The copper complexing of dissolved organic matter released from hydrochar(HDOM)affects the former’s environmental behavior.In this study,how hydrothermal temperatures(180,220 and 260℃)influence the molecular-level c...The copper complexing of dissolved organic matter released from hydrochar(HDOM)affects the former’s environmental behavior.In this study,how hydrothermal temperatures(180,220 and 260℃)influence the molecular-level constitutions and Cu(II)binding features of HDOM were elucidated via fourier transform ion cyclotron resonance mass spectrometry and multi-spectroscopic analysis.The findings demonstrated that the almost HDOM molecules had the traits of lower polarity and higher hydrophobicity.As the hydrothermal temperature increased,the molecules with particularly high relative strength gradually disappeared,average molecular weight,percentages of CHON and aliphatic compounds of HDOM reduced while the percentages of CHO and aromatic compounds increased.In general,the fluorescence quenching of Cu(II)weakened as hydrothermal temperature rose and the Cu(II)binding stability constants of fluorophores in HDOM were 4.50–5.31.In addition,the Cu(II) binding order of fluorophores in HDOM showed temperature heterogeneities, andpolysaccharides or aromatic rings of non-fluorescent substances had the fastest responsesto Cu(II) binding. Generally, fluorescent components tend to bind Cu(II) at relatively traceconcentrations (0–40 μmol/L), whereas non-fluorescent substances tend to the bind Cu(II)at relatively higher concentrations (50–100 μmol/L). This study contributed to the predictionof the potential environmental behaviors and risks of Cu(II) at the molecular level afterhydrochar application.展开更多
Due to their resistance to degradation,wide distribution,easy diffusion and potential uptake by organisms,microplastics(MPs)pollution has become a major environmental concern.In this study,PEG-modified Fe_(3)O_(4)magn...Due to their resistance to degradation,wide distribution,easy diffusion and potential uptake by organisms,microplastics(MPs)pollution has become a major environmental concern.In this study,PEG-modified Fe_(3)O_(4)magnetic nanoparticles demonstrated superior adsorption efficiency against polyethylene(PE)microspheres compared to other adsorbents(bare Fe_(3)O_(4),PEI/Fe_(3)O_(4)and CA/Fe_(3)O_(4)).Themaximumadsorption capacity of PEwas found to be 2203 mg/g by adsorption isotherm analysis.PEG/Fe_(3)O_(4)maintained a high adsorption capacity even at low temperature(5℃,2163 mg/g),while neutral pH was favorable for MP adsorption.The presence of anions(Cl^(-),SO_(4)^(2-),HCO_(3)^(-),NO_(3)^(-))and of humic acids inhibited the adsorption of MPs.It is proposed that the adsorption process was mainly driven by intermolecular hydrogen bonding.Overall,the study demonstrated that PEG/Fe_(3)O_(4)can potentially be used as an efficient control against MPs,thus improving the quality of the aquatic environment and of our water resources.展开更多
AgCl/ZnO/g-C_(3)N_(4), a visible light activated ternary composite catalyst, was prepared by combining calcination, hydrothermal reaction and in-situ deposition processes to treat/photocatalyse tetracycline hydrochlor...AgCl/ZnO/g-C_(3)N_(4), a visible light activated ternary composite catalyst, was prepared by combining calcination, hydrothermal reaction and in-situ deposition processes to treat/photocatalyse tetracycline hydrochloride(TC-HCl) from pharmaceutical wastewater under visible light. The morphological, structural, electrical, and optical features of the novel photocatalyst were characterized using scanning electron microscopy(SEM), UV-visible light absorption spectrum(UV–Vis DRS), X-ray diffractometer(XRD), Fourier transform infrared spectroscopy(FT-IR), X-ray photoelectron spectroscopy(XPS), and transient photocurrent techniques. All analyses confirmed that the formation of heterojunctions between AgCl/ZnO and g-C_(3)N_(4)significantly increase electron-hole transfer and separation compared to pure ZnO and g-C_(3)N_(4). Thus, AgCl/ZnO/g-C_(3)N_(4)could exhibit superior photocatalytic activity during TC-HCl assays(over 90% removal) under visible light irradiation. The composite could maintain its photocatalytic stability even after four consecutive reaction cycles. Hydrogen peroxide(H_(2)O_(2)) and superoxide radical(·O_(2)) contributed more than holes(h+) and hydroxyl radicals(·OH) to the degradation process as showed by trapping experiments. Liquid chromatograph-mass spectrometer(LC-MS) was used for the representation of the TC-HCl potential degradation pathway. The applicability and the treatment potential of AgCl/ZnO/gC_(3)N_(4)against actual pharmaceutical wastewater showed that the composite can achieve removal efficiencies of 81.7%, 71.4% and 69.0% for TC-HCl, chemical oxygen demand(COD) and total organic carbon(TOC) respectively. AgCl/ZnO/g-C_(3)N_(4)can be a prospective key photocatalyst in the field of degradation of persistent, hardly-degradable pollutants, from industrial wastewater and not only.展开更多
Hydrochar from waste biomass is a promising material for removing emerging contaminants(e.g.,antibiotics)in water/soil environment.Abundant small-sized hydrochar particles(HPs)with a high content of reactive functiona...Hydrochar from waste biomass is a promising material for removing emerging contaminants(e.g.,antibiotics)in water/soil environment.Abundant small-sized hydrochar particles(HPs)with a high content of reactive functional groups and high mobility are easily released into ecosystems through hydrochar applications.However,the photodegradation ability and corresponding structures of HPs are largely unknown,which hinder accurate estimation of the remediation effect of hydrochar in ecosystems.Herein,photodegradation performance of HP towards targeted norfloxacin(NOR,a typical antibiotic)under light irradiation(visible and UV light)were investigated after adsorption processes upon release into soil/water,and its reactive species and photoactive structures were clarified and compared with those of residual bulk hydrochar(BH)comprehensively.The results showed that:(1)photodegradation percentages of HPs were 4.02 and 4.48 times higher than those of BHs under UV and visible light,in which reactive species of both HPs and BHs were·OH and·O2−;(2)density functional theory(DFT)results identified that the main photoactive structure of graphitic-N decreased the energy gap(Eg)of HPs,and C=O,COOH groups improved electron donating ability of BHs;(3)well-developed graphitization structure of HP resulted from higher polymerization reaction was an significant photoactive structure involving its superior photodegradation ability relative to that of BH.The distinct heterogeneities of photodegradation ability in HP and BH and underlying photoactive structures provide an in-depth understanding of hydrochar application for removing emerging contaminants in soil/water environment.Identifying photoactive structures is helpful to predict photodegradation ability of hydrochar according to their abundance.