TASK™ Anionic Surfactant Blend

  Surfactant-Enhanced Aquifer Remediation (SEAR)

  Safety Data Sheet (SDS)   •    Technical Data Sheet SEAR

Product Overview

TASK™ Anionic Surfactant Blend is a proprietary, site-tailored surfactant formulation developed by Tersus Environmental for Surfactant-Enhanced Aquifer Remediation (SEAR). TASK™ is designed to mobilize and recover non-aqueous phase liquids (NAPLs), including LNAPL and DNAPL, that are otherwise trapped in the subsurface by capillary forces.

Unlike conventional off-the-shelf surfactants, TASK™ formulations are engineered using site-specific groundwater, soil, and NAPL samples to achieve ultra-low interfacial tension and controlled NAPL mobilization under hydraulic control.

Technical Basis

Capillary Forces and NAPL Entrapment

NAPLs remain trapped in the subsurface due to capillary forces created at the oil–water interface. These forces prevent free movement of NAPL and significantly limit mass recovery through conventional pumping or flushing methods.

TASK™ overcomes these forces by dramatically reducing oil–water interfacial tension, allowing NAPL to be mobilized and recovered efficiently.

Mobilization vs. Solubilization

Surfactants enhance NAPL removal through two mechanisms:

• Solubilization, where micelles dissolve NAPL into groundwater (often requiring large surfactant volumes)
• Interfacial tension reduction, where NAPL is mobilized as a separate phase and recovered directly

TASK™ is specifically designed to favor mobilization, not excessive solubilization. By achieving ultra-low interfacial tension and forming middle-phase microemulsions, TASK™ enables efficient NAPL recovery while minimizing surfactant use and downstream treatment requirements 

Applications

TASK™ is used as part of a hydraulically controlled SEAR system for removal of separate-phase contamination.

Typical applications include:

• LNAPL and DNAPL source-zone remediation
• Removal of gasoline, diesel, heating oil, and chlorinated solvents
• Pre-treatment to enhance bioremediation or chemical oxidation
• Mass removal prior to long-term polishing remedies

Removal of NAPL mass improves the effectiveness of subsequent remedial technologies and reduces long-term contaminant loading.

Integration with Tersus Technologies

TASK™ serves as the surfactant platform within Tersus’ SEAR design and implementation services. Each TASK™ formulation is customized based on laboratory testing using site-specific samples to:

• Minimize oil–water interfacial tension
• Achieve middle-phase microemulsion behavior
• Design fast-breaking emulsions that simplify separation and treatment

TASK™ is deployed within injection-and-extraction systems designed to maintain hydraulic control, maximize recovery, and minimize surfactant loss to the formation matrix.

Features & Benefits

Features

• Proprietary anionic surfactant blend
• Site-specific formulation using actual groundwater and NAPL
• Ultra-low interfacial tension capability
• Fast-breaking emulsions
• Readily biodegradable components

Benefits

• Up to 95% NAPL mass removal in 1–1.4 pore volumes
• Effective at <1% surfactant concentration by weight
• Reduced surfactant demand compared to nonionic systems
• Simplified waste handling and treatment
• Lower disposal volumes and overall project cost
• Enhanced opportunity for NAPL recovery and recycling

Typical Application

TASK™ is shipped as a concentrated formulation and typically diluted with water to 0.5–2% prior to injection, depending on site conditions and laboratory testing results. Injection and extraction are performed under controlled hydraulic gradients to ensure capture of mobilized NAPL.

Application rates, surfactant concentrations, and flushing volumes are site-specific and based on NAPL characteristics, groundwater chemistry, and formation properties.

Physical Characteristics

Refer to the Safety Data Sheet (SDS) for complete compositional, handling, and hazard information.

Environmental Fate and Decomposition

TASK™ surfactants are biodegradable. Residual surfactants remaining in the formation after a surfactant flood will degrade aerobically. Alcohol components degrade rapidly, and intermediate byproducts such as acetone further decompose to carbon dioxide.

Laboratory testing indicates:

• 97% primary biodegradation of active surfactants
• Degradation pathways consistent with linear alkylbenzene sulfonates
• No long-term persistence in groundwater under typical post-SEAR conditions 

Transportation

• Proper Shipping Name: Flammable liquids, n.o.s.
• UN Number: UN1993
• DOT Hazard Class: Class 3
• Packing Group: II 

Packaging

TASK™ Anionic Surfactant Blend is available for shipping in 55-gallon drums, 275-gallon IBC totes, or bulk tankers, providing flexibility for projects of any scale.