| 镁改性芦苇生物炭控磷效果及其对水体修复 |
| 摘要点击 2056 全文点击 776 投稿时间：2019-10-05 修订日期：2019-11-28 |
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| 中文关键词 芦苇 生物炭 水体 底泥 磷 |
| 英文关键词 reed biochar water sediment phosphorus |
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| 中文摘要 |
| 将收割的芦苇制成生物炭，投加到底泥中以控制内源磷释放，是一种将芦苇资源化利用的新途径.将芦苇通过氯化镁浸渍改性，分别在300、450和600℃条件下高温裂解，制得3种镁改性芦苇生物炭，通过等温吸附实验分析3种炭对磷酸盐的吸附特征，选择了对磷酸盐吸附效果较好的生物炭MBC-450作为研究材料.以某校园河道底泥和上覆水为研究对象，探讨镁改性芦苇生物炭在不同投加方式（混合和覆盖）下对上覆水磷酸盐的吸附作用及内源磷释放的控制效果.结果表明，混合和覆盖投加可有效降低上覆水DIP浓度，与对照组相比磷累积吸附量分别提高了17.3%和11.7%；混合投加对间隙水磷的控制效果更明显，与对照组相比，间隙水DIP从0~2 cm至4~6 cm分别降低了14.7%、18.9%和35.36%，而覆盖投加对应分别降低了33.3%、-28.2%和12.9%.与对照组相比，生物炭混合和覆盖分别导致0~2 cm和2~4 cm底泥中NH4Cl-P占TP的比例分别升高了15%、15%（混合）和12%、2%（覆盖），而BD-P占TP的比例分别降低了7%、9%（混合）和6%、3%（覆盖），Al-P占TP的比例分别降低了7%、6%（混合）和7%、-1%（覆盖），其余形态磷变化不明显.生物炭混合和覆盖投加均能提高表层底泥微生物的活性，混合投加方式对更深层底泥微生物活性的提高更显著. |
| 英文摘要 |
| Adding biochar from harvested reed to sediments is a new method to control the release of sedimentary phosphorus. Three types of Mg-modified biochars were prepared by pyrolysis of reed modified by magnesium chloride at 300, 450, and 600℃.The phosphate adsorption characteristics of the three types of biochars were analyzed by isothermal adsorption experiments. Biochar MBC-450 with good phosphate adsorption effects was selected as the material for the following experiments. Taking the sediment and overlying water of a campus river as the experimental object, we studied the adsorption of phosphate in overlying water and the control of sedimentary phosphorus by Mg-modified biochar under different dosage modes (mixing and covering). The concentration of DIP in the overlying water could be effectively reduced by biochar mixing and covering, and the accumulative phosphorus adsorption capacity increased by 17.3% (mixing) and 11.7% (covering) compared with that of the control. The control effect of sedimentary phosphorus by biochar mixing was more obvious; the DIP in sedimentary water decreased by 14.7%, 18.9%, and 35.36% from 0-2 cm to 4-6 cm compared with the control. The DIP in sedimentary water decreased by 33.3%, -28.2%, and 12.9% when covered with biochar. Compared with the control, the proportion of NH4 Cl-P in the sediment of 0-2 cm and 2-4 cm increased by 15% and 15% (mixing) and 12% and 2% (covering), respectively, while BD-P in TP decreased by 7% and 9% (mixing) and 6% and 3% (covering), respectively, and the Al-P in TP decreased by 7% and 6% (mixing) and 7% and -1% (covering), respectively. The other forms of phosphorus did not change significantly. Biochar mixing and covering can both improve the microbial activity in surface sediment, and biochar mixing can improve the microbial activity in deeper sediments more significantly. |
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