MEMORANDUM 

TO: Ron Jordan, EPA 

FROM: Anna Dimling, ERG 

 

DATE: September 30, 2015 

SUBJECT: Notes from Meeting with Liberty Hydro on September 23, 2014 

EPA held a meeting with staff from Liberty Hydro on Tuesday, September 23, 2014 at 1:00 PM 

to discuss the operation and performance of Liberty Hydro’s zero valent iron (ZVI) technology 

for FGD wastewater treatment. Table 1 identifies the people that participated in the meeting. 

Table 1. Meeting Participants 

Name Company 

Affiliation 

Phone Number Email 

Phil Farina Liberty Hydro, Inc. (419) 346-8848 phil.farina@libertyhydro.com 

Mark J. Kropilak Liberty Hydro, Inc. (610) 710-5381 mark@libertyhydro.com 

John G. Taylor Liberty Hydro, Inc. (304) 941-3020 john.taylor@libertyhydro.com 

Phillip Flanders EPA (202) 566-8323 Flanders.Phillip@epa.gov 

Jessica Hall EPA (202) 564-3376 Hall.Jessica@epa.gov 

Ron Jordan EPA (202) 566-1003 Jordan.Ron@epa.gov 

Jan Matuszko EPA (202) 566-1035 Matuszko.Jan@epa.gov 

Sharon DeMeo (phone) EPA/ Region 1 (617) 918-1995 DeMeo.Sharon@epa.gov 

Anna Dimling ERG (703) 633-1692 Anna.Dimling@erg.com 

TJ Finseth ERG (703) 633-1698 Thomas.Finseth@erg.com 

This memorandum summarizes the meeting discussion points. 

Introduction 

Liberty Hydro, located in South Charleston, WV, was incorporated as a spinoff of the MidAtlantic Technology and Research Innovation Center (MATRIC) in 2010. Liberty Hydro, Inc. 

has a focus in wastewater treatment and developed the ZVI BlueTM reactive media (patent issued 

on March 11, 2014). Several bench- and pilot-scale experiments integrating the ZVI BlueTM

reactive media have been completed, including 

 Coal mines; 

 Patriot Coal in West Virginia and project in Idaho (2009) - reduced selenium 

concentrations in acid mine drainage (AMD) to less than 5 ppb, 

 Another West Virginia coal mine was a success, but coal mine closed during study, 

 A nickel mine (Madagascar); 

 99% Chromium removal, 

 Discussions about Tanneries in Northern India; 

 For Removal of Chromium, 
Memorandum 

October 30, 2015 

Page 2 

 Coal-fired power plants; 

 Completed two pilot studies on FGD wastewater that reduced selenium 

concentrations to less than 10 μg/L, 

After completing the successful pilot-test studies on flue gas desulfurization (FGD) wastewater 

at coal-fired power plants, Liberty Hydro was asked by a company to design and prepare a cost 

estimate for a full-scale implementation with a chemical precipitation system, biological 

treatment system, and ZVI BlueTM system to treat FGD wastewater at a flow rate of 350 gallons 

per minute (gpm). 

ZVI BlueTM Reactive Media 

In general, the ZVI process removes pollutants by contacting wastewater with an iron powder, 

reducing the pollutant to its elemental form, and removing the pollutant. ZVI has been proven to 

remove several heavy metals from FGD wastewater (i.e. arsenic, mercury, copper, chromium, 

etc.); however, the focus is on the removal of selenium in the selenate, selenite, and other forms. 

The equations below demonstrate the redox reaction where the ZVI donates electrons to the 

selenate (Equation 1) or selenite (Equation 2), which are reduced to elemental selenium, which is 

much easier to remove. 

 3Fe0(s) + SeO4

2-(aq) + 4H2O(l)→ 3Fe2+(aq) + Se0

(s) + 8OH-(aq) (Equation 1) 

 2Fe0

(s) + SeO3

2-(aq) + 3H2O(l) → 2Fe2+(aq) + Se0

(s) + 8OH-(aq) (Equation 2) 

Specifically, the ZVI BlueTM reactive media is a system that contains fine ZVI shavings adhered 

to a porous polymer foam media. Moreover, the FGD wastewater is percolated upwards through 

several stacks of the ZVI BlueTM reactive media and the elemental selenium is captured within 

the media. 

First Pilot Study 

A pilot study was performed at a coal-fired power plant. This study incorporated the ZVI 

BlueTM reactive media after the FGD wastewater was treated by a rudimentary chemical 

precipitation and simple biological (Bio) system (see Figure 1). 

