Pilot-Scale Remediation Strategies

Based on problematic constituents that have been identified, Southern Research develops remediation strategies using biogeochemical data (thermodynamic and/or kinetic software models), experimental results from gray and published manuscripts, and data from previous laboratory experiments. Southern Research engineers utilize these data sources to design small-scale physical models (i.e., treatments systems) that can be evaluated to determine the system's performance for site-specific waters. Physical models designed to treat the problematic constituents can vary in size and system components and include bench-scale testing (jar and bucket test) and pilot-scale testing (microcosms). Pilot-scale systems offer the following advantages:

• The ability to test numerous treatment system designs
• Cost-efficient means for screening successful treatment system designs
• Test method requiring small volumes of pre-treated water
• Method to determine upset conditions of the treatment water system
• Data for scaling to the full-scale design and completion of the permitting process

Pilot-Scale Testing

A pilot-scale wetland treatment system is used as a physical model to determine the performance of the system in decreasing the concentration of the problematic constituents and/or bioavailability. Pilot-scale wetland treatment systems can be designed with multiple reactors in series, each of which can treat different problematic constituents. Southern Research offers the capability to design and evaluate the performance of traditional and hybrid pilot-scale constructed wetland treatment systems to remediate targeted constituents in order to achieve treatment goals (i.e., compliance for NPDES permits). In addition to constructed wetland treatment systems, pilot-scale testing can include assessment of existing treatment system designs to enhance the performance and stability of these systems.

Benefits of Traditional Surface Flow Constructed Wetland Treatment Systems

• Provide treatment of nutrients, metals, and organics (e.g., oil and grease)
• Decrease bioavailability and toxicity of constituents
• Require minimal capital and low operation and maintenance (O&M) costs
• Provide long treatment period (>30 years)

Benefits of Hybrid Constructed Wetland Treatment Systems

• Provide treatment of nutrients, metals, and organics (e.g., oil amp; grease)
• Can provide more efficient treatment of problematic constituents (e.g., selenium)
• Include amendments of soluble and/or solid organic carbon types for enhancing targeted constituents
• Decrease land requirements (~ 3 to 5 acres for treatment of 1 MGD) compared to traditional surface flow constructed wetland treatment systems (~8 to 12 acres)