展开更多
The significant volatilization of NH_(3)during aerobic composting causes nitrogen(N)losses and environmental risks.Both iron(Fe)and biochar(BC)can influence the N conversion process in composting.Fe application can de...The significant volatilization of NH_(3)during aerobic composting causes nitrogen(N)losses and environmental risks.Both iron(Fe)and biochar(BC)can influence the N conversion process in composting.Fe application can delay the maturation of materials,while biochar can enhance the quality of organic fertilizer.The combination of these two conditioners may help decrease NH_(3)emissions and improve organic fertilizer quality.Therefore,this study investigates the effects of different doses of FeCl_(3)and BC on NH_(3)emissions and organic fertilizer quality during composting.The results demonstrated that Fe/BC co-conditioners reduced the accumulation of NH_(3)emissions during composting by 11.1-48.2%,increased the total nutrient content by 0.6-15.3%,and enhanced economic and environmental benefits by 0.1-23.6$t^(−1).At the high-temperature stage of composting,Fe/BC co-conditioners decreased the pH by 0.3-1.2,but there was no significant difference compared to the control at the end of composting,and they did not affect compost maturation.The structural equation model analysis suggested that the reduction in NH_(3)emis-sions was related to ammonia-oxidizing bacteria(AOB),NH_(4)^(+)-N,and total nitrogen(TN).As a result,the Fe/BC co-conditioners reduced NH_(3)emissions by lowering the pH at the beginning of composting and increasing the content of NH_(4)^(+)-N.This study concludes that Fe/BC co-conditioners could complement each other to significantly reduce NH_(3)emissions and improve the quality of organic fertilizers.展开更多
Hydrochar has potential applications in soil improvement and heavy metal remediation.Hydrochar would undergo the process of aging when introduced into the soil,altering its properties.However,recent studies have focus...Hydrochar has potential applications in soil improvement and heavy metal remediation.Hydrochar would undergo the process of aging when introduced into the soil,altering its properties.However,recent studies have focused mainly on the artificial aging of hydrochar,which could not reveal the cumulative effect of multiple environmental factors.Therefore,the periodical monitoring of the property and sorption behavior of hydrochar after amending soils is necessary to better understand the multifaceted mechanisms associated with the natural aging of hydrochar.This study selected the sludge-derived hydrochar(SLHC)as a typical hydrochar and applied a 16-month rice-wheat-rice rotation to mimic the natural aging of hydrochar,focusing on changing properties and cadmium(Cd)sorption and literature contrast between aging strategies and biochar types.The porosity,O abundance,and ash content of 16-month aged SLHC increased by 37%,47%,and 8.5%,respectively,facilitating Cd sorption due to surface complexation,pore sorption,and precipitation.The sorption percentage of Cd to SLHC was in the range of 11-14%for SLHC-A0 and increased to 17-31%for SLHC-A4 and 20-32%for SLHC-A16 after natural aging.The natural aging of SLHC induced by ash content played an essential role in Cd sorption site heterogeneity.Linear regression analysis showed that aging strategies on sorption behavior significantly differed between biochars.Thus,studies involving natural aging with multiple environmental factors are preferred over those involving chemical or biological aging.Future studies should continue to explore the mechanisms of natural aging-induced heavy metal sorption between hydrochar and pyrochar.These results improve insights to appraise the potential of SLHC as soil amendments to alleviate the adverse effects of heavy metal contamination and provide an essential basis for researchers and staff in soil management and environmental prevention.展开更多
Water washing is a meaningful method to improve the surface’characteristic of hydrochar produced using hydrothermal carbonization and minimize the negative effect on crop growth.However,the greenhouse effect resultin...Water washing is a meaningful method to improve the surface’characteristic of hydrochar produced using hydrothermal carbonization and minimize the negative effect on crop growth.However,the greenhouse effect resulting from water-washed hydrochar application was unclear in agricultural ecosystems.Hence,the effect of water-washed hydrochar on methane and nitrous oxide emissions was analyzed in an infertile paddy soil based on a soil-column experiment.Sawdust-derived hydro-char(WSH)and wheat straw-derived hydrochar(WWH)after water washing were selected and applied with low(5‰,w/w;8.5 t ha^(−1))or high addition rate(15‰,w/w;25.5 t ha^(−1)).The study indicated that water-washed hydrochar could increase the grain yield;the difference between WWH with 5‰application rate and CKU treatments was significant.WSH signifi-cantly decreased CH4 and N2O emissions in comparison with WWH addition treatments.For the same material,there were trends in reducing greenhouse gas(GHG)emissions at low application rate,although the differences were not significant.Compared with all treatments,WSH with 5‰application rate achieved the lowest seasonal emissions for both GHGs.The mcrA gene was the critical factor affecting CH4 emission;soil NO_(3)^(−)-N concentration and the copy numbers of nirK,nirS,and nosZ jointly affected N2O emissions.Benefits from the high yield and low global warming potential,GHG emission intensity(GHGI)at low application rate was lower than at high application rate for WSH.Overall,the response of GHG emissions to water-washed hydrochar varies with the derived feedstock;WSH is a good additive for the mitigation of GHGI.展开更多
