β⁃FeOOH modified sludge biochar(FSBC)was prepared and investigated in this work to remove phosphate from water via adsorption.FSBC exhibited superior adsorption performance for phosphate with the maximum adsorption a...β⁃FeOOH modified sludge biochar(FSBC)was prepared and investigated in this work to remove phosphate from water via adsorption.FSBC exhibited superior adsorption performance for phosphate with the maximum adsorption amount of 27.17 mg/g at 25℃.The specific adsorption capacity of FSBC was 57.8%higher than that of commercial activated carbon at pH 5 with the initial phosphate concentration of 10 mg/L.Coexisting anions can inhibit the adsorption of phosphate,but cations(Cr(VI)and Cd^(2+))exhibited some promotion effect.The results of kinetic and isotherm models and characterization analysis in combination indicated chemical adsorption,as electrostatic interaction,metal phosphate precipitation and hydrogen bonding may be the dominant process.The adsorption of phosphate onto FSBC was a monolayer adsorption,and the process was endothermic.After four adsorption/desorption cycles,the adsorption capacity of FSBC for phosphate decreased by 36.4%,which was in a distinct comparison with the 57.5%of SBC.展开更多
Soil application of biochar from sewage could potentially enhance carbon sequestration and close urban nutrient balances. In sub-Saharan Africa, comparative studies investigating plant growth effect and nutrients upta...Soil application of biochar from sewage could potentially enhance carbon sequestration and close urban nutrient balances. In sub-Saharan Africa, comparative studies investigating plant growth effect and nutrients uptake on tropical soils amended with sewage sludge and its biochar are very limited. A pot experiment was conducted to investigate the effects of sewage sludge and its biochar on soil chemical properties, maize nutrient and heavy metal uptake, growth and biomass partitioning on a tropical clayey soil. The study compared three organic amendments; sewage sludge （SS）, sludge biochar （SB） and their combination （SS＋SB） to the unamended control and inorganic fertilizers. Organic amendments were applied at a rate of 15 t ha-1 for SS and SB, and 7.5 t ha-1 each for SS and SB. Maize growth, biomass production and nutrient uptake were significantly improved in biochar and sewage sludge amendments compared to the unamended control. Comparable results were observed with F, SS and SS＋SB on maize growth at 49 d of sowing. Maize growth for SB, SS, SS＋SB and F increased by 42, 53, 47, and 49%, respectively compared to the unamended control. Total biomass for SB, SS, SS＋SB, and F increased by 270,428, 329, and 429%, respectively compared with the unamended control. Biochar amendments reduced Pb, Cu and Zn uptakes by about 22% compared with sludge alone treatment in maize plants. However, there is need for future research based on the current pot experiment to determine whether the same results can be produced under field conditions.展开更多
In view of the risks induced by the inhibitory effects of applying impracticably large amounts of sewage sludge biochar(SSB)to the alkaline soil,this field study investigated the influence of moderate biochar amendmen...In view of the risks induced by the inhibitory effects of applying impracticably large amounts of sewage sludge biochar(SSB)to the alkaline soil,this field study investigated the influence of moderate biochar amendments(0,1500,4500,and 9000 kg/hm2)on corn growth,alkaline soil properties,and the uptake of potentially toxic elements(PTEs).The results showed that applying more SSB would decrease the ammonium nitrogen concentration and increase the available phosphorus and potassium concentrations,which inhibited corn plant growth because of high background nutrient levels of the alkaline soil.When the alkaline soil was amended with 1500 kg/hm2 SSB,the dry weight of 100 niblets increased from 32.11 g in the control to 35.07 g.There was no significant variation in the total concentration of PTEs in the soil.The concentrations of Mn,Ni,Cu,and Zn in niblets decreased from 5.54,0.83,2.26,and 27.15 mg/kg in the control to 4.47,0.62,1.30,and 23.45 mg/kg,respectively.Accordingly,the health risk from corn consumption was significantly reduced.Furthermore,the combination of SSB and fertilizer improved corn growth and reduced the risk of consumption of PTEs.Therefore,considering the increase in corn fruit yield and the decrease in consumption risk,applying 1500 kg/hm2 of biochar to alkaline soils is a realistically achievable rate,which can broaden the utilization of SSB for remediation of different types of soil.展开更多
Municipal wastewater sludge can be pyrolyzed as biochars to better use nutrients and stabilize carbon compared with other typical technologies,such as landfill and incineration.However,sludge-derived biochars might co...Municipal wastewater sludge can be pyrolyzed as biochars to better use nutrients and stabilize carbon compared with other typical technologies,such as landfill and incineration.However,sludge-derived biochars might contain large amounts of potentially toxic elements(PTEs),such as Zn,Cu,Cr,Ni,Pb,and As.The stability of PTEs in biochars might be improved by higher pyrolytic temperatures,which can be further improved by different modifications.Herein,PO4-modification at 300°C and Cl-modification at 700°C were carried out,respectively,to enhance the stability of PTEs.Various leaching tests have been performed to assess the stability