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Modifying biochar with nano-nutrients is one of the most effective methods in improving the efficiency of biochar in reducing the adverse effects of environmental stresses such as salinity on plant growth and productivity. The possible effects of solid biochar, nano-silicon dioxide enriched biochar, nano-calcium carbonate enriched biochar, and combined application of these enriched biochars on physiological performance of safflower (Carthamus tinctorius L.) were evaluated under different levels of salt stress (non-saline, 6 and 12 dSm−1). Salt stress increased sodium content, reactive oxygen species generation, and antioxidant enzymes activity, but decreased potassium, calcium, magnesium, iron, zinc, silicon, photosynthetic pigments, leaf water content, and seed yield (by about 36%) of safflower plants. The addition of biochar forms to the saline soil improved growth (up to 24.6%) and seed yield (up to 37%) of safflower by reducing sodium accumulation (by about 32%) and ROS generation and enhancing nutrient uptake, photosynthetic pigments, and water contents of leaves. The combined forms of enriched biochars were the best treatment on reducing salt stress effects on safflower plants. Therefore, application of enriched biochars has a high potential to reduce the harmful effects of salt stress on plants. Enriching biochar with calcium and silicon nanoparticles is a practical method to improve the ability of biochar to adsorb and immobilize harmful elements such as sodium in the rhizosphere. This enrichment enhanced safflower plant growth and physiological efficiency under salt stress by reducing sodium absorption and increasing the availability of beneficial nutrients. [ABSTRACT FROM AUTHOR]

Soil salinity caused a widespread detrimental issue that hinders productivity in agriculture and ecological sustainability, while waste-derived soil amendments like biochar have drawn attention for their capacity to act as a mitigating agent, by enhancing the physical and chemical features of soil, and contributing to the recovery of agricultural waste resources. However, the information concerning biochar and salinity which affect the physicochemical characteristics of soils, crop physiology, and growth is limited. To investigate whether biochar mitigates the salinity stress on wheat crop seedlings, we grow them with salinity stress (120 mM), and biochar (20 tons ha−1), and its interactive effects. The soil properties of soil organic carbon (SOC), soil organic matter (SOM), dissolved organic carbon (DOC), and soil available phosphorus (SAP) decreased in the saline soil by 36.71%, 46.97%, 26.31%, and 15.00%, while biochar treatment increased SOC, DOC, and SAP contents by 7.42%, 31.57%, and 15.00%, respectively. On the other hand, dissolved organic nitrogen (DON) contents decreased in all the treatments compared to the control. The root growth traits, SPAD values, leaf nitrogen, photosynthetic parameters, antioxidant enzymes, and reactive oxygen species decreased in the saline treatment while increasing in the biochar and interactive treatment. Thus, these activities resulted in higher leaves and root biomass in the biochar treatment alone and interactive treatment of salinity and biochar. According to principal component analysis, redundancy analysis, and the mantel test, using biochar in conjunction with salinity treatment was found to be more effective than salinity treatment alone. The results of this study suggest that biochar can be used as a sustainable agricultural technique and a means of mitigation agent by lowering soil salinity while increasing the biomass of crops. Biochar improves the physical and nutritional quality of soil and plant function. Salinity stress declined the physiological activities and biomass of the crop. Biochar mitigates the salinity stress in soil and enhances the plant functioning. Exposure to both treatments enhances the antioxidant enzyme activity and biomass. [ABSTRACT FROM AUTHOR]

This study focuses on the improvement of bioremediation of textile dye Reactive Red 195 using agro-industrial waste, groundnut oil cake (GNOC) obtained after oil-pressing. The treatment of GNOC with 1 N H2SO4 had resulted in physiochemical changes on the insoluble porous adsorbent, which improved their adsorption efficiency. The dye removal efficiency increased from 55% to 94% on acidification of GNOC. The raw groundnut oil cake (RGNOC) and acid-treated groundnut oil cake (AGNOC) were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction, and zeta potential. The rate and efficiency of dye adsorption were examined using adsorption kinetics and isotherm models. The results confirm that acid-treated GNOC eliminates impurities, alter the surface functional groups, and significantly increase porous surface areas of RGNOC. The investigation of key factors such as contact time, initial concentration of dye, static/agitation impact, particle size, and adsorbent dose had significantly influenced adsorption capacity of GNOC. Adsorption of dye fits best into the Langmuir model and equilibrium data of dye on AGNOC was explained by psuedo-second-order reaction with maximum adsorption capacity of 12.65 mg/g. This emphasis AGNOC has a very excellent potential to remove the textile dye Reactive Red dye from industrial effluent. This study reports the primary investigation exploring the application of groundnut oil cake (RGNOC) and its acid-modified (AGNOC) version for the bioremediation of industrially used textile dye Reactive Red 195 (RR195). The core objective of this study is to use a low-cost biosorbent to remove RR195 dye from effluent that pose risk to the health and environment. This study analyses the adsorption capacity of RGNOC and its acid-modified version AGNOC to treat contaminated water and the influencing parameters. AGNOC adsorption potential for RR195 dye sequestration was shown to be higher compared to RGNOC. Acidification of the adsorbent is simple, cost expensive, and more efficient alternate approaches to scale up for industrial application. As a result, an attempt has been made to add a new adsorbent to the database. [ABSTRACT FROM AUTHOR]

To investigate the effect of various levels of salinity and biochar on the growth and biochemical traits of Catharanthus roseus L., a medicinal plant, a factorial experiment with three levels of biochar (0, 2, and 4%) and four levels of salinity (0, 1,000, 2,000, and 3,000 mg/kg soil) was conducted in pots under greenhouse conditions, in three replications, 36 pots, and 6 plants/plot. Salinity reduced the vegetative and reproductive growth and Ca and K uptake, and chlorophyll content of the plants, and increased the Na+, Cl−, electrolyte leakage, and antioxidant enzyme (SOD, CAT, GPX) activities. Biochar improved all the vegetative and reproductive growth and biochemical traits of Catharanthus roseus L. and enhanced soil fertility. The application of biochar at the rate of 2% at all four levels of NaCl reduced the activity of antioxidants and decreased electrolyte leakage, reflecting the alleviation of salinity effects and the retention of cell health for survival. The application of biochar 2% was more effective than biochar 4% in alleviating salinity stress. Therefore, by using 2% biochar, it is possible to improve saline soils (soils containing 1,000 or 2,000 mg/kg NaCl) and grow periwinkle ornamental-medicinal plant in it. The plants showed acceptable performance at salinity levels of 1,000 or 2,000 mg/kg with biochar 2%. [ABSTRACT FROM AUTHOR]

Abstract\nNovelty statementThe agro-waste derived valuable products are prime interest for effective management of toxic heavy metals (THMs). The present study investigated the efficacy of biochars (BCs) on immobilization of THMs (Cr, Zn, Pb, Cu, Ni and Cd), bioaccumulation and health risk. Agro-wastes derived BCs including wheat straw biochar (WSB), orange peel biochar (OPB), rice husk biochar (RHB) and their composite biochar (CB) were applied in industrial contaminated soil (ICS) at 1% and 3% amendments rates. All the BCs significantly decreased the bioavailable THMs and significantly (p < 0.001) reduced bioaccumulation at 3% application with highest efficiency for CB followed by OPB, WSB and RHB as compared to control treatment. The bioaccumulation factor (BAF), concentration index (CI) and ecological risk were decreased with all BCs. The hazard quotient (HQ) and hazard index (HI) of all THMs were <1, except Cd, while carcer risk (CR) and total cancer risk index (TCRI) were decreased through all BCs. The overall results depicted that CB at 3% application rate showed higher efficacy to reduce significantly (p < 0.001) the THMs uptake and reduced health risk. Hence, the present study suggests that the composite of BCs prepared from agro-wastes is eco-friendly amendment to reduce THMs in ICS and minimize its subsequent uptake in vegetables.The present study has a scientific research scope, based on reduction of bioavailability and bioaccumulation of toxic heavy metals (THMs) by the addition of biochars derived from agro-wastes and their composite biochar (CB), thereby decreasing the potential health risk. Limited study has been conducted, especially on the impact of CB in THMs-contaminated soil. This study could fill the scientific research gap and provides useful information for mitigation of THMs present in contaminated soil, which could be followed by the Environmental Protection Agency, Ministry of Agriculture and farmers in degraded lands. [ABSTRACT FROM AUTHOR]

In this paper, dispersive micro-solid phase extraction technique was developed for the purpose of extracting and preconcentrating organochlorine pesticide residues in juice samples before their separation and quantitative analysis by gas chromatography-mass spectrometry. A sorbent composed of a silica-supported Fe2O3-modified khat leftover biochar nanocomposite (SiO2-Fe2O3-KLBNC) was implemented in the process. To improve the dispersion of the sorbent in the solution, vortex mixer was employed. Experimental parameters influencing the performance of the method were optimized, and the optimal conditions were established. With these conditions, linear dynamic ranges ranged from 0.003 to 100.0 ng/mL were achieved, with a correlation coefficient (r2) ≥ 0.9981. The limits of detection and quantification, determined by signal-to-noise ratios of 3 and 10, respectively, were found to be in the ranges of 0.001–0.006 ng/mL and 0.003–0.020 ng/mL. Intra- and inter-day precision, values ranging from 0.3–4.8% and 1.7–5.2% were obtained, respectively. The matrix-matched extraction recoveries demonstrated favorable outcomes, falling within the range of 83.4–108.3%. The utilization of khat leftover as an adsorbent in contemporary sample preparation methodologies offers a cost-effective alternative to the currently available, yet expensive, adsorbents. This renders it economically viable, particularly in resource-constrained regions, and is anticipated to witness widespread adoption in the coming future. [ABSTRACT FROM AUTHOR]

