Manure-derived biochar is widely used for soil remediation,yet the long-term effects of aging on the stability of its endogenous heavy metals remain unclear.This study aims to investigate how freeze-thaw(FT)cycle agin...Manure-derived biochar is widely used for soil remediation,yet the long-term effects of aging on the stability of its endogenous heavy metals remain unclear.This study aims to investigate how freeze-thaw(FT)cycle aging influences the physicochemical properties and endogenous heavy metal stability of chicken manure(CM)-derived biochars produced at different pyrolysis temperatures(350℃,550℃,and 750℃).By subjecting these biochars to accelerated FT aging,we compared changes in structural integrity and heavy metal speciation.FT cycles significantly induced physical fragmentation in porous biochar,reducing pH,graphitization,and stability while increasing the total specific surface area(SSA)and oxygen-containing functional groups.Biochars produced at higher pyrolysis temperatures demonstrated greater susceptibility to structural breakdown during FT aging,which led to increased leachability and phyto-availability of heavy metals.Chemical speciation analysis revealed that biochar produced at 750℃(CMB-750)experienced a pronounced transformation of heavy metals into less stable forms during FT aging,with acidsoluble(F1)fractions of Zn,Cu,Ni,Cr,Pb,and Cd in aged biochar(ACMB-750)increasing to 34.97%,18.06%,18.34%,13.16%,31.23%,and 6.31%,respectively.These findings highlight the risks of presuming that higher pyrolysis temperatures always enhance heavy metals retention and emphasize the importance of considering the entire biochar lifecycle,from fabrication and soil remediation to aging,when optimizing its safe and sustainable agricultural use.展开更多
The forms of phosphorus(P)in animal manure and peat are different from synthetic P fertilizers and will affect soil P fractions when they are used as P amendments.Effects of chicken manure(CMB)and peat(PB)derived bioc...The forms of phosphorus(P)in animal manure and peat are different from synthetic P fertilizers and will affect soil P fractions when they are used as P amendments.Effects of chicken manure(CMB)and peat(PB)derived biochars(CMB and PB)alone or in combination with P fertilizer(KH_(2)PO_(4))and rock phosphate(RP)on plant/soil health and soil P fractions in an acidic ultisol were examined with greenhouse pot experiments.The total P rate was constant at 120 mg kg^(−1) in all treatments.Soil P fractions,P uptake,and maize growth were determined after 56 days.Application of CMB combined with P fertilizer or alone significantly increased soil pH,water extractable and relatively labile P,dry matter yield of maize,chlorophyll contents in maize leaves,while decreasing the Fe and Al binding P.Moreover,sole application of CMB and PB showed greater effects than application of P fertilizer alone regarding plant growth and P fractionation.Integration of syn-thetic inorganic P sources with CMB or sole application of CMB is more beneficial than application of inorganic P sources to improve plant growth and P availability.展开更多
基金funded by the Natural Science Foundation of Xinjiang Uygur Autonomous Region(Grant No.2022D01C737).
文摘Manure-derived biochar is widely used for soil remediation,yet the long-term effects of aging on the stability of its endogenous heavy metals remain unclear.This study aims to investigate how freeze-thaw(FT)cycle aging influences the physicochemical properties and endogenous heavy metal stability of chicken manure(CM)-derived biochars produced at different pyrolysis temperatures(350℃,550℃,and 750℃).By subjecting these biochars to accelerated FT aging,we compared changes in structural integrity and heavy metal speciation.FT cycles significantly induced physical fragmentation in porous biochar,reducing pH,graphitization,and stability while increasing the total specific surface area(SSA)and oxygen-containing functional groups.Biochars produced at higher pyrolysis temperatures demonstrated greater susceptibility to structural breakdown during FT aging,which led to increased leachability and phyto-availability of heavy metals.Chemical speciation analysis revealed that biochar produced at 750℃(CMB-750)experienced a pronounced transformation of heavy metals into less stable forms during FT aging,with acidsoluble(F1)fractions of Zn,Cu,Ni,Cr,Pb,and Cd in aged biochar(ACMB-750)increasing to 34.97%,18.06%,18.34%,13.16%,31.23%,and 6.31%,respectively.These findings highlight the risks of presuming that higher pyrolysis temperatures always enhance heavy metals retention and emphasize the importance of considering the entire biochar lifecycle,from fabrication and soil remediation to aging,when optimizing its safe and sustainable agricultural use.
基金This study was supported by the National Key Research and Development of China(No.2016YFD0200302).
文摘The forms of phosphorus(P)in animal manure and peat are different from synthetic P fertilizers and will affect soil P fractions when they are used as P amendments.Effects of chicken manure(CMB)and peat(PB)derived biochars(CMB and PB)alone or in combination with P fertilizer(KH_(2)PO_(4))and rock phosphate(RP)on plant/soil health and soil P fractions in an acidic ultisol were examined with greenhouse pot experiments.The total P rate was constant at 120 mg kg^(−1) in all treatments.Soil P fractions,P uptake,and maize growth were determined after 56 days.Application of CMB combined with P fertilizer or alone significantly increased soil pH,water extractable and relatively labile P,dry matter yield of maize,chlorophyll contents in maize leaves,while decreasing the Fe and Al binding P.Moreover,sole application of CMB and PB showed greater effects than application of P fertilizer alone regarding plant growth and P fractionation.Integration of syn-thetic inorganic P sources with CMB or sole application of CMB is more beneficial than application of inorganic P sources to improve plant growth and P availability.
