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In order to meet the demand for mercury removal in the oxy-combustion atmosphere, a new mercury adsorbent was prepared by using rice husk char as raw material and co-modification of acid and halogen. The experimental results indicate that the specific surface area of the combined modified char is smaller than those modified by HNO3 and NH4Br alone, but it has better mercury removal performance. X-ray photoelectron spectroscopy (XPS) analysis shows that the co-modification can effectively promote the formation of C-O* and C-Br. The high activity of Br will induce the Hg0 adsorption, while C-O* will convert the easily decomposed HgBr2 into more stable HgO, which may be the reason why the combined modified char maintains high mercury removal efficiency. When the reaction temperature reaches 150°C, the mercury removal efficiency of RHC (Br+N) is almost 100%. Both above and below the optimum reaction temperature will affect the activity of chemical functional groups and inhibit mercury removal. According to the density functional theory (DFT) results, the addition of O and Br atoms can stably combine with the carbonaceous surface to form covalent compounds (C=O, C-Br), both of which can induce the charge transfer of surrounding C atoms, which makes the C atoms have stronger electronegativity and easier to chemically adsorb Hg0. [ABSTRACT FROM AUTHOR]

In this work, the kiwifruit branch, a kind of agricultural waste, was reused as a raw material to prepare biochar adsorbent for the removal of Pb(II) from aqueous solution. Then pristine biochar (BC) was further modified to form acid–alkali modified biochar (OBC) and chitosan modified biochar (CBC) to enhance adsorption efficiency toward Pb(II). Characterization experiments with SEM, FTIR and XRD suggested that surface functional groups and crystallization degree of OBC and CBC were all increased in comparison with BC. Batch sorption experiments showed that, compared with BC, the adsorption capacity of Pb(II) by OBC and CBC were improved by 19.57 and 8.37%, respectively. The pseudo-second-order model and the Freundlich model were better for describing the kinetics and isotherms for Pb(II) adsorption onto OBC and CBC, respectively. Accordingly, chemisorption on the heterogeneous adsorption surface played a dominant role in Pb(II) removal. [ABSTRACT FROM AUTHOR]

The particle size of biochar is a vital parameter adjusting the soil CO2 production, whereas the effect of biochar addition with different particle sizeon soil CO2 production is still largely unclear. Furthermore, combined effects of biochar addition and temperature on CO2 production are still unknown. To address this gap, a series of incubation experiments were conducted to examine the single and interactive effects of biochar addition with three particle sizes (1–0.5 mm, 0.5–0.1 mm, and <0.1 mm) and temperature on CO2 production in a temperate forest, China. The soil samples were collected from a poplar (Populus nigra) forest in the sandy area of the ancient Yellow River in western Shandong Province, China. Cumulative CO2 production of fine-grained biochar addition (<0.1 mm) was 88.13–92.67% of that of coarse-grained biochar (1–0.5 mm). The addition of fine-grained biochar decreased CO2 production by reducing soil nitrogen availability (i.e., nitrate and ammonium) and increasing soil pH compared to the coarse-grained biochar. Biochar addition promoted the temperature sensitivity (Q10) of CO2 production by increasing the relative abundance of recalcitrant carbon fractions. Interactive effects of biochar addition and increasing temperature was synergistic due to the raising Q10 value of CO2 production. Our results highlight the importance of particle size of biochar on CO2 production, less particle size of biochar, the less CO2 production. We suggest that the simultaneous effect of biochar addition and temperature on CO2 production may be underestimated basing on their single effects. Our results suggest that <0.1 mm is a threshold value of biochar particle size that is helpful to soil carbon sequestration. [ABSTRACT FROM AUTHOR]

The adsorption of chlorinated aromatic compounds (CACs) on pristine biochar was often limited. Surface modification can greatly improve the adsorption capacity of biochar. In this work, by pyrolysis activation of rubber-seed shell wastes, nitrogen auto-doped biochar (RSS-NBC) was synthesized and used for purifying CACs-containing wastewater. Systematic characterization results showed that after proper treatment, the as-prepared RSS-NBC had high specific surface area, abundant surface oxygen- and nitrogen-containing functional groups, and nano-scale pore structure. Batch adsorption experiments were conducted with using three typical CACs probing pollutants, i.e. 1,2-dichlorobenzene (1,2-DCB), 2,4-dichlorophenol (2,4-DCP) and 2,4-dichlorobenzoic acid (2,4-DCBA). The adsorption experiments results showed that the maximum adsorption amounts of 1, 2-DCB, 2,4-DCP, and 2,4-DCBA could reach 2284, 1921, and 1142 mg/g at 298.15 K. Moreover, 90% of the equilibrium adsorption amount can be reached within 0.5 h. The adsorption kinetic results showed that the adsorption processes of the three CACs followed the pseudo-second-order rate model and were dominated by chemisorption. Also, the adsorption isotherms of 1, 2-DCB and 2, 4-DCP belonged to the Freundlich model and were valid for multilayer adsorption, while the adsorption of 2,4-DCBA followed Langmuir model and single-layer adsorption. The thermodynamics data indicated that the spontaneous adsorption process of 1, 2-DCB and 2, 4-DCP was endothermic while that of 2,4-DCBA was exothermic. After 5 cycles of adsorption-regeneration, the removal efficiency of RSS-NBC particles still remained more than 80% for the three typical CACs, indicating that it could be reused as an effective and retrievable adsorbent in the treatment of CACs-containing effluents. [ABSTRACT FROM AUTHOR]

Owing to the scarcity of raw materials and environmental concerns, concrete industry demands a suitable environment friendly material, which can substitute it partially while maintaining its required characteristics. Biochar from agricultural biomass is sustainable product for construction uses without any adverse effect on environment. It acts as effective binder/filler for enhancing performance of construction material, including mechanical/rheological properties, water absorbing capacity, insulating nature, chemical stability and environmental safety. This review presents significant aspects of biochar as additive to cementitious materials. It highlights its role in improving the performance of concrete for various applications in construction industry. It also suggests that a suitable permutation and combination is necessary for optimizing its properties and effectiveness. It can be derived from the studies carried out in this domain that on average, 1–3% addition of biochar derived from various lignocellulosic biomass can serve as optimum concentration for enhancing performance in building constituents. The review also highlights the economic viability and environmental benefits of biochar addition in cementitious composition. This article will provide deep insight and understanding about appropriateness of biochar as important constituent in construction industry. It will be encouraging for the researchers to strengthen their observations and outcomes, helping in categorizing biochar as 'green concrete' in upcoming time. Biochar is an efficient binder for cement to be used for costruction/buildings. Advantages offered by it to buildings include mainly improved rheology, chemical stability, water retention ability and protection from cracks. It helps in maintaining indoor temperature of builidngs. It is an economically feasible additive for construction purpose and reduces environmental pollution by sequestring CO2. Being able to be produced from agricultural wastes, it acts as a measure to waste management also. [ABSTRACT FROM AUTHOR]