AbstractThe Fourier Transform Infrared technique was utilized to measure the infrared spectra of bone and dung chars at ambient temperature. The spectra of the investigated char samples showed some notable similarities, suggesting that the compounds have functional groups which display bands at similar wavenumbers in IR spectrum. Additionally, correlations between the chars and the terra preta soils were found. This implies that the investigated biochars and the terra preta soils share comparable characteristics. Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy showed the existence of calcium, phosphorus, magnesium and oxygen in the bone char which are classified as macronutrients. In addition, the bone char contained two micronutrients (nickel and chlorine) and one non-essential nutrient (sodium). The dung char was constituted with all the macronutrients found in the bone char and in addition it had traces of sulfur which is also a macronutrient. Iron, manganese and chlorine were present in the dung char as micronutrients. There was also the presence of sodium and aluminum which are classified as non-essential nutrients. Zinc which is also fundamental in soil fertility was detected using Atomic Adsorption Spectroscopy in all the chars. Both the samples are alkaline with pHs ranging between 9 and 11. The results of this research will be useful in determining which biochars are best suited for production of synthetic fertilizers. [ABSTRACT FROM AUTHOR]

Amending soil with different materials is gaining acceptance as an effective and inexpensive technique for reclamation of salt-affected soils. The main idea of this study was to investigate the effects of biochar, compost of municipal solid waste and different water salinities level on soil physical quality (SDexter) and soil productivity index (SPI). The treatments were as followed: Control: Soil without biochar or compost and irrigated with tap water, S1: Soil without biochar or compost and irrigated with saline water (EC = 4.5 dS m−1), S2: Soil without biochar or compost and irrigated with saline water (EC = 9 dS m−1), B: Soil amended with 1.5%w/w biochar and irrigated with tap water, B+S1: Soil amended with 1.5%w/w biochar and irrigated with saline water (EC = 4.5 dS m−1), B+S2: Soil amended with 1.5%w/w biochar and irrigated with saline water (EC = 9 dS m−1), C: Soil amended with 1.5%w/w compost and irrigated with tap water, C+S1: Soil amended with 1.5%w/w compost and irrigated with saline water (EC = 4.5 dS m−1), C+S2: Soil amended with 1.5%w/w compost and irrigated with saline water (EC = 9 dS m−1). Soil water characteristic curve (SWCC), Field capacity (FC), Plant wilting point (PWP), Plant available water (PAW), Dexter's index of soil physical quality (SDexter) and SPI were examined in a greenhouse experiment. The SPI was calculated by integrating the effects of six soil quality indices: plant available water, organic matter (OM), Electrical conductivity (EC), pH, Bulk density (BD) and Root weighting factor (RF) for all treatments were calculated. The results showed that the B treatment had a slightly higher effect on SWCC. The applied B and C treatments caused insignificant increase in PAW relative to the control. In addition, application of biochar or compost to soil significantly increased the SDexter. The application of C treatment had insignificantly higher value of SDexter compared to other treatments. Compared with the control, SPI was significantly higher for the B and C treatments. Overall, the application of biochar/compost minimized the destructive effects of saline irrigation water and improved the quality of the salt-affected fine-textured soil. [ABSTRACT FROM AUTHOR]

Biochar-based fertilizers (BBFs) agronomic performance depends on its nutrient pools, electrical conductivity (EC) and pH, conventionally assessed by laboratory classical wet methods that are non-environmentally friendly, time-consuming, and costly. However, the nutrient pools and properties of BBFs can be predicted by partial least square regression (PLS) based on Fourier Transform Infrared Spectroscopy (FTIR) analysis. Thus, we aimed to use PLS regression based on FTIR analysis to predict the pH, EC and nitrogen (N), phosphorus (P), and potassium (K) pools in BBFs produced by different routes. Sixteen BBFs were produced by mixing, previously or after the pyrolysis process of low-grade phosphate acidulated with different inorganic acids (sulfuric, hydrochloric and nitric acids), addition or no different sources of Mg (magnesium chloride and serpentinite). PLS models based on the normalized FTIR dataset in BBFs are considered good when R2 during calibration and cross-validation phases are higher than 0.81, values founded in our study to prediction of pH, EC, total, and mineral N, total P, and P soluble in water, citric acid, formic acid, and neutral ammonium citrate, and total K of BBFs. Besides, the difference between R2 of calibration and cross-validation lower than 0.2 founded indicated no overfitting. Furthermore, the PLS models had high prediction capacity (R2 of prediction higher than 0.55) and high accuracy (R2 to y-randomization <0.50). Thus, PLS regression models based on the normalized FTIR dataset in BBFs were models characterized by the good performance, robustness, and nonrandom able to predict the nutrient pools, pH, and EC in BBFs. [ABSTRACT FROM AUTHOR]

AbstractThe decline in crop yields is attributed to uneven chemical fertilization practices and poor soil fertility. From a sustainability perspective, the application of beneficial microorganisms alongside a blend of inorganic and organic fertilizers significantly influences crop productivity and food security. Concerns within the scientific community arise from the haphazard and negligent use of fertilizers. Farming communities predominantly reliant on chemical fertilizers often overlook the application of organic alternatives, leading to a gradual decline in soil organic matter and native nutrient levels, ultimately resulting in decreased crop yields. In diverse cropping systems, the amalgamation of chemical, biological, and organic sources sustains soil health, replenishes nutrients, and optimizes crop yields. Plant residues enhance soil microbial activity, expedite nutrient cycling and availability, and aid in preserving soil health through carbon sequestration. Regular utilization of plant residues and other organic materials enriches soil organic matter content, enhancing soil health and productivity. Integrating organic and chemical fertilizers presents a potential avenue to enhance maize and soybean yields in maize-wheat cropping systems, subsequently benefiting wheat crop productivity and profitability. The efficacy of specific soil nutrients can be heightened by combining organic sources with various chemical fertilization techniques. Hence, incorporating phosphorus fertilization alongside phosphorus-mobilizing and solubilizing agents (such as Trichoderma & PSB), along with the integrated management of peach waste materials including residues, compost, and biochar, is imperative for promoting crop growth, increasing seed yields, and fostering environmental sustainability. [ABSTRACT FROM AUTHOR]

AbstractBiochar is a carbon-rich product obtained by biomass pyrolysis and is considered as a means of carbon sequestration. However, there is limited knowledge regarding responses of soil respiration and C-cycle enzyme activities to BC in a calcareous soil. In this study, different biochar AS, TS, PP, CS were applied to the soil at different rates (0.5, 1.0, and 1.5%) The highest increase in soil organic C content was observed in the TS treatment, while the AS treatment caused a slight increase of soil organic C. The highest MBC content was recorded in AS treatment and the lowest was observed in TS. The highest CO2-C emission was recorded in the TS treatment. In contrast, the lowest CO2-C emission was observed in the PP treatment due to its high recalcitrant C content and was attributed to a positive priming effect, stabilizing BC mineralization to improve the soil. The highest β-galactosidase enzyme activity was observed in the CS treatment and the lowest activity was observed in AS. The highest change in β-glycosidase enzyme activity was observed of PP treatment and the lowest was in AS biochar application. Thus, TS treatment is recommended to increase the organic C content of soils, and the PP biochar can be used to reduce CO2-C emission. The TS, PP, and CS can be applied to increase enzyme activities. The study clearly shows that the addition of BC to arid soils may have a high potential to improve soil enzyme activities and subsequent carbon sequestration and biochemical cycles. [ABSTRACT FROM AUTHOR]

AbstractIn spite of okra’s importance to food security in developing countries, its production is limited by low soil nutrient and health status. A screenhouse study examined soil chemical properties, okra growth and yield under complementary application of biochar, organic and inorganic fertilizer in an Ultisol. The treatments comprised 5 kg soil each amended with 5 t biochar ha−1, 5 t poultry manure compost (SPM) ha−1, urea at 56 kg N ha−1, urea (28 kg N ha−1) + 5 t biochar ha−1, 5 t ha−1 (2:1, PM: biochar) (SPMB), urea (28 kg N ha−1) + 5 t ha−1 (2:1, PM: biochar) (SPMBF2). The treatments, replicated thrice, were arranged in a completely randomized design. There were two sets of plants terminated at 50% flowering (dry matter yield (DMY) and nutrient uptake) and at 10 wk post-planting for growth and yield determination. Results revealed that soil chemical properties, okra growth and yield increased responsively to the organic amendments. The SPM, followed by SPMB and SPMBF, enhanced soil pH (0.18–0.19 unit), total N (79–100%), organic carbon (75–100%), available P (55–58%) and exchangeable cations over the control and others (p < 0.05). These treatments also increased the plant’s agronomic parameters: plant height (10–19%), number of leaves, leave area (21–31%), stem girth (33–51%), DMY (59–67%), and tissue Ca, Mg and K. The SPMBF2 – treated soil had the highest fruit yield (45 g pot−1). Conclusively, sole and complementary applications of biochar and compost improved soil chemical properties, and okra growth and yields. [ABSTRACT FROM AUTHOR]

