| Ca改性生物炭对土壤磷赋存形态影响及稳定化机制 |
| 摘要点击 1186 全文点击 200 投稿时间：2022-11-15 修订日期：2023-04-21 |
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| 中文关键词 改性生物炭 土壤 新增淹没区 磷酸盐 赋存形态 |
| 英文关键词 modified biochar soil new submerged area phosphorus chemical speciation |
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| 中文摘要 |
| 针对湖库周边农田淹没后土壤磷释放风险控制的问题，采用共热解法制备Ca改性生物炭（Ca-BC），通过X射线光电子能谱分析（XPS）、X射线多晶粉末衍射分析（XRD）、吸附实验和模拟培养实验等，进行Ca-BC 对土壤磷赋存形态影响和稳定化机制研究.结果表明，Ca-BC 吸附磷的过程符合Langmuir（R2 = 0.940）和一级吸附动力学模型（R2 = 0.961），表明该吸附过程为化学作用主导的单层吸附，最大吸附量达到267.93 mg·g-1.模拟培养实验表明，当Ca-BC添加量为1%时，土壤中较活跃性的交换态磷形态从7.42%下降至4.59%. XRD结果表明，Ca-BC吸附磷后出现Ca3（PO4）2和Ca5（PO4）3（OH）吸收峰，证明磷酸盐在生物炭表面形成较稳定的晶体沉淀.XPS分析表明，生物炭表面羰基官能团参与磷固定过程，提高了生物炭对磷的吸附能力.总体来讲，Ca-BC 添加量大于1%时，对磷的释放有较好的固定能力，具备对土壤磷释放控制的潜在应用价值. |
| 英文摘要 |
| To control of phosphorus release from soil after farmland inundation around the lake and reservoir， calcium modified biochar （Ca-BC） was prepared using the coprecipitation method. Through X-ray photoelectron spectroscopy （XPS）， X-ray polycrystalline powder diffraction （XRD）， adsorption experiments， and simulated culture experiments， the effects of Ca-based biochar on the fraction of soil phosphorus （P） and its stabilization mechanism were studied. The results showed that the adsorption process of Ca-based modified biochar conformed to Langmuir （R2 = 0.940） and the first-order adsorption kinetic model （R2 = 0.961）， indicating that the P adsorption was a single-layer adsorption dominated by chemical action， and the maximum adsorption capacity was 267.93 mg·g-1. The simulated culture experiment indicated that when the modified biochar was 1%， the exchangeable fraction of phosphorus in the soil decreased from 7.42% to 4.59%. The XRD results demonstrated that Ca3（PO4）2 and hydroxyapatite absorption peaks appeared after adsorbed phosphorus on biochar， which proved that phosphate formed a relatively stable crystal precipitation. As shown in the XPS spectrum analysis， the carbonyl functional groups participated in the phosphorus fixation process， which improved the adsorption capacity of biochar for phosphorus. In general， when the concentration of Ca-based modified biochar was greater than 1%， it had a good fixation capacity for phosphorus release and had potential application value for controlling phosphorus release in soil. |
