Sep 21, 2020
Thrasivoulos Panayiotou, EIT

What new technologies have you been evaluating or implementing?

The New York City Department of Environmental Protection (NYCDEP) has put its research focus toward next-generation technologies to help us target some of the strategic initiatives set forth by the 2018 DEP Strategic Plan, including:

  • Managing our assets to ensure the long-term sustainability and optimal efficiency of our water and wastewater services
  • Transitioning wastewater treatment plants to wastewater resource recovery facilities (WRRFs)
  •  Expanding the use of technology to improve performance

NYCDEP is currently evaluating the following next-generation technologies that align with these initiatives:

  • Thermal Hydrolysis Process (THP): The thermal hydrolysis process is being evaluated to understand the potential benefits that include: Higher digested gas production for energy generation, reduction in total solids for handling and disposal, improved dewaterability, reduced sludge viscosity for easier pumping and mixing, and the production of Class A biosolids.
  • Biofilter Odor Control Pilot Program: The goal is to apply this technology to large-scale odor sources at various WRRFs to lower operating costs and remove the need for chemicals while addressing broader odor issues.
  • Ceramic Membrane Pilot: Evaluating a novel disinfection technology alternative to treat combined sewer overflows (CSOs) to better manage bacterial loadings while meeting environmental stewardship and sustainability goals.
  • Induced Struvite Precipitation through Magnesium Hydroxide Addition: NYCDEP is investigating the use of magnesium hydroxide to prevent struvite formation, and to recover phosphorus for potential reuse.
  • Deammonification: NYCDEP’s goal is to provide a cost-effective route to maintain nitrogen removal and greenhouse gas reduction while reducing supplemental carbon use.


What technologies are you interested in investigating?

NYCDEP is interested in investigating technologies that will optimize nutrient removal/recovery while reducing chemical additions, and those that could reduce solids volume and enhanced biosolids quality for future reuse. NYCDEP would be interested in deammonification (fixed film and granular technologies), advanced aeration control systems, struvite recovery technologies (Ostara and Induced Struvite Precipitation using Mg(OH)2), integrated fixed-film activated sludge system (IFAS), and thermal hydrolysis.

What are your facility drivers/needs?

NYCDEP, while consistently upholding its values of protecting the environment and public health, is faced with challenges that will require us to achieve a higher level of efficiency to be successful. Some of these challenges include: 

  • Regulations and Social Mandates: NYCDEP is anticipating new nitrogen control mandates in two estuaries that NYC WRRFs discharge to: the Upper East River and Jamaica Bay. These mandates will require NYCDEP to achieve a higher level of nitrogen control in severely footprint constrained sites, with new residential and commercial development in the immediate vicinity of the facilities. Capital commitments in excess of $5 billion dollars would be required to achieve anticipated nutrient controls in the Upper East River WRRFs alone.
  • Chemical Costs: NYCDEP has spent tens of millions of dollars for nitrogen removal in energy and chemicals alone. Over 30,000 gallons of chemicals (caustic and glycerin) are transported into the City per day, costing DEP over $1M per month, with the associated additional biosolids production effectively doubling the cost.
  • The transition from a Treatment Plant to a Resource Recovery Facility: Like other utilities, NYCDEP is slowly tapping into the resources available in our wastewater process, and there is ongoing research into next-generation nutrient removal/recovery technologies. However, due to DEP’s size and resource constraints, it has been a challenge to provide our employees with the information and materials needed to become familiar with the new direction DEP is taking.


How has LIFT helped, or how would you like LIFT to help your facility?

The LIFT SEE IT program is an invaluable tool that will help us as we transition from wastewater treatment to wastewater resource recovery. Thanks to LIFT, we can connect with wastewater utilities outside of New York that have accepted wastewater resource recovery as the new status quo. Site visits to Hampton Roads Sanitation District (HRSD) will allow our operations staff to see first-hand the potential that shifting to a resource recovery focus can offer, while providing lessons learned that will allow us to avoid costly mistakes as we go through the process. Visiting utilities will help alleviate concerns for adopting new technologies and embrace the new direction wastewater treatment is headed.


If there were one technology you would pilot or collaborate on tomorrow, what would it be?

That’s a very tough question; we’ve been eager to pilot a variety of technologies that could enhance our WRRF processes, but if we had to narrow it down to a specific category, we would want to pilot a technology focused on nitrogen removal, like the deammonification process. As mentioned before, we are expecting new nitrogen control mandates and that could lead to a whole new set of challenges for us as we try to meet compliance.


Thrasivoulos Panayiotou, EIT

Assistant Environmental Engineer/R&D Coordinator