Surfactant Assisted Chemical Oxidation (SACO)
Surfactant assisted chemical oxidation is widely recognised as a means for treating soils impacted with organic contaminants.
In the late 1990s Enviropacific Services Managing Director Matt Fensom worked on two Sydney sites where the remediation approach involved the application ofex-situ surfactant assisted chemical oxidation. Matt says … “the first site was a Department of Defence site impacted with PAHs and the second was an AAMI inspection depot impacted with solvents, TPH and low level PAHs.The technology outperformed on TPH and solvents although there were inconsistent and mixed results with the PAHs particularly with the more recalcitrant compounds such as benzo[a]pyrene”.
Building on this earlier work, Enviropacific Services (Enviropacific) have performed a number of bench-scale trials over the last 3 years examining chemical oxidation of PAHs, TPH and solvent contaminated soils. Results from these trials have been encouraging and have demonstrated significant reductions in PAH and TPH concentrations.
Our Technical Manager Dr Annette Nolan says … “the use of locally produced plant-based surfactants has been shown to substantially improve the rate of oxidation compared to results with oxidant alone” (refer to Table 1). Based on the results of the Surfactant Assisted Chemical Oxidation (SACO) in Table 1, Enviropacific are progressing towards the full-scale SACO treatment of 30,000 tonnes of PAH contaminated soil.
Our new laboratory (see photo left) enables SACO treatment trials to be conducted in a safe and efficient manner with oversight from our Technical Manager. With the ability to conduct these trials in-house, we not only rapidly quantify the capacity of SACO to destroy the contaminants but also the respective commercial viability.
Matt says …“We pride ourselves on the ability to propose the most appropriate technology for any given application to our clients. Thus, we’re pleased to have invested further R&D funds to the SACO technology over the past years such that we can now include chemical oxidation as one of the range of technologies we offer.”
Advantages of Surfactant assistedChemical Oxidation (SACO)
- Contaminants are destroyed
- Applicable to a wide range of organic contaminants
- Applicable to insitu and exsitu treatment processes
- Insitu application of surfactants requires substantive test work and modelling to determine their mobilising effect on contaminants under variable subsurface conditions. The modelling and design of an insitu campaign would need to be undertaken by environmental consultants.
- Ex situ/soil blendingApplicable to shallow, accessible contaminated soil
> Faster reaction kinetics
> Less constrained by site lithology
> Higher degree of certainty
- Activated persulfate has several advantages -
> Longer stability in subsurface
> Low pH conditions not required (compared with traditional Fenton’s reagent)
- Economically viable treatment for low to highly contaminated wastes
- Evaluate application with or with out SACO for grossly contaminated waste
- Relationship with FNC persulphate supplier and technical expertise
Enviropacific Services has a range of specialised purpose engineered equipment for insitu or exsitu application of the SACO technology throughout Australia. Our personnel are trained in the operation of this equipment and we operate to the highest accredited QHSE standards.
Enviropacific Services are able to design, construct, install and operate equipment as required for any given application.
We have close working relationships with a number of piling companies for innovative injection at larger scales.