Lead complexation by functionalized nanospheres.

摘要

Nanomaterials are widely used for various applications. However they have not been extensively studied for environmental remediation purposes. This study was aimed at evaluating lead complexation efficiency of innovative functionalized nanospheres by studying the impact of pH, the impact of the amount of nanospheres used, and the role of the functional groups. In this study, five different materials were studied, namely, carboxyl-functionalized polyethylene glycol based nanospheres (ACW-06), hydroxyl-functionalized polyethylene glycol based nanospheres (ACW-03), polyethylene glycol based polymer without functional groups (BP1), polyethylene glycol based polymer without functional groups and carbon side chains (BP2), and polyethylene glycol polymer. Bench-scale experiments were conducted by mixing each material after dissolving in distilled water with free lead ion for 30 minutes at room temperature. Residual free lead ion concentration in the mixture was measured by an ion selective electrode. NMR analysis was performed on ACW-06 complexed with lead to understand the complexation mechanism using nanospheres. The following results were obtained: (1) ACW-06 had the highest lead complexation efficiency of 93.5%, followed by ACW-03 of 89.9%, BP1 of 71.4%, BP2 of 52.2% and polyethylene glycol of 21.2%; (2) lead complexation efficiency was pH dependent; it increased with the increase in pH for all the materials except for ACW-03 and BP1. ACW-06 was further studied and the results include: (1) lead complexation efficiency increased with the amount of nanospheres used; (2) lead complexation efficiency increased with the increase in the number of functional groups; (3) NMR data clearly showed that benzene rings, functional groups, carbon side chains, and polyethylene glycols in ACW-06 all participated in lead complexation.