There is a need to find eco-friendly methods for preventing toxic heavy metals from subsuming into food chain due to their deadly impact on plants and animals. A study was employed to investigate cadmium adsorption efficiency of biowastes and their derived products. The bio-wastes included apple pomace and sawdust based vermicompost, later converted to biochar. The study elucidated the impact of changing pH, initial concentration and contact time on cadmium adsorption efficiency of biowastes. Among different adsorbents, the biochars efficiently removed Cd (II) and attained equilibrium at a faster rate. The equilibrium data best fitted to Freundlich and Langmuir isotherm. Among different adsorbents, maximum adsorption (qmax) (35.075 mg g−1) from Langmuir adsorption isotherm was reported for vermicompost derived from 100% sawdust. Among biochars highest qmax (3.0 mg g−1) was reported for biochar obtained from 100% apple pomace. All adsorption systems were exothermic, with AT values ranging from 0.05–0.75 J/mol at pH 8 and 0.118–0.485 J/mol at pH 2. The pseudo-second order kinetic model was best fit at all concentrations implying chemisorption of Cd2+ ions by bioabsorbents. The adsorption could complete in optimum time frame required for industrial application for treating contaminated water at large scale. [ABSTRACT FROM AUTHOR]

Soil salinity is a major challenge in agriculture, particularly in calcareous soils with high calcium carbonate levels. Biochar, produced from biomass pyrolysis, is being considered as a potential solution for mitigating salinity effects. A greenhouse pot experiment was conducted using calcareous soil from a saline field to investigate the effects of sugarcane biochar applied at different rates (0.0%, 2.0%, and 5.0%) on soil properties and wheat (Triticum aestivum L.) growth. Results showed that both Low Rate (2.0% biochar) and High Rate (5.0% biochar) treatments significantly improved soil pH, reduced electrical conductivity (EC), and increased soil organic matter (SOM) content. Plant growth indicators such as plant height, stem diameter, and leaf chlorophyll content also showed significant improvement with biochar application. High Rate had more pronounced effects compared to Low Rate. The analysis confirmed the significant effects of biochar on soil properties and plant growth, indicating its potential as a beneficial soil amendment. Sugarcane biochar has the potential to mitigate salinity stress and enhance crop productivity in calcareous soils. Further research is needed to explore the long-term effects of sugarcane biochar application and its interactions with other soil management practices in different crop systems. These findings highlight the promising role of biochar as a sustainable approach for mitigating salinity stress in agriculture and improving soil quality for crop production. The study's findings highlight the potential industrial applications of sugarcane biochar in addressing soil salinity issues prevalent in calcareous soils, particularly in agriculture. The research underscores the positive impact of biochar on soil attributes, plant growth, and nutrient availability. With its ability to improve soil pH, reduce salinity, increase soil organic matter, and enhance plant growth, sugarcane biochar emerges as a promising soil amendment for agricultural use. This presents an opportunity for industries involved in sustainable agriculture, soil management, and crop enhancement to explore the integration of biochar into their practices. Additionally, the study emphasizes the need for further research and field trials to optimize biochar application rates, assess economic feasibility, and ensure environmental sustainability. The insights gained from this study offer a pathway for industrial stakeholders to explore biochar's role in enhancing soil quality, promoting plant growth, and ensuring sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

\nHIGHLIGHTSBiochar is a soil amendment made from organic waste pyrolysis that has the potential to enhance crop growth and reduce soil contamination. A recent study examined the effects of biochar application on rice plant growth, yield, biomass, and total petroleum hydrocarbon (TPH) contamination in soil. The study included four treatments: control, biochar (2.0% and 4.0% addition), TPH (4.0%, 6.0%, and 8.0%), and biochar+TPH. Results showed that biochar application was effective in mitigating the negative effects of TPH contamination on soil-physiochemical properties, increasing soil pH, organic matter, and available nutrients. Additionally, biochar application significantly increased rice plant height compared to the control and mitigated the negative impact of TPH on rice plant height in TPH-contaminated soil. Biochar application at 4.0% and 6.0% resulted in higher grain yield and biomass than the control group under all TPH contamination levels, with 6.0% being the most effective. Overall, the study highlights the potential of biochar as a sustainable approach for crop production in contaminated areas. However, further research is required to understand the underlying mechanisms, sustainability, and long-term effects of biochar application in agricultural systems. SBB has the potential to mitigate the negative effects of TPH contamination on soil properties.SBB can increase soil pH, organic matter, and available nutrients, making it a valuable tool for soil remediation.SBB reduces TPH removal from contaminated soil, possibly due to adsorption or soil property modifications.SBB has a positive effect on rice height, mitigating the negative impact of TPH contamination.Higher levels of SBB result in taller rice plants, and lower levels of TPH result in taller rice plants.SBB application at 4.0% and 6.0% improves grain yield and biomass across all TPH contamination levels.SBB has promising potential as a sustainable strategy for managing contaminated soils for crop production.SBB has the potential to mitigate the negative effects of TPH contamination on soil properties.SBB can increase soil pH, organic matter, and available nutrients, making it a valuable tool for soil remediation.SBB reduces TPH removal from contaminated soil, possibly due to adsorption or soil property modifications.SBB has a positive effect on rice height, mitigating the negative impact of TPH contamination.Higher levels of SBB result in taller rice plants, and lower levels of TPH result in taller rice plants.SBB application at 4.0% and 6.0% improves grain yield and biomass across all TPH contamination levels.SBB has promising potential as a sustainable strategy for managing contaminated soils for crop production. [ABSTRACT FROM AUTHOR]

Quantitative speciation of metals and their variability over time is a critical concept in environmental soil chemistry. Chromium is a heavy metal that has negative effects on the environment and human health. There have been several attempts to study the behavior of chromium in soils and its removal from soil. However, there is relatively little knowledge about the immobilization of chromium and its chemical speciation in contaminated and uncontaminated soils when different organic amendments are applied. A laboratory incubation experiment was conducted in a completely randomized design to evaluate the effect of organic amendments on the speciation of chromium in contaminated and uncontaminated soils. Four organic amendments were used: farmyard manure (FYM), rice straw compost (RSC), vermicompost (VC), and biochar (BC). Each of them was applied at 1% to contaminated as well as uncontaminated soils. In both the amended and unamended soils, chromate (CrO42-), bichromate (HCrO4−), and calcium chromate (CaCrO4) in soil-water system followed the order CrO42-> HCrO4−> CaCrO4. The application of FYM, RSC, VC, and BC significantly decreased the CrO42- and CaCrO4 in the soil-water system of both soils. However, only the application of BC affected the HCrO4− contaminated soils. In both soils, HCrO4− exists as the predominant chromium species in the pH range of 2.0 to 6.25. At pH 6.25, CrO42- and HCrO4− each contribute 50% of the total dissolved chromium in soil solution. CrO42- dominated in the system as the pH increased from 6.25 till 8.0. The maximum concentration of CrO42- was at pH 8.0. At pH <3.0, CrO3SO42- contributes less than 10%. Overall, organic amendments decreased the concentration of Cr species in both soils. However, the decrease in concentration was highly dependent on the nature of the amendment applied. Therefore, organic amendments can be exploited to remediate chromium-contaminated soils. [ABSTRACT FROM AUTHOR]

Salinity is a major environmental problem that adversely affects plant growth by increasing soil osmotic pressure and disrupting plant nutrition. Using organic amendments is a viable tool for reducing physiological and morphological effects of excessive soil salinity on plants. To show the impacts of tea waste, compost and biochar on nutrient status and growth parameters of spinach (Spinacia oleracea L.) raised in salinity conditions, this study has employed factorial CRD with two treatments involving soil salinity (2.5 and 8 dS m−1) and organic materials (spent tea waste (STW), spent tea waste compost (STWC) and spent tea waste biochar (STWB)) at 0 and 3% w/w in three replications. As soil salinity increased from 2.5 to 8 dS m−1, fresh weight and dry matter production decreased by 31.5% and 30.4%, respectively. Phosphorous and potassium concentrations in plant tissue also decreased significantly due to the increase in salinity. Organic amendments (except STW) due to their physicochemical properties increased the nutrients uptake and growth parameters of the plant. Compared to other amendments, biochar reduced salinity effects on plant growth more effectively, which is possibly due to its high nutrient adsorbing and water holding capacity. In saline conditions, the highest potassium to sodium ratio belonged to the biochar treatment, which was 3.22 and 2.78 times greater than spent tea waste and compost, respectively. Therefore, it was preferred to change the spent tea waste into biochar before being used as soil amendment. [ABSTRACT FROM AUTHOR]

