Effect of Modified Biochar with Organic Fertiliser on the Growth and Development of Chinese Rose

In order to reduce the waste of resources and environmental pollution caused by excessive application of chemical fertilizers, improve the utilization rate of fertilizers, and promote the large-scale and high-quality development of the Chinese rose industry. In this experiment, corn stover biochar, phosphoric acid modified biochar and organic fertilizer were used as test materials, and the effects of mixed application of modified biochar and organic fertilizer on the growth and development of Chinese rose as well as soil physicochemical properties were investigated by using the method of pot planting test. The results showed that modified biochar with organic fertilizer had the most significant effect on the enhancement of soil pH, organic matter content and soil carbon-to-nitrogen ratio. After 120 d of planting, modified biochar with organic fertilizer had the most significant effect on the enhancement of plant height and crown width of Chinese rose;both organic fertilizer and modified biochar with organic fertilizer significantly increased the chlorophyll content of Chinese rose. The number of flowers and the number of branches were the highest in the modified biochar with organic fertilizer treatment. In conclusion, the application of modified biochar with organic fertilizer can better improve the soil pH, and increase the soil organic matter content and carbon-to-nitrogen ratio to change the biological traits of Chinese rose. The results of this study provide a theoretical basis for the reduction of chemical fertilizers and the resource utilization of agricultural wastes and guarantee the sustainable development of the cut flower industry.

Enhanced removal of sulfonamide antibiotics from water by phosphogypsum modified biochar composite

Antibiotic pollution has become a global eco-environmental issue.To reduce sulfonamide antibiotics in water and improve resource utilization of solid wastes,phosphogypsummodified biochar composite(PMBC)was prepared via facile one-step from distillers grains,wood chips,and phosphogypsum.The physicochemical properties of PMBCwere characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FTIR),Zeta potential,X-ray diffraction(XRD),etc.The influencing factors,adsorption behaviors,and mechanisms of sulfadiazine(SD)and sulfamethazine(SMT)onto PMBC were studied by batch and fixed bed column adsorption experiments.The results showed that the removal rates of SD and SMT increased with the increase of phosphogypsum proportion,while decreased with the increase of solution pH.The maximum adsorption capacities of modified distillers grain and wood chips biochars for SD were 2.98 and 4.18 mg/g,and for SMT were 4.40 and 8.91mg/g,respectively,which was 9.0–22.3 times that of pristine biochar.Fixed bed column results demonstrated that PMBC had good adsorption capacities for SD and SMT.When the solution flow rate was 2.0 mL/min and the dosage of PMBC was 5.0 g,the removal rates of SD and SMT by modified wood chips biochar were both higher than 50%in 4 hr.The main mechanisms of SD and SMT removal by PMBC are hydrogen bonding,π-πdonor-acceptor,electrostatic interaction,and hydrophobic interaction.This study provides an effective method for the removal of antibiotics in water and the resource utilization of phosphogypsum.

Geo-environmental and mechanical behaviors of As(V)and Cd (Ⅱ)co-contaminated soils stabilized by goethite nanoparticles modified biochar

Goethite nanoparticles modified biochar(FBC)could address the weak effectiveness of conventional biochar commonly to process heavy metal(loids)(HMs)co-contamination with different charges.However,few studies have focused on the change of soil mechanical properties after stabilization.In this study,FBC was synthesized to stabilize simultaneously arsenic(As(V))(anions)and cadmium(Cd (Ⅱ))(cations)in co-contaminated soils.Batch adsorption,leaching toxicity,geotechnical properties and micro-spectroscopic tests were comprehensively adopted to investigate the stabilization mechanism.The results showed that FBC could immobilize As(V)mainly through redox and surface precipitation while stabilizing Cd (Ⅱ)by electrostatic attraction and complexation,causing soil agglomeration and ultimately making rougher surface and stronger sliding friction of contaminated soils.The maximum adsorption capacity of FBC for As(V)and Cd (Ⅱ)was 31.96 mg g^(−1) and 129.31 mg g^(−1),respectively.Besides,the dosages of FBC required in contaminated soils generally were approximately 57%higher than those in contaminated water.FBC promoted the formation of small macroaggregates(0.25-2 mm)and the shear strengths of co-contaminated soils by 21.40%and 8.34%,respectively.Furthermore,the soil reutilization level was significantly improved from 0.14-0.46 to 0.76-0.83 after FBC stabilization according to TOPSIS method(i.e.,technique for order preference by similarity to an ideal solution).These findings confirm the potential of FBC in immobilizing As(V)and Cd (Ⅱ)of co-contaminated soils and provide a useful reference for green stabilization and remediation of HMs co-contaminated sites.