Biochar has been widely deemed as a soil conditioner to modify the physicochemical and biological properties of soil. In this research, the influence of different biochar application conditions on the effect of heavy metal Cu in soil was detected. In batch experiments, the combinations could definitely enhance the adsorption abilities, and under the combination ratio of 4 wt % biochar, 3 wt % wheat straw, and 5 wt % cow manure compost in the soil, the adsorption rate would be more than 97% in 60 mins. The adsorption kinetics showed the adsorption processes were multiphase diffusion processes and the conversion of activation energy in soil surface was obvious, while the isotherms analysis suggested the adsorption of Cu by the soil under various amendments was mainly monolayer adsorption as well as some other complex reactions. However, in the eluviation experiments, more and more Cu was lost in the leaching solutions when wheat straw and compost were added into the soil as well as biochar. pH values changes indicated that the connections among Cu and solids may be mostly related to the precipitation reaction in the eluviation experiments. FTIR analysis implied that the addition of wheat straw and compost in the biochar could indeed enhance the reaction between heavy metal Cu and soil, however, the reactions were rather complicated, and under the eluviation condition, there was not enough time to form the stable bonds, so more Cu was dissolved into the leaching water. [ABSTRACT FROM AUTHOR]

Since cement manufacturing contributes significantly to CO2 pollution worldwide, biochar provides a novel opportunity to integrate it into the construction materials and eventually substitute a portion of cement usage. Consequently, this investigation aims to explore the response surface methodology (RSM) to predict compressive strength and identify optimal values for each parameter that affects the preparation of bio-mortars cement with biochar produced from Washingtonia filifera waste pyrolysis (WFWB). The status of the 7-days and 28-days samples compressive strength, porosity, as well as thermal conductivity of the bio-mortars produced by partially substituting cement at different rates (0%, 1%, 2%, 3%, 4%, and 5%) with pyrolyzed WFWB biochar at varying temperatures (300°C, 400°C, and 500°C) were examined experimentally and statistically. Moreover, the parameter effect on the experimental data performance was identified through analysis of variance (ANOVA). Results indicated an increase in the compressive strength at 28 days of almost 12%, 3%, and 2% at an optimum biochar content of 1% for the WFWB500, WFWB400 and WFWB300 samples respectively. In addition, the findings confer the feasibility of producing bio-mortars with a compressive strength of 63.81 MPa at 28 days with a 1% replacement rate of WFWB500 and coefficient of thermal conductivity of 0.52 W/m.K. [ABSTRACT FROM AUTHOR]

In the current study, new prediction models were suggested to predict the compressive strength, porosity, and thermal conductivity of bio-mortar samples by replacing cement by weight with pyrolysis of Washingtonia filifera waste biochar (WFWB). Bio-mortars containing different biochar contents were prepared with the addition of 1%, 2%, 3%, 4%, and 5% pyrolyzed biochar at different temperatures 300°C, 400°C, and 500°C. The mortar samples produced were evaluated for compressive strength at 7 and 28 days. Relation between compressive strength porosity and thermal conductivity values (dependent values), and biochar replacement ratios and pyrolysis temperatures (independent values) was predicted by artificial neural network (ANN) machine learning techniques based on the Levenberg Marquardt algorithm. The results revealed compressive strength increase at 28 days of nearly 12%, 3%, and 2% at 1% optimal biochar replacement content for WFWB500, WFWB400, and WFWB300 specimens, respectively. Moreover, these results provide confidence in the manufacturability of bio-mortars with a compressive strength of 63.81 MPa at 28 days using only 1% substitution of WFWB500 and a thermal conductivity coefficient of 0.52 W/m.K. The importance measure of the variables shows that the most influential variables are the percentage of biochar. The statistical and experimental results also revealed satisfactory agreement. [ABSTRACT FROM AUTHOR]

Biochar (BC) is a soil fertility enhancer, regarded as a potential carbon sequester and nutrient leaching preventer. Various studies have shown better phosphorus (P) availability with adding biochar. However, limited reporting is available on absorption–desorption behaviour of added P and dose optimisation of biochar. Rice straw biochar (RSB) and acacia biochar (ACB), prepared by slow pyrolysis at optimised temperature and pyrolysis time, were incubated at different rates (0, 5, and 10 g kg−1) in loamy sand and clay loam soils to study P sorption compared to the unamended control. The data was observed to be best fitted into Langmuir adsorption isotherm for P adsorption. The effects on maximum P adsorption, bonding energy, and adsorption rate constants were lower in loamy sand compared to clay loam soil. The values of maximum P desorption (Dm) and desorption rate constant (Kd) decreased with the application of biochar. A linear regression equation optimised the amount of P addition for soil amendments. For the soil with inherent P content, rice biochar was the best option (5 g kg−1), while for soils lacking in P, ACB is optimised at 5 g kg−1 with external P input of 1 mg P kg−1 of test soil. This data can be recommended to the farmers as a best practice for the P addition, along with managing farm wastes as biochars to enhance nutrient availability. [ABSTRACT FROM AUTHOR]

Intensive potato production may reduce the soil organic matter content (SOM), which may impact several soil functions and increase the incidence of potato diseases. We examined if cover crop and addition of organic materials may counteract these effects. Organic materials were one application of biochar mixed with liquid digestate (BLD); solid digestate (SD); or farmyard manure (FYM); with or without winter rye as cover crop, in a field with regular potato growing. Organic amendment increased SOM, especially for FYM and BLD, while cover crop did not affect SOM. Yet, cover crop increased tuber yields in the second year, and reduced the severity of potato diseases by 10% in post-harvest potatoes in both years. In the second year, the number of marketable potatoes after storage increased by 37% with cover crop. Organic amendments did not affect potato yield or quality, but the proportion of marketable potatoes tended to be higher in the amended soil. By lab incubation, BLD showed the largest potential for SOM storage, up to 32 years, followed by FYM and SD. Cover crops and organic amendments is recommended in potato production, especially for early potatoes where there is sufficient time after harvest to establish a good cover crop. [ABSTRACT FROM AUTHOR]

Hyperthermophilic composting (HTC) is regarded as an effective method for processing sewage sludge. The aim of the study was to investigate effects of using biochar as an amendment on the preservation of nitrogen and passivation of heavy metal during the HTC process of sewage sludge. Results showed that HTC improved the fermentation efficiency and the compost maturity by increases in the temperature and germination index (GI) value, and decreases in the moisture and C/N ratio compared to conventional thermophilic composting. HTC process and the biochar addition resulted in a decrease of the nitrogen loss compared with the control pile during composting by promoting transforming ammonium into nitrite nitrogen. Adding biochar to composting inhibited the transformation of Cu, Zn and Pb into more mobile speciation compared to the control pile although their contents increased during composting, which lead to reduction in availability of heavy metals. Thus, HTC process with the addition of biochar is viable for the reduction of the nitrogen losses and mobility of heavy metal in compost. Implications: The treatment of sewage sludge is imminent due to its threat to general health and ecosystems. This work represents the effects of adding biochar on the preservation of nitrogen and passivation of heavy metal during hyperthermophilic composting of sewage sludge. Our results indicate that the additions of biochar and hyperthermophilic composting engendered the several of positive effects on the preservation of nitrogen and passivation of heavy metal. Thus, HTC process with the addition of biochar is viable for the reduction of the nitrogen losses and mobility of heavy metal in compost. [ABSTRACT FROM AUTHOR]

