(187e) Hydrogel Immobilized Nanoparticles for TCE and PCBs Dechlorination

It has long been known that chlorinated organics are stubborn ground water contaminant because of the hydrophobic nature and chemical stability. It's a promising way to use zero valent metal nanoparticles for the dechlorination of chlorinated organics due to their high surface area and high free energy. However, nanoparticles are so easy to aggregate that the dechlorination rate decreases. Stabilizers including ligand, surfactant and polymers have been reported to overcome this problem. In this research, a novel strategy for stabilizing metal nanoparticles with hydrogel as stabilizer was established. Hydrogel immobilized nanoparticles possess many advantages: prevention of aggregation, tunable nanoparticle size and morphology, adjustable reactivity by the variance of hydrophobicity and hydrophilicity. In-situ synthesis of reactive nanoparticles with controlled size and structure in hydrogel network is successfully demonstrated by TEM, SEM and high resolution STEM-EDS mapping analysis. The particles show uniform size and distribution immobilized in polymer domain. The hydrogel immobilized metallic nanoparticles exhibit fast reduction capacity. TCE dechlorination by nanoparticles immobilized in hydrogel and in solution phase were conducted separately and the results show that the reactivity in hydrogel network was decreased while the stability was increased.