus in the desorption solution is 99.64%.

With the widespread application of plant remediation technology in the field of soil remediation, there was an increasing stock of hyperaccumulating plant tissues containing heavy metals, but there was currently a lack of effective disposal methods. In the preliminary research process, researchers used the copper hyperaccumulating plant Elsholtzia Harchowensis to prepare biochar material electrodes and successfully used them in the electrocatalytic reduction of carbon dioxide (CO2) process. Due to the previous research being conducted in aqueous solutions, the hydrogen evolution reaction (HER) on the working electrode surface has a certain impact on the Faraday efficiency (FE) of carbon-containing products. In order to further improve the electrocatalytic reduction performance of biochar materials, this study was based on B- and N-doped biochar prepared from Elsholtzia Harchowensis as raw material. The influence mechanisms of electrode surface hydrophobicity and electrolyte components (PC/water) on the CO2RR and HER were studied, respectively. After dropwise coating PTFE on the surface of Cu/C-BN material, the hydrophobicity of Cu/C-BN-PT material was improved, and the effect on the active sites of the catalyst was relatively small without changing the structure and elemental characteristics of the original electrode. In a 1.0 M KHCO3 solution, the Faraday efficiency of H2 in Cu/C-BN-PT material decreased by 20.1% compared to Cu/C-BN at −0.32 V (vs. RHE), indicating that changing the hydrophilicity of the material can significantly inhibit the HER. In a solution of PC/water at a ratio of 9:1 (V:V), the FE of converting CO2 to methane (CH4) at −0.32 V (vs. RHE) reached 12.0%, and the FE of carbon monoxide (CO) reached 64.7%. The HER was significantly inhibited, significantly improving the selectivity of electrocatalytic CO2.

The study assessed the influence of pyrolysis temperature on the properties of hickory sawdust and peanut shells based biochar, particularly its pore structure, surface functional groups, and adsorption capacity. Results from SEM analysis demonstrated that higher pyrolysis temperatures led to an enhanced pore structure and surface roughness in biochars, providing increased adsorption capacity. Raman spectrum analysis revealed higher levels of disorder and graphitization in biochars pyrolyzed at elevated temperatures. Quantification of surface functional groups using the Boehm method indicated a shift in the abundance of basic and acidic groups under high pyrolysis conditions. Employing the FHH model, fractal characteristics were observed in the pore structure of different biochars, with high-temperature biochars displaying increased disorder. The study also explored the mechanism of SMX adsorption onto biochars, revealing higher adsorption capacity for biochars with richer pore structures and rougher surfaces. The Elovich model proved to be the best fit for describing the chemisorption process of SMX onto the biochars. Moreover, the study demonstrated the impact of urine ions on SMX adsorption onto the biochars. These findings provide valuable insights into the properties and potential applications of biochars in environmental remediation.