Biochar with maize straw and nitrogen application may provide better crop growth conditions with respect to soil C/N, organic carbon fractions, and available nutrients than biochar applied alone. An incubation experiment was conducted in which biochar of maize straw pyrolyzed at 500 °C was applied with maize straw and nitrogen over 150 days. The treatments consisted of three rates of biochar applied at 0 (BC), 30 (BC3), and 60 g kg−1 (BC6), two rates (0 and 2 g kg−1) of maize straw (S), and two rates (0 and 0.1 g kg−1) of nitrogen (N) fertilizer (ammonium bicarbonate). The control (CK) was blank soil unfertilized with BC, N, and S. Sampling was done at 30, 60, and 150 days, respectively. The treatments of BC3 and BC6 significantly increased the content of soil total organic carbon by 840–1735%, oxidizable organic carbon (KMnO4–C) by 151–250%, dissolved organic carbon (DOC) by 221–976%, microbial biomass carbon (MBC) by 113–274%, available phosphorus (AP) by 969–4820%, and available potassium (AK) by 715–2413% in the sandy soil. Biochar reduced the ammonium nitrogen and nitrate nitrogen (NH4+–N and NO3−–N) contents, while it increased the carbon-nitrogen ratio (C/N) to 42. Nitrogen addition increased the contents of NH4+–N by 395% and NO3−–N by 661% compared with the CK after 30 days. Straw only affected the contents of DOC and MBC. The S + N treatment increased the content of MBC and available nitrogen compared with the CK. The contents of KMnO4–C, DOC, MBC, NH4+–N, NO3−–N, AP, and AK in the BC + N and BC + S treatments were higher than those in the BC treatments. The BC + N and BC + S treatments could decrease the high C/N that resulted from biochar alone. The contents of KMnO4–C, DOC, MBC, NH4+–N, NO3−–N, AP, and AK in the BC + S + N treatment were higher than those in the BC + S and BC + N treatments. Therefore, we recommend using BC6 + S + N to improve the organic carbon fractions and available nutrients in sandy soil. If straw is lacking in the field, BC6 + N is a suitable alternative. [ABSTRACT FROM AUTHOR]

Nano-black carbon is a high carbonate modification created by the absence of oxygen or limited supply of a wide variety of feedstocks. Nano-black carbon typically has a high level of area, capacity for cation exchange, reactive functional groups, and highly reactive carbon. Due to these characteristics, Nano-black carbon has been widely associated with multiple abiotic stress reductions to enhance crop growth, development, production, soil fertility, and soil quality. Nano-black carbon application in agriculture possesses the potential to tolerate abiotic stress. Organic biomass thermal degradation in limited oxygen forms a solid coproduce known as Nano-black carbon (biochar). There is a growing interest worldwide in Nano-black carbon application in agriculture and farm produce. The main reasons for Nano-black carbon application in agriculture and cultural practices might be due to (a) a source of renewable biofuels and carbon sequestration (ii) Many biomass waste materials can be treated by pyrolysis and thus converted into fuel sources. (iii) The long-term sequence of carbon dioxide that can be introduced into the atmosphere by adding Nano-black carbon to the soil. Nano-black carbon amendment into the soil improving soil fertility and crop productivity. To meet global food security, crop production faces several real challenges, including declining trend of soil fertility and organic matter, climatic extremes, unmanaged rainfall patterns, and pathogens. Abiotic pressures such as heat and cold, drought, salinity, water storage, and heavy metal pressure are emerging as important factors in reducing crop production globally. [ABSTRACT FROM AUTHOR]

Biochar application to soil contaminated with potentially toxic elements has been paid particular attention as an effective amendment. This study was carried out to investigate the effect of wheat straw biochar on adsorption and accumulation of Cd2+ in paddy soil and rice. Biochar was applied once in four treatments of 10, 20, 30, and 40 t ha−1 and a control check (CK) was set up in Changsha County, China. The results showed that under biochar addition the Cd2+ adsorption process was dominated by inhomogeneous multi-surface adsorption. Biochar significantly increased adsorption capacity for Cd2+ and the maximum of sorption at A40 was 2713 mg kg−1. The available Cd concentration was also decreased by transforming S1 (decreased by 25%, acid soluble Cd) to S2 (increased by 40%, oxidizable Cd) and S3 (increased by 24%, reducible Cd). Also, biochar application resulted in significant reduction in Cd concentration in rice by inhibiting migration from soil to rice. The study demonstrated that the biochar of 40 t ha−1 reduced rice grain Cd concentration to 0.18 mg kg−1, which was within the Chinese safety limit. Therefore, the dose of 40 t ha−1 would be proper for reducing risk due to Cd contamination in agricultural production. [ABSTRACT FROM AUTHOR]

The responses of soil P availability and cotton growth to biochar addition under different P supply levels are not well documented. Thus, a pot experiment was conducted to investigate the effects of biochar addition on soil nutrient status, microbial characteristics related to P cycling and cotton growth with or without adequate P supply. Biochar was added to soil grown cotton at three rates of 0, 3 and 30 t ha−1 under two P fertilizer levels of 0 and 150 kg P2O5 ha−1, respectively. Results showed that biochar addition had significantly positive effects on soil P availability, phosphate solubilizing bacteria number, phosphatase activities (except acid phosphatase activity), cotton nutrients uptake and seedcotton yield, regardless of P fertilization level. The magnitude of soil available P content increase after biochar addition with P fertilizer was greater than without P fertilizer. And 3 t ha−1 biochar was better than 30 t ha−1 biochar for converting soil P into available P. Under a given P fertilizer level, biochar addition had fertilizer-like diminishing effect on seedcotton yield. Conclusively, the co-application of P fertilizer and the appropriate amount of biochar could be beneficial for soil P availability in cotton production. [ABSTRACT FROM AUTHOR]

The technological evolution of electronic equipment in the field of computers and household appliances, along with shorter life of most items, is creating a great concern for managing this waste stream. The main aim of the present investigation was to convert waste keyboard keys into high-quality pyrolysis oil using a microwave catalytic pyrolysis process. Iron (Fe), Nickel (Ni), were doped in different ratios on Biochar (BC) by wet impregnation method, and it was used as a green catalyst for clean fuel production. Initially, a non-catalytic pyrolysis process was conducted and found a maximum pyrolysis oil yield of 49.6 wt.%. Further, microwave catalytic pyrolysis was conducted with variable amount of metal loading and found that highest oil yield of 61.33 wt.% was achieved using 15%Fe-5%Ni/BC catalyst due to the presence of a higher quantity of iron. The produced pyrolysis oil at this condition consists of 45.07% single-ring compounds and reduced the undesirable polycyclic aromatic hydrocarbons (PAHs) in the pyrolysis oil. This work provides a pathway for preparing green catalysts and safe disposal of electrical and electronic plastic waste with better resource recovery. [ABSTRACT FROM AUTHOR]