Accurately predicting and estimating the squeezing and ground response to tunneling remains challenging.Moreover,tunnel-squeezing hazards are much more likely to occur in deeply buried long tunnels with complex engine...Accurately predicting and estimating the squeezing and ground response to tunneling remains challenging.Moreover,tunnel-squeezing hazards are much more likely to occur in deeply buried long tunnels with complex engineering-geological environments.There-fore,a high-performance predictive model for tunnel squeezing is necessary.A superior ensemble classifier is put forward in this study,which is composed of four individual classifiers(gradient boosting classifier,extra-trees classifier,AdaBoost classifier,and Logistic regression classifier)and two optimization algorithms(Bayesian optimization(BO)and sparrow search algorithm(SSA)).The training database covers five parameters:tunnel depth(H),rock tunneling quality index(Q),tunnel diameter(D),support stiffness(K),and strength stress ratio(SSR),about which the basic information is accessible at the early design phases.However,the dataset compiled from the literature is insufficient.Thus,the ten proposed methods are used to replace the missing values.During the model training pro-cess,BO shows its strong ability to optimize seventeen hyperparameters.When applied to tune the classifiers’weights,SSA achieves a fast and efficient performance.The novel Shapley Additive Explanations–LightGBM method indicates that the K is the most important input feature,followed by SSR,Q,H,and D,respectively.The ensemble classifier is then validated using the test set and additional his-torical case projects.The validation shows that the model can achieve an accuracy of 98%(i.e.,the error rate is 2%)on the test set,higher than those achieved by previous prediction models.Moreover,the predicted probability could provide warning information for timely support measures.Finally,the application results are illustrated through tests on the tunnel sections that have not yet been excavated in the line of the Sichuan–Xizang railway project.The applied predictive tendencies and laws are in line with the practical experience.In sum-mary,the proposed model’s prediction results are reasonable,and its prediction will be more accurate as more data is collected and trained for prewarning the tunnel squeezing hazard.展开更多
The development of biochar-based granule-like adsorbents suitable for scaled-up application has been attracting increasing attention in the field of water treatment.Herein,a new formable porous granulated biochar load...The development of biochar-based granule-like adsorbents suitable for scaled-up application has been attracting increasing attention in the field of water treatment.Herein,a new formable porous granulated biochar loaded with La-Fe(hydr)oxides/montmorillonite(LaFe/MB)was fabricated via a granulation and pyrolysis process for enhanced phosphorus(P)removal from wastewater.Montmorillonite acted as a binder that increased the size of the granulated biochar,while the use of Fe promoted the surface charge and facilitated the dispersion of La,which was responsible for selective phosphate removal.LaFe/MB exhibited rapid phosphate adsorption kinetics and a high maximum adsorption capacity(Langmuir model,52.12 mg P g^(−1)),which were better than those of many existing granulated materials.The desorption and recyclability experiments showed that LaFe/MB could be regenerated,and maintained 76.7%of its initial phosphate adsorption capacity after four adsorption cycles.The high hydraulic endurance strength retention rate of the developed material(91.6%)suggested high practical applicability in actual wastewater.Electro-static attraction,surface precipitation,and inner-sphere complexation via ligand exchange were found to be involved in selective P removal over a wide pH range of 3-9.The thermodynamic parameters were determined,which revealed the feasibility and spontaneity of adsorption.Based on approximate site energy distribution analyses,high distribution frequency contributed to efficient P removal.The research results provide a new insight that LaFe/MB shows great application prospects for advanced phosphate removal from wastewater.展开更多
Soil aggregation is one of the crucial processes that facilitate carbon sequestration and maintain soil fertility.So far,the effect of biochar amendment on soil aggregation remains inconclusive.Here,we tested the hypo...Soil aggregation is one of the crucial processes that facilitate carbon sequestration and maintain soil fertility.So far,the effect of biochar amendment on soil aggregation remains inconclusive.Here,we tested the hypothesis that the response of soil aggregation to biochar addition varied with incubation duration and biochar chemistry.A one year microcosm experiment of soil with biochar was conducted that included biochar produced at three different temperatures(300,450,and 600°C),and three biochar application rates,i.e.,0,1,and 3 wt%.It was observed that after one and three months,biochar mainly(>90%)distributed in the micro-aggregates,and slightly reduced aggregate stability and increased proportion of micro-aggregates,which was demonstrated to result from the mechanical mixture of amended biochar with soil.Contrastingly,when the duration was prolonged to six months and one year,a significant increase in macro-aggregates(6.6-38.5%)and aggregate stability(7.3-29.4%)was detected,with the increasing extent being apparently higher for low-temperature biochar.This was related to the comparatively strong interaction of biochar particles with soil minerals or microbes after long-time incubation.The strong interaction was directly supported by the significant increase in H/C,O/C ratios of isolated biochar from treated soils,the detection of typical soil mineral elements on the surface of isolated biochar,and the increase in microbial biomass carbon of treated soils.The findings of this study highlighted the role of biochar type and amendment duration in mediating the effect of biochar application on soil aggregation.展开更多