of PTEs in biochars,including the synthetic precipitation leaching procedure(SPLP),toxicity characteristic leaching procedure(TCLP),diethylenetriamine pentaacetate(DTPA)extraction,and in vitro simple bioaccessibility extraction test(SBET).The morphological structure,elemental mapping,and mineral formation of the pristine and modified biochars were studied by scanning electron microscopy–energy-dispersive X-ray spectroscopy(SEM–EDS)and X-ray diffraction(XRD).Our results suggested that the leachability,mobility,plant-availability,and bioaccessibility of most PTEs were decreased by pyrolysis,yet the total contents of PTEs were elevated,especially at 700°C.Generally,modification by phosphates and MgCl2 enhanced the stability of PTEs in biochars.Nevertheless,it should be noted that higher bioaccessibility of PTEs was observed in biochars of P-modification than Cl-modification,which is associated with the dissolution of phosphate precipitates under acidic conditions(pH<2).Additionally,Cl-modification leads to higher plant-available Zn and Cu and bioaccessible Zn compared with the unmodified biochar produced at 700°C.展开更多
China's extensive sludge production has necessitated the development of advanced pyrolysis modification techniques,particularly those involving alkaline metals such as CaO and KOH.Previous studies have shown that ...China's extensive sludge production has necessitated the development of advanced pyrolysis modification techniques,particularly those involving alkaline metals such as CaO and KOH.Previous studies have shown that CaO effectively captures phosphorus,whereas KOH promotes organic cracking.This study investigated dual-alkali-driven sludge pyrolysis processes for the production of biochar with stabilized heavy metals and enriched phosphorus contents.To elucidate the mechanisms underlying the pyrolysis process,advanced analytical techniques,including thermogravimetric analysis-Fourier transform infrared-gas chromatography-mass spectrometry(TG-FTIR-GC-MS),were employed to analyze the gas emissions from the CaO/KOH-modified sludge.Furthermore,infrared spectroscopy and X-ray diffraction phase analysis were used to characterize the resulting biochar.The results demonstrate that the influence of alkali metals on biochar composition and structure is closely related to the content of Lewis acids and bases in the sludge,and the reaction paths of CaO/KOH with typical functional groups(such as-COOH,-C-N and-C-OH)are given.For instance,CaO facilitates nitrogen volatilization,reducing its content by 17%-38%,whereas KOH retains nitrogen,increasing its content by 17%.The synergistic application of CaO and KOH significantly enhances the apatite phosphorus(AP)and total phosphorus(TP)ratio from 24%-35%to 87%-88%,and the AP to non-apatite inorganic phosphorus(NAIP)ratio from 0.32-0.54 to 5.74-43.77,thereby enabling the tuning of soil phosphorus availability and slow-release properties.Additionally,while CaO promotes phosphorus accumulation and assists in the sequestration of heavy metals,particularly Cr and Zn,KOH activates certain metals in the slag,potentially reducing their retention in the biochar.展开更多
In this study,four biochars prepared from different crop residue waste i.e.sugarcane bagasse(SBB),coconut shell(CNB),paddy straw(PDB),and distilled waste of lemongrass(LGB)were evaluated for removal of Remazol Brillia...In this study,four biochars prepared from different crop residue waste i.e.sugarcane bagasse(SBB),coconut shell(CNB),paddy straw(PDB),and distilled waste of lemongrass(LGB)were evaluated for removal of Remazol Brilliant Blue R from the aqueous system.The RBBR adsorption capacities of biochar were 97-79%for SBB,99.9-99.47%for CNB,66.1-48%for PDB,and 78-68%for LGB,dominantly controlled by their aromaticity and mineral content.The Langmuir and Freundlich isotherms and pseudo-second-order kinetic models have described the chemisorption of RBBR on biochar surfaces.The thermodynamic data suggested that adsorption was spontaneous and endothermic.These biochars demonstrated excellent reusability(till four cycles with 50-61%regeneration).The purified water and biochar dye sludge demonstrated no phytotoxicity.The findings obtained in this study may provide supports for the potential of biochars for anionic dye removal from water and utilization of generated sludge for zero waste-producing technologies in the future.展开更多
基金Sponsored by the National Natural Science Foundation of China (Grant No. 51608166)。
文摘β⁃FeOOH modified sludge biochar(FSBC)was prepared and investigated in this work to remove phosphate from water via adsorption.FSBC exhibited superior adsorption performance for phosphate with the maximum adsorption amount of 27.17 mg/g at 25℃.The specific adsorption capacity of FSBC was 57.8%higher than that of commercial activated carbon at pH 5 with the initial phosphate concentration of 10 mg/L.Coexisting anions can inhibit the adsorption of phosphate,but cations(Cr(VI)and Cd^(2+))exhibited some promotion effect.The results of kinetic and isotherm models and characterization analysis in combination indicated chemical adsorption,as electrostatic interaction,metal phosphate precipitation and hydrogen bonding may be the dominant process.The adsorption of phosphate onto FSBC was a monolayer adsorption,and the process was endothermic.After four adsorption/desorption cycles,the adsorption capacity of FSBC for phosphate decreased by 36.4%,which was in a distinct comparison with the 57.5%of SBC.
