Grantee Research Project Results

2022 Progress Report: Tertiary Wastewater Treatment through Aquaponics

EPA Grant Number: SU840154
Title: Tertiary Wastewater Treatment through Aquaponics
Investigators: Murray, Kelsey , Mitchell, Bryan , Loverich, James , Eisenbraun, Kaden , Anderson, Todd
Institution: Western Dakota Technical Institute
EPA Project Officer: Page, Angela
Phase: I
Project Period: December 1, 2020 through November 30, 2021 (Extended to November 30, 2023)
Project Period Covered by this Report: December 1, 2021 through November 30,2022
Project Amount: $24,995
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2020) RFA Text |  Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources

Objective:

To design an aquaponics system suitable for treating wastewater effluent to both recapture nutrients for use in agriculture (thus preventing nutrient contamination of surface water) and to reduce total coliform bacteria levels (thus preventing bacterial contamination of surface water).

The winning design was a mobile trailer with a hydroponic/aquaponic system that can be used onsite at a Wastewater treatment Plant. The following construction deliverables/activities describe the planning, build, and execution of the project design.

Progress Summary:

For this project, a mobile hydroponics trailer equipped with an automated crop production system was designed, constructed, and is currently being tested for use in tertiary wastewater treatment. For the design work, we have completed a Creo assembly model of the design, rendered 3D images, created an augmented reality experience of the design, and provided dimensioned working drawings of the system. For construction, we have designed and engineered a NFT mounting system and trays were installed. A custom-made water distribution system, consisting of a continuous loop with two separate pumps was designed and installed. The water distribution system has ports for water quality monitoring equipment, a manifold system for control, and valves. An automated electrical control system (Micro PLC/panel view program) was designed and installed for control over full-spectrum LED and UV lights, pump timing, water flow rate (adjustable), and integration of water quality monitoring equipment and associated database for data capture. Upon completion of construction of this mobile tertiary treatment plant, data concerning its ability to deplete nutrients from tertiary wastewater using hydroponics will be analyzed.
(2) Complete details of all technical aspects of the project--both negative and positive-- the recipient's findings, conclusions, and results, including the associated quality assurance results.

Due to unforeseen circumstances related to the COVID-19 pandemic (increased instructor workload due to social distancing and reduced class sizes, employee turnover, and quarantine of multiple students/faculty working on the project), we have not been able to complete the project as originally outlined. The pandemic also caused insurmountable supply chain issues, including a long wait for water monitoring equipment.

These delays also meant that the duration of the grant project period was primarily spent on designing and building the system, and there was little time for data collection. Without data it is impossible to say if this aquaponics system suitable for treating wastewater effluent to both recapture nutrients for use in agriculture (thus preventing nutrient contamination of surface water) and to reduce total coliform bacteria levels (thus preventing bacterial contamination of surface water). However, the research that went into the actual design indicates that this system has potential to do just that.

 

 

1. Computer-Aided Design: The following CAD deliverables were completed:
• Creo assembly model of the design
• Rendered 3D images of the assembly created with Creo
• Augmented Reality experience developed with Creo
• Dimensioned working drawings of the assembly and components

The original thought was that students would create a dome-like structure for the hydroponic/aquaponics system. However, the winning design ended up being an enclosed trailer. Because of that, the anticipated CAD deliverables related to Virtual Reality and 3D images of the dome were discontinued.
Because the winning design was different that what was anticipated, we had to adapt and find a way to get a trailer. Additional funding for the trailer was acquired, the trailer was purchased, and branding was completed in 2022. The build-out of the trailer included:

• A sealed floor (waterproofing/anti-slip)
• A mounting system for NFT trays.
o After constructing the initial set-up, we re-designed and rearranged the space to maximize grow space and minimize “hallway” space. Additionally, we made engineering modifications to the structural support system
• A separation wall between the laboratory space and the data collection space.