In this study, biochar production from electrical pyrolysis and microwave-assisted pyrolysis of corn straw was detailed. The yields and surface topographies of biochars produced from electrical pyrolysis and microwave pyrolysis at different pyrolysis temperatures (700, 750, 800, 850, and 900°C), biomass loads (9, 12, 15, 18, and 21 g), and residence times (60, 90, 120, 150, and 180 min) were elaborated in the study. The results showed that the biochar yields were in the range of 21.14–38.7 wt. %, and they gradually decreased when there were decreases in the biomass loads or increases in the pyrolysis temperatures or residence times. Increases in pyrolysis temperatures and residence times or decreases in biomass loads increased the porosity and pore densities and reduced the pore sizes. As compared with electrical pyrolysis, microwave pyrolysis increased the bochar yields, i.e. by 21.24% at 800°C, 180 min, and 15 g (21.4 wt. % vs. 25.3 wt. %). Biochar produced from electrical pyrolysis had heterogeneous pore size distribution, whereas biochar obtained from microwave pyrolysis had identical sizes and round shapes on its surface. This study quantitatively revealed the relationships between biochar yields and experimental conditions (pyrolysis temperature, biomass load, residence time). [ABSTRACT FROM AUTHOR]

Biochar is gaining popularity as a reinforcing filler in composite manufacturing. Applied to rubber composites, biochar shows potential as a greener filler, but is not yet a drop-in substitute for fillers like carbon black. Through optimizing the pyrolysis process, biochar may be engineered to have ideal filler characteristics. This review identifies the key properties of highly reinforcing filler materials as particle size, structure, and surface activity. It subsequently focuses on the techniques to optimize biochar for applications as a rubber-reinforcing filler. Finally, the mechanical performance of biochar as a filler in rubber is reviewed and compared with industry-adopted reinforcing fillers. [ABSTRACT FROM AUTHOR]

The fluoride with high-concentration in industrial wastewater will cause great harm to the environment and calcium-modified biochar is an effective adsorbent for the removal of fluoride. Biochar composites were prepared from mature and dried dead leaves and eggshell to remove fluoride from the aqueous solution. The effects of raw material ratio, pH, contact time, adsorbent dosage, temperature, initial concentration of fluoride, and the coexisting ions on the removal efficiency of fluoride were explored. The biochar composites before and after fluoride removal were characterized by the SEM, FTIR, XRD, and XPS, which showed CaF2 precipitation was formed during the adsorption. The kinetics and isotherm study showed that chemical adsorption was the primary step for the fluoride adsorption of the biochar composites. The removal efficiency of fluoride can reach 98.53% when the amount of adsorbent was 1.6 g/L and the fluoride concentration was 500 mg/L. The BET-specific surface area of platanus acerifoli leaves biochar was 410.14 m2/g, which was suitable for the adsorption carrier. The adsorption capacity of the biochar composite materials was as high as 308 mg/g. The platanus acerifoli leaves-eggshell biochar composite with large pore size and high removal efficiency may be used as an efficient and low-cost adsorbent for treating high-concentration fluoride-containing wastewater. [ABSTRACT FROM AUTHOR]

Heavy metals from dental wastewater raised serious environmental health concerns. To address this, an environmental waste-based biochar by eggshell and fly ash was synthesized and characterized. The adsorption characteristics of lead and chromium by biochar were explored and a novel alternative stepwise adsorption process was proposed to improve the removal efficiency. Results indicated that the specific surface area was determined to be 537.6 m2/g. The maximum adsorption capacity for lead and chromium were 149.3 mg/g and 119.0 mg/g, respectively. A theoretical calculation model was developed to predict the concentration of the effluent, followed by experimental validation. The findings indicated that the concentrations of lead and chromium in the effluent remained stable, while the average removal efficiency of lead and chromium increased by 5.56% and 7.02%, respectively, compared to the conventional adsorption method. The calculated values aligned well with the experimental results, demonstrating the success of this innovative adsorption process. [ABSTRACT FROM AUTHOR]

A novel strategy for reclamation and reuse of phosphate from aqueous solution was developed using Mg-enriched biochar prepared from anaerobically digested sludge (ADBC). The ADBC pyrolyzed at 600°C (ADBC-600) exhibited the maximum phosphate removal capacity of 23.2 mg/g, which was much higher than that of raw sludge biocha (10.1 mg/g). Adsorption kinetic and isotherm experiments showed that the adsorption of phosphate on ADBC-600 could be well described by the pseudo-second-order model and Langmuir model, indicating that the adsorption was mainly dominated by chemisorption process. The postsorption characterization results suggested that Mg-induced precipitation was likely the main P adsorption mechanism by ADBC. Moreover, the spent biochar was re-utilized as an efficient phosphate fertilizer for improving wheat seed germination and growth. Provided a sustainable and eco-friendly strategy for sludge treatment and phosphate recovery in wastewater treatment plants (WWTPs) and potential agronomic application. [ABSTRACT FROM AUTHOR]

Meadow soils are one of the important agricultural soil types, biochar is a good soil amendment, whereas the studies on the effects of biochar additions on carbon and nitrogen contents, as well as bacterial communities of meadow soils, were seldom carried out. The effects of one nitrogen addition rates (no addition, 0.2% addition) and two biochar addition patterns (no addition, 1% addition, 3% addition) on the carbon and nitrogen contents, as well as bacterial communities of meadow soils, were investigated by conducting a one-year indoor incubation experiment. Biochar addition increased the relative abundance of Proteobacteria, Chloroflexi and Bacteroidota. The combination of biochar and nitrogen source significantly increased the total organic carbon, ammonium nitrogen, nitrate nitrogen and total nitrogen content of the meadow soil. Therefore, the addition of moderate amounts of biochar to meadow soils can contribute to sustainable ecological agriculture as a form of soil improvement. [ABSTRACT FROM AUTHOR]

Discrimination of the catalytic ability of heterogeneous biochar components is often challenging. Herein, a sewage sludge-derived biochar (SDBC) was prepared to activate peroxydisulfate (PDS) for tetracycline (TC) degradation. To verify the contribution of different carbon components, SDBC was bleached with NaClO2 and CH3COOH to remove noncondensed aromatic carbon (NAC) contained in biochar, which was confirmed by 13C Nuclear Magnetic Resonance. The batch degradation experiment revealed that NAC removal decreased TC degradation by SDBC from 84.1% to 33.2% within 2 h, indicating its significant role in PDS activation. The quenching and electron paramagnetic resonance experiments suggested a very minor contribution of radical pathway in TC degradation. Instead, the electron transfer pathway predominated TC degradation mechanism as inferred by electrochemical tests. This is likely ascribed to formation of a biochar-PDS metastable complex, facilitating electron transfer from tetracycline-like compounds. An X-ray photoelectron spectroscopy confirmed that the percent of graphitic N in SDBC decreased after the degradation reaction, which suggested graphitic N is an important active site in biochar. Besides, acid-washed SDBC did not change TC degradation behavior excluding significant contribution of minerals in SDBC to PDS activation. Thus, the roles of biochar components in catalyzing PDS were quantified for the first time, proving insight for selection and manipulation of biochar in catalyzing PDS in environmental application. [ABSTRACT FROM AUTHOR]

The annual cumin and perennial fennel are economically important medicinal crops of cold dry regions of Pakistan. We hypothesized that the cumin, which produces 2-3 times less biomass, will respond to lower rates of mixture of biochar with synthetic NPK fertilizer or manure, compared to fennel. The NPK, poultry manure and their mixture with wood-derived or cow manure-derived biochars were applied for three consecutive years. No positive relation between application rate of biochar-mixed fertilizers and yield of both crops was observed over three years of study, except that manure-derived biochar-NPK mixture had a positive relation (R² = 0.99, P = 0.01) with the yield of fennel only during the third year. Significant positive influences of biochar-based fertilizers compared to control were observed for cumin and fennel of third year cropping. The co-amendment of NPK (0.14 kg ha-1) with manurederived biochar (6.6 t ha-1) consistently increased the yield of cumin during the first two years of cropping, as opposed to NPK fertilizer. Cumin had a greater seed:stover biomass ratio when it received the co-amendment of wood-derived biochar with NPK or poultry manure. Our findings indicate that there is some potential for biochar-fertilizer amendments to improve the growth of these high-value medicinal crops. [ABSTRACT FROM AUTHOR]

