Grantee Research Project Results
Final Report: Point of Source Sewage Treatment Device
EPA Contract Number: 68HERC21C0037Title: Point of Source Sewage Treatment Device
Investigators: Holbrook, Kalan F
Small Business: FHNC Ltd. Co.
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2021 through August 31, 2021
Project Amount: $100,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2021) RFA Text | Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Water , SBIR - Clean and Safe Water
Description:
Prior to being awarded an EPA SBIR Phase 1, FHNC had already developed a proprietary grease interceptor (the Neptune Grease Trap or “NGT”) capable of removing 95% of fats, oils and greases from a restaurant kitchen wastewater stream. The purpose of this award was to develop a device capable of reclaiming the water exiting the NGTI for reuse on site. Our research had five objectives:
- Build a prototype Neptune Greywater Removal System (“NGRS”) that would be installed downstream of the existing Neptune Grease Trap (“NGT”)
- Use this prototype NGRS to determine the allowable uses of the recycled wastewater under current industry safety standards and trends
- Determine any maintenance requirements or adjustments of the NGRS prototype as a result of the operating conditions
- Assess commercial feasibility based on production and installation costs, operating costs, and allowable uses
- Hypothesize and prioritize prototype NGRS changes that could increase allowable uses, or decrease costs for future study and compare with the feasibility analysis
Summary/Accomplishments (Outputs/Outcomes):
The NGRS was constructed during the first two months of the project and then tested during the remainder of the project. The device largely consisted of a NGT, a pump, a holding tank, a solids filter and strainer, and a pressure vessel. The below figure is depicted for easy viewing of each component.
Figure 1. An illustration of the Neptune Greywater Removal System (“NGRS”).
During testing, we found that the NGRS produced water did not meet NSF 350 standards for turbidity and TSS. However, it was a significant improvement in quality compared with the feedstock wastewater. The output of the NGRS was pathogen free and olfactorily acceptable to flush toilets or use as irrigation. We hypothesize that the output of the NGRS may not need to meet NSF 350 based upon its intended use of toilet flushing or irrigation. See the below images to compare input feedstock to the output of the NGRS. Note that the settled layer in the after image would be removed before reuse:
Figure 2. This image compares input feedstock (left) to the output of the NGRS (right).
As mentioned, the output of NGRS did not meet the NSF 350 standards for turbidity, TSS, BOD or CBOD. The table below illustrates the output of NGRS vs the NSF 350 standard:
Test Type NSF 350 NGRS Output
CBOD | mg/L | 10 | 166 |
BOD | mg/L | 10 | 183 |
TSS | mg/L | 10 | 12.2 |
Turbidity | NTU | 2 | 12.5 |
E Coli. | cfu/100mL | 2.2 | BDL |
Total Coliform | chf/100mL | 2.2 | BDL** |
pH | SU | 6.0-9.0 | 11.3 |
HEM | mg/L | n/a | BDL |
Conclusions:
During the Phase 1 project, the Neptune team adapted quickly to solve technical challenges and move rapidly toward commercialization.
At the conclusion of Phase 1, the team has six important observations:
- Clarifying reagents must be used to remove suspended solids and turbidity
- Neptune NGT needs to be optimized further to maximize the amount of water sent to NGRS for reuse while minimizing the amount of fats, oils and greases in the feed water
- Longer term trials (3-6 months) of continuous operation need to be completed to assess service requirements
- Meeting NSF 350 standard is likely not necessary for the intended use but further research is required in this area
- The NGT and NGRS devices must be assembled in-house to control costs and quality
- The unit economics of the NGT and NGRS are attractive for commercialization
We believe that the product is feasible from a technical perspective. Further research needs to be conducted including longer term trials, deriving an automated separation system for clarifying agents and optimizing the NGT to maximize the amount of wastewater fed to the NGRS. None of these items are technically difficult, but they will require more time and resources to complete.
From an economic perspective, we believe the product is feasible. Our costing and willingness to pay analysis indicated that the market would bear a price about 45% higher than the cost to produce the device. Due to the state of greywater regulations, the regulatory path to market is unclear for the NGRS. Based on the greywater’s intended use, we anticipate that the product does not need to be NSF 350 compliant. Due to a lack of greywater regulation and comparable products in the market, we hypothesize that each municipality will make a decision independently whether to allow the reuse of kitchen wastewater.
Ultimately, we are extremely enthusiastic about the results of this SBIR phase 1 and strongly believe that the product is both technically and commercially feasible. Even though the regulatory environment is unknown, there is a significant opportunity to decrease water consumption in restaurants by as much as 30%. Given the size of the opportunity, we plan to continue pursuing the development and launch of the NGRS product.
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.