Date of Award

2019

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering (MSCE)

Department

Civil Engineering

First Advisor

Dr. Stephanie Luster-Teasley

Second Advisor

Dr. Manoj K Jha

Abstract

In this study, sodium persulfate was encapsulated in polyvinyl acetate (PVAc) polymer to investigate the potential of activated persulfate to remediate total coliform and E. coli bacteria from contaminated water through a control release system. Controlled release structures were produced with the polymer and persulfate melted to form pellets at two different baking times. CRP structures containing 60 weight % sodium persulfates blended with 40 weight % polyvinyl acetate (PS- PVAc) were baked for 4 minutes and 10 minutes at 120ºC. The kinetics release of sodium persulfate was studied in a water system and in sand columns. Experimental results showed that for a baking time of 4 minutes, the pellets appear to release the oxidant at a higher rate than the pellets baked for 10 minutes in water. The average total percent release of sodium persulfate from the 10-minute baked (high-bake time) 60%PS-40%PVAC pellets in water was (95.95 ± 1.4)%, which was lower when compared to the 4-minute baked (low bake time) pellets which were at (99.57± 0.4) %. For soil column, the average percent release of sodium persulfate from 4-minute pellets was (82.69± 4.58) % whereas 10-minute pellet released (17.87± 3.54) % for the same experimental time frame. For the second phase of the study, pellets consisting of 20% PS-80%PVAC were investigated. Controlled release pellets were made with catalysts. Controlled release Fe, base, and KMnO4 were produced and combined in a batch reactor with the encapsulated persulfate pellets. Additionally, heat was evaluated as a potential catalyst in the studies. The goal for this portion of the study was to observe if controlled release persulfate remediation could be enhanced with controlled release catalysts that would activate the persulfate in solution for bacteria remediation. The catalysts of heat and controlled release Fe2+, NaHCO3 or KMnO4 were studied in water for 72 hours. Among all the catalyst only KMnO4 showed potential of bacteria 2 inactivation. The controlled release system with Fe2+ activated persulfate required 9 hours to achieve complete bacteria remediation. Controlled release persulfate activated with base required 6 hours and the controlled release system with KMnO4 activated persulfate required 3 hours for bacteria inactivation. Controlled release persulfate activated with heat completed coliform inactivation within 15 hours. Experiment results show that while only persulfate (non-activated) completed the disinfection in 30 hours, persulfate activated in CRP system were able achieved complete coliform remediation by half of that treatment time.

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