Preliminary Analyses of Controlled Release of Potassium Permanganate Encapsulated in Polycaprolactone

Abstract

Potassium permanganate (KMnO 4) has been used widely as an oxidant for remediation of contaminated soil and water systems. The present study evaluates the release of this oxidant from Polycaprolactone (PCL) polymer as part of a patented controlled release process (CRP) to be applied for targeted removal of contaminants from water. KMnO 4 was encapsulated into PCL at a 1:5 oxidant to polymer ratio and placed in batch reactor systems with reagent water to be evaluated over a 96 hour period. SEM images showed that over time, the number of cavities and their sizes increased on the waxy surface of the PCL polymer. The experimental data from the release of KMnO 4 from PCL was found to fit non-Fickian diffusion model after dissolution (R 2 = 0.93) similar to other systems that describe the dispersal of other oxidants from wax matrices. In addition, the model parameters for data of this present study were also found to be comparable to previous release studies with the same oxidant encapsulated in different wax matrices at similar ratios. Overall, the similarity of release data between the diversity of polymers shows that the controlled release biodegradable polymer utilizing PCL provides effective release of the KMnO 4 with the added benefit biodegradable nature of PCL.

Comparison of Release Efficiencies for the Controlled-Release of Potassium Permanganate in Polycaprolactone

“…The present study focused on a CRBP system to measure the discharge of varied levels of KMnO 4 oxidant into aqueous systems. In the batch systems, dissolution of the PCL polymer releasing the KMnO 4 corresponded to what had been seen in other controlled-release systems [5] [23] [25] and, more specifically, with systems utilizing the same polymer oxidant system [20] [27]. As the amount of KMnO 4 in the PCL polymer pellets increased, a greater fraction of the oxidant was released as a function of time (Figure 2).…”

“…These SEM images show the circular cavities or crevices within the polymer surface increase as a function of time of pellet contact in water increases. This resulting growth in cavities due to dissolution has also been seen in similar controlled release systems using KMnO 4 [15] [24] [27]. The growing crevices displayed in the SEM images (Figure 5) as time increased were indicative of the biphasic trends shown by the release data (Figure 4).…”

“…More recently, PCL has been used within environmental engineering as a controlled-release polymer with a total degradation expectancy of 2 to 4 years [29]. Advantages for the use of PCL for controlled-release are its characteristic properties including low melting point (60˚C), controlled degradation kinetics, exceptional blending capabilities with other materials, as well as easy formability through physical manipulation for shaping purposes [27].…”

“…Previous studies have shown the successful implementation of encapsulated KMnO 4 as a viable in-situ slow-release remediation method and confirmed that PCL is biodegradable in nature [15] [22] [23]. Though there has been research into the overall utilization of KMnO 4 in other CRM systems [24] [25] [26], there has been limited study to examine release kinetics associated with this particular CRBP system for potential treatment of aqueous systems [27]. This present study examines the kinetics of a controlled release of KMnO 4 oxidant encapsulated in PCL at various oxidant to polymer ratios.…”

Analysis of the effects of in-situ chemical oxidation on microbial activity using Pseudomonas putida F1

“…Table 1 provides the list of chemicals studied in the paper ( Huling and Pivetz, 2002 ; Khodaveisi et al., 2011 ; Miao et al., 2015a , 2015b , and 2015c ). Permanganate is available as a salt (KMnO4 and NaMnO4) and has been widely used as an ISCO oxidant for the remediation of contaminated soil and groundwater systems ( King et al., 2021 ; Khodaveisi et al., 2011 ; Li and Schwartz, 2004 ). Previous studies ( Liu et al., 2014 ; Waldemer and Tratnyek, 2006 ) have suggested that permanganate is less powerful than other oxidative species but reacts quickly with specific contaminants including chlorinated ethenes.…”