Biosolid-borne heavy metals are the main concern in soils. Therefore, the effects of biosolid biochar application in soils were evaluated in our study through a rice-wheat rotation in fields. The results showed that after the application of biosolid biochar, soil organic matter (SOM), soil pH, and soil total heavy metal concentrations (Cd, Zn, Cu, and Pb) were significantly increased. But the CaCl2 extracted metals concentrations were decreased, and no significant differences in metal concentrations of soil deeper layers (20-100 cm) were found among different treatments. The Cd, Zn, Cu, and Pb concentrations in rice decreased by 13.2%, 37.0%, 9.92%, and 63.0%, respectively, and the concentrations of Cd, Zn, Cu, and Pb in wheat decreased by 20.85%, 19.7%, 48.6%, and 23.6%, respectively, compared with the control treatment. Biosolid biochar can decrease metal availability in soils and increase crop production in fields, thus is suggested to use in fields. [ABSTRACT FROM AUTHOR]

In this interview, Dominic Woolf, a senior research associate at Cornell University, describes a potential method for removing excess carbon dioxide from the atmosphere: converting biomass into a long-lived, charcoal-like material that would be added to soil. Called biochar, this material could not only sequester some of the carbon fixed by plants during photosynthesis – and prevent it from returning to the atmosphere – but could also improve soil fertility. Woolf explains some of the tradeoffs and uncertainties associated with biochar and other methods of soil carbon sequestration, and the challenges to scaling up these approaches for global climate change mitigation. [ABSTRACT FROM AUTHOR]

Composition of the biomixture is crucial for the success of a bio-purification system. The rice straw-compost biomixture (BM) was mixed with the rice husk ash (RHA, 5 and 10%), sugarcane bagasse ash (SBA, 5 and 10%) and wheat straw biochar (WBC, 1, 5 and 10%) and adsorption of atrazine and fipronil was studied. Fipronil was more sorbed than atrazine in all biomixtures. Both ashes and biochar increased sorption of atrazine, but the effect varied with the level of the amendment. The adsorption coefficient (Kd) values for atrazine in biomixtures were 6.82 (BM), 8.64 (RHA5%), 8.80 (RHA10%), 7.26 (SBA5%), 7.66 (SBA10%), 8.26 (WBC1%), 26.79 (WBC5%) and 46.68 (WBC10%). Ashes did not have much effect of fipronil sorption [48.92 (BM), 49.68 (RHA5%), 54.04 (RHA10%), 45.35 (SBA5%), 46.11 (SBA10%)]; however, WBC1% biomixture showed 100% fipronil sorption. The adsorption data were subjected to the Freundlich, the Langmuir and the Temkin isotherms. Among the three isotherms used for adsorption data modelling, the Freundlich isotherm best explained the pesticide sorption. This study suggested that ashes/biochar mixed rice straw-compost biomixtures can be exploited in bio-purification systems. [ABSTRACT FROM AUTHOR]

Pharmaceutical and personal care products have received increasing more attention worldwide. Diclofenac was found to be one of the most detected pharmaceuticals in environmental matrixes and has acute toxicity against micro-living organisms. The present study aimed to investigate the application of magnetic gelatin modified peanut shell biochar (PBG) as an environmentally friendly adsorbent for the removal of sodium diclofenac (DCF) in the aqueous phase. Through SEM, EDS, BET, XRD, XPS, and FTIR characterisation techniques, the surface morphology, element components, specific surface area as surface functional groups of PBG were different from the pristine biochar. Batch adsorption experiment showed that PBG performed very high DCF adsorption capacity (qmax = 348.9 mg/g at pH = 6.5, T = 298 K). The adsorption capacity was significantly affected by pH solution with a decrease trend when pH >6. The experimental results could be satisfactorily fitted by Pseudo-second order kinetic model, and Temkin isotherm model. Thermodynamic study indicated that the adsorption process was non-spontaneous and endothermic. Some external agents such as humic acid and common ions exhibited a negative effect on the removal of DCF in the co-solute system. The adsorption capacity of the PBG adsorbent remained at 71.5% even after five cycles of regeneration, which demonstrated the stability and reusability for further removal of DCF. Besides, the proposed adsorption mechanism might contain electrostatic interactions, hydrogen bonds interactions, and π-π interactions. Considering the simple fabrication approach and the excellent adsorption performance, the PBG adsorbent can be evaluated as a potential material for environmental remediation applications. [ABSTRACT FROM AUTHOR]

Using rice straw as a carbon source, photoluminescent carbon nanodots (CNDs) were quickly prepared by pyrolysis under insufficient air flow and ultrasonic methods without the addition of other chemical reagents. This method is simple and environmentally friendly. The prepared CNDs have quasispherical nanoparticles with the average diameter of 5.8 nm observed from TEM image, and have good fluorescence performance with the quantum yield of 5.1%. The CNDs possess a clear correlation between photoluminescence wavelength and intensity and excitation wavelength, as well as good water solubility and salt resistance. In addition, the luminescent CNDs can not only be effectively taken up by HeLa cells and HUVECs but also exhibit low cytotoxicity and good biocompatibility from CCK8 test and laser confocal imaging observations, respectively, making them promising complement to future cellular imaging assay applications. Moreover, the prepared CNDs can be used as ion sensors to selectively and sensitively detect Fe3+ ions in the concentration range of 0–1000 μM with a detection limit of 300 nM. Our proposed strategy for preparing carbon nanodots explores a new way to obtain fluorescent carbon materials and avoid environmental pollution caused by burning straw. [ABSTRACT FROM AUTHOR]

The aim of the current research is to eliminate the Cu(II) ions from aqueous solution using biochar, namely sulphuric acid-modified Annona reticulata seeds (SMARS). The removal process followed the Freundlich and pseudo-first-order models. At optimum conditions, Langmuir adsorption capacity of the SMARS for Cu(II) ions was calculated as 561.1 mg/g. The results of this work indicate that the adsorption was feasible, spontaneous and exothermic, which was controlled by film diffusion. An adsorber has been designed based on Freundlich model. Desorption results indicate that 0.2 N of the hydrochloric acid solution provides the maximum elimination of heavy metals from the Cu(II) ions loaded adsorbent. The column influencing parameters like Cu(II) ions concentration, bed height and flow rate have been experimented. The best operating condition for removal of Cu(II) ions by SMARS in column mode of operation has been recorded as flow rate = 5 mL/min, bed height = 8 cm, adsorbent amount = 16 g, solution pH = 6.0 and at the temperature = 30°C. The column experimental data have been characterised by applying Bed Depth Service Time and Thomas models. The results indicate that the SMARS has exceptional adsorption behaviour in the elimination of heavy metals from the aqueous solution. [ABSTRACT FROM AUTHOR]