Ensuring food safety while reducing agricultural non-point source pollution is quite challenging,especially in developing and underdeveloped countries.Effective systematic strategies and comprehensive technologies nee...Ensuring food safety while reducing agricultural non-point source pollution is quite challenging,especially in developing and underdeveloped countries.Effective systematic strategies and comprehensive technologies need to be developed for agricultural non-point source pollution control at the watershed scale to improve surface water quality.In this review,a proposal is made for a full time-space governance strategy that prioritizes source management followed by endpoint water pollution control.The 4R chain technology system is specifically reviewed,including source reduction,process retention,nutrient reuse and water restoration.The 4R chain technology system with the full time-space governance strategy was applied at the scale of an administrative village and proved to be a feasible solution for reducing agricultural non-point source pollution in China.In the future,a monitoring system needs to be established to trace N and P transport.Additionally,new smart fertilizer and intelligent equipment need to be developed,and relevant governance standards and supportive policies need to be set to enhance the efficacy of agricultural non-point source pollution control.展开更多
Hydrothermal carbonization(HTC)technology has increasingly been considered for biomass conversion applications because of its economic and environmental advantages.As an HTC conversion product,hydrochar has been widel...Hydrothermal carbonization(HTC)technology has increasingly been considered for biomass conversion applications because of its economic and environmental advantages.As an HTC conversion product,hydrochar has been widely used in the agricultural and environmental fields for decades.A CiteSpace-based system analysis was used for conducting a bibliometric study to understand the state of hydrochar environmental application research from 2011 to 2021.Researchers had a basic understanding of hydrochar between 2011 and 2016 when they discovered hydrochar could apply to agricultural and environmental improvement projects.Keyword clustering results of the literature published in 2017-2021 showed that soil quality and plant growth were the major research topics,followed by carbon capture and greenhouse gas emissions,organic pollutant removal,and heavy metal adsorption and its bioavailability.This review also pointed out the challenge and perspective for hydrochar research and application,namely:(1)the environmental effects of hydrochar on soils need to be clarified in terms of the scope and conditions;(2)the influence of soil microorganisms needs to be investigated to illustrate the impact of hydrochar on greenhouse gas emissions;(3)combined heavy metal and organic contaminant sorption experiments for hydrochar need to be conducted for large-scale applications;(4)more research needs to be conducted to reveal the economic benefits of hydrochar and the coupling of hydrochar with anaerobic digestion technology.This review suggested that it would be valuable to create a database that contains detailed information on how hydrochar got from different sources,and different preparation conditions can be applied in the environmental field.展开更多
The cellulose-based hydrogel has been widely applied for soil water retention and nutrient re-lease agents for several decades.Embedding the inorganic materials into hydrogels is an excellent strategy to improve the i...The cellulose-based hydrogel has been widely applied for soil water retention and nutrient re-lease agents for several decades.Embedding the inorganic materials into hydrogels is an excellent strategy to improve the inherent limits of the cellulose-based hydrogel.Notably,municipal sludge-derived hydrochar(HC)has reduced the environmental burden and offered a potential hydrogel carrier to control water-retention and nutrient-release.However,the above function for plant growth of hydrochar-embedded carboxymethyl cellulose-g-poly(acrylic acid)(CMC-g-PAA/HC)is unknown,and relevant reports are lacking.This study investigated the water retention,nutri-ent release behavior,and effect of germination and plant growth of CMC-g-PAA/HC hydrogel.Characterization results showed that HC was successfully incorporated into CMC-g-PAA/HC with 6.0%higher thermostability,7.2-21.0%lower swelling ratio(SR)in water,and substantial SR in phosphate solution(P-solution).The water loss rate of CMC-g-PAA/HC in P-solution or wa-ter owned a more significant temperature response(7.9-15.0 folds)than CMC-g-PAA(8.2-10.0 folds).Moreover,4.0%higher n value and more 18.5%released P for CMC-g-PAA/HC were also observed.These phenomena were due to restricting the polymer chains movement and the wa-ter molecules diffusion inside the hydrogels with HC.Phytotoxicity assessments showed that HC in CMC-g-PAA/HC could effectively alleviate the inhibition effects on rape germination retained with 78.3%germination vigor and 80.0%germination ratio,even dramatically improved plant growth to 28 d.The results of this study demonstrated a new route for developing eco-friendly CMC-g-PAA/HC hydrogel,advantageous as a water retention agent and nutrient carrier in arid and semiarid regions.展开更多
基金supported by the National Natural Science Foundation of China(No.42307090)the Open Subject from State Environmental Protection Key Laboratory of Aquatic Ecosystem Health in theMiddle and Lower Reaches of Yangtze River(No.AEHKF2023008).
