Rhizosphere activity induced mobilization of heavy metals immobilized by combined amendments in a typical lead/zinc smelter-contaminated soil.
Rhizosphere activity induced mobilization of heavy metals immobilized by combined amendments in a typical lead/zinc smelter-contaminated soil.
复制标题
DOI：
10.1016/j.chemosphere.2022.137556
复制
发表时间：
2022-12
期刊：
影响因子：
8.8
通讯作者：
Youfa Luo;Chuanjing Tan;Yu-Fen He;Yulu Chen;Zuyan Wan;Tianling Fu;Yonggui Wu
中科院分区：
文献类型：
--
作者：
Youfa Luo;Chuanjing Tan;Yu-Fen He;Yulu Chen;Zuyan Wan;Tianling Fu;Yonggui Wu
改良剂对重金属污染土壤的稳定作用的持久性是人们非常关注的问题。本文通过盆栽试验研究了连续两季蔬菜栽培对不同施用比例（0、20、40和80 g kg−1，标记为C0、C2、C4和C8）的复合改良剂（石灰：海泡石：生物炭：腐殖酸= 2：2：1：1）固定的重金属（Cu、Pb、Zn和Cd）的活化作用。结果表明，在对照（CK）处理中，HM的生物有效性随着复合改良剂施用比例的增加而降低。连续两季蔬菜栽培过程中，蔬菜叶片DOC含量、HM生物有效性和HM含量均呈上升趋势，pH值呈下降趋势，但C2、C4和C8处理的HM生物有效性低于C0处理。过氧化氢酶，尿素酶，碱性磷酸酶，脱氢酶活性的组合修正处理与蔬菜相比，在C0处理。不同处理的优势菌门相对丰度第一季为放线菌门>变形菌门>绿黄杆菌门>酸性细菌门>芽单胞菌门>拟杆菌门，第二季为变形菌门>放线菌门>绿黄杆菌门>酸性细菌门>拟杆菌门>芽单胞菌门。相关性分析表明，连续两季蔬菜栽培的pH和DOM特性是影响HM生物有效性、酶活性和细菌群落组成的重要因素。细菌群落组成的转变间接影响固定化的HMs的联合修正案的动员。因此，根际活动诱导动员的固定HMs在连续两个季节的蔬菜种植的组合修正案。
The persistence of the stabilization effect of amendments on heavy metals (HMs) is of great concern when they are used for remediating HM-contaminated soil. Here, pot experiments were conducted to investigate the effects of two consecutive seasons of vegetable cultivation on the mobilization of HMs (Cu, Pb, Zn, and Cd) immobilized by different application ratios (0, 20, 40, and 80 g kg−1, labelled C0, C2, C4, and C8) of a combined amendments (lime: sepiolite: biochar: humic acid = 2:2:1:1). The results showed that HM bioavailability decreased with increasing application ratios of the combined amendments in control (CK) treatments. The DOC contents, HM bioavailability, and HM contents in the leaves of vegetables increased, but the pH decreased during two consecutive seasons of vegetable cultivation; however, the HM bioavailability in the C2, C4, and C8 treatments was lower than that in the C0 treatments with vegetables. Catalase, urease, alkaline phosphatase, and dehydrogenase activities in the combined amendment treatments with and without vegetables were decreased compared to those in the C0 treatments. The relative abundances of the dominant bacterial phyla in the different treatments wereActinobacteria>Proteobacteria>Chloroflexi>Acidobacteria>Gemmatimonadetes>Bacteroidetesfor the first season andProteobacteria>Actinobacteria>Chloroflexi>Acidobacteria>Bacteroidetes>Gemmatimonadetesfor the second season. Correlations showed that the pH and DOM properties during two consecutive seasons of vegetable cultivation were important factors influencing HM bioavailability, enzyme activity, and bacterial community composition. The bacterial community composition shift indirectly influenced the mobilization of HMs immobilized by the combined amendments. Thus, rhizosphere activity induced the mobilization of HMs immobilized by combined amendments during two consecutive seasons of vegetable cultivation.