This study suggests a new application of biochar particles into the cementitious material as a sustainable solution to prevent depletion of virgin aggregates and increase of carbon footprint. Biochar from olive stone wastes (OSB) is suggested for production of lightweight mortar to replace 25%, 45% and 60% of coarse sand (%V) with biochar. Some experiments are planned to assess the viability of inclusion of coarser particles of biochar in the cement mortar and its effect on the density, water absorption, UPV, modulus of elasticity, thermal conductivity and compressive strength. The experimental results are discussed and the possible correlation between the properties is established. The results show that the replacement of coarse sand with OSB up to 60% does not compromise the performance of cement mortar. They imply the promising effect of biochar addition on reduction of dead load and improvement of thermal and sound insulation of the lightweight mortar. [ABSTRACT FROM AUTHOR]

To meet the global demand for energy, biochar can be a substitute and a green source of energy for fossil fuels and their derivatives. Biochar has its own supremacy to meet the requirements of the energy sector and replace coking coal for metallurgical purposes, and the mitigation of CO2 emissions from the Iron and Steel industry. This study includes the characterisation and comparative study of the reduction of iron ore pellets and iron ore fines using saw dust char (SDC) as one of the biomass wastes. The results show that the reduction of iron ore fines with comparable ratios with SDC gives the maximum degree of reduction than that of iron ore pellets. Thus, SDC can play an important role in the premium quality of coking coal reserves. [ABSTRACT FROM AUTHOR]

Salinity is among the most significant threats hindering global food security. The impact of Trichoderma, biochar, and combination on Spinach plants under salt stress conditions was investigated. Our results confirmed that salt stress (75, 150 mM) negatively affected morphological and physiological parameters of Spinach plants such as shoot (26.4%, 45.9%), and root length (16.1%, 51.2%), fresh and dry weights of root and shoot, membrane stability index (9.8%, 18.5%), relative water content(4.5%, 16.8%), chlorophyll content, mineral contents, endogenous phytohormones (auxin, gibberellins, abscisic acid, jasmonic acid, and salicylic acid) and total soluble protein content. However, electrolyte leakage, lipid peroxidation, reactive oxygen species production (such as hydrogen peroxide and hydroxyl radical), sodium, soluble sugars, proline contents, and antioxidant enzymes activities (peroxidase, catalase, and superoxide dismutase) significantly increased as a response to salt stress. The use of Trichoderma, biochar, and combination led to significant increases in all the above parameters; nevertheless, these treatments led to significant decreases in EL%, MDA, ROS, and sodium content in the stressed plants. The results proved the combination of Trichoderma and biochar is the most effective in alleviating the damaging impacts of salt on Spinach plants by increasing the up-regulation of antioxidants and decreasing membrane leakage and ROS. [ABSTRACT FROM AUTHOR]

Lead (Pb) is a biologically non-essential element in the soil that brutally affects plants and other living organisms in soil; hence, its removal has become a worldwide concern. In this work, a multifunctional nanoscale zerovalent-iron assisted biochar (nFe°/BC) was used to minimize the Pb bioavailability in soil with aim of alleviating the Pb-induced toxicity in sunflower. Results revealed that nFe°/BC treatment had significantly improved plant growth (58%), chlorophyll contents (66%), intracellular permeability (60%), and ratio factor (93%), while decreasing the Pb uptake (78%) in plants. The Pb-immobilization and transformation mechanisms were proposed, suggesting that the presence of organic functional groups over the nFe°/BC surface might induce the complex formation with Pb by the ions exchange process in soil solution. The XPS analysis confirmed that surface-active components (Fe+, O2−, O*, C═O) were the key factor for high Pb-immobilization within soil matrix. In addition, 87% of stable Pb species, including PbCO3, PbO, Pb (OH)2, and Pb-O-Fe were found in the soil surface. Current findings have exposed the diverse functions of nFe°/BC on plant health and established a phenomenon that nFe°/BC application could improve the plant agronomic attributes by regulating the homeostasis of antioxidants and Pb uptake. [ABSTRACT FROM AUTHOR]

As the first version of synthetic hydrogel, poly(2-hydroxyethyl methacrylate) hydrogels have found broad applications. However, their poor mechanical performances have been long-standing hurdles for practical deployments. Herein, we report on strengthening the poly(2-hydroxyethyl methacrylate) hydrogels with biochar nanoparticles and hydrophobic aggregations, which are induced by solvent exchange and reinforced by freeze-thaw. Both the vast anchoring points on the multifunctional surfaces of the biochar nanoparticles and the aggregates formed between poly(2-hydroxyethyl methacrylate) chains engender strong and dissipative physical crosslinks. The resulting hydrogels exhibit marked mechanical properties, encompassing high stretchability ~7, high fracture toughness ~1360 J m−2, high elastic modulus ~180 kPa, low friction coefficient ~0.2, self-recovery, and non-swellability. Furthermore, we demonstrate the versatility of the proposed strategy by using water/ionic liquid binary solvent as the solvent system, Laponite as the nano-reinforcement, and dry-anneal as the hydrophobic aggregation enhancer to synthesize mechanically robust hydrogels. Poly(2-hydroxyethyl methacrylate) hydrogels of superior mechanical properties are expected to enable previously inaccessible applications in biomedicine and engineering. [ABSTRACT FROM AUTHOR]

As a form of pollution source control and a low-impact development measure, bioretention is a convenient, economical, and effective method for the removal of heavy metals from stormwater runoff, which can adapt to the randomness and uncontrollability of non-point source pollution. However, few studies have assessed the performance of bioretention in the simultaneous removal of multiple heavy metals and the impact of heavy metal migration on the bioretention life cycle. In this study, the removal rates of various heavy metals: copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd), were enhanced using a biochar modified bioretention cell, as compared to the traditional sandy soil bioretention process. Following treatment with the biochar modified bioretention cell, the average concentrations of Cu, Zn, Pb, and Cd were 55%, 61%, 19.66%, and 36.43% lower than the traditional sandy soil bioretention effluent, respectively. These results show that biochar significantly improves the removal of heavy metals by the bioretention process, especially Cu and Zn. This study also evaluated the effect of biochar on the inhibition of heavy metal migration in the filler material, by sampling and analysing the filler and retained water at different filler depths, then repeating the filler leaching experiment after simulated rainfall. The content of heavy metals at a filler depth of 45 cm in the traditional sandy soil bioretention system, was significantly higher than in the biochar modified bioretention system, showing that biochar plays an important role in the inhibition of heavy metal migration. [ABSTRACT FROM AUTHOR]

Straw had huge annual production, burning it in the air will cause serious air pollution. Burning straw into biochar and returning biochar to the field will not only make effective use of straw resources, but also improve soil quality. Different preparation conditions and addition levels of biochar were used to investigate the ammonia nitrogen, nitrate nitrogen, and total nitrogen contents in the soil leaching solution. The results showed that biochar had a favorable adsorption effect on ammonia nitrogen, the cumulative leaching of ammonia nitrogen reduced by 80.16% in the 2% and 400°C biochar addition treatment compared to that without adding biochar. The final leaching solution electrical conductivity value of the experimental group of biochar prepared at 500°C with 1% addition was the highest at 445 μS/cm. Sequencing of microorganisms revealed that biochar altered the structure and abundance of the soil microbial community, particularly increased the relative abundance of nitrifying bacteria. [ABSTRACT FROM AUTHOR]

