Grantee Research Project Results
Final Report: An On-Site Biological Graywater Treatment System Suitable for a Small Business
EPA Grant Number: SU835330Title: An On-Site Biological Graywater Treatment System Suitable for a Small Business
Investigators: Martin, Jack , Houser, James , Hambourger, Michael , Bandala, Erick R. , Swinson, Bobbie Jo , Davis, Joseph , Edge, Chase , Martin, Benjamin , Neff, Eric , Johnson, Jennifer , Willett, Howard , Roden, Elizabeth , Bethman, Travis , deJong, Emil , Homes, Anna Maria
Institution: Appalachian State University
EPA Project Officer: Hahn, Intaek
Phase: II
Project Period: August 15, 2012 through August 14, 2014 (Extended to August 14, 2016)
Project Amount: $89,708
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2012) Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources , P3 Challenge Area - Sustainable and Healthy Communities , Sustainable and Healthy Communities
Objective:
Researchers at Appalachian State University proposed to create a biological on-site grey water treatment system for a small business in Boone, NC to help conserve fresh water and reduce the business water bill. The business is a beauty salon. Phase I research was designed to show proof-of-concept. In Phase I our objective was to demonstrate that a biological treatment system, or "living system", would be able to lower the concentration of contaminates in salon grey water coming from the sinks where hair treatments and shampooing occur. In addition we wanted to start the process of designing the actual prototype system that would be installed in the salon. Research was conducted to ascertain the type of plants best suited for a "living system". Plants where purchased and grown in a hydroponic system within one of the university greenhouses.
Design, testing and installation of the prototype "living system" in the salon and educational outreach is the primary focus of Phase Il research. Additional plant species will be tested for efficacy in the proposed design, with a focus on species that are shade tolerant. It is also an important aspect of the research to determine which species are best suited for the size limitations of the proposed design. In addition to determining optimal plant species, a small portion of the project is devoted to determining the most appropriate means of pest control, should such problems arise. The first year of Phase Il was devoted to designing and testing a scaled model to research the best configuration and type of components to obtain adequate flow rates, dissolved oxygen, plant health and contaminant removal. During this time we collected salon service data to compile water usage records to accurately size the structure, worked with the building inspector to ensure that the grey water treatment system would meet all building code requirements and educated the community and students about innovative technologies such as our proposed design.
The interior design, building science, and appropriate technology teams worked to develop and construct the most attractive, energy efficient, affordable and sustainably built structure possible for the modern salon within the small space that we have to work with. Figures I shows the original simple trough design and the modified design concept proposed. Ultimately, we currently have decided to go with a modified trough system for ease of construction and modularity. Modularity being the concept that green walls could be designed to treat any amount of grey water by just adding or subtracting troughs (components). However, some of these concepts have been melded into our current final proposed design (presented in the Conclusions section) for the salon which is based on our experiences with the prototype testing and the salon owner's desires for the system. The salon owner wants a wall that can be seen from both sides and which would still permit a coffee bar on the side opposite of the shampoo bowls.
Figure 1. Original trough design and alternative "garden wall" design (front and back) by Stephanie Roark
Throughout the Phase Il research period, students will be involved in creating a website for the project, as well as hold educational seminars, give class presentations relating to the proposed project and design, and present papers at conferences while preparing a paper for journal submission. The salon setting also provides an ideal setting for educating the community about ecological design concepts, specifically grey water filtration scenarios.
The objectives for Phase Il were the following:
- Objective A: Continue characterization of removal efficiencies of pilot-scale system.
- Objective B: Finish and test prototype design through consultation with salon owner.
- Objective C: Install and monitor prototype system on-site in salon.
- Objective D: Outreach project to local and University community Objective E: Integrate process into University curriculum.
