Project Info

Constructed Wetlands: Next Generation Applications for Sustainable Water Treatment

Josh Sharp

Project Goals and Description:

This project investigates nature-based water treatment using a novel type of constructed wetland (Jasper 2013). While more traditional wetlands are colonized by emergent plants such as bullrush, the wetlands for this project rely on microscopic algae (diatoms) and bacteria to attenuate heavy metals (Yang 2023), nutrients (Brady 2021; Scholes 2021), and pharmaceuticals (Vega 2023). Current research focuses on the application of these wetlands to different types of impaired waters including acