Hopewell Regional Wastewater Treatment Facility

Aquaculture tanks filled with bubbling water, pipes, and wires in greenhouse.

Summary

Location: Hopewell Regional Wastewater Treatment Facility, Virginia, USA

Project commenced: 2013 - Pilot- mixed industrial treatment

Purpose: Nitrogen & persistent chemicals removal

About the Project

The Hopewell Regional Wastewater Treatment Facility was a ‘Pilot project’ for ALGAESYS to prove that the system could treat industrial effluents. The treatment facility had to treat 85% industrial effluents, including from four major industries which included:

  • AdvanSix (producing caprolactam),

  • WestRock (craft pulp & paper mill),

  • Ashland (speciality organic chemicals include paint thickeners, coatings, Teflon, binding agents), and,

  • Virginia American Water Company.

The existing treatment system was a UNOX direct oxygen injection activated sludge system, where wastewater temperatures typically ranged from 40-50 degrees Celsius. This meant that the plant was unable to effectively treat ammonium in wastewater. Thus, the facility was forced to purchase ‘Ammonia Credits’ from other treatment facilities that discharged into the James River and ultimately Chesapeake Bay (an environmentally sensitive catchment) at a cost of over $1.4 million USD per year.

ALGAESYS was deployed as a pilot program to act as a tertiary treatment system for the removal of ammonia.

One of the most difficult chemicals to remove in the system was Methyl Ethyl Ketone Oxime (MEKO), which is used as an anti-skinning agent in surface coatings. The results from testing influent and effluent water from the ALGAESYS system is shown below.

This was a very challenging first trial of the system, as the wastewater contained chemical constituents with multiple inhibitory effects. In addition, most of the industrial wastewater is process related and had been deionised, causing slow algae growth. It was further investigated and discovered that this was due to the lack of trace metal nutrients, silica and other trace elements necessary for algal growth.

Overall, the performance of the pilot plant achieved not only the ammonia removal targets to meet regulatory discharge requirements but also met the proposed future TN limits. The plant would have been able to recoup up to half a million USD per year in the sale of nitrogen credits for the Chesapeake Bay catchment.

Table showing influent and effluent MEKO levels over specified dates. Influents range from 3.4 to 5.8 mg/L; effluent levels are not detected.

Water Quality Testing Results - Hopewell 2012