基金the Swedish International Foundation for Science (IFS) (C-5266-1) awarded to Willis Gwenzi for funding the research
文摘Soil application of biochar from sewage could potentially enhance carbon sequestration and close urban nutrient balances. In sub-Saharan Africa, comparative studies investigating plant growth effect and nutrients uptake on tropical soils amended with sewage sludge and its biochar are very limited. A pot experiment was conducted to investigate the effects of sewage sludge and its biochar on soil chemical properties, maize nutrient and heavy metal uptake, growth and biomass partitioning on a tropical clayey soil. The study compared three organic amendments; sewage sludge （SS）, sludge biochar （SB） and their combination （SS＋SB） to the unamended control and inorganic fertilizers. Organic amendments were applied at a rate of 15 t ha-1 for SS and SB, and 7.5 t ha-1 each for SS and SB. Maize growth, biomass production and nutrient uptake were significantly improved in biochar and sewage sludge amendments compared to the unamended control. Comparable results were observed with F, SS and SS＋SB on maize growth at 49 d of sowing. Maize growth for SB, SS, SS＋SB and F increased by 42, 53, 47, and 49%, respectively compared to the unamended control. Total biomass for SB, SS, SS＋SB, and F increased by 270,428, 329, and 429%, respectively compared with the unamended control. Biochar amendments reduced Pb, Cu and Zn uptakes by about 22% compared with sludge alone treatment in maize plants. However, there is need for future research based on the current pot experiment to determine whether the same results can be produced under field conditions.
基金supported by the National Key Research and Development Project[2020YFC1908904]Science and Technology Program of Xiamen[3502Z20193076]+1 种基金Natural Science Foundation of Fujian Province[2019J01135]Strategic Priority Research Program of the Chinese Academy of Sciences[XDA23020504]。
文摘In view of the risks induced by the inhibitory effects of applying impracticably large amounts of sewage sludge biochar(SSB)to the alkaline soil,this field study investigated the influence of moderate biochar amendments(0,1500,4500,and 9000 kg/hm2)on corn growth,alkaline soil properties,and the uptake of potentially toxic elements(PTEs).The results showed that applying more SSB would decrease the ammonium nitrogen concentration and increase the available phosphorus and potassium concentrations,which inhibited corn plant growth because of high background nutrient levels of the alkaline soil.When the alkaline soil was amended with 1500 kg/hm2 SSB,the dry weight of 100 niblets increased from 32.11 g in the control to 35.07 g.There was no significant variation in the total concentration of PTEs in the soil.The concentrations of Mn,Ni,Cu,and Zn in niblets decreased from 5.54,0.83,2.26,and 27.15 mg/kg in the control to 4.47,0.62,1.30,and 23.45 mg/kg,respectively.Accordingly,the health risk from corn consumption was significantly reduced.Furthermore,the combination of SSB and fertilizer improved corn growth and reduced the risk of consumption of PTEs.Therefore,considering the increase in corn fruit yield and the decrease in consumption risk,applying 1500 kg/hm2 of biochar to alkaline soils is a realistically achievable rate,which can broaden the utilization of SSB for remediation of different types of soil.
基金the financial supports by the National Natural Science Foundation for Young Scientists of China(No.42007142)the Guangdong Basic and Applied Basic Research Foundation(No.2019A1515110927)the Key Scientific and Technological Project of Foshan City(No.2120001008392).
