Evaluation of Chemical Treatments for a Mixed Contaminant Soil

Waisner, Scott A.; Medina, Victor F.; Morrow, Agnes B.; Nestler, Catherine C.

doi:10.1061/(asce)0733-9372(2008)134:9(743)

Cited by 24 publications

(14 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Sulfate is the major inorganic byproduct of persulfate reactions and is an extremely weak conjugate base. Thus, where protons are produced from persulfate reactions, there is potential for a drop in pH; this has been observed in many persulfate systems (Sperry et al, 2002;Block et al, 2004;Waisner et al, 2008). However, the severity of the pH drop is likely a function of the aquifer buffering capacity, as well as the oxidant dose.…”

Section: Impact Of Ph On Radical Intermediatesmentioning

confidence: 90%

“…For instance, Block et al (2004) noted a pH drop from 7 to nearly 2 in unbuffered batch systems with nearly all activation methods except alkaline activation. Even with alkaline activation, pH changes can occur; Waisner et al (2008) observed a pH drop from 11 to 9, which could reduce oxidant activation effectiveness. At a field site, Sperry et al (2002) noted a drop in pH from 5.7 to only 5.3 in monitoring wells, potentially indicating that pH shifts observed under field conditions may be smaller than those in the laboratory.…”

Section: Impact Of Ph On Radical Intermediatesmentioning

confidence: 94%

“…Reaction intermediates were not quantified, but even in one of the most highly treated systems, a 23% TOC content remained, indicating that perhaps some organic byproducts are formed. Waisner et al (2008) …”

Section: Polychlorinated Biphenylsmentioning

confidence: 97%

“…At this pH, propagation reactions favor hydroxyl radical as the major reactant over sulfate radical (Liang et al, 2007b). Acid production by the oxidant may cause the pH to drift back down deactivating the oxidant (Waisner et al, 2008).…”

Section: Alkaline Activationmentioning

confidence: 99%

See 3 more Smart Citations

Fundamentals of ISCO Using Persulfate

Petri

Watts

Tsitonaki³

et al. 2010

SERDP/ESTCP Environmental Remediation Technology

View full text Add to dashboard Cite

ScopeChemistry and use of persulfate for in situ chemical oxidation of subsurface contaminants, including free radical and other reaction mechanisms, catalysts, subsurface transport, and contaminant treatability. Key ConceptsPersulfate reaction chemistry is complex. Persulfate can react through direct electron transfer or free radical reactions. Electron transfer reactions are relatively slow and selective. Upon activation, the free radicals generated have nonspecific reactivity that allows for the degradation of a wide range of organic contaminants. The radicals that are presently understood to play a major role in reactions are the sulfate radical and the hydroxyl radical. However, there is emerging evidence that the superoxide anion and the perhydroxyl radical also may be important. Persulfate activation may be achieved by heat, chelated or non-chelated transition metals (especially iron), hydrogen peroxide, and alkaline pH conditions. The efficiency, effectiveness, and reaction products may vary between contaminants, activation methods, and the porous media to be treated. Carbonate, bicarbonate, or chloride ions can act as free radical scavengers and reduce reaction efficiency and effectiveness. The kinetics of reaction between persulfate and target compounds is complex. To simplify, pseudo first-order kinetics are often assumed. However, these usually require laboratory estimation because extrapolating between systems is difficult. The interaction of aquifer solids and persulfate is not well understood; persulfate does react with aquifer solids resulting in oxidant consumption, but the rate and magnitude of this process are not well characterized. Persistence varies from days to months, depending on conditions. The impact of persulfate on metal mobility is not well understood. Conceivably, persulfate could impact metal concentrations in groundwater through modification of pH, oxidation of metals, injection of activation amendments, and other mechanisms.

show abstract

Section: Impact Of Ph On Radical Intermediatesmentioning

confidence: 90%

Section: Impact Of Ph On Radical Intermediatesmentioning

confidence: 94%

Section: Polychlorinated Biphenylsmentioning

confidence: 97%

Section: Alkaline Activationmentioning

confidence: 99%

See 2 more Smart Citations

Fundamentals of ISCO Using Persulfate

Petri

Watts

Tsitonaki³

et al. 2010

SERDP/ESTCP Environmental Remediation Technology

View full text Add to dashboard Cite

show abstract

“…At pilot-scale, the reaction performed best when the lime was mixed well into the soil, bringing the hydroxide ion into close contact with the explosive material. The calcitic, hydrated lime (Ca(OH) 2 ), used primarily in engineering applications, proved most amenable to soil treatment for alkaline hydrolysis [17,18].…”

Section: Introductionmentioning

confidence: 99%

Hydrated lime for metals immobilization and explosives transformation: Treatability study

Martin

Larson

Nestler

et al. 2012

Journal of Hazardous Materials

View full text Add to dashboard Cite

a b s t r a c tFragmentation grenades contain Composition B (RDX and TNT) within a steel shell casing. There is the potential for off-site migration of high explosives and metals from hand grenade training ranges by transport in surface water and subsurface transport in leachate. This treatability study used bench-scale columns and mesocosm-scale laboratory lysimeters to investigate the potential of hydrated lime as a soil amendment for in situ remediation of explosives and metals stabilization in hand grenade range soils. Compared to the unamended soil there was a 26-92% reduction of RDX in the leachate and runoff water from the lime treated soils and a 66-83% reduction of zinc in the leachate and runoff water samples; where the hand grenade range metals of concern were zinc, iron, and manganese. The amended soil was maintained at the target pH of greater than 10.5 for optimum explosives decomposition. The treatability study indicated a high potential of success for scale-up to an in situ field study.Published by Elsevier B.V.

show abstract