First bottle of Butanol that was produced with the Algae Turf Scrubber in NY

On a national scale, the United States is supporting and funding many different algae projects. It is still very unique to see a statewide initiative to support algae and even more unique to see a citywide algae initiative. The New York City Department of Environmental Protection has started a project that is looking to use algae to clean wastewater. John McLaughlin, the Director of Ecological Services for the NYC DEP, answered some questions on what their program is all about and how is has been fairing.

1. Why did the NYC Department of Environmental Protection look into algae to treat wastewater?

As part of the Jamaica Bay Watershed Protection Plan and PlaNYC the Department was eager to pursue innovative and sustainable ways to help reduce nutrients for improved water quality and as a means to investigate biofuel production potential. Additional co-benefits such as carbon sequestration and increases in dissolved oxygen were also considered.

2. Are you partnered with any companies or research organizations with your work?

The work is being done by a consultant team under the supervision of DEP. Additional support is coming from HydroMentia, Inc. (the company that developed the Algal Turf Scrubber System) and the University of Arkansas (they convert the algae to butanol for us).

3. Are the nutrients this system filters out those that would have had to be filtered out some other way or are they ones that would typically just be released into the environment?

The nutrients being filtered would be those beyond the acceptable standard treatment of the wastewater process. The system is viewed more as “polisher” than a stand alone nutrient reduction system.

4. What have the early results shown?

Early results are encouraging but we do not want to make any conclusions as the first year of operation was more of calibration and tweaking phase. But nutrient reduction and dissolved oxygen increases were observed.

5. Do you have any early estimates on what the cost of this system is compared to other non-algae systems?

The cost of construction was $375,000. I don’t know has this compares to other systems.

6. How easily can this system scale up from treating less than 1% of the water of a plant?

The scale up of the system is relatively easy and is very doable in terms of construction. The challenge is finding available land space. Although there are no current plans to do so, we are looking at ways to decrease the actual footprint should such a larger scaled up system in the future.

7. When you scale up the system, how are you accounting for the day/night cycles and seasonal changes?

As previously mentioned there are no plans to scale up the system. To account for seasonal variations in light intensity we would look at artificial lighting from solar charged batteries or using hydropower generated from the wastewater treatment process. The water temperature of the wastewater stream is relatively high and early indications suggest that algae could continue to grow – albeit at a slower rate during the colder months if sufficient light were present.

8. Do you control what species of algae grows? If so, how?

That could be an ultimate goal but there are challenges to having the system be a specific species as they change naturally over the growing season and over different environmental conditions.

9. If you don’t control the species of algae, how do you determine what kind of bioproducts can be produced from the algal biomass?

The purpose of the pilot was to test the water quality improvements and the potential for biofuel production – no other by products are considered, but it is possible that the dried algae could also be used as soil amendment fertilizer as the nitrogen content would be helpful.

10. What is the overall goal of this project?

To test the system and determine the potential benefits to water quality, biofuel production and other to try and quantify some of the other less tangible co-benefits.

11. Any closing remarks?

The Department is extremely excited with this project and the low tech approach using sustainable natural systems to improve water quality and reduce nutrients. We think this is important first step in introducing this system in the climate of the northeast and will continue to evaluate the potential for scale up and other co-benefits.

John McLaughlin
Director of Ecological Services
New York City Department of Environmental Protection
http://www.nyc.gov/html/dep/

Check out the original press release announcing the DEP’s algae project:
NYC DEP Unveils New Algae Biofuel Pilot Project Press Release

Tags: John McLaughlin, NYC DEP