Figure 1. Process Flow Diagram for the First Pilot Study 
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October 30, 2015 

Page 3 

The study was performed from November 2013 through March 2014 and the FGD wastewater 

influent (1-2 gallons per minute (GPM)) to the pilot study was pulled from a settling pond; 

therefore, some total suspended solids (TSS) was being removed prior to treatment in the 

chemical precipitation system. At the beginning of the pilot study, there was no chemical 

precipitation system and the FGD wastewater (1-2 gpm) was sent directly to the biological 

treatment system following the settling pond. After some time and because none of the pilot tests 

were performing well, the rudimentary chemical precipitation system was added to the pilot test. 

The chemical precipitation system consisted of lime, ferric chloride, and polymer addition, 

followed by a settling basin to remove the sludge. The chemical precipitation effluent was then 

sent through a “simple” Bio system containing microbes specifically designed to remove nitrates 

from the wastewater. 

According to Liberty Hydro, the ZVI BlueTM system can remove nitrates, but the addition of a 

simple Bio system allows the microbiology to focus on the heavy removal of nitrates if present 

and a matter of concern, thereby allowing the ZVI process to selectively focusing on selenium 

and other metals without competition from nitrates. The ZVI BlueTM system consisted of a filter 

and three or more reactor vessels containing media. Hydrochloric acid (HCl) was also added 

before the media tanks for alkalinity and buffering. After the addition of the chemical 

precipitation system, the ZVI BlueTM pilot study demonstrated a selenium removal greater than 

99% and consistently contained less than 10 μg/L selenium in the treated wastewater. 

Second Pilot Study 

Liberty Hydro participated in a 12-week pilot study at a coal-fired power plant from March 2014 

through July 2014. The plant has a full-scale chemical precipitation system for treating its FGD 

wastewater prior to discharge; therefore, the pilot test was conducted on the effluent from the 

chemical precipitation system. The FGD wastewater at the plant does not contain a large amount 

of nitrates, so Liberty Hydro chose to run the pilot study without the “simple” bio system or 

other type of pre-treatment scavenger unit. However, Liberty Hydro recently submitted a 

proposal to continue running at the plant with the addition of a “simple” bio system. Liberty 

Hydro noted that the pilot test unit was still intact at the plant at the time of this meeting. 

The influent into the system was 1-2 gpm and the treated wastewater was sampled two times 

every week. Over the 12 week time period, the average selenium concentration in the treated 

wastewater was less than 10 μg/L (all the reading were below 10 μg/L except one reading that 

was presumed invalid). After the 12-week study was complete, Liberty Hydro proposed to 

increase the flow rate to the pilot system beyond the design parameters to determine at what 

point the system would “break” (i.e., at what flow rate would the system not achieve 10 ppb 

selenium). According to Liberty Hydro, when the influent flow rate was increased to 4 gpm, the 

selenium concentration increased to above 10 μg/L; but the system was still removing the vast 

majority of selenium. 
Memorandum 

October 30, 2015 

Page 4 

Future Full-Scale Treatment System 

Liberty Hydro is in the process of drafting a design for a full-scale FGD wastewater treatment 

system with an engineering firm. The initial full-scale design consists of a chemical precipitation 

system, “simple” Bio system, ZVI BlueTM system, and filtration system. The full-scale model 

will be designed for a FGD wastewater flow of 350 gpm. The bio system will consist of a reactor 

containing carbon-rich media and microbes, which utilize the carbon and nitrates as energy 

sources. The ZVI BlueTM system, in its initial design, was to contain 15 reactor vessels that 

contain stacks of media (see Figure 2). Adjustments to the design configuration will be 

evaluated over time. 

Figure 2. Full-Scale Design Process Flow Diagram for the ZVI BlueTM System 

The reactor system is designed in a way that if any particular stack of media is not operating 

properly, that particular stack can be removed and repaired without causing a system shut-down. 

Liberty Hydro is still working on methods for cleaning and regenerating the media and if the 

cleaning wastewater can be recycled back into the system. Liberty Hydro indicated that the 

media is able to last anywhere between 6 months to 5 years and more studies need to be 

performed to refine the longevity estimates for different operating conditions. Liberty Hydro has 

been collaborating with an engineering firm to prepare capital and operation and maintenance 

(O&M) cost estimates for the system.