Objectives A through E each will be achieved with input from both the Department of Chemistry and Department of Technology and Environmental Design, along with the involvement of students from multiple departments. A key milestone for Objective A is the selection of a final set of ten to fifteen plant species and essential system design parameters that allow for effective remediation of grey water while maintaining appropriate aesthetics; Objective B is the complete design of a prototype system incorporating input from the business owner and community that meets aesthetic requirements of the business owner and the technical specifications for grey water treatment (this last will require testing of mock-up designs); Objective C is the implementation of the above plan including construction of the prototype system in the business and successful testing of grey water remediation efficiency and public acceptance of the actual system in operation; Objective D is the successful achievement of enhanced University and community awareness of wastewater remediation options and involvement in the implementation of the project; Objective E is the integration of aspects of the project into the curriculum of specific courses offered through the Department of Technology and Environmental Design. Objective A was largely fulfilled during Phase I research. It is envisioned that these tasks will be completed and phased out over the first 12 — 18 months of Phase Il funding. As these preliminary activities wind down, construction and testing of the actual installed prototype system will ramp up and be sustained through the end of the funding period. Outreach and curriculum integration will take place throughout the funding period.
Summary/Accomplishments (Outputs/Outcomes):
Prototype Development and Construction
Students in the Department of Sustainable Technology and the Built Environment (formally the Department of Technology and Environmental Design) designed a number of potential systems upon which our first small full-scale prototype was built. The prototype was a two trough system with a 20 gallon storage reservoir. Previous reports explained the design and testing of this first prototype. A second prototype based on the design wishes of John Mena, the owner of Haircut 101, was developed for display at the P3 Sustainable Design Expo April 24th through 27 th, 2014 (see Figure 2) .
Figure 2. Prototype 2 on display at P3 Sustainable Design Expo with student
Figure 3. Schematic Of final system design for treatment of hair salon sink grevwater for reuse in toilets
Figure 4. Heavy duty saddle frame
This second prototype was based on a very simple three-trough system with one trough on top of the wall in the hair salon and the other two on opposite sides Of the wall. Prototype 3 an exact replica of the system to be installed in the hair salon (see Figure 3) was built during the past year and is in the process of being tested. Testing of this prototype has been the subject Of an undergraduate Thesis (submitted under separate cover), and final testing of the prototype is the subject of a Master's Thesis which will be completed in May 2016. Modifications to Prototype 3 were based on hydraulic testing of Prototype 2 and design criterion dictated by the business owner.
A specialized saddle-like frame was constructed to go over the wall unit in Haircut 101 so that the system troughs can sit on this frame (see Figure 4) and no modifications or penetrations need be made to the wall. This facilitates both installation and removal of the system. Transparent plexi-glass troughs were built and piped for testing Prototype 3 to allow for complete transparency of the system (see Figure 5).
Preliminary Analysis of Prototype 3
A control test with uncovered troughs, no plants and no biofilter was performed. In order to achieve more accurate test data, the decision was made to produce synthetic greywater (SGW) for each test. Before tests were conducted, a trip to Haircut 101 was done for information regarding typical hair products and quantities used. The purpose of the hair product analysis was to manufacture consistent batches of greywater for testing purposes. The SGW was made fresh prior each test. The SGW consisted of three dyes, shampoo and conditioner. The system capacity was measured and holds 60 gallons. The SGW solution was mixed outside the system before being fed into the system and diluted with tap water. Our measurements of water quality were based on the recent NSF/ANSI 350-2011 standard "Onsite residential and commercial water reuse treatment systems." Following this standard, the following parameters were chosen for analysis - temperature, pH, turbidity, total suspended solids (TSS), and chemical oxygen demand (COD). These tests were taken as a Figure 5. Prototype 3 with plexi-glass troughs reasonable subset of the specifications listed in the NSF/ANSI 350-2011 standard.
