改性膨润土和沉水植物联合作用处理沉积物磷

首次将改性膨润土（modified bentonite，MB）作为原位吸附材料与沉水植物苦草（Vallisneria spiralis，V.spiralis）联合处理沉积物磷.研究结果表明，MB可以促进沉水植物V.spiralis的生长， V.spiralis可能通过根系分泌作用促进溶磷或是通过促进根际微生物群落的P代谢活性增加沉积物中的生物可利用性P含量.MB与沉水植物V.spiralis对沉积物P的联合作用效果优于MB和沉水植物V.spiralis单独作用之和.厚度5cm MB和V.spiralis联合作用对沉积物TP，IP，OP，Fe/Al-P和Ca-P的去除率可达59.8%，57.1%，67.8%，66.7%和44.7%.微生物试验结果表明，厚壁菌门Erysipelotrichaceae科的菌属PSB-M-3是联合组相比单一V.spiralis组或单一MB组微生物群落P代谢功能增强的主要贡献者.本研究还首次发现了Erysipelotrichaceae科微生物可作为沉积物中潜在的除磷菌.研究结果表明MB和沉水植物联合控制沉积物磷技术可进一步应用到富营养化湖泊沉积物控制工程.

Synergistic removal of sediment P by combining the modified bentonite and Vallisneria spiralis

The removal efficiency of sediment phosphorus (P) with the in-situ synergistic effect of modified bentonite (MB) granules and Vallisneria spiralis (V. spiralis) in West Lake, Hangzhou, China was investigated for the first time in the study. Results showed that MB could promote the growth of V. spiralis, and the residual P of the sediment not adsorbed on MB was changed through root oxygenation and nutrition allocation, and then enhanced the extra P adsorption on MB. The combination of MB and V. spiralis exhibited a synergistic removal effect higher than the summation of MB and V. spiralis applied separately. The results of microcosm experiments showed that the combination of MB and V. spiralis enhanced the function of P metabolism by increasing the special genus that belongs to the family Erysipelotrichaceae.