文摘The copper complexing of dissolved organic matter released from hydrochar(HDOM)affects the former’s environmental behavior.In this study,how hydrothermal temperatures(180,220 and 260℃)influence the molecular-level constitutions and Cu(II)binding features of HDOM were elucidated via fourier transform ion cyclotron resonance mass spectrometry and multi-spectroscopic analysis.The findings demonstrated that the almost HDOM molecules had the traits of lower polarity and higher hydrophobicity.As the hydrothermal temperature increased,the molecules with particularly high relative strength gradually disappeared,average molecular weight,percentages of CHON and aliphatic compounds of HDOM reduced while the percentages of CHO and aromatic compounds increased.In general,the fluorescence quenching of Cu(II)weakened as hydrothermal temperature rose and the Cu(II)binding stability constants of fluorophores in HDOM were 4.50–5.31.In addition,the Cu(II) binding order of fluorophores in HDOM showed temperature heterogeneities, andpolysaccharides or aromatic rings of non-fluorescent substances had the fastest responsesto Cu(II) binding. Generally, fluorescent components tend to bind Cu(II) at relatively traceconcentrations (0–40 μmol/L), whereas non-fluorescent substances tend to the bind Cu(II)at relatively higher concentrations (50–100 μmol/L). This study contributed to the predictionof the potential environmental behaviors and risks of Cu(II) at the molecular level afterhydrochar application.
基金supported by the National Key Research and Development Program of China(No.2021YFD1700803)the Province Key Research and Development Program of Jiangsu,China(No.D21YFD17008)the National Natural Science Foundation of China(No.41771295).
文摘Due to their resistance to degradation,wide distribution,easy diffusion and potential uptake by organisms,microplastics(MPs)pollution has become a major environmental concern.In this study,PEG-modified Fe_(3)O_(4)magnetic nanoparticles demonstrated superior adsorption efficiency against polyethylene(PE)microspheres compared to other adsorbents(bare Fe_(3)O_(4),PEI/Fe_(3)O_(4)and CA/Fe_(3)O_(4)).Themaximumadsorption capacity of PEwas found to be 2203 mg/g by adsorption isotherm analysis.PEG/Fe_(3)O_(4)maintained a high adsorption capacity even at low temperature(5℃,2163 mg/g),while neutral pH was favorable for MP adsorption.The presence of anions(Cl^(-),SO_(4)^(2-),HCO_(3)^(-),NO_(3)^(-))and of humic acids inhibited the adsorption of MPs.It is proposed that the adsorption process was mainly driven by intermolecular hydrogen bonding.Overall,the study demonstrated that PEG/Fe_(3)O_(4)can potentially be used as an efficient control against MPs,thus improving the quality of the aquatic environment and of our water resources.
基金supported by National Natural Science Foundation of China (No. 41771295)。
文摘AgCl/ZnO/g-C_(3)N_(4), a visible light activated ternary composite catalyst, was prepared by combining calcination, hydrothermal reaction and in-situ deposition processes to treat/photocatalyse tetracycline hydrochloride(TC-HCl) from pharmaceutical wastewater under visible light. The morphological, structural, electrical, and optical features of the novel photocatalyst were characterized using scanning electron microscopy(SEM), UV-visible light absorption spectrum(UV–Vis DRS), X-ray diffractometer(XRD), Fourier transform infrared spectroscopy(FT-IR), X-ray photoelectron spectroscopy(XPS), and transient photocurrent techniques. All analyses confirmed that the formation of heterojunctions between AgCl/ZnO and g-C_(3)N_(4)significantly increase electron-hole transfer and separation compared to pure ZnO and g-C_(3)N_(4). Thus, AgCl/ZnO/g-C_(3)N_(4)could exhibit superior photocatalytic activity during TC-HCl assays(over 90% removal) under visible light irradiation. The composite could maintain its photocatalytic stability even after four consecutive reaction cycles. Hydrogen peroxide(H_(2)O_(2)) and superoxide radical(·O_(2)) contributed more than holes(h+) and hydroxyl radicals(·OH) to the degradation process as showed by trapping experiments. Liquid chromatograph-mass spectrometer(LC-MS) was used for the representation of the TC-HCl potential degradation pathway. The applicability and the treatment potential of AgCl/ZnO/gC_(3)N_(4)against actual pharmaceutical wastewater showed that the composite can achieve removal efficiencies of 81.7%, 71.4% and 69.0% for TC-HCl, chemical oxygen demand(COD) and total organic carbon(TOC) respectively. AgCl/ZnO/g-C_(3)N_(4)can be a prospective key photocatalyst in the field of degradation of persistent, hardly-degradable pollutants, from industrial wastewater and not only.
基金supported by the National Natural Science Foundation of China(No.42207276)National Key Research and Development Program of China(2021YFD1700805).
文摘Hydrochar from waste biomass is a promising material for removing emerging contaminants(e.g.,antibiotics)in water/soil environment.Abundant small-sized hydrochar particles(HPs)with a high content of reactive functional groups and high mobility are easily released into ecosystems through hydrochar applications.However,the photodegradation ability and corresponding structures of HPs are largely unknown,which hinder accurate estimation of the remediation effect of hydrochar in ecosystems.Herein,photodegradation performance of HP towards targeted norfloxacin(NOR,a typical antibiotic)under light irradiation(visible and UV light)were investigated after adsorption processes upon release into soil/water,and its reactive species and photoactive structures were clarified and compared with those of residual bulk hydrochar(BH)comprehensively.The results showed that:(1)photodegradation percentages of HPs were 4.02 and 4.48 times higher than those of BHs under UV and visible light,in which reactive species of both HPs and BHs were·OH and·O2−;(2)density functional theory(DFT)results identified that the main photoactive structure of graphitic-N decreased the energy gap(Eg)of HPs,and C=O,COOH groups improved electron donating ability of BHs;(3)well-developed graphitization structure of HP resulted from higher polymerization reaction was an significant photoactive structure involving its superior photodegradation ability relative to that of BH.The distinct heterogeneities of photodegradation ability in HP and BH and underlying photoactive structures provide an in-depth understanding of hydrochar application for removing emerging contaminants in soil/water environment.Identifying photoactive structures is helpful to predict photodegradation ability of hydrochar according to their abundance.
