Persulfate (S2O8(2-)) is being used increasingly for in situ chemical oxidation (ISCO) of organic contaminants in groundwater, despite an incomplete understanding of the mechanism through which it is converted into reactive species. In particular, the decomposition of persulfate by naturally occurring mineral surfaces has not been studied in detail. To gain insight into the reaction rates and m...

by MARISSA C. MERKER, M.S.C.E. Washington State University August 2010 Chair: Richard J. Watts Persulfate is a promising in situ chemical oxidation treatment (ISCO) for the remediation of low-permeability strata because it is more stable in the subsurface and can rapidly degrade recalcitrant contaminants compared to other technologies. ISCO technologies include catalyzed hydrogen peroxide propa...

In situ chemical oxidation (ISCO) has been widely used in recent years for the remediation of VOC contaminated soil and groundwater. Among several chemical oxidizing agents injected into the subsurface for ISCO, persulfate has often been selected due to the advantage of being less reactive and longer-lived in the subsurface environment. Through this research, the effect of side reactions occurr...

Acrylate grouting material has been widely used in dams, tunnels and other underground buildings. This paper introduces the basic components of acrylate grouting material, then the reaction mechanism and dynamics of gelation process are discussed based on the theory of free radical polymerization. By measuring the relationship between gelation time and the concentration of initiator ammonium pe...

In this paper, a novel gelatin-based hydrogel was synthesized through crosslinking graft copolymerization of methacrylic acid (MAA) onto gelatin, using ammonium persulfate (APS) as a free radical initiator in the presence of methylenebisacrylamide (MBA) as a crosslinker. A proposed mechanism for hydrogel formation was suggested and the structure of the product was established using FTIR spectro...

In this short communication, the demonstration of a new integrated process concept involving the use of a bio-based material for detoxification of Cr(VI)-contaminated water is presented. Specifically, the bio-based material is a polyaniline/cellulose fiber composite prepared by in situ polymerization of aniline in the presence of cellulose fibers, using the industrially favorable hydrogen perox...

In this paper, we demonstrate for the first time that poly(m-phenylenediamine) (PMPD) nanospheres and nanorods can be selectively synthesized via chemical oxidation polymerization of m-phenylenediamine (MPD) monomers using ammonium persulfate (APS) as an oxidant at room temperature. It suggests that the pH value plays a critical role in controlling the the morphology of the nanostructures and f...

Hydrogels have been extensively explored for biomedical applications due to their ability to absorb high water content in its structure, which gives excellent biocompatibility. This work aims at obtaining biocompatible hydrogels with potential for use in increasing the mechanical strength of bone substitutes, or controlled drug release. Poly (N-vinyl-2-pyrrolidone) hydrogels were prepared by fr...

We reported the functionalization of multiwalled carbon nanotube (MWCNT) with 4-aminobenzoic acid by a ‘‘direct’’ Friedel–Crafts acylation reaction in a mild polyphosphoric acid (PPA)/phosphorous pentoxide (P2O5) medium. The resulting 4aminobenzoyl-functionalized MWCNT (AF-MWCNT) was used as a platform for the grafting of polypyrrole (PPy) in ammonium persulfate (APS)/aqueous hydrochloric acid ...

Biochar (BC) supported nanoscale zerovalent iron (nZVI) composite was synthesized and used as an activator for persulfate to enhance the trichloroethylene (TCE) removal in aqueous solutions. The degradation efficiency of TCE (0.15mmolL(-1)) was 99.4% in the presence of nZVI/BC (4.5mmolL(-1), nZVI to BC mass ratio was 1:5) and persulfate (4.5mmolL(-1)) within 5min, which was significantly higher...