Biochars have received much attention as efficient adsorbents for water pollutants. Besides, the chemical treatment of biochars performed to increase the adsorption capacity usually causes secondary chemical pollution and increases the cost of the process. The biomass feedstock utilised in biochar preparation impacts significantly the surface properties and adsorption capacity. Thus, the need to prepare new biochars from new feedstock with potentially high uptake capacities. Herein, we prepared new biochar (POBC) from Platanus occidentalis waste leaves (POL), which was utilised for the ultrasonic-aided adsorption of bromophenol blue (BRB) and thiazolyl blue tetrazolium bromide (TTB). The FTIR, SEM, EDX, TGA, BET, pHpzc, and elemental characterisations of POBC revealed potent surface characteristics desirable for efficient dye adsorption. An increase in the surface area from 14.31 m2/g to 31.94 m2/g and the pore volume from 0.0214 cm3/g to 0.0326 cm3/g was obtained after the conversion of the POL to POBC. Besides, the SEM images of POBC revealed a highly porous surface structure of the adsorbent. The Freundlich and pseudo-second-order model presented the best fit to the isotherm and kinetics based on the high coefficient of determination (R2 > 0.9) and low sum square errors (SSE < 0.31). The heterogeneous surface nature of POBC was inferred from the independent-oriented site model. The monolayer adsorption capacity of 45.03 mg/g and 48.8 mg/g were obtained for BRB and TTB, respectively. Thermodynamics showed an endothermic, feasible, and random uptake, and POBC displayed efficient potentials to be reused. The obtained results revealed that novel POBC is an efficient low-cost biochar with high adsorption capacity for dyes. [ABSTRACT FROM AUTHOR]

Sandy and acidic soil conditions are the major factors limiting the production of some vegetable crops in acidic soils. This study aims to examine the effect of various amendments on the growth, yield and mineral nutrients uptake of stem amaranth. Two pot experiments were conducted separately in two generic soils. Six treatments viz. T0 = control (without amendment), T1= lime, T2 = lime + wetland bottom sediment, T3 = lime + vermicompost, T4 = lime + rice straw biochar (RSB) and T5 = RSB were used for both experiments following CRD with four replications. Results revealed that plant heights (45.96 and 50.33 cm) of amaranth grown in alluvial and hill soils, respectively, were the highest in T4 treatment. Similarly, treatment T4 showed the highest fresh (118.53 and 116.11 g pot−1, respectively) and dry biomasses (16.98 and 19.54 g pot−1, respectively) for both soils. For both soils, treatment T4 resulted better nutrient uptake of N, P, K, S, Zn, Fe and Mn by edible stem, while non-amended soil gave the lowest result at all parameters. Analytical values of post-harvest soils indicated that T4 and/or T5 treatments resulted in an improvement in soil pH, organic carbon, total N, exchangeable K and extractable P, S and Zn. Treatment T3 showed elevated concentrations of extractable soils Fe and Mn. The amendment RSB combined with lime can be preferably used in strong acidic soils for cultivation of stem amaranth. [ABSTRACT FROM AUTHOR]

Phaseolus vulgaris is one of the most widely consumed legumes across the globe. It is rich in protein, carbohydrates, fiber, bioactive compounds, and mineral contents. Occurrences of drought under changing climate have posed a challenge to the quality and quantity of the crop yield. Our study, taking Phaseolus vulgaris as a test legume, reports that as a soil amendment, biochar and farmyard manure mitigated drought-induced damage in the plant. The experiment was set up in a greenhouse with 1 m2 blocks together arranged in factorial randomized block design. Water withdrawal was done for 15 days in either vegetative or reproductive stage of the crop to simulate drought conditions. Biochar or Farmyard manure was applied at the rate of 10t ha−1 as soil amendment and each treatment was replicated thrice. Higher photosynthesis (up to 23% and 16%, respectively), leaf protein (41% and 30%, respectively), grain protein (4% and 19%, correspondingly), and in-vitro protein digestibility (60% and 254%, respectively) were noted under application of both the amendments. Grain quality in terms of protein content, in-vitro protein digestibility, and protein fractions of Phaseolus vulgaris was improved under drought due to the addition of biochar and farmyard manure. However, the application of those amendments at the rate of 10t ha−1, especially farmyard manure, had a negative impact on the antinutritional factor (phytic acid) and mineral bioavailability. Between the two amendments studied, farmyard manure proved to be more efficient in promoting the overall grain quality of P. vulgaris, but its inimical effects must be concorded. [ABSTRACT FROM AUTHOR]

AbstractIn the study, the removal of dye (methyl blue) from aqueous solutions by batch/agitation adsorption method was investigated using Pinus brutia (PB). For this purpose, first, PB wood was collected and made into wood chips (PB), and then Pinus brutia biochar (PBB) was made. The PBB was modified to gain nano-magnetic properties. The biochar structure was characterized by FT-IR. PBB and nM-PBB were used for the removal of MB dye. The adsorbent amount, temperature, pH, time and dye concentration were investigated in the adsorption process with adsorption isotherms, kinetics and thermodynamics to estimate their MB removal efficiency. Sorption equilibrium for MB dye was reached by nM-PBB within 60 min and adsorption efficiency up to 99.007% was reached. While the adsorption kinetics followed a pseudo-second-order kinetic model, the Langmuir isotherm model, with a maximum adsorption capacity of 107.527 mg/g (nM-PBB), showed homogeneous physiochemical adsorption. The efficiency was found to be a spontaneous endothermic reaction. It can be suggested that nM-PBB can be used to remove MB. [ABSTRACT FROM AUTHOR]

It is believed that processing biomass into biofuel is an efficient way to create clean energy with no carbon footprint while also assuring suitable waste disposal methods. The objective of this study was to assess the qualities of biochar, a solid biofuel made from coconut fibres using the carbonisation process. A retort heating system was used to create the biochar, which was then subjected to a number of analytical techniques to assess its physical characteristics. The findings demonstrated that the biochar has better thermal stability than raw biomass and a high resistance to degradation. The biochar is mesoporous and has pore diameters of 3.0 nm and a BET surface area of 167.3 m2/g. The composition analysis of the biochar revealed that it contains a number of inorganic components, such as nitrogen, phosphorus, and potassium, indicating its usefulness for the creation of fertilisers and the improvement of soil nutrients. The biochar's porous structure and the many pores seen during the morphological study further support its ability to act as an adsorbent. The study aids in the production of solid fuel biochar, which can be used for a variety of applications, as well as waste management associated with increased coconut farming. [ABSTRACT FROM AUTHOR]

Using banana peel as raw material, the composite material CuFe2O4@BC was synthesised and used it to activate peracetic acid (PAA) to remove tetracycline (TC) in water. The crystal phase, morphology, and chemical bonding of the composite were analysed by XRD, SEM, FTIR, XPS, and other characterisation techniques. In the degradation experiments, CuFe2O4@BC showed high catalytic activity and found that the best dosage ratio of CuFe2O4@BC and PAA is 300 mg/L: 3 mmol/L, and under this condition, the removal rate of TC in 60 min reached 85%. CuFe2O4@BC showed degradation effect in a wide pH range, and the catalytic activity was found to be the best under acidic conditions. At the same time, after five cycles of test, the composite still maintained more than 80% of TC removal rate. The free radical quenching experiments proved that the main active species in the reaction were •OH, CH3COO• and CH3COOO•. [ABSTRACT FROM AUTHOR]

The adsorption mechanism of S-Metolachlor in an aqueous solution by sawdust biochar derived from Acacia auriculiformis (SAB) was studied. SAB was manufactured at 500 °C for 4 h under oxygen-limited conditions and characterized for SEM, EDS, pHpzc, BET, and FTIR. The adsorption kinetics, isotherm, and diffusion studies of S-Metolachlor and SAB were further explored. Moreover, the effects of the solution pH were examined on the adsorption of S-Metolachlor by SAB. The BET analysis of SAB was achieved at 106.74 m2.g−1 and the solution pH did not significantly influence the S-Metolachlor adsorption. The adsorption data were fitted into a Langmuir isotherm and the PSO model. The film diffusion coefficient Df (4.93 × 10−11 to 8.17 × 10−11 m2.s−1) and the particle diffusion coefficient Dp (1.68 × 10−11 to 2.65 × 10−11 m2.s−1) were determined and the rate-limiting step of S-Metolachlor adsorption and SAB was governed by liquid film diffusion. The S-Metolachlor adsorption process onto SAB was controlled by multiple mechanisms, including pore filling, H-bonding, hydrophobic interaction, and π-π EDA interactions. H-bonding is the main interaction for the adsorption of S-Metolachlor and SAB. Conclusively, the study illustrates that biochar produced from Acacia auriculiformis sawdust possessed effective adsorption properties for S-Metolachlor herbicide. [ABSTRACT FROM AUTHOR]

