Use of lanthanum/aluminum co-modified granulated attapulgite clay as a novel phosphorus (P) sorbent to immobilize P and stabilize surface sediment in shallow eutrophic lakes
Use of lanthanum/aluminum co-modified granulated attapulgite clay as a novel phosphorus (P) sorbent to immobilize P and stabilize surface sediment in shallow eutrophic lakes
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DOI：
10.1016/j.cej.2019.123395
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发表时间：
2020-04
影响因子：
15.1
通讯作者：
Hongbin Yin;Pan Yang;M. Kong;Wei Li
中科院分区：
文献类型：
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作者：
Hongbin Yin;Pan Yang;M. Kong;Wei Li
在富营养化浅水湖泊中，沉积物再悬浮频繁，pH值较高，因此开发一种吸附剂对沉积物中移动的磷进行吸附是非常重要的。在这项研究中，将镧（La）和铝（Al）共掺入颗粒状热处理富钙凹土（TCAP）中，制备一种新型磷吸附剂，以克服富营养化湖泊管理中的这些问题。La/Al共改性TCAP（LA@TCAP）对磷的最大吸附容量为10.6mg/g，颗粒状吸附剂在较宽的pH值范围内对磷有较好的吸附性能。124 d的底泥培养试验（好氧培养34 d，厌氧培养90 d）表明，与对照处理相比，理论投加量可使上覆水中可溶性活性磷（SRP）降低50%以上。在整个培养过程中，理论投加量可减少40%以上的沉积物-水界面磷通量，表层沉积物中60%的移动的磷被还原并转化为NaOH-rP（Al-P）和HCl-P（Ca-P）等稳定的惰性磷。结果还表明，颗粒LA@TCAP可以稳定表面沉积物，从而减少悬浮物，SRP，和TP在模拟频繁的沉积物再悬浮的水柱相比，传统的磷吸附剂（硫酸铝）。此外，沉积物中的失活磷形态在pH值升高时保持相对稳定。XPS分析表明，LA@TCAP吸附的P主要与Al和La形成球内络合。本研究的所有结果表明，LA@TCAP具有修复浅水富营养化湖泊沉积物磷的潜力。
It is crucial to develop a phosphorus (P) sorbent to immobilize sediment mobile P from shallow eutrophic lakes with frequent sediment resuspension and high pH values. In this study, lanthanum (La) and aluminum (Al) were co-incorporated into granulated thermally treated calcium-rich attapulgite (TCAP) to prepare a novel P sorbent to overcome these problems in eutrophic lake management. The maximum P sorption capacity of the La/Al co-modified TCAP (LA@TCAP) is 10.6 mg/g, and the granulated P sorbent performs well in a wide range of pH values during sorption from solution. A total of 124 days of sediment incubation study (34 days of aerobic incubation and 90 days of anaerobic incubation) indicated that more than 50% of the soluble reactive phosphorus (SRP) in overlying water can be reduced with the theoretical dosage in comparison with the control treatment. More than 40% of P flux across the sediment–water can be reduced with a theoretical dosage, and 60% of the mobile fraction of P in surface sediment can be reduced and transformed into stable inert P fractions such as NaOH-rP (Al-P) and HCl-P (Ca-P) during the whole period of incubation. Results also indicated that the granule LA@TCAP can stabilize surface sediment and thus reduce suspended solids, SRP, and TP in a water column in simulated frequent sediment resuspension when compared with traditional P sorbent (aluminium sulfate). Furthermore, the inactivated P forms in sediment remained relatively stable under elevated pH values. XPS analysis indicated that P sorbed by LA@TCAP mainly formed by inner-sphere complexation with Al and La. All results of this study indicate that LA@TCAP has the potential for sediment P remediation from shallow eutrophic lakes.