Insights into influence of aging processes on zero-valent iron modified biochar in copper(II) immobilization: from batch solution to pilot-scale investigation

The zero-valent iron modified biochar materials are widely employed for heavy metals immobilization.However,these materials would be inevitably aged by natural forces after entering into the environment,while there are seldom studies reported the aging effects of zero-valent iron modified biochar.In this work,the hydrogen peroxide and hydrochloric acid solution were applied to simulate aging conditions of zero-valent iron modified biochar.According to the results,the adsorption capacity of copper(II)contaminants on biochar,zero-valent iron modified biochar-1,and zero-valent iron modified biochar-2 after aging was decreased by 15.36%,22.65%and 23.26%,respectively.The surface interactions were assigned with chemisorption occurred on multi-molecular layers,which were proved by the pseudo-second-order and Langmuir models.After aging,the decreasing of capacity could be mainly attributed to the inhibition of ion-exchange and zero-valent iron oxidation.Moreover,the plant growth and soil leaching experiments also proved the effects of aging treatment,the zero-valent iron modified biochar reduced the inhibition of copper(II)bioavailability and increased the mobility of copper(II)after aging.All these results bridged the gaps between bio-adsorbents customization and their environmental behaviors during practical agro-industrial application.

Fabrication of bimetallic Ag/Fe immobilized on modified biochar for removal of carbon tetrachloride

As an effective conventional absorbent, biochar exhibited limited adsorption ability toward small hydrophobic molecules. To enhance the adsorption capacity, a novel adsorbent was prepared by immobilizing nanoscale zero-valent iron onto modified biochar（MB） and then the elemental silver was attached to the surface of iron（Ag/Fe/MB）. It＇s noted that spherical Ag/Fe nanoparticles with diameter of 51 nm were highly dispersed on the surface of MB. As the typical hydrophobic contaminant, carbon tetrachloride was selected for examining the removal efficiency of the adsorbent. The removal efficiencies of carbon tetrachloride by original biochar（OB）, Ag/Fe, Ag/Fe/OB and Ag/Fe/MB were fully investigated. It＇s found that Ag/Fe/MB showed higher carbon tetrachloride removal efficiency, which is about 5.5 times higher than that of the OB sample due to utilizing the merits of high adsorption and reduction. Thermodynamic parameters revealed that the removal of carbon tetrachloride by Ag/Fe/MB was a spontaneous and exothermic process, which was affected by solution p H, initial carbon tetrachloride concentration and temperature. The novel Ag/Fe/MB composites provided a promising material for carbon tetrachloride removal from effluent.

Study on dynamic sorption characteristics of modified biochars for ammonium in biogas slurry

The objective of this study was to investigate the relationship between ammonium(NH^(+)_(4)-N)dynamic sorption capacity and physicochemical properties of modified biochars.Biochars,producing from three species of agricultural wastes of cornstalk(A),corncob(B)and sawdust(C)at 550°C,600°C and 650°C,were modified by four methods of NaOH plus microwave(NaM),KOH(K),FeCl 3(Fe)and HNO 3(H).The static and dynamic adsorption experiments were conducted to investigate sorption characteristics of modified biochars on NH^(+)_(4)-N in slurry of piggery manure anaerobic digestate.Four modified biochars with better NH^(+)_(4)-N adsorption rates were selected through static kinetics adsorption tests,which showed that chemical reactions might have occurred during the NH^(+)_(4)-N sorption process and the maximum NH^(+)_(4)-N removal rates of B-550-Fe,A-550-NaM,A-550-K and C-600-NaM were 66.64%,57.50%,52.39%and 45.20%,respectively.The dynamic adsorption column experiment was conducted in a three-stage adsorption column packed with the selected three modified biochars.NH^(+)_(4)-N dynamic adsorption depended on the slurry inflow flow rate,the type of biochar and the depth of packed biochar.The optimal adsorption process was elected by the method of orthogonal experiment.The data showed that using deeper packed biochar and applying lower flow rates could be a better strategy to increase NH^(+)_(4)-N adsorption.The maximum NH^(+)_(4)-N removal rate in the slurry could reach 85.60%in the three-stage adsorption process.It concluded that NH^(+)_(4)-N adsorption in three-stage adsorption process could be an effective method to recover nitrogen from piggery manure anaerobic digestate.

