摘要
通过磷酸(H_(3)PO_(4))和焦磷酸(H_(4)P_(2)O_(7))对生物炭改性能够使其更适于农业应用。探明H_(3)PO_(4)和H_(4)P_(2)O_(7)改性生物炭的P赋存形态与结合方式,将有助于揭示其表面P的生物有效性。以麦秆生物炭(WBC)与棉秆生物炭(CBC)为原料,分别通过H_(3)PO_(4)和H_(4)P_(2)O_(7)制备了HPO改性生物炭(P-WBC和P-CBC)和HPO改性生物炭(PA-WBC和PA-CBC)。利用拉曼光谱(Raman)与扫描电镜能谱(SEM-EDS)对改性生物炭结构与P分布变化进行表征,采用傅里叶红外光谱(FTIR)和X射线光电子能谱(XPS)探究改性生物炭表面P结合方式,并结合Hedley磷分级方法与可见分光光度法,定量分析改性前后生物炭中P形态及含量变化。结果表明,H_(3)PO_(4)和H_(4)P_(2)O_(7)改性后生物炭I/I值增大,石墨化结构增强,形成了含P颗粒状结构。H_(3)PO_(4)和H_(4)P_(2)O_(7)改性促进了生物炭表面羧基(—COOH)、P—O—P和P—H等酸性官能团与含P基团的形成,且HPO改性生物炭和HPO改性生物炭表面官能团种类相似。XPS结果显示,与WBC和CBC相比,改性处理中的O(1s)峰相对含量显著增加了13.15%~32.44%,P(2s)峰相对含量显著增加了18.54%~27.02%(p<0.05)。反褶积分峰将P(2s)与O(1s)分为C—P—O,C—O—P,OPO,CO与(或)PO,C—O—C与(或)P—O—C和P—O—P六类。较HPO改性而言,HPO改性能够促进更多C—O—P,OPO,C—O—C与(或)P—O—C和P—O—P键的形成。改性也使得生物炭中总P含量显著增加,且PA-WBC和PA-CBC中P含量显著高于P-WBC和P-CBC。与WBC和CBC相比,改性处理中活性P含量显著提高2.36~14.77 g·kg^(-1),稳定态P含量显著降低0.06~0.17 g·kg^(-1)(p<0.05)。与P-WBC和P-CBC相比,PA-WBC和PA-CBC的活性P、中等活性P分别显著增加了5.27~15.66和0.53~0.64 g·kg^(-1),稳定态P含量减少了0.03~0.34 g·kg^(-1)(p<0.05)。H_(3)PO_(4)和H_(4)P_(2)O_(7)改性改变了P在生物炭表面的结合方式,同时增加了P的活性。H_(3)PO_(4)和H_(4)P_(2)O_(7)改性生物炭间,不同形态P含量和结合方式的差异对进一步探究P的生物有效性具有重要意义。
They can be applied to agriculture by changing the properties of biochar by phosphoric acid(H_(3)PO_(4))and pyrophosphoric acid(H_(4)P_(2)O_(7)).It is helpful to revealing the bio-availability of P on its surface for identifying P occurrence form and binding mode of changed biochar for H_(3)PO_(4)and H_(4)P_(2)O_(7).This paper adopts wheat stalk biochar(WBC)and cotton stalk biochar(CBC)as raw materials.Meanwhile,this paper prepares changed HPO(P-WBC and P-CBC)and changed biochar of HPO(PA-WBC and PA-CBC)by H_(3)PO_(4)and H_(4)P_(2)O_(7)respectively.This paper adopts Raman spectroscopy(Raman)and scanning electron microscopy(SEM)to characterize the structure and P distribution of the changed biochar.In addition,this paper adopts Fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS)to investigate the P-binding mode of changed biochar surface.Meanwhile,this paper quantitatively analyzes the changes of P form and content in biochar before and after changing by combining the Hedley phosphorus classification method with visible spectro-photometry.The result shows that the I/Ivalue of biochar increases and the graphitization structure enhances to form the P-containing granular structure after changing the properties of H_(3)PO_(4)and H_(4)P_(2)O_(7).It has promoted the formation of carboxyl(—COOH),P—O—P and P—H acid functional groups on the surface of biochar for changes of H_(3)PO_(4)and H_(4)P_(2)O_(7).They are similar to functional groups on the surface of changed biochar of HPOand changed biochar of HPO.XPS result shows that it increases by 13.15%~32.44%significantly by compared with WBC and CBC for the relative content of O1 s peak in the changed treatment.Meanwhile,it also shows that it increases by 18.54%~27.02%significantly for the relative content of the P(2s)peak(p<0.05).They have divided P(2s)and O(1s)into C—P—O,C—O—P,OPO,CO and(or)PO,C—O—C and(or)P—O—C and P—O—P for the deconvolution integral peaks.It can promote the formation of C—O—P,OPO,C—O—C and/or P—O—C and P—O—P bonds for the changed properties of HPOby comparing with the changed properties of HPO.It also significantly increases the total P content in biochar for the changed properties.Meanwhile,it is significantly higher than that in P—WBC and P—CBC for the P content in PA-WBC and PA-CBC.The active P content in the changed treatment significantly increases by 2.36~14.77 g·kg^(-1)compared with WBC and CBC.In addition,the stable P content significantly decreases by 0.06~0.17 g·kg^(-1)(p<0.05).The active P and moderate active P of PA-WBC and PA-CBC significantly increase by 5.27~15.66 and 0.53~0.64 g·kg^(-1)respectively.The stable P content decreases by 0.03~0.34 g·kg^(-1)(p<0.05).In conclusion,it has changed the binding mode of P on biochar surface and increased the activity of P for the changed properties of H_(3)PO_(4)and H_(4)P_(2)O_(7).The difference in the content and binding mode of P in different forms between H_(3)PO_(4)and H_(4)P_(2)O_(7)modified biochar are of great significance for further exploring the bioarailability of P.
作者
王旭阳
孙涛
朱新萍
唐光木
贾宏涛
徐万里
WANG Xu-yang;SUN Tao;ZHU Xin-ping;TANG Guang-mu;JIA Hong-tao;XU Wan-li(College of Resources and Environment Science,Xinjiang Agricultural University,Urumqi 830052,China;Institute of Soil and Fertilizer&Agricultural Sparing Water,Xinjiang Academy of Agricultural Sciences,Urumqi 830091,China)
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2022年第10期3084-3090,共7页
Spectroscopy and Spectral Analysis
基金
国家重点研发计划项目(2018YFD0200406)
国家自然科学基金项目(31660073)资助。
关键词
生物炭
改性
磷形态
光谱分析
Biochar
Modification
Phosphorus species
Spectral analysis
