Grantee Research Project Results
Final Report: User-friendly Design Tools for Sustainable Wastewater Treatment in Rural and Disadvantaged Communities
EPA Grant Number: SU835722Title: User-friendly Design Tools for Sustainable Wastewater Treatment in Rural and Disadvantaged Communities
Investigators: Gude, Veera Gnaneswar , Martinez-Guerra, Edith , Fast, Sara Ann , Lee, Gordon , Jiang, Yi
Institution: Mississippi State University
EPA Project Officer: Hahn, Intaek
Phase: I
Project Period: August 15, 2014 through August 14, 2015
Project Amount: $15,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2014) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Safe and Sustainable Water Resources , P3 Awards , Sustainable and Healthy Communities
Objective:
The objective of this project is to provide wastewater treatment design solutions to small disadvantaged communities that are not currently able to utilize the effective technologies available to larger, more privileged communities. In this report, a “small community” is defined as one with a total population less than 20,000 people, and a “disadvantaged community” is defined as one with a median household income less than 80 percent of the statewide average. The scope of the project focuses on the delta region of Mississippi for two reasons. First, the characteristics of the communities in this region are consistent with the types that the project is designed to serve. Second, the social and physical geography of the Delta suggests that the Mississippi River could see increased protection from nutrient pollution by improving the wastewater treatment practices within the region. Although the Phase I solution will be specifically designed for the Mississippi Delta, it can be easily adapted to fit the needs of similar communities across the nation and may have future significance in providing infrastructure for the developing world.
The ultimate goal and thus the product of Phase I is an online-accessible tool that uses existing wastewater data from communities in the area of interest to generate design proposals for an effective wastewater treatment plant. The recommended designs will meet the specific needs of the communities by prioritizing affordability and nutrient removal efficiency. The website that presents the design tool will also include linked pages of extensive research about the environmental and human health impacts of wastewater, strategies for managing small and decentralized wastewater treatment facilities, and available wastewater treatment technologies that include nutrient removal. In addition to an overview of available technologies, the information on the website will include relevant case studies and economic analyses.
Summary/Accomplishments (Outputs/Outcomes):
A variety of research activities were performed by the team members in Phase I, including investigation of current water quality issues, available nutrient removal technologies, and decentralized treatment strategies. The outcomes from this research will be presented on a dedicated project website. Potential environmental impacts and effects on human health were examined, and a number of relevant case studies were identified/reviewed for comparison. Data for representative wastewater treatment facilities in the region of interest has been analyzed using GIS models and techno-economic/lifecycle assessments from ExtendSim® and GPS-X® software to generate design criteria. The acquired information was used for preliminary design purposes. Microsoft Excel spreadsheets were employed to produce models for the design of treatment processes. These models will ultimately be employed in the creation of design calculators on the team website. In addition, each team member analyzed the economic aspects and feasibility of potential nutrient removal processes, and these contributions were combined into a cumulative analysis. A summary of the gathered information to be included in the website is described within the report. After studying and experimenting with different wastewater treatment processes. The team has concluded that the calculations in the website will be based on the process shown in Fig. I, which consist of an equalization tank, an aerobic reactor, and anoxic reactor, and a secondary clarifier in sequence before discharge. Fig. II shows the results for 1 m depth and 20 m3 volume of both aerobic and anoxic tanks. The results include data from 5 different processes where it can be noticed that the target pollutants were tremendously reduced by the modified “P3 Design” when compared to other processes. The desired nutrients and COD results were only met by our selected process.
Fig. I. Nutrient Removal Process
Wastewater Treatment Methods
Fig. II. Effluent quality from different nutrient removal processes
Conclusions:
The design analysis from simulation exercises concluded that biological nutrient removal (BNR) and enhanced biological phosphorous removal (EBPR) would be the processes used in all design recommendations. BNR utilizes aerated and anoxic zones to allow nitrifying and denitrifying bacteria to convert ammonia nitrogen into nitrogen gas, N2(g), through a series of biochemical reactions. EBPR is incorporated into the BNR process by the addition of an anaerobic zone that works in conjunction with the aerobic BNR zone to allow phosphate-accumulating organisms (PAOs) to consume phosphorous species. The BNR and EBPR processes may be implemented through different mechanisms including suspended growth and biofilm reactors, and these mechanisms may be arranged into a variety of configurations. Each configuration of the available technologies was analyzed based on its overall cost and removal efficiency. This analysis provides the criteria for selecting the best design for a specific community.
Given the technical and financial limitations of rural areas, decentralized systems for wastewater treatment are considered as a long-term solution for small communities because they are reliable, cost effective, and easy to operate. Commonly used primary treatment methods of decentralized systems include septic tanks and Imhoff tanks. These technologies do not effectively remove nutrients and pathogens; therefore, a secondary treatment method such as BNR is required. The aerated lagoon was found to be one of the most effective secondary treatment options, achieving up to 60% nitrogen removal and 50% phosphorous removal. After treatment, the wastewater may be discharged into subsurface or constructed wetlands or surface waters. Decentralized approaches with primary and secondary treatment were found to be promising solutions to wastewater issues in rural and small communities.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
Other project views: | All 1 publications | 1 publications in selected types | All 1 journal articles |
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Sarpong G, Gude VG. Codigestion and combined heat and power systems energize wastewater treatment plants-Analysis and case studies.RENEWABLE & SUSTAINABLE ENERGY REVIEWS2021;144(110937). |
SU835722 (Final) SU835717 (Final) |
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Supplemental Keywords:
Disadvantaged communities, design tools, wastewater treatment, sustainable communities, and water reuseThe 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.