基金National Key Research and Development Program of China(2021YFD1700805)the National Natural Science Foundation of China(No.42277332)+2 种基金Natural Science Foundation of Jiangsu Province(SBK2022022675)Yunnan Branch of China National Tobacco Corporation(2022530000241022)Y.F.Feng thanks the support of“333”High-level Talents Training Project of Jiangsu Province(2022-3-23-083).
文摘The significant volatilization of NH_(3)during aerobic composting causes nitrogen(N)losses and environmental risks.Both iron(Fe)and biochar(BC)can influence the N conversion process in composting.Fe application can delay the maturation of materials,while biochar can enhance the quality of organic fertilizer.The combination of these two conditioners may help decrease NH_(3)emissions and improve organic fertilizer quality.Therefore,this study investigates the effects of different doses of FeCl_(3)and BC on NH_(3)emissions and organic fertilizer quality during composting.The results demonstrated that Fe/BC co-conditioners reduced the accumulation of NH_(3)emissions during composting by 11.1-48.2%,increased the total nutrient content by 0.6-15.3%,and enhanced economic and environmental benefits by 0.1-23.6$t^(−1).At the high-temperature stage of composting,Fe/BC co-conditioners decreased the pH by 0.3-1.2,but there was no significant difference compared to the control at the end of composting,and they did not affect compost maturation.The structural equation model analysis suggested that the reduction in NH_(3)emis-sions was related to ammonia-oxidizing bacteria(AOB),NH_(4)^(+)-N,and total nitrogen(TN).As a result,the Fe/BC co-conditioners reduced NH_(3)emissions by lowering the pH at the beginning of composting and increasing the content of NH_(4)^(+)-N.This study concludes that Fe/BC co-conditioners could complement each other to significantly reduce NH_(3)emissions and improve the quality of organic fertilizers.
基金the National Natural Science Foundation of China(Nos.41877090 and 42107398)Natural Science Foundation of Jiangsu Province(BK20181165 and BK20210358)+1 种基金China Postdoctoral Science Foundation(2020M68618)Yunnan Branch of China National Tobacco Corporation(2022530000241022).
文摘Hydrochar has potential applications in soil improvement and heavy metal remediation.Hydrochar would undergo the process of aging when introduced into the soil,altering its properties.However,recent studies have focused mainly on the artificial aging of hydrochar,which could not reveal the cumulative effect of multiple environmental factors.Therefore,the periodical monitoring of the property and sorption behavior of hydrochar after amending soils is necessary to better understand the multifaceted mechanisms associated with the natural aging of hydrochar.This study selected the sludge-derived hydrochar(SLHC)as a typical hydrochar and applied a 16-month rice-wheat-rice rotation to mimic the natural aging of hydrochar,focusing on changing properties and cadmium(Cd)sorption and literature contrast between aging strategies and biochar types.The porosity,O abundance,and ash content of 16-month aged SLHC increased by 37%,47%,and 8.5%,respectively,facilitating Cd sorption due to surface complexation,pore sorption,and precipitation.The sorption percentage of Cd to SLHC was in the range of 11-14%for SLHC-A0 and increased to 17-31%for SLHC-A4 and 20-32%for SLHC-A16 after natural aging.The natural aging of SLHC induced by ash content played an essential role in Cd sorption site heterogeneity.Linear regression analysis showed that aging strategies on sorption behavior significantly differed between biochars.Thus,studies involving natural aging with multiple environmental factors are preferred over those involving chemical or biological aging.Future studies should continue to explore the mechanisms of natural aging-induced heavy metal sorption between hydrochar and pyrochar.These results improve insights to appraise the potential of SLHC as soil amendments to alleviate the adverse effects of heavy metal contamination and provide an essential basis for researchers and staff in soil management and environmental prevention.
基金supported by The National Natural Science Foundation of China(4187709042077092)+3 种基金The National Key R&D Program,Ministry of Science and Technology,China(2017YFD0300104)Open Project of Key Laboratory for Crop and Animal Integrated Farming of Ministry of Agriculture and Rural Affairs,P.R.China(202001)The National Key Research and Development Program,P.R.China(2016YFD0300908-02)Baoshan Xing acknowledges the UMass Amherst Conti Faculty Fellowship。
文摘Water washing is a meaningful method to improve the surface’characteristic of hydrochar produced using hydrothermal carbonization and minimize the negative effect on crop growth.However,the greenhouse effect resulting from water-washed hydrochar application was unclear in agricultural ecosystems.Hence,the effect of water-washed hydrochar on methane and nitrous oxide emissions was analyzed in an infertile paddy soil based on a soil-column experiment.Sawdust-derived hydro-char(WSH)and wheat straw-derived hydrochar(WWH)after water washing were selected and applied with low(5‰,w/w;8.5 t ha^(−1))or high addition rate(15‰,w/w;25.5 t ha^(−1)).The study indicated that water-washed hydrochar could increase the grain yield;the difference between WWH with 5‰application rate and CKU treatments was significant.WSH signifi-cantly decreased CH4 and N2O emissions in comparison with WWH addition treatments.For the same material,there were trends in reducing greenhouse gas(GHG)emissions at low application rate,although the differences were not significant.Compared with all treatments,WSH with 5‰application rate achieved the lowest seasonal emissions for both GHGs.The mcrA gene was the critical factor affecting CH4 emission;soil NO_(3)^(−)-N concentration and the copy numbers of nirK,nirS,and nosZ jointly affected N2O emissions.Benefits from the high yield and low global warming potential,GHG emission intensity(GHGI)at low application rate was lower than at high application rate for WSH.Overall,the response of GHG emissions to water-washed hydrochar varies with the derived feedstock;WSH is a good additive for the mitigation of GHGI.