Figure 5. Prototype 3 with plexi-glass troughs
For each test, Standard Methods (Standard Methods for the Examination of Water and Wastewater, 20th ed, 1998, Washington DC. Clesceri, Greenberg, and Eaton editors) were followed - temperature (SM 2550 B); pH, electrometric (SM 4500-H+B); turbidity, nephelometric (SM 2130B); total suspended solids (SM 2540 D); chemical oxygen demand (COD), (SM 5220 D); and dissolved oxygen. Turbidity will be the main criterion for determination of water quality and when the greywater will be diverted to tanks for toilet flushing. Color from dyes has proven to be a difficult constituent to remove from the salon greywater, and since the processed greywater according to code must be colored before sending it to the toilets for reuse, it is important to reduce color in the greywater to avoid off-colored water in the toilets (we would like to have a nice pastel blue). Chase Edge completed a Masters Thesis in December 2015 looking at the ability of the Fenton reaction to remove color from a solution with dye. His findings may apply to the ultimate system incorporated into Haircut 101. A mini-Fenton reaction reactor may need to be added to the system.
All measurements were taken from a sample collected from the biofilter housing compartment of the system. Dissolved oxygen and temperature were taken with a senslON+ DOG portable meter. The pH was taken with an Extech PH220-C hand held pH meter. Turbidity was measured using a Thermo Scientific Aquafast AQ4500. Standard solutions were used as quality controls to ensure appropriate measurement of total suspended solids and chemical oxygen demand.
Data from the physical greywater treatment components was retrieved from tests with and without the UV clarifier light in order to establish the baseline system performance. Once the SGW was added to the system through the biofilter input, the pump was run for 30 minutes prior to taking the initial sample at time zero. This allowed the SGW concentrate to fully mix with the tap water in the system. After 30 minutes a sample was collected and initial measurements were taken. The remaining samples were taken after 2, 4, 8, 12, 24, 48, 72 and 96 hours. Each sample analyzed, dissolved oxygen (D.O.), temperature, pH and turbidity. Each measurement was taken three times. Additionally, a sample blank measurement was taken from a sample of Harris Teeter brand distilled water to ensure the instruments were operating correctly. The pump was put on a timer set to on and off for 30 minutes each. During the 30 minute on period the pump cycles on and off approximately 10 times. Total water sent through the system for the half hour on cycle was approximately 67.5 gallons.
The first test conducted analyzed the mechanical contributions of the system without the UV clarifier unit. After each test the system was drained and cleaned thoroughly. Tap water was cycled through the system for a minimum of 30 minutes before being drained again and prepared for another test. The second test was conducted with the UV clarifier unit in place and constantly on for the 96 hour test period.
The initial turbidity reading taken at time zero for the first test without the UV clarifier unit was 26.27 ± 0.17 NTU (95% confidence interval, n=3). After the 96 hour test period the turbidity to 18.27 ± 0.0 NTIJ (95% confidence interval, n=3). A Paired Two Sample for Means t-Test was performed which analyzed the turbidity at time O and at time 96. Based on the t-Test the turbidity at time O hr was significantly higher than at time 96 hr (p < 0.05). Figure 6 shows the change in turbidity overtime based on the mean of the measurements taken for each sample.
Figure 7 shows D.O. concentrations in percent compared to temperature readings for Test I without the
UV clarifier unit. The mean temperature was 56.27 ± 0.54 O F. The temperature at time 0 was fairly similar to time 96 hr. The D.O. for Test I had a range between 50.70 ± 0.19 % and 58.23 ± 0.0 %. A single factor Anova analysis indicated that there was a significant difference between all measurements (P<0.05). And a t-Test indicated that the D.O. at time 0 hr was significantly different than at time 96 hr.
Figure 6. Synthetic Greywater turbidity overtime for Test 1
Figure 7. -D.O. and Temperature over time for Test 1
The second test analyzed the same parameters as the first but with the UV clarifier unit installed and on for the 96 hour test period. The turbidity taken at time zero was 34.93 ± 0.23 NTU and declined over the 96 hour test period to 18.9 ± 0.05 NTU, a statistically significant difference. Figure 8 shows the turbidity overtime and is based on the mean of the 3 the measurements collected from each sample.