Recently a large number of extensive studies have amassed that describe the removal of dyes from water and wastewater using natural adsorbents and modified materials. Methyl orange dye is found in wastewater streams from various industries that include textiles, plastics, printing and paper among other sources. This article reviews methyl orange adsorption onto natural and modified materials. Despite many techniques available, adsorption stands out for efficient water and wastewater treatment for its ease of operation, flexibility and large-scale removal of colorants. It also has a significant potential for regeneration recovery and recycling of adsorbents in comparison to other water treatment methods. The adsorbents described herein were classified into five categories based on their chemical composition: bio-sorbents, activated carbon, biochar, clays and minerals, and composites. In this review article, we want to demonstrate the capacity of natural and modified materials for dye adsorption which can yield significant improvements to the adsorption capacity of dyes such as methyl orange. In addition, the effect of critical variables including contact time, initial methyl orange concentration, dosage of adsorbent, pH, temperature and mechanism on the adsorption efficiency will be covered as part of this literature review. The novelty of this review article describes the utility of various natural and modified materials employed to remove methyl orange (MO) from water, wastewater and aqueous solutions. Natural sorbents are very popular adsorbents because the majority of them are affordable and readily accessible in terms of addressing key challenges concerning water security that are relevant to MO adsorption processes. This review is significant since it will be useful in guiding researchers on the selection of an adsorbent that would be suitable for MO adsorption. Furthermore, our findings provide a basis for researchers interested in the design of composite adsorbents based on the selection of constituent components. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) and arsenic (As) are toxic elements that threaten plants and human health. Due to the opposite transformations of Cd and As, their simultaneous immobilization poses numerous concerns. Thus, there is an urgent need to simultaneously reduce Cd and As mobility and plant uptake in co-contaminated soil. Our previous work found that goethite-modified biochar amendments effectively reduced Cd and As uptake by Chinese cabbage; however, their residual impact on subsequent crops must be investigated. In the current work, the following maize (Zea mays L.) was grown after Chinese cabbage in Cd and As co-contaminated soil amended by biochar (BC), goethite (G), and goethite-modified biochar (GBC) at a 1% application rate. The synthesis of GBCs involved two different initial mass ratios of iron/biochar (Fe/BC), with GBC1 having a Fe/BC ratio of 1:1 and GBC2 having a Fe/BC ratio of 2:1. The current study assessed the residual impacts of BC, G, and GBC amendments on Cd and As mobility, uptake by maize, and their impacts on maize growth. The results revealed that GBC amendments enhanced maize growth, chlorophyll content, and gas exchange parameters compared to raw BC and G. Moreover, the GBC1 amendment lowered Cd and As uptake by maize shoots (29.48% and 61.56%) and roots (33.07% and 37.32%), respectively, compared to unamended soil (CK). The GBC1 amendment decreased the bioaccessibility of Cd and As by 24.37% and 37.44%, respectively, compared with CK. In general, the results demonstrated that GBC has a significant residual impact on maize growth and Cd and As uptake in co-contaminated soil. [ABSTRACT FROM AUTHOR]

Industries play a substantial role in contaminating the freshwater sources. This study was performed to appraise the potential of biochar activated with 85% phosphoric acid was used as chemisorbent for the removal of Chromium III and VI (Cr III and VI)) and desorbed chromium was utilized for replacing the conventional basic chromium sulfate to ensure circular economy. In our previous studies, the factors for biosorption of Cr were optimized through Box–Behnken model under Response Surface Methodology. Batch adsorption studies revealed that the optimum conditions for maximum Cr (VI) biosorption by activated biochar is pH = 2, biosorbent dose: 1%, biosorbent size: 1 mm, solute concentration: 985 mg L−1 and reaction time 35 h. Based on these results a column experiments were carried out and flow rate was optimized as 0.5 ml m−1 where prominent "S" shaped breakthrough curves were noticed. The predicted values under Thomas model for the adsorption of Cr was 3827.2 µg g−1, which was in close agreement with experimental value of 3566.1 µg g−1. The percent Cr sorption varied from 70.05 to 88.75% in first cycle and showed decreasing trend in the subsequent cycles. The elutant 0.5 M H2SO4 desorbed 89.56% of chromium furthermore eluted chromium was utilized for leather tanning. Reusing of recovered chromium for tanning experiments does not alter the leather Tensile (240.82 kg cm−2) and tear strengths (32.41 kg mm−1). This study suggested that recovered chromium from biosorbent can be well utilized for leather tanning to attain the leather of equivalent qualities as that of conventional methods which could save 20–22% of the production cost besides defending the environment from Cr contamination. [ABSTRACT FROM AUTHOR]

In the last decade, there has been increasing scrutiny of using biochar to remove pollutants from the waste water. However, due to particle size of biochar and the difficulty of its separation after the adsorption process, the use of these adsorbents has always been a challenge, until magnetic biochar (MB) was proposed by researchers. The production of MB is divided into pre-pyrolysis and post- pyrolysis methods. The MB activation/modification methods included physical and chemical activation/ammonization, sulfurization, oxidation, polymerization and MB production without modification/activation was investigated. In this research, studies that produced MB as a one-step heating and post-pyrolysis method reviewed. The results showed that the capacity of different MB to remove lead, cadmium, chromium, copper, and arsenic was calculated to be 96.9, 91.2, 90.5, 97.6 and 55.42%, respectively. In these studies, the weight ratio of the magnetic fraction to biochar, temperature, and carbonization time were 1.2 (g/g), 575 °C, and 130 min, respectively. During the absorption process, the adsorption capacity of magnetic biochar increased and then reached a constant value. Therefore, the magnetic biochar has good ability to hold the adsorbed pollutants to the end of process. Also, as the initial pollutant concentration increased, the adsorption capacity unexpectedly increased and eventually reached its maximum, indicating a high affinity of the magnetic biochar with the pollutants. [ABSTRACT FROM AUTHOR]

Recycling of phosphorus (P) from feedstocks to soils can provide sustainability in agriculture. In our incubation study, we investigated the effects of adding cow manure-derived vermicompost (CMV), cow manure (CM), sugarcane trash biochar (STB), and triple super phosphate (TSP) to extractable P in a sandy loam soil. P was added to the soil at rates of 0, 50, 100, 200, and 300 mg kg−1 based on their total P contents. The amended soils were incubated for 1, 4, 8, and 16 weeks (wk) at room temperature and extractable P samples were measured (by water, Olsen, Mehlich-3 and Bray and Kurtz) and soil pH was monitored. After 1 wk of incubation, the extractable P values were 1.4 mg kg−1 with STB at the smallest while the highest was 79 mg kg−1 with TSP. The corresponding P values in the CMV and CM amended soils were 33 mg kg−1 and 31 mg kg−1. The reductions of extractable P from 1 to 16 wks of incubation were 40%, 35%, and 80% in the CMV, CM and TSP amended soils, respectively, while they increased from 1.43 mg kg−1 to 6.05 mg kg−1 ((320%) in the STB amended soil. Among the amendments, a significant positive relationship was observed between extractable P and the pH in soils amended with STB. The findings revealed that varying P extractability in soils depends on amendment types and duration of incubation. Sugarcane trash biochar did not exhibit an ability to substitute inorganic P fertilizer for assessing bioavailable P. [ABSTRACT FROM AUTHOR]

Retention and degradation of co-applied atrazine and fipronil was studied in laboratory constructed bio-augmented biobeds containing rice straw-compost (BM) and compost replaced with 10% rice husk ash [RHABM(10%)] or 1% wheat straw biochar [WBCBM(1%)] biomixtures. Atrazine (5000 µg, 50% WP) and fipronil (5000 µg, 0.3 G) were co-applied in 100 mL water. After 30 days, 7.31, 4.65, and 11.21 µg g−1 atrazine and 21.59, 7.41, and 37.20 µg g−1 fipronil remained undegraded in the top 3–4 cm of BM, RHABM(10%), WBCBM(1%) biobeds, respectively, suggesting that degradation of both pesticides significantly varied (p < 0.05) among the three biobeds. After 60 days 94.5%–98.3% of initially applied atrazine and 80.3%–86.9% fipronil degradation was observed. Hydroxyatrazine and sulphone were detected as the metabolites of atrazine and fipronil, respectively. Out of 5000 µg of initially applied pesticides, BM, RHABM(10%), and WBCBM(1%) biobeds accounted for 95.2%, 93.1%, and 95.2% of atrazine + hydroxyatrazine and 62.8%, 67.0%, and 71.5% of fipronil + sulphone degradation, respectively. Maximum amounts of recovered atrazine (68.8%–81.1%) and fipronil (89.8%–94.6%) were retained in the 0–5 cm sections of the biobeds. No significant effect of co-applied atrazine + fipronil was evident on the microbial parameters. This study suggested that RHA/WBC-mixed rice straw-compost biomixtures can be exploited for the detoxification of these pesticides in bio-purification systems. [ABSTRACT FROM AUTHOR]

Using carbon-based materials (CBMs) to facilitate phytoremediation shows great promise for simultaneously enhancing the restoration efficiency of contaminated soil and reducing carbon dioxide in the context of global warming, which is still in the exploring and attempting phase. In addition to direct degradation or alteration of pollutant bioavailability, CBMs can enhance phytoremediation by alleviating plant nutrient deprivation and oxidative stress, as well as by modulating soil microbial communities and root secretions. Photosynthetic carbon fixation predominantly affects both phytoremediation efficiency and carbon cycle turnover in terrestrial ecosystems. In this regard, CBMs have extremely positive properties in facilitating plant carbon capture, with intrinsic mechanisms including (1) promoting photosynthetic pigment synthesis and acting as artificial built-in antennae to improve photon capture efficiency, (2) accelerating the photosynthetic electron transport rate in photosystems, (3) improving the Calvin cycle, and (4) maintaining the structural integrity of chloroplasts. Besides, as an ultra-stable type of CBM derived from waste biomass, biochar can preserve the native biomass carbon in the soil environment for decades and attenuate the rhizosphere priming effect by influencing the structure of rhizosphere soil aggregates and microbial communities, thus retarding the native soil organic carbon efflux. This review critically elaborates on the mechanisms by which CBMs assist in improving the efficiency of phytoremediation and their positive effects on the plant-root soil carbon balance. Additionally, a simple full-life cycle analysis encompassing cost analysis as well as ecological, economic, and social benefits is concluded to evaluate the feasibility and sustainability of CBMs-phytoremediation systems. [ABSTRACT FROM AUTHOR]

Biochar is widely used as a good soil amendment, while knowledge of modified biochar application in tea garden soils contaminated by fluoride (F) and cadmium (Cd) is insufficient. The tea seedling (Camellia sinensis L.) growth assay was performed to evaluate interaction of soil Cd and F and the improving effect of aluminum trichloride-modified corn stalk biochar (Al-BC) on their speciation, phytoaccumulation and phytotoxicity. Results showed that soil F speciation ratio sequence was as follows: residual > exchangeable > organic-bound > water-soluble > Fe/Mn oxide-bound. Soil exchangeable Cd was the largest Cd speciation (>35.6%), probably due to the low pH values in the acid tea gardens. Root F contents showed a strong significant relationship with soluble F contents (r = 0.92, P <.01) and similarly root Cd highly connected with exchangeable Cd (r = 0.86, P <.01). Seedling height, fresh and dry weight, root surface area, length, and photosynthetic pigment showed different sensitivities to F or Cd oxidative stress and toxicity effects, and only root F contents significantly inversely correlated with them (r = 0.74–0.80, P <.01). The interaction of Cd and F, could influence their speciation distribution and antagonized each other in root accumulation. Meanwhile, joint simulation models showed that antagonistic effects were observed in the F and Cd mixture soils for most cases at Enshi. Biochar application reduced bioavailable F and Cd contents, and thus decreased F and Cd accumulation in tea roots and obviously alleviated toxicity effects. For instance, biochar application significantly reduced root F contents, which had 33.2% to 62.2% declines at Enshi and 39.7% to 77.2% declines at Huanggang. Meanwhile, the soil properties were improved as biochar added, with an increase in soil pH, EC, CEC and organic matter. Overall, Al-modified biochar was beneficial environmental materials for reducing both F and Cd bioavailability. [ABSTRACT FROM AUTHOR]

The disposal of industrial effluents containing cadmium and copper ions is a significant environmental concern. This study aims to address this issue by evaluating the adsorption capacity of adsorbents derived from residual biomass from second-generation ethanol production. The objective is to effectively remove cadmium and copper ions from aqueous solutions. The biochar utilized in the study was characterized as microporous and exhibited characteristic bands associated with carboxyls and hydroxyls. The pHPZC (point of zero charge) was determined to be 8.0. The kinetic study revealed that the PSO (pseudo-second-order) model provided the best fit, indicating that the adsorption rate depends on the amount of solute adsorbed onto the adsorbent's surface. In the equilibrium study, it was observed that adsorption occurred in a monolayer, as evidenced by the superior fit of the Langmuir model. Furthermore, the equilibrium experimental data for the bicomponent system was more accurately represented by the empirical models of Extended Freundlich and Modified Redlich-Peterson. These findings demonstrate the potential of biochar derived from the residue of second-generation ethanol production, a novel application, in effectively removing cadmium and copper ions from aqueous solutions. [ABSTRACT FROM AUTHOR]

Soil application of treated sewage sludge is considered a beneficial management option for agriculture and environment. Sludge treated with clay minerals or biochar was evaluated as soil amendment, in comparison with limed or untreated sludge. Bentonite, vermiculite, biochar or lime was added to dewatered sewage sludge at 0 and 15% rates, in three replications and air-dried. Then, the treated and untreated sludge were added to two soils, one acid and one alkaline, at 0 (control), 1 and 3% rates, in three replications. The results showed that the pH of acid soil significantly increased compared to control upon addition of treated and untreated sludge at both rates, but remained acidic (<6.0) in all cases except for limed sludge. Upon addition of 3% treated or untreated sludge to both soils, organic carbon (OC) significantly increased compared to control. The same stands for soil available ammonium nitrogen (NH4-N), phosphorus (P), potassium (K), copper (Cu), zinc (Zn) and boron (B) for both soils and rates. Soil total heavy metals, which regulate sludge's agronomic use, were below the legislative limits. However, the 3% addition rate of all kinds of sludge, especially of untreated, to both soils increased the electrical conductivity of saturation extract (ECse >2 dS m−1) at unacceptable levels for sensitive crops and available P, B and Zn 2–3, 2–4 and 6–12 times above the initial, respectively. Consequently, sewage sludge treated with bentonite, vermiculite or biochar could be used as a soil amendment but at rates lower than 3% (≈120 Mg ha−1). [ABSTRACT FROM AUTHOR]

The Prosopis koelziana genus, a member of the Fabaceae family, is crucial to the ecology and economy of arid areas. It is commonly used to restore deserts, forests, and degraded soil with low fertility and high salt concentration. However, recent studies found that the seedlings of P. koelziana are highly susceptible to salinity stress despite having a high tolerance to it. To address this issue, an experiment was conducted to determine if plant growth-promoting rhizobacteria (PGPR) pretreatment and biochar application could enhance the seedlings' tolerance to saline conditions. The research showed that salinity stress decreased seedling growth but increased proline content, soluble sugar content, and antioxidant enzyme activity. Na+ ions increased in plants under salt stress, while K+ ions decreased. The results indicated that the pretreatment of plants with biochar and bacteria increased the fresh weight of seedlings by about 23%, 58%, and 50% in 200, 400, and 600 mM NaCl, respectively, compared with non-pretreated plants. Biochar and bacteria application also increased the proline content by about 62%, 46%, 32%, and 45% in 0, 200, 400, and 600 mM NaCl. This experiment showed that bacteria and biochar pretreatment of plants reduced oxidative stress and sodium uptake (20%, 28%, and 10% decrement of root Na uptake in 200, 400, and 600 mM NaCl). Therefore, these two bio stimulators should be used together for more significant effects on the salinity mitigation of P. Koelziana seedlings and the production of resistant seedlings that have a high ability to transfer to the field. [ABSTRACT FROM AUTHOR]

This study investigated the interactive effects of drought stress with biochar on plant growth, the physiological and biochemical attributes of soybean seedlings. A pot trial tested the effect of amending a loamy sandy soil with biochar at three doses: 0%, 3% and 6% in the alleviation of drought stress, imposed by adjusting soil moisture content at three levels (in terms of soil field capacity, FC): 100% FC, 75% FC and 50% FC. Water deficit negatively influenced the growth of soybean seedlings and chlorophyll content of leaves, particularly in non-amended plants whereas biochar amendment boosted the growth and chlorophyll content, particularly under drought stress. Drought stress elevated malondialdehyde (MDA), hydrogen peroxide (H2O2), proline, sucrose and abscisic acid (ABA) contents as well as the antioxidant enzyme activity [peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD)] of soybean leaves but reduced the contents of indole acetic acid (IAA) and gibberellic acid (GA); biochar amendment counteracted the impact of drought. The findings of the study indicate that biochar amendment can enhance soybean growth by modulating the plant physiology and biochemistry under drought stress. [ABSTRACT FROM AUTHOR]

This study focuses on applying phytoremediation as a low-effective and simple process to treat wastewater laden with 1,4 dioxane (DIOX). A floating macrophyte (Eichhornia crassipes) was cultivated under hydroponic conditions (relative humidity 50–67%, photoperiod cycle 18:6 h light/dark, and 28-33 °C) and subjected to different DIOX loads between 0.0 (control) and 11.5 mg/g fresh mass (FM). The aquatic plant achieved DIOX and chemical oxygen demand (COD) removal efficiencies of 76–96% and 67–94%, respectively, within 15 days. E. crassipes could tolerate elevated DIOX-associated stresses until a dose of 8.2 mg DIOX/g, which highly influenced the oxidative defense system. Malondialdehyde (MDA) content, hydrogen peroxide (H2O2), and total phenolic compounds (TPC) increased by 7.3, 8.4, and 4.5-times, respectively, in response to operating the phytoremediation unit at a DIOX load of 11.5 mg/g. The associated succulent value, proteins, chlorophyll-a, chlorophyll-b, and pigments dropped by 39.6%, 45.8%, 51.5%, 80.8%, and 55.5%, respectively. The suggested removal mechanism of DIOX by E. crassipes could be uptake followed by phytovolatilization, whereas direct photodegradation from sunlight contributed to about 19.36% of the total DIOX removal efficiencies. Recycling the exhausted E. crassipes for biochar production was a cost-efficient strategy, making the payback period of the phytoremediation project equals to 6.96 yr. Eichhornia crassipes could be used in phytoremediation of 1,4 dioxane (DIOX)-laden water at DIOX load< 8.2 mg/g FM. E. crassipes removed 77–97% DIOX via uptake and phytovolatilization. Recycling exhausted-plant to produce biochar was cost-efficient with 7 yr-payback period. [ABSTRACT FROM AUTHOR]