基金supported by the National Natural Science Foundation of China(Grant Nos.U21A20153,41941018,52074258,41807250,42177140)the Key Research and Development Project of Hubei Province,China(Grant No.2021BCA133).
文摘Accurately predicting and estimating the squeezing and ground response to tunneling remains challenging.Moreover,tunnel-squeezing hazards are much more likely to occur in deeply buried long tunnels with complex engineering-geological environments.There-fore,a high-performance predictive model for tunnel squeezing is necessary.A superior ensemble classifier is put forward in this study,which is composed of four individual classifiers(gradient boosting classifier,extra-trees classifier,AdaBoost classifier,and Logistic regression classifier)and two optimization algorithms(Bayesian optimization(BO)and sparrow search algorithm(SSA)).The training database covers five parameters:tunnel depth(H),rock tunneling quality index(Q),tunnel diameter(D),support stiffness(K),and strength stress ratio(SSR),about which the basic information is accessible at the early design phases.However,the dataset compiled from the literature is insufficient.Thus,the ten proposed methods are used to replace the missing values.During the model training pro-cess,BO shows its strong ability to optimize seventeen hyperparameters.When applied to tune the classifiers’weights,SSA achieves a fast and efficient performance.The novel Shapley Additive Explanations–LightGBM method indicates that the K is the most important input feature,followed by SSR,Q,H,and D,respectively.The ensemble classifier is then validated using the test set and additional his-torical case projects.The validation shows that the model can achieve an accuracy of 98%(i.e.,the error rate is 2%)on the test set,higher than those achieved by previous prediction models.Moreover,the predicted probability could provide warning information for timely support measures.Finally,the application results are illustrated through tests on the tunnel sections that have not yet been excavated in the line of the Sichuan–Xizang railway project.The applied predictive tendencies and laws are in line with the practical experience.In sum-mary,the proposed model’s prediction results are reasonable,and its prediction will be more accurate as more data is collected and trained for prewarning the tunnel squeezing hazard.
基金National Key Research and Development Program of China(2021YFD1700805)National Natural Science Foundation of China(41807132,22078136,41877090)the Jiangsu Province Agricultural Independent Innovation Fund(CX(19)2003).
文摘The development of biochar-based granule-like adsorbents suitable for scaled-up application has been attracting increasing attention in the field of water treatment.Herein,a new formable porous granulated biochar loaded with La-Fe(hydr)oxides/montmorillonite(LaFe/MB)was fabricated via a granulation and pyrolysis process for enhanced phosphorus(P)removal from wastewater.Montmorillonite acted as a binder that increased the size of the granulated biochar,while the use of Fe promoted the surface charge and facilitated the dispersion of La,which was responsible for selective phosphate removal.LaFe/MB exhibited rapid phosphate adsorption kinetics and a high maximum adsorption capacity(Langmuir model,52.12 mg P g^(−1)),which were better than those of many existing granulated materials.The desorption and recyclability experiments showed that LaFe/MB could be regenerated,and maintained 76.7%of its initial phosphate adsorption capacity after four adsorption cycles.The high hydraulic endurance strength retention rate of the developed material(91.6%)suggested high practical applicability in actual wastewater.Electro-static attraction,surface precipitation,and inner-sphere complexation via ligand exchange were found to be involved in selective P removal over a wide pH range of 3-9.The thermodynamic parameters were determined,which revealed the feasibility and spontaneity of adsorption.Based on approximate site energy distribution analyses,high distribution frequency contributed to efficient P removal.The research results provide a new insight that LaFe/MB shows great application prospects for advanced phosphate removal from wastewater.
基金This research was supported by the Program for Guangdong Introducing Innovative and Enterpreneurial Teams(2019ZT08L213)Youth Program of National Natural Science Foundation of China(42007013)Guangdong Basic and Applied Basic Research Foundation(2019A1515110777).
文摘Soil aggregation is one of the crucial processes that facilitate carbon sequestration and maintain soil fertility.So far,the effect of biochar amendment on soil aggregation remains inconclusive.Here,we tested the hypothesis that the response of soil aggregation to biochar addition varied with incubation duration and biochar chemistry.A one year microcosm experiment of soil with biochar was conducted that included biochar produced at three different temperatures(300,450,and 600°C),and three biochar application rates,i.e.,0,1,and 3 wt%.It was observed that after one and three months,biochar mainly(>90%)distributed in the micro-aggregates,and slightly reduced aggregate stability and increased proportion of micro-aggregates,which was demonstrated to result from the mechanical mixture of amended biochar with soil.Contrastingly,when the duration was prolonged to six months and one year,a significant increase in macro-aggregates(6.6-38.5%)and aggregate stability(7.3-29.4%)was detected,with the increasing extent being apparently higher for low-temperature biochar.This was related to the comparatively strong interaction of biochar particles with soil minerals or microbes after long-time incubation.The strong interaction was directly supported by the significant increase in H/C,O/C ratios of isolated biochar from treated soils,the detection of typical soil mineral elements on the surface of isolated biochar,and the increase in microbial biomass carbon of treated soils.The findings of this study highlighted the role of biochar type and amendment duration in mediating the effect of biochar application on soil aggregation.