Nanobiochar for the remediation of contaminated soil and water:challenges and opportunities

Although research on biochar has received increasing attention for environmental and agricultural applications,the significance of nanobiochar for environmental pollutant remediation is poorly understood.In contrast to bulk biochar,nanobiochar has superior physicochemical properties such as high catalytic activity,unique nanostructure,large specific surface area and high mobility in the soil environment.These unique characteristics make nanobiochar an ideal candidate for pollution remediation.Thus far,the research on nanobiochar is still in its infancy and most of the previous studies have only been conducted for exploring its properties and environmental functions.The lack of in-depth summary of nanobiochar’s research direction makes it a challenge for scientists and researchers globally.Hence in this review,we established some key fabrication methods for nanobiochar with a focus on its performance for the removal of pollutants from the environment.We also provided up-to-date information on nanobiochar’s role in environmental remediation and insights into different mechanisms involved in the pollutant removal.Although,nanobiochar application is increasing,the associated drawbacks to the soil ecosystem have not received enough research attention.Therefore,further research is warranted to evaluate the potential environmental risks of nanobiochar before large scale application.

A theoretical study of the effect and mechanism of FeN_(3)-doped biochar for greenhouse gas mitigation

Paddy fields are a major emission source of greenhouse gases(GHGs)[for instance,methane(CH_(4)),nitrous oxide(N_(2)O),and carbon dioxide(CO_(2))]among agricultural fields.Biochar has been deemed a potential candidate for the reduction of GHGs in paddy fields.However,there is no consistent conclusion that biochar can simultaneously reduce emissions of CH_(4),N_(2)O,and CO_(2).Herein,we proposed the FeN_(3)-doped biochar(FG)as an excellent material for GHGs restriction in paddy fields via the first-principles calculation.The computation results indicated that the FG exhibited satisfactory adsorption ability for CH_(4),CO_(2),and N_(2)O,which improved the adsorption energies to−1.37,−1.54,and−2.91 eV,respectively.Moreover,the density of state(DOS)analyses revealed that the factor responsible for FeN_(3)-doped biochar to exhibit excellent adsorption ability was the occurrence of drastic energy up-or down-shift of the electron for Fe d,C p,O p,or N p orbital upon adsorption of CH_(4),CO_(2),or N_(2)O.Our study suggested an advanced modified biochar material for reducing the GHGs emissions in paddy fields,in addition to exploring the adsorption properties and mechanisms of FeN_(3)-doped biochar for GHGs mitigation,which provided a strategy to explore biochar modification and efficient emission reduction materials.

Density functional theory for selecting modifiers for enhanced adsorption of tetracycline in water by biochar

Antibiotics and their metabolic byproducts are found in wastewater and natural water as a result of increased consumption,posing a major threat to humans and other living organisms.One of the most promising methods for their removal is adsorption using biochar because it offers excellent adsorption potential and is both affordable and environmentally beneficial.However,raw biochar frequently has a low adsorption capacity due to its limited pore structure and unfavorable surface characteristics.Biochar surface modifications using modifiers such as H3PO4,KOH,and NaOH have improved the surface area and thereby the adsorption capacity.Experimental methods for assessing the effectiveness and adsorption mechanism of modified biochar are costly and time-consuming.Density functional theory(DFT)was used to investigate the interfacial interactions and adsorption mechanism of tetracycline(TC),a widely used antibiotic for personal care and veterinary medication,on unmodified and modified biochar.The DFT calculations showed that the adsorption energy of TC on unmodified and modified biochar is in the following order:KOH-modified biochar(−2.38 eV)<NaOH-modified biochar(−2.20 eV)<unmodified biochar(−1.56 eV)<H3PO4-modified biochar(5.48 eV).The lower adsorption energy is associated with a stronger and more stable interaction between the adsorbent and the contaminant.This suggests that the adsorption of TC on KOH-modified biochar is more prolific and stable compared to the other biochar.This study provides an understanding of the mechanism underlying the adsorption of TC by modified biochar and can be used as a guide to screen for biochar with promising adsorption potential prior to experimental efforts.