文摘Municipal wastewater sludge can be pyrolyzed as biochars to better use nutrients and stabilize carbon compared with other typical technologies,such as landfill and incineration.However,sludge-derived biochars might contain large amounts of potentially toxic elements(PTEs),such as Zn,Cu,Cr,Ni,Pb,and As.The stability of PTEs in biochars might be improved by higher pyrolytic temperatures,which can be further improved by different modifications.Herein,PO4-modification at 300°C and Cl-modification at 700°C were carried out,respectively,to enhance the stability of PTEs.Various leaching tests have been performed to assess the stability of PTEs in biochars,including the synthetic precipitation leaching procedure(SPLP),toxicity characteristic leaching procedure(TCLP),diethylenetriamine pentaacetate(DTPA)extraction,and in vitro simple bioaccessibility extraction test(SBET).The morphological structure,elemental mapping,and mineral formation of the pristine and modified biochars were studied by scanning electron microscopy–energy-dispersive X-ray spectroscopy(SEM–EDS)and X-ray diffraction(XRD).Our results suggested that the leachability,mobility,plant-availability,and bioaccessibility of most PTEs were decreased by pyrolysis,yet the total contents of PTEs were elevated,especially at 700°C.Generally,modification by phosphates and MgCl2 enhanced the stability of PTEs in biochars.Nevertheless,it should be noted that higher bioaccessibility of PTEs was observed in biochars of P-modification than Cl-modification,which is associated with the dissolution of phosphate precipitates under acidic conditions(pH<2).Additionally,Cl-modification leads to higher plant-available Zn and Cu and bioaccessible Zn compared with the unmodified biochar produced at 700°C.
基金supported by the National Natural Science Foundation of China(Nos.52200142 and 42206170)the Anhui Province Key Research and Development Plan Project(No.2023t07020011)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515010392)the Zhuhai Basic and Applied Basic Research Project Foundation(No.ZH22017003200021PWC)。
文摘China's extensive sludge production has necessitated the development of advanced pyrolysis modification techniques,particularly those involving alkaline metals such as CaO and KOH.Previous studies have shown that CaO effectively captures phosphorus,whereas KOH promotes organic cracking.This study investigated dual-alkali-driven sludge pyrolysis processes for the production of biochar with stabilized heavy metals and enriched phosphorus contents.To elucidate the mechanisms underlying the pyrolysis process,advanced analytical techniques,including thermogravimetric analysis-Fourier transform infrared-gas chromatography-mass spectrometry(TG-FTIR-GC-MS),were employed to analyze the gas emissions from the CaO/KOH-modified sludge.Furthermore,infrared spectroscopy and X-ray diffraction phase analysis were used to characterize the resulting biochar.The results demonstrate that the influence of alkali metals on biochar composition and structure is closely related to the content of Lewis acids and bases in the sludge,and the reaction paths of CaO/KOH with typical functional groups(such as-COOH,-C-N and-C-OH)are given.For instance,CaO facilitates nitrogen volatilization,reducing its content by 17%-38%,whereas KOH retains nitrogen,increasing its content by 17%.The synergistic application of CaO and KOH significantly enhances the apatite phosphorus(AP)and total phosphorus(TP)ratio from 24%-35%to 87%-88%,and the AP to non-apatite inorganic phosphorus(NAIP)ratio from 0.32-0.54 to 5.74-43.77,thereby enabling the tuning of soil phosphorus availability and slow-release properties.Additionally,while CaO promotes phosphorus accumulation and assists in the sequestration of heavy metals,particularly Cr and Zn,KOH activates certain metals in the slag,potentially reducing their retention in the biochar.
基金financial support by the Department of Biotechnology(DBT),New Delhi(BT/PR24706/NER/95/822/2017)under the twinning program.
文摘In this study,four biochars prepared from different crop residue waste i.e.sugarcane bagasse(SBB),coconut shell(CNB),paddy straw(PDB),and distilled waste of lemongrass(LGB)were evaluated for removal of Remazol Brilliant Blue R from the aqueous system.The RBBR adsorption capacities of biochar were 97-79%for SBB,99.9-99.47%for CNB,66.1-48%for PDB,and 78-68%for LGB,dominantly controlled by their aromaticity and mineral content.The Langmuir and Freundlich isotherms and pseudo-second-order kinetic models have described the chemisorption of RBBR on biochar surfaces.The thermodynamic data suggested that adsorption was spontaneous and endothermic.These biochars demonstrated excellent reusability(till four cycles with 50-61%regeneration).The purified water and biochar dye sludge demonstrated no phytotoxicity.The findings obtained in this study may provide supports for the potential of biochars for anionic dye removal from water and utilization of generated sludge for zero waste-producing technologies in the future.
