Start-up of a Pilot-scale Ecological Wastewater Treatment System: Water Quality Fluctuations as an Indicator of Ecosystem Development
Open Access
- Author:
- Mckee, Sean Peter
- Area of Honors:
- Civil Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Rachel Alice Brennan, Thesis Supervisor
Eric Todd Donnell, Thesis Honors Advisor - Keywords:
- wastewater treatment
ecological engineering
biological engineering - Abstract:
- The Pennsylvania State University has one of the few research-dedicated ecological wastewater treatment systems (or Eco-Machines™) in the United States. An Eco-Machine™ cleans contaminated water by passing it through a series of aquatic tanks typically housed inside a greenhouse. The ecosystem within an Eco-Machine™ consists of bacteria, fungi, algae, plants, snails, and other beneficial organisms, which together feed on waste products and effectively clean the water to the same standards as conventional wastewater treatment plants, but with a smaller energy footprint. Unfortunately, there is no established protocol for starting these systems, and typically it takes as long as 6 months after the introduction of wastewater to achieve efficient treatment. To better understand the requirements of the dominant organisms in the system and thereby minimize start-up times, our research team is analyzing how the microbial community develops throughout the 6-month start-up period of the pilot-scale Eco-Machine™ on campus. During this time, the system experienced changes in water quality, particularly in the following parameters: 1) dissolved oxygen (DO); 2) conductivity; 3) oxidation-reduction potential (ORP); 4) pH; 5) temperature; 6) chemical oxygen demand (COD); and 7) the concentration of dissolved nutrients like carbon, nitrogen, and phosphorous. The COD results confirmed the system’s treatment efficacy to that of conventional wastewater treatment standards. Additional water samples were collected, centrifuged, and the resulting pellet preserved at -80 oC for later DNA extraction. Now that the system has reached the desired treatment efficiency, the DNA corresponding to the dates when water quality improved is currently being sequenced and analyzed by graduate students in the laboratory. Hopefully, the combined analysis of the DNA and water samples will yield valuable information about the microbial populations responsible for these improvements and the conditions that optimized their growth. The ultimate goal of this project is to develop a standard protocol for improving the start-up efficiency of ecological wastewater treatment systems, so that they can be more easily applied for improving water quality in developed and developing nations.