基金supported by grants from the National Key Research and Development Program of China(2021YFD1700803)Jiangsu Agriculture Science and Technology Innovation Fund,China(CX(19)1007).
文摘Ensuring food safety while reducing agricultural non-point source pollution is quite challenging,especially in developing and underdeveloped countries.Effective systematic strategies and comprehensive technologies need to be developed for agricultural non-point source pollution control at the watershed scale to improve surface water quality.In this review,a proposal is made for a full time-space governance strategy that prioritizes source management followed by endpoint water pollution control.The 4R chain technology system is specifically reviewed,including source reduction,process retention,nutrient reuse and water restoration.The 4R chain technology system with the full time-space governance strategy was applied at the scale of an administrative village and proved to be a feasible solution for reducing agricultural non-point source pollution in China.In the future,a monitoring system needs to be established to trace N and P transport.Additionally,new smart fertilizer and intelligent equipment need to be developed,and relevant governance standards and supportive policies need to be set to enhance the efficacy of agricultural non-point source pollution control.
基金National Natural Science Foundation of China(Nos.42107398,42277332 and 42207453)Natural Science Foundation of Jiangsu Province(BK20210358 and BK20221428)+2 种基金Ecological Environment Research Project of Jiangsu Province(Policy Guidance 2021006)China Postdoctoral Science Foundation(2020M68618)Y.F.Feng thanks the support of“333”High-level Talents Training Project of Jiangsu Province(2022-3-23-083).
文摘Hydrothermal carbonization(HTC)technology has increasingly been considered for biomass conversion applications because of its economic and environmental advantages.As an HTC conversion product,hydrochar has been widely used in the agricultural and environmental fields for decades.A CiteSpace-based system analysis was used for conducting a bibliometric study to understand the state of hydrochar environmental application research from 2011 to 2021.Researchers had a basic understanding of hydrochar between 2011 and 2016 when they discovered hydrochar could apply to agricultural and environmental improvement projects.Keyword clustering results of the literature published in 2017-2021 showed that soil quality and plant growth were the major research topics,followed by carbon capture and greenhouse gas emissions,organic pollutant removal,and heavy metal adsorption and its bioavailability.This review also pointed out the challenge and perspective for hydrochar research and application,namely:(1)the environmental effects of hydrochar on soils need to be clarified in terms of the scope and conditions;(2)the influence of soil microorganisms needs to be investigated to illustrate the impact of hydrochar on greenhouse gas emissions;(3)combined heavy metal and organic contaminant sorption experiments for hydrochar need to be conducted for large-scale applications;(4)more research needs to be conducted to reveal the economic benefits of hydrochar and the coupling of hydrochar with anaerobic digestion technology.This review suggested that it would be valuable to create a database that contains detailed information on how hydrochar got from different sources,and different preparation conditions can be applied in the environmental field.
基金This work was funded by the National Undergraduate Training Program for Innovation and Entrepreneurship(No.202010288024Z)National Natural Science Foundation of China(No.42107398)+1 种基金Natural Science Foundation of Jiangsu Province(BK20210358)China Postdoctoral Science Foundation(2020M68618).
文摘The cellulose-based hydrogel has been widely applied for soil water retention and nutrient re-lease agents for several decades.Embedding the inorganic materials into hydrogels is an excellent strategy to improve the inherent limits of the cellulose-based hydrogel.Notably,municipal sludge-derived hydrochar(HC)has reduced the environmental burden and offered a potential hydrogel carrier to control water-retention and nutrient-release.However,the above function for plant growth of hydrochar-embedded carboxymethyl cellulose-g-poly(acrylic acid)(CMC-g-PAA/HC)is unknown,and relevant reports are lacking.This study investigated the water retention,nutri-ent release behavior,and effect of germination and plant growth of CMC-g-PAA/HC hydrogel.Characterization results showed that HC was successfully incorporated into CMC-g-PAA/HC with 6.0%higher thermostability,7.2-21.0%lower swelling ratio(SR)in water,and substantial SR in phosphate solution(P-solution).The water loss rate of CMC-g-PAA/HC in P-solution or wa-ter owned a more significant temperature response(7.9-15.0 folds)than CMC-g-PAA(8.2-10.0 folds).Moreover,4.0%higher n value and more 18.5%released P for CMC-g-PAA/HC were also observed.These phenomena were due to restricting the polymer chains movement and the wa-ter molecules diffusion inside the hydrogels with HC.Phytotoxicity assessments showed that HC in CMC-g-PAA/HC could effectively alleviate the inhibition effects on rape germination retained with 78.3%germination vigor and 80.0%germination ratio,even dramatically improved plant growth to 28 d.The results of this study demonstrated a new route for developing eco-friendly CMC-g-PAA/HC hydrogel,advantageous as a water retention agent and nutrient carrier in arid and semiarid regions.