Figure 8. Mean Synthetic Greywater turbidity overtime for Test 2
Dye removal was observed rather than tested. The copper/rame dye used in the SGW visually colored the SGW the most turning it a murky brown color. Figure 9 shows an image of the SGW color taken at time zero and another image taken after 72 hours. Differences in dye removal appeared consistent in both test one and two.
Figure 9. SGW color taken at time zero (left) and SGW color taken after 72 hours (right)
Figure 10 shows D.O. concentrations in percent compared to temperature readings for Test 2 with the UV clarifier unit. The mean temperature was 55.00 ± 1.38 o F. The D.O. for Test 2 had a range between 50.80 ± 0.01 % and 59.07 ± 0.70 %. The D.O. at time O hr was statistically different at time 96 hr.
Figure 10. D.O. and Temperature over time for Test 2
Education / Classroom Education
This project has been used as the context for the Quantitative Analysis Laboratory course taught in the Department of Chemistry. At the beginning of the semester, students are told about the goals of the P3 project. Students have the opportunity to tour the prototype living system later in the semester. Throughout the-semester, students in this course learn analytical techniques while studying water samples obtained before and after filtration through the prototype living system. The analytical methods taught using P3 water samples include measurement of water hardness, dissolved iron, phosphate, and alkalinity. Later in the semester, students use water samples from the P3 project to also learn flame atomic absorption spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP-OES), ion chromatography (IC), and high performance liquid chromatography. Students in the Quantitative Analysis Laboratory course have been extremely receptive to this project, and enjoy participating in a research experience.
Discussion of this project is part of the Biofuels Technology course in the Department of Technology and environmental design. One o the current undergraduates working on t e project first learned about it in Biofuels Technology and has volunteered his time to help with the construction and testing of Prototype 3. A graduate student is currently using the testing of Prototype 3 as their Master's Thesis research.
Most recently this research was honored by receiving an Annual Sustainability Research Forum Award, presented by the Office of Sustainability, the Hubbard Programs for Faculty Excellence and the Office of Research, at Appalachian State University in Fall of 2014. A presentation on the research was giving for a general audience and we had a panel of graduate and undergraduate students, faculty and the owner of Haircut 101 that fielded questions from the audience.
Conclusions:
A final prototype design has been-arrived at through consultation with the business owner and plumbing professionals. The final design as it will appear in the hair salon is shown in Figure 11. It is a very simple three trough system that will require no modification of the wall or existing space and which will be easy to remove if the owner have been made to the latest prototype to address concerns that had come up in the testing of the previous prototypes. One is the pump. Rather than having a pump that is continually running we are using a sump pump automatically switch on when water levels reach a certain height in the greywater storage tank and then automatically switch off once the tank has been emptied. In order to ensure that the plant roots will always be in water even if the system is shut down for extended periods of time, there is a rough within each trough where the plants are placed. Water fills those troughs and then overflows from them into the larger trough that is drained, hence there is always water in the plant troughs (Figure 12). A large problem we had with initial prototypes was lack of DO in the greywater. We believe we have resolved that issue through the use of an inlet pipe that uses the power of the pump to draw large amount of air into the pipe discharge (Figure 13). Figure 14 shows the plant holding system for final prototype. We are currently in the process of testing our final prototype and beginning the bidding process for the final installation in the Haircut 101.
Figure 11. Final design for salon grey water system.
Figure 12. Trough within a trough system. Figure 13. Bubbles within trough from inlet pipe aeration system driven by pump. Figure 14. Plant holding system incorporated with aeration.
Journal Articles:
No journal articles submitted with this report: View all 5 publications for this projectSupplemental Keywords:
Living system, greywater treatment, sustainable water management, water purification technologies, sustainable development, ecological water purification, pharmaceuticals in water, treatment technologies, sustainable urban planning, environmental planning, bioengineering, biofiltration technologyProgress and Final Reports:
Original AbstractP3 Phase I:
An On-Site Biological Graywater Treatment System Suitable for a Small Business | Final ReportThe 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.