镧改性膨润土钝化湖泊中的磷及其生态风险的研究进展

Advances in researches on phosphorus immobilization by lanthanum modified bentonite in lakes and its ecological risk

磷的过度输入是湖泊富营养化的关键原因,由于内源(沉积物)磷的释放,即使外源磷输入得到控制,富营养化湖泊的水质仍难以改善.近年来,利用镧改性膨润土(lanthanum modified bentonite,LMB)原位钝化沉积物中的磷,抑制湖泊内源磷释放备受关注.为了更好地理解和应用镧改性膨润土钝化磷技术,本文首先介绍镧改性膨润土的组成和其钝化磷的原理,其次梳理LMB磷钝化技术在富营养化湖泊中的应用效果,再分析影响LMB钝化磷效率的因素,最后阐述LMB在应用过程中可能产生的生态风险;并根据以上分析,提出LMB磷钝化技术应用中需要注意的方面,对该技术的后续研究方向进行展望.

Phosphorous(P) has been considered a key factor in inducing eutrophication. The internal P loading(mainly P release from the sediment) has been found to delay the lake recovery following the reduction of external loading from the watershed. The control of internal loading by chemical immobilization of P using the lanthanum(La) modified bentonite(LMB) has been widely applied in recent years. This paper reviews the advances in the immobilization of P by LMB, including the following aspects:(1) the composition of LMB and mechanism of LMB to immobilize P;(2) the response of P and lake ecosystem to LMB treatment;(3) the factors affecting the treatment efficiency of LMB technology, and(4) the possible ecological risks in the application LMB. After that, the cautions during the LMB application are pointed out and the possible research in this field is proposed.