In situ stabilization of arsenic in soil with organoclay,organozeolite,birnessite,goethite and lanthanum-doped magnetic biochar

Arsenic(As)is a known carcinogen and naturally occurring semi-metal in soils and in the Earth's crust.Contamination of soils and water with As poses a serious threat to millions of people worldwide due to its health hazards and toxicological properties.Hence,devising novel and efficient methods for remediation of contaminated areas has attracted a great deal of interest across the globe.In this study,we investigated the usefulness of synthetic birnessite,goethite,hexadecylpyridinium chloride-modified montmorillonite(HDPC-M),hexadecylpyridinium bromide-modified zeolite(HDPB-Z),and lanthanum(La)-doped magnetic biochar produced from eucalyptus bark(La-Euchar)as adsorbents at 10%dosage for As stabilization in a soil spiked with 1000 mg kg^(-1)As.The effectiveness of the above adsorbents in As immobilization in soil was assessed using single-step extractions with 2 mol L^(-1)HNO_(3)and deionized water,the simplified bioaccessibility extraction test(SBET)method,and sequential extraction with the modified Community Bureau of Reference(BCR)method.Application of the adsorbents shifted the exchangeable fraction of As to more recalcitrant fractions and dramatically reduced the exchangeable fraction by 6%-99%and the extractable amounts with HNO_(3),deionized water,and SBET method by 30%-92%,17%-95%,and 12%-90%,respectively,compared to the unamended control.The immobilizing effects of adsorbents on As decreased in the sequence of birnessite>La-Euchar>goethite>HDPB-Z>HDPC-M.Birnessite exhibited great affinity for As and drastically reduced As extractability by more than 90%in all single extractions.The results revealed that HDPC-M,HDPB-Z,La-Euchar,birnessite,and goethite are promising immobilizing agents for in situ stabilization of As in terrestrial environments.

Progress in the Preparation and Application of Modified B

Modified biochar(BC)is reviewed in its preparation,functionality,application in wastewater treatment and regeneration.The nature of precursor materials,preparatory conditions and modification methods are key factors influencing BC properties.Steam activation is unsuitable for improving BC surface functionality compared with chemical modifications.Alkali-treated BC possesses the highest surface functionality.Both alkali modified BC and nanomaterial impregnated BC composites are highly favorable for enhancing the adsorption of different contaminants from wastewater.Acidic treatment provides more oxygenated functional groups on BC surfaces.Future research should focus on industry-scale applications and competitive sorption for contaminant removal due to scarcity of data.

Effect and mechanism of changes in physical structure and chemical composition of new biochar on Cu(Ⅱ)adsorption in an aqueous solution

To improve the adsorption effect of biochar on heavy metal Cu(II),we prepared new biochar and explored its modification process influence on original biochar’s physical structure and chemical composition as well as its adsorption mechanism for Cu(II)in an aqueous solution.Through research work,we have reached some significant conclusions:(1)The modified biochar(M2-800)can adsorb Cu(II)at the rate of 98.039 mg g–1,38.8 times higher than that of the original biochar C800(2.525 mg g–1);(2)The biochar modification process boosts its etching and pore expansion,helping Cu(II)enter the inner surface of the adsorbent,but chemical adsorption is still the most essential fixation method for Cu(II);(3)The alkaline modification process promotes the formation of oxygen-containing functional groups,in which–OH/–COOH and iron ions would form C-O-Fe structures such as hydroxyl bridges(Fe-O–)and carboxy bridges(Fe-OOC–);(4)Carboxyl is the primary site of Cu(II)fixation in M2-800,and M2-800 has higher electronegativity(–47.8 mV)and larger pH(11.61),so that Cu(II)can be removed by electrostatic attraction and precipitation.