Present study focused on Phosphorus (P) enriched i.e., eutrophic biochar and its solubilization utilizing Pseudomonas aeruginosa (NCIM 8650). Previously established processes for lesser toxic and P rich biochar production (T-B-400, T-B-600 and T-B-800) using phosphogypsum pond wastewater soaked banana peduncles at three different pyrolysis temperatures (400, 600 and 800 °C) were utilized for the experiments. Bacteria inoculated in biochar loaded Pikovskaya (PVK) broth (modified: 0.2 g biochar/100 ml) was analyzed for 15 days about P solubilization along with control (modified broth without Pseudomonas aeruginosa). Gradual increase of P solubilization was observed with maximum values for T-B-400 and T-B-600 on 9th day in variation to 11th day of T-B-800. Different organic acids (Carbamic, Propanoic and Stearic hydrazide) ascertained through GCMS analysis along with significant pH change (7 to 3.41, 4.1 and 3.26 for T-B-400, T-B-600 and T-B-800 respectively) played major role toward P solubilization of modified PVK broth and highlighted significantly (p < 0.05) high release of P from T-B-400 (76%) than T-B-600 (65%) and T-B-800 (71%) over control. The FE-SEM, FTIR and XRD analysis (9th day: T-B-400/T-B-600; 11th day: T-B-800) of biochar residues in modified broth showed distinct morphological, structural and mineralogical changes in comparison to control. The findings highlights the potential of P solubilization by Pseudomonas aeruginosa from euthophic biochar, and hence provide opportunities for nutrients recovery from wastes. [ABSTRACT FROM AUTHOR]

As the demand for tea (Camellia sinensis) has grown across the world, the amount of biomass waste that has been produced during the harvesting process has also increased. Tea consumption was estimated at about 6.3 million tonnes in 2020 and is anticipated to reach 7.4 million tonnes by 2025. The generation of tea waste (TW) after use has also increased concurrently with rising tea consumption. TW includes clipped stems, wasted tea leaves, and buds. Many TW-derived products have proven benefits in various applications, including energy generation, energy storage, wastewater treatment, and pharmaceuticals. TW is widely used in environmental and energy-related applications. Energy recovery from low- and medium-calorific value fuels may be accomplished in a highly efficient manner using pyrolysis, anaerobic digestion, and gasification. TW-made biochar and activated carbon are also promising adsorbents for use in environmental applications. Another area where TW shows promise is in the synthesis of phytochemicals. This review offers an overview of the conversion procedures for TW into value-added products. Further, the improvements in their applications for energy generation, energy storage, removal of different contaminants, and extraction of phytochemicals have been reviewed. A comprehensive assessment of the sustainable use of TWs as environmentally acceptable renewable resources is compiled in this review. [ABSTRACT FROM AUTHOR]

Access to clean water is still limited in a number of regions, especially country sides, rural, and mountainous areas in Vietnam. Therefore, studies on clean water production by using sustainable and affordable processes for locals to access to clean water are of great importance. In this research, we produced laterite-based adsorbents by thermal treatment of natural laterite. The produced adsorbents were characterized in terms of morphology, crystallite, chemical composition, surface functional groups, surface charges, and surface area. The adsorption processes of Ni2+ and Cu2+ onto thermally treated laterite were studied. The treated laterite was also deployed to the removal of pollutants from real rain water. Finally, treated laterite was used in a combination system to purify rain water to produce drinking water for households in Hai Dong commune, Hai Hau district, Nam Dinh province. The results showed that the adsorption of Ni2+ and Cu2+ by thermally treated laterite reached equilibrium after 40 min and followed the Langmuir sorption isotherm, with the maximum uptake of 27.6 mg/g for Cu2+ and 17.4 mg/g for Ni2+. The second-order-kinetic model described the best the adsorption of Cu2+ and Ni2+ from aqueous solution, implying chemisorption was predominant mechanism. The treated laterite was suitable for heavy metal removal but less effective for the removal of anions from water. The combination of solar heating system with treated laterite, sand, and activated carbon allowed to safely produce drinking water from rain water, which presented the water quality respecting the Vietnam national standard for drinking water (QCVN 01:09/BYT). [ABSTRACT FROM AUTHOR]

Silkworm excrement (SE) and silkworm excrement-derived biochar (BC) were applied to atrazine-contaminated soil at the rates of 0% and 0.5% (w/w), respectively. The effect of organic amendments on sorption capacity, microbial biomass carbon, enzyme activity (dehydrogenase, urease and catalase) and bacterial composition in soil were evaluated. Atrazine significantly decreased the microbial activity and diversity in soil. Both SE and BC treatments increased the sorption of atrazine in soil. SE treatment significantly increased the microbial biomass carbon and enzyme activity in contaminated soil. Unlike the addition of silkworm excrement, BC treatment had no significant effect on dehydrogenase activity. Additionally, Illumina-MiSeq sequencing analyses showed that the two organic amendments increased the Shannon index of bacteria. SE treatment improved the relative abundance of Bacteroidetes. BC treatment improved the Proteobacteria in atrazine contaminated soil. [ABSTRACT FROM AUTHOR]

The chemically activated biochar was produced through the pyrolysis of rice husk. Thermal gravimetric and elemental analysis were conducted to characterize the raw rice husk. The activated biochar product underwent evaluation through SEM, BET and, FT-IR analysis. This cost-effective activated carbon was utilized as an adsorbent for the elimination of environmental pollutants. At a temperature of 25 °C, the activated biochar product exhibited an impressive maximum CO2 adsorption capacity of 152 mg/g. This exceptional performance can be attributed to its notable surface area and porosity, measuring at 2,298 m2/g and 0.812 cm3/g, respectively. This product was also utilized to remove methyl red (MR) dye from an aqueous solution. The optimal parameters for the removal of MR were determined as follows: a pH of 6.0, a temperature of 25 °C, an initial MR concentration of 50 mg/L, and an adsorbent dosage of 0.4 g/L. At a duration of 140 min, the system attained its maximum equilibrium adsorption capacity, reaching a value of 62.06 mg/g. Furthermore, the calculated maximum MR removal efficiency stood at an impressive 99.31%. The thermodynamic studies demonstrated that the MR removal process was spontaneous, exothermic, and increased randomness. Kinetic studies suggested that the pseudo-second-order model can fit well. Rice is the staple food for a significant portion of the world's population. Rice husk, which is released during the production and processing of rice, is one of the most important agricultural wastes worldwide. In this study, low cost activated carbon was produced by converting renewable resource such as rice husk biomass into a product with high added value. The resulting product, with its high surface area, can offer a more sustainable, cost-effective, and versatile alternative for a range of industrial, environmental, and medical applications. Carbon-based activated biochar was produced from rice husk, which is one of the lignocellulosic agricultural wastes, by performing pyrolysis and activation processes together. The structural properties of the biochar product were improved using KOH-activation technique. The usability of activated biochar in CO2 capture and removal of MR dye were investigated. The potential of the product obtained by the pyrolysis of rice husk wastes to be a raw material source for the production of chemical that can be used as an alternative to commercial activated carbon in the removal of environmental pollutants was evaluated. [ABSTRACT FROM AUTHOR]

Dyes are frequently used in industries such as textile, leather, paper and printing, to water sources causes harmful effects on the environment and human health. Therefore, it is crucial to effectively remove colored contaminants from water in order to protect the environment and public health, maintain biodiversity and preserve the esthetic aspects of water resources. In this study, wood chips obtained from Pinus brutia (PB) tree grown in many parts of the world were turned into biochar and then modified and used for the removal of malachite green, a cationic dye. For this purpose, biochar (PBB) was made by collecting PB wood and turning it into chips (PB). Later, PBB was modified to gain nano-magnetic properties. The structure of the obtained PBB and nM-PBB adsorbents was characterized by FT-IR. pH (2–9), temperature (25 °C–55 °C), time change (15 min-240 min), adsorbent amount change (0.05 g–0.45g) and MG concentration (25 mg/L–250 mg/L) were investigated in MG removal of PBB and nM-PBB. The process was found to be pseudo-second-order and spontaneous endothermic reaction. PBB and nM-PBB were found to be suitable for Langmuir isotherm in MG removal (qmax=13.004 mg/g for PBB, qmax=18.215 mg/g for nM-PBB). Various adsorbents are used to remove different substances from water. The use of pinus brutia tree, which is a biochar product, in the removal of malachite green dyes from aqueous solutions has not been found in the literature. The findings revealed that Pinus brutia could be used to extract malachite green, a cationic dyestuff. Pinus brutia is a widely distributed, easy-to-access, low-cost species with many uses. Our study, in which Pinus brutian is used as an adsorbent, will contribute to the literature in this respect, and its use in the removal of different anionic and cationic dyes will be discussed in the future. [ABSTRACT FROM AUTHOR]

Global mines of phosphates, which are a main source for the manufacturing of phosphorus (P)-fertilizers, are running out. To solve this problem, the recovery of P by struvite (NH4MgPO4·6H2O) precipitation as a slow-release P-fertilizer (SRPF) has been a growing interest of recent research. This study aimed to assess the effect of struvite/biochar composites as SRPFs on the growth yield, nutrient uptake responses of maize in two soils (with different amounts of calcium carbonate equivalent), and calculation of P use efficiency indices. The greenhouse experiment was designed with six P fertilizer treatments, i.e. triple super-phosphate (TSP), four types of struvite/biochar composites (S/G0, S/G25, S/G50, and S/G75), and control (no P fertilizer applied) with three replication. Results showed that struvite/biochar composite with high amounts of biochar i.e. S/G75 is the best treatment for improving biomass's of maize (63 and 39%), plant height (25 and 16%), SPAD value (31 and 26%) compared to control and TSP in soil-1 with the low amount of calcium carbonate equivalent, respectively. Applying S/G75, S/G50, S/G25, and S/G0 composites, and TSP concentration of P increased by 2, 1.85, 1.76, 1.73, and 1.34 times over control in soils, respectively. Using of composites significantly influenced P uptake, and recovery efficiency of P by plants, while the S/G75 composite was showed superior to other P-fertilizers. Overall, the struvite/biochar composites showed great potential as efficient SRPF for enhanced maize growth, and the presence of biochar in struvite composite with high amount (S/G75) increased the efficiency of fertilization in calcareous soil. [ABSTRACT FROM AUTHOR]

Two cost-effective packing materials were used for n-butyl acetate removal in lab-scale biofilters, namely waste spruce root wood chips and biochar obtained as a byproduct from a wood gasifier. Three biofilters packed with spruce root wood chips: without biochar (SRWC), a similar one with 10% of biochar (SRWC-B) and that with 10% of biochar impregnated with a nitrogen fertilizer (SRWC-IB) showed similar yet differing maximum elimination capacities of 206 ± 27, 275 ± 21 and 294 ± 20 g m−3 h−1, respectively, enabling high pollutant removal efficiency (>95% at moderate loads) and stable performance. The original biochar adsorption capacity was high (208 ± 6 mgtoluene g−1), but near 70% of it was lost after a 300-day biofilter operation. By contrast, the exposed impregnated biochar drastically increased its adsorption capacity in 300 days (149 ± 7 vs. 17 ± 5 mgtoluene g−1). Colony forming unit (CFU) and microscopic analyses revealed significant packing material colonization by microorganisms and grazing fauna in all three biofilters with an acceptable pressure drop, up to 1020 Pa m−1, at the end of biofilter operation. Despite a higher price (14 vs. 123 €m−3), the application of the best performing SRWC-IB packing can reduce the total investment costs by 9% due to biofilter volume reduction. [ABSTRACT FROM AUTHOR]

Bioelectrochemical systems (BESs) that combine electrochemistry with biological methods have gained attention in the remediation of polluted environments, including wastewater, sludge, sediments, and soils. The most attractive advantage of BESs is that the solid electrode is used as an inexhaustible electron acceptor or donor, and biocurrent directly converted from organics can afford the reaction energy of contaminant breakdown, crossing the internal energy barrier of endothermic degradation, which achieves a continuous biodegradation process without the simultaneous use of exogenetic chemicals and bioelectricity recovery. However, soil BESs are hindered by expensive electrode materials, difficult pollutant and electron transfer, low microbial competitive activity, and biocompatibility in contamination remediation. Fortunately, introducing biochar into soil BESs could reveal a high potential in addressing these BES inadequacies. The characteristics of biochar, e.g., conductivity, transferability, high specific surface area, high porosity, large functional groups, and biocompatibility, can improve the performance of soil BESs. In fact, biochar not only carries electrons but also transfers nutrients, pollutants, and even bacteria by facilitating transmission in the bioelectric field of BESs. Consequently, the abilities of biochar make for better functionality of BESs. This review collates information on the roles, application, and progress of biochar in soil BESs, and future prospects are given. It is beneficial for environmental researchers and engineers to extend BES application in environmental remediation and to assist the progress of carbon sequestration and emission reduction based on the inertia of biochar and the blocking of electron flow to form methane. A feature comparison between BES and conventional techniques was made. Biochar characteristics match the deficiencies of bioelectrochemical remediation. Behind roles of biochar in the contamination remediation were summarized. Application potential and direction of biochar in BES were emphasized. [ABSTRACT FROM AUTHOR]

Nitrogen compounds like ammonia and nitrite can antagonistically affect the environment and human health in many ways. The high rise in demand for food has led to excessive use of fertilisers eventually causing increased losses of reactive nitrogen to the environment. Ammonia and nitrite can be introduced into the environment through agricultural runoff, wastewater discharges and other anthropogenic activities. The over-accumulation of different forms of nitrogen (ammonia and nitrite) in the ecosystem can be noxious to many life forms including humans and aquatic life. High concentrations of both nitrogenous forms led to nutrient pollution, decreased oxygen levels in the water bodies ultimately resulting in dead zones and eutrophication. In humans elevated nitrite levels can cause methemoglobinemia. Remediation of these contaminants has become a crucial environmental concern in the recent past. To prevent nutrient pollution and reduce their harmful effects several mechanisms including physical and chemical treatments have been introduced and it is also required to fix the remaining of the pollutants by these biological and chemical agents. Current review deals with the mechanism, organisms, enzymes involved in the transformation and their fixation by various mechanisms (fixation using chemicals, using modified biochar, solidification, phytostabilisation, nano material-related compounds, etc.) [ABSTRACT FROM AUTHOR]

The occurrence of pharmaceuticals in water bodies is of growing concern as they pose potential toxicity to wildlife and humans. Since the removal of these compounds via conventional wastewater treatment plants is typically not efficient, advanced processes such as oxidation and adsorption are considered alternatives. In this review study, ozonation combined with adsorption filtration systems is evaluated for the removal of pharmaceuticals and their transformation products from municipal wastewater effluents. Ozonation has a large capacity for the removal of pharmaceuticals from municipal wastewater; however, potential toxic transformation products can be created which require a post-treatment step to mitigate the adverse effects in recipient waters. Various sorption methods have been investigated as post-treatment, with activated carbon being addressed as the most common one. Other sorption technologies such as ion exchange, biochar, constructed wetlands, and biofiltration were also evaluated in this review article. Biochar was considered to have great potential as a promising alternative adsorbent which is known as a more sustainable material. The combination of ozonation with the adsorption method enables the limitations of each single treatment to be reduced and allows the treatment train to become more efficient. [ABSTRACT FROM AUTHOR]

As heavy metals are very noxious for health also known as one of the most poisonous classes of water contaminants. Typically, metal pollutants are non-biodegradable and impervious towards oxidants, heat, and light. Thus, it is a precisely demanding task to eliminate them from water to reduce water pollution. In current studies, the process of adsorption was employed for deracination of Zn and Fe with modified surface of natural material as an adsorbent. TiO 2 NPs were synthesized by using leaf extract of Putranjiva roxburghii and its nanocomposites were made with the fish scale biomass. Prime conditions for proficient removal of zinc were recognized at pH = 4 and for iron at pH = 6 having an initial concentration 100 mg/L, adsorbent dose rate of 0.1 g and contact time 120 minutes. Thermodynamic study revealed that process was spontaneous, and exothermic, resulted in increase in entropy with rise in temperature. Adsorption process has been certified with different isotherm and kinetic models, where the experimental data was brought into being good agreement with pseudo second order ( R 2 = 0.986) and Freundlich isotherm ( R 2 = 0.993) as compared with other models. For characterization of synthesized adsorbents scanning electron microscopy, UV–visible spectroscopy and Fourier-transform Infrared spectroscopy, X-ray diffraction, and energy-dispersive X-ray were used. Average particle size of the adsorbent used ranged from 1 to 5 µm. [ABSTRACT FROM AUTHOR]

Living organisms are at great risk from the highly toxic metal cadmium (II). It is not allowed to be in industrial effluent or drinking water that is dumped into cadmium-containing water bodies. It has been classified as a carcinogen by the IARC and the US EPA. Thus, it is essential to discover a practical and economical technique for removing cadmium from an aqueous solution. In the present work, a novel and easy-to-prepare component of graphene oxide/orange peel/chitosan composite (GO-OP-CS) was prepared and examined using various analytical techniques as a hybrid product with improved physicochemical properties and metal ion Cd(II) adsorption capabilities. The results showed that Cd (II) ion adsorption occurred initially fairly fast and that a pH of 6 was optimal for both adsorption and removal of Cd (II) ions. The thermodynamic analysis revealed that the adsorption of Cd(II) is spontaneous and exothermic. The experimental results showed that the functional groups present on the adsorbent surfaces (such as hydroxyl, carboxyl, epoxy, amine, and so on) led to the improvement of the Cd(II) metal's ability to absorb. This novel composite exhibited a high adsorption capacity (qmax) of 537.63 mg/g. The results of the toxic Cd(II) sorption using the synthesized composite showed that its adsorption kinetics and sorption isotherm confirmed the pseudo-second-order and Langmuir models, respectively. The proposed method is also reliable for Cd(II) sorption for preconcentration and remediation before Cd testing from genuine samples, such as wastewater, digested tobacco, and e-battery samples. [ABSTRACT FROM AUTHOR]