The physicochemical properties and heavy metals adsorption capacities of biochars derived from cattle manure (CM) and cherry wood (CW) were systematically investigated and compared. The results showed that the yields, pH and the ash content of cattle manure biochars (CMB) were higher due to high levels of mineral constituents in CM. CMB6 and CWB6 showed higher aromaticity and polarity, whereas CMB4 and CWB4 carried higher oxygen-containing functional groups. CMB6 exhibited the maximum adsorption capacities for Pb2+ (40.8 mg·g−1), Cd2+ (24.2 mg·g−1), and Ni2+ (25.1 mg·g−1), with relatively higher adsorption capacities for Pb2+. The adsorption isotherms fitted Langmuir model, indicating that the heavy metal adsorptionoccurred via a combination of physical and chemical adsorption mechanisms. The quantitative analysis showed that the interaction with minerals was the dominant mechanism, especially accounting for about 70% in CMB6. This study provides important information for comprehensive recycling utilization of biomass for sustainable development. [ABSTRACT FROM AUTHOR]

The application of magnetic biochar (MBC) has attracted significant attention due to its recyclability and adsorption capacity for Hg from aqueous solutions. However, its applicability is still inadequate, relying on poor selectivity. Some chemical substances could improve the sorption capacity of MBC. This review offers an advanced technological route to modify-MBC composition with significant adsorption volume toward Hg. Non-polluting humic acid-sodium salts (Ha-Na) were proposed to optimize Fe3O4-modified biochar (FBC), while the pyrolyzed substrate for the initial biochar (BC) production originated from any agricultural biomass material. The non-polluting Ha-Na can improve the FBC-specific surface area, the number and structure of pores, moderate the pH and adsorb Hg(II) from aqueous solutions. Further, the interaction of three simple projected equation mechanisms is proposed for BC, FBC, and Ha-Na. BC modified with the support of Fe3O4 and optimized by Ha-Na can be applied to improve Hg(II) adsorption, while insights and future investigations are suggested. [ABSTRACT FROM AUTHOR]

Although biochar has been investigated extensively to stabilize soil heavy metals, there were limited investigation on the stabilization of soil heavy metals by using biochar under the natural ageing processes of alternate-cooling/heating. In this study, wheat-straw-biochar-treated soil samples contaminated with Pb(II) ions/PbO were subjected to 12 h-freeze/12 h-thaw cycles simulating the natural alternate-cooling/heating process. After the freeze-thaw process, the mobile fractions of leadreduced by 30.0% (500 mg·kg−1 Pb(II) spiked soil) and 19.5% (PbO spiked soil) due to biochar's addition evaluating via 0.01 M HCl batch extraction. Compared with the control, the mobile Pb in treated groups decreased in column leaching. Exchangeable lead decreased by 6.4% – 80.9% due to biochar addition. Freeze-thaw ageing had no significant effects on lower lead leaching and lower exchangeable lead resulted from biochar's addition. Therefore, wheat-straw-biochar treatment is helpful for stabilization of both dissolved Pb and particulate Pb in soil under the alternate-cooling/heating ageing process. [ABSTRACT FROM AUTHOR]

Biochar is a porous carbonaceous material containing abundant redox functional groups and inorganic minerals, making it a potential electrode material. Nine electrodes were prepared with biochar produced from three different feedstocks at three pyrolysis temperatures, and their oxygen reduction reaction (ORR) activity and electrochemical impedance spectroscopy (EIS) were investigated. The results showed that all biochar electrodes had certain electrocatalytic activity as their current density ranged from 0.26 to 2.17 mA cm−2, half-wave potential at 0.24–0.41 V, electron transfer number at 2.1–3.9, Rct at 9.2–61.2 Ω, and Cdl at 1.1 × 10−6 – 2.2 × 10−4 F. For most biochar electrodes, the current density and half-wave potential increased as the pyrolysis temperature increased from 500°C to 700°C, which was closely related to the increase in aromatization degree (H/C) of biochar. Dairy manure biochar showed much lower current density and half-wave potential than sewage sludge biochar and wood chip biochar, probably due to its relatively smaller surface area. This study indicated that biochars could be converted to carbon electrodes, and both feedstock and pyrolysis temperature could influence the ORR activity of biochar electrodes. [ABSTRACT FROM AUTHOR]

Studies on the effects of biochar and phosphorus fertilizer on soil productivity and yield of cowpea (Vigna unguiculata) are scarce. Therefore, experiments were conducted in 2019 and 2020 to evaluate the effects of sole and combined application of biochar and phosphorus fertilizer on soil properties, nodulation, growth, and yield of cowpea. The treatments consisted of: biochar at 10 t ha−1 (B10), biochar at 20 t ha−1 (B20), triple super phosphate fertilizer at 60 kg P ha−1 (P), biochar at 10 t ha−1 + P (B10 + P), biochar at 20 t ha−1 + P (B20 + P), and the control. The experimental design was a randomized complete block design with three replications. Results revealed that biochar and P fertilizer applied alone or in combination improved soil properties, growth, nodulation, and yield of cowpea compared with the control. Results also showed that combined applications of biochar with P fertilizer improved these properties most, especially at a higher rate of biochar (B20 + P). B20 + P increased grain yield of cowpea by 155%, 69%, 53%, 69%, and 21% respectively compared with the control, B10, B20, P fertilizer, and B10 + P. This was adduced to raise soil pH and reduced soil bulk density as a result of biochar application which induces P solubility and availability, increased N fixation, and enhanced root growth, increased nodulation leading to improved growth and yield of cowpea. Application of biochar with P fertilizer could therefore be used as a strategy for improving P availability in low pH soils of cowpea growing areas of the tropics. [ABSTRACT FROM AUTHOR]

Sepiolite and biochar effectively immobilize Cd and atrazine in vegetable soils. This study further investigated the effects of sepiolite and biochar on the photosynthetic and antioxidative defence systems of pakchoi under Cd and atrazine stress. The results showed that after adding sepiolite and biochar to contaminated soil, the chlorophyll content was restored and the photosynthetic rate increased, whereas the soluble sugar content of pakchoi decreased. In the antioxidant system of the plants, the activities of peroxidase, ascorbate peroxidase, and superoxide dismutase decreased, while the activity of catalase increased. The content of malondialdehyde, glutathione, and O2·− increased, but the content of H2O2 decreased. In general, remediation materials reduced the bioavailability of Cd and atrazine, reduced the stress on pakchoi, and restored and improved the rate of photosynthesis and function of antioxidants. [ABSTRACT FROM AUTHOR]