A custom-made water distribution system consisting of two pumps, one continuous loop of Pex and PVC, ports for water quality monitoring equipment, valves to shut off parts of the system, and a manifold to use the main pump either to move water internally or to fill onboard circulation tank. WDT plumbing students (6 in total) along with their instructor designed and installed the plumbing.
o The plumbing system went through the engineering design process and multiple iterations were tested to allow for control over the flow.
• A worktable and sink
• A custom-designed control system that can be operated manually through a touch screen (specifically developed for this project) and operated automatically independent of manual control. Control system includes lighting control with control over full spectrum LED and UV lights, pump timing, water flow rate (adjustable), integration of water quality monitoring equipment for data capture, and a ventilation system.
o The control system uses Allen Bradley hardware and Rockwell Automation software.
o Hach Water Quality Monitoring equipment (pH, DO, temperature) was integrated into the system. The continuous monitoring was written into the process control and we were able to convert the data from Hach monitoring to a trending graph on the human machine interface.
• Remote continuous water monitoring equipment
• Plant lighting and convenience lighting
o Conduit and wires were installed for lighting and controls
o Foil was added to the walls to maximize the lighting available for the plants.
o Lighting was tested and modified after the initial construction as the original design did not provide sufficient light for optimal growth of plants. Multiple lights from various manufacturers were tested to achieve optimal PAR (photosynthetically active radiation)/lux for target crops. We upgraded to Heliospectra lights.
o Duration and intensity were added to the automation system
• A ventilation system was engineered and implemented to control for internal air flow.

2. Electrical Trades Deliverables: The following Electrical Trades Deliverables were completed:
• Detailed description of the electrical control process, including a flow chart of the sequence of events
• Working Micro 820 PLC/panel view program.

3. Environmental Engineering and Controlled Environment Agriculture Deliverables
• Detailed environmental monitoring plan, including necessary water quality monitoring equipment, frequency, and criteria for water quality parameters
• Biological surface area calculations for the system
• Measurements of nutrients in wastewater effluent and in aquaponics effluent and efficiency calculations
• Measurements of coliform bacteria in wastewater effluent and in aquaponics effluent

4. Farm and Ranch Management Deliverables
• Justification for the chosen plant and animal species in the system, including ideal growth parameters and approximate harvest cycles
o Some preliminary work outside of the trailer has been done to see how quickly nutrients can be depleted from a hydroponics system.

5. Project Deliverables
• Timeline for design and construction of the aquaponics units
• Parts list, including retail cost

 

Though the pandemic drastically altered the project original plan, student learning and leadership in the project was still incredibly strong. Students were instrumental not only in the research, design, and building of the unit but reported unexpected gains in their ability be flexible, creative, and adaptable to such extreme circumstances. 
(3) An evaluation of (a) the technical effectiveness and economic feasibility of the methods or techniques investigated or demonstrated, if applicable and (b) an explanation of how the research adds to the understanding of or solutions for environmental problems or is otherwise of benefit to the environment and human health. This discussion should be a minimum of one paragraph long and written in terms understandable by the educated layman.
The technical effectiveness and economic feasibility of the methods and techniques are largely unknown as we are still in the preliminary data collection phase. We will continue to collect and analyze data. One unintended result was the cost effectiveness of this unit. Original cost estimates on building a domed structure were much higher than the actual costs to fit-out an enclosed trailer. If the data shows this system is effective, replication will be much more affordable than originally thought. 

(4) A discussion of subaward monitoring activities under 2 CFR 200.331(d). Examples of items that must be reported if the information is available are: 1. Summaries of results of reviews of financial and programmatic reports. 2. Summaries of findings from site visits and/or desk reviews to ensure effective subrecipient performance. 3. Environmental results the subrecipient achieved. 4. Summaries of audit findings and related pass-through entity management decisions. 5. Actions the pass-through entity has taken to correct deficiencies such as those specified at 2 CFR 200.331(e), 2 CFR 200.207 and the 2 CFR Part 200.338 Remedies for Noncompliance. N/A

Future Activities:

Though the period of performance for this grant is over, we are moving forward with data collection so we can ultimately determine if this system will produce the results we anticipate.

Progress and Final Reports:

Original Abstract

2021 Progress Report

Final Report