Vermicompost (CV) and nanomaterials have been identified as potential amendments to adsorb environmentally toxic heavy metals. This study analyzes multi-aspect properties of CV and its nanocomposite (CV-nCa) with nano calcium oxide (nCaO), which include pH, electrical conductivity (EC), cation exchange capacity (CEC), ash content and surface characteristics, aiming to compare their potential for removing aqueous Pb(II) and Cd(II). The results demonstrated that CV-nCa had a higher pH, EC, CEC, ash content, pore parameters and specific surface area than CV. Adsorption isotherm studies showed that CV-nCa had a higher adsorption capacities for Pb(II) and Cd(II), with the maximum adsorption capacities being 255.1 mg/g and 137.7 mg/g. The adsorption rates (ARs) by CV-nCa were both above 99.72% within the initial concentration of Pb(II) being 200–800 mg/L and Cd(II) being 100–200 mg/L. In addition, CV-nCa can effectively remove Pb(II) and Cd(II) within a wider pH range (3–6) and a lower mass concentration (MC) of 4 g/L. Kinetic studies showed that the Pb(II) and Cd(II) adsorption by CV-nCa were both best fitted with the pseudo-second-order model. FTIR analysis demonstrated that the interaction of CV and CV-nCa with Pb(II) and Cd(II) mainly depended on thearomatic/aliphatic acids, some primary/secondary alcohols and some silicate and carbonates. XRD analysis showed that the addition of nCaO into CV mainly increased CaCO3 content and affected the adsorption characteristics. Thus, combining nCaO with vermicompost may broaden heavy metal remediation and vermicompost utilization in the environment. [ABSTRACT FROM AUTHOR]

The main objective of this work was to study the adsorption characteristics of Cd by adding corn stover biochar and saline-alkali soil after freezing and thawing, and the saline-alkali land in Lesheng Town, Da'an City, Jilin Province was selected as the model/representative area. The artificially simulated freezing and thawing environments was conducted in the experiments. After the soil is incubated, adsorption experiments were carried out. FTIR spectra analysis indicated that biochar amendment increased the aromatic contents of the soil. Moreover, the results showed that regardless of biochar amendment, the freezing-thawing could increase hydroxyl, carboxyl, and aromatic hydrocarbon contents. In contrast, freezing-thawing reduced the soil pH, cation exchange capacity, conductivity, and exchangeable sodium (regardless of biochar amendment). In all cases, Cd adsorption isotherms and kinetic curves were best fit by the Langmuir equation and quasi-second-order kinetic equation, respectively, and the thermodynamic parameters of Cd adsorption (ΔG < 0, ΔH > 0, and ΔS > 0) suggested that the process was consistently spontaneous, endothermic, and disordered. A significant increase in soil Cd adsorption capacity was observed in the with increasing pH. [ABSTRACT FROM AUTHOR]

Alginate-based composites have been studied for adsorption technology as adsorbents due to their biocompatible, non-toxic, and cost-effective properties. In this work, groundnut husk biochar (GHB), calcium alginate (CA), and groundnut husk biochar/calcium alginate novel composites (%10) (CA-GHB1) and (% 20) (CA-GHB2) are synthesized and characterized using BET, SEM, EDX, FTIR, TGA. Adsorption performance is compared among GHB, CA, CA-GHB1, and CA-GHB2 composites to remove Cu(II), Zn (II) from aqueous solutions. Factors affecting adsorption, as well as kinetics, equilibrium, and thermal properties of adsorption, were studied using conventional equations. Adsorption isotherm models were used for two and three-parameter isotherm models to understand the interaction between the adsorbent and the adsorbate. 24.3, 44.6, 45.6, and 40.73 mg g−1 for removal of Cu(II) on GHB, CA, CA-GHB1, and CA-GHB2 and 32.16, 25.07, 36.09, and 40.55 mg g−1 for removal of Zn(II) on GHB, CA, CA-GHB1, and CA-GHB2 found maximum adsorption capacity (Qm) calculated from Langmuir isotherm. According to D-R isotherm data, the adsorption process is classified as physical adsorption. Thermodynamically, the adsorption process is non-spontaneous and endothermic. [ABSTRACT FROM AUTHOR]

Zero-valent iron [Fe(0)]-biochar composites, namely, Fe(0)-included biochar and biochar-coated Fe(0), were synthesized and their catalytic performance in the activation of persulfate for phenol degradation in water was evaluated. In the presence of the Fe(0)-biochar composites, Fe(0)-included biochar-persulfate and biochar-coated Fe(0)-persulfate systems showed higher phenol removal than a Fe(0)-persulfate system by 11.6% and 20.7%, respectively. The difference in phenol removal by persulfate between Fe(0)-included biochar and biochar-coated Fe(0) was because of the high surface area of and oxygen-containing surface functional groups on the biochar coating of the latter. Differences in the properties of these two composites may also be responsible for the different optimal persulfate concentrations and doses of the composites required in the Fe(0)-included biochar-persulfate and biochar-coated Fe(0)-persulfate systems. Under optimal conditions, phenol degradation in the aqueous phase exceeded 95% for both composites. Electron paramagnetic resonance analysis revealed that hydroxyl and sulfate radicals were formed in the Fe(0)-biochar composite-persulfate systems. The results of this study suggest that Fe(0)-biochar composites can enhance phenol degradation by persulfate in water. [ABSTRACT FROM AUTHOR]

The application of bio-inoculant and biochar can be an effective strategy for stimulating crop growth, while improving soil fertility in an environmentally friendly manner. A greenhouse experiment was conducted to study the effects of biochar and TUAT-1 bio-inoculant under two N fertilization modes (basal and split) on the yield of forage rice and nutrient distribution in the soil rhizosphere. Positive effects of the biochar and bio-inoculant, either alone or in combination, on growth, photosynthesis rate, and yield components were depended on the mode of N application. There was no change in either microbial biomass carbon (MBC) or microbial biomass nitrogen (MBN) with the treatments of biochar and bio-inoculant with split N fertilization, whereas both these treatments, either alone or in combination, resulted in higher MBC and MBN with basal N fertilization. The NO3−–N concentration of surface floodwater under biochar treatment was significantly reduced immediately after soil N fertilization, whereas biochar addition did not reduce the NH4+–N concentration of surface floodwater at each of our monitoring points. The findings indicate that biochar and the mode of N fertilization have the potential to improve forage rice productivity and soil nutrient availability, while minimizing the potential of nitrate (NO3−–N) leaching. [ABSTRACT FROM AUTHOR]

Magnetic biochar (Fe3O4-BCPP) was prepared by using iron oxide nanoparticles, and biochar which is obtained from pomegranate peel. The Fe3O4-BCPP were characterized by Brunauer-Emmett-Teller analysis, X-ray diffraction analysis, scanning electron microscopy, and vibrating sample magnetometer. The adsorption properties of Fe3O4-BCPP for sulfadiazine in water were investigated. The Fe3O4-BCPP had good adsorption properties and separated well from aqueous solution by a permanent magnet due to superparamagnetic property and magnetic saturation value. Therefore, Fe3O4-BCPP has potential application for the removal of sulfadiazine from water samples. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the properties of hybrid biochar produced from date palm (D) and pistachio (P) residues and their co-pyrolysis at mixing ratios of 60:40 (by weight). Biochars were produced at 500 °C through pyrolysis in a tube furnace and subsequently characterized. Results indicated that pistachio biochar (PBC) had a high carbon content (81.02 wt%) and a low oxygen content (17.57 wt%). Conversely, the date palm biochar (DBC) had a high ash content (28.11 wt%) and a low carbon content (40.08 wt%). Blending D and P at the specified ratios improved the biochar samples' gross and elemental contents. Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence spectroscopy (XRF), thermogravimetric analysis (TGA), and field emission scanning electron microscopy (FESEM) were utilized to determine the morphology and structure of the produced biochar. [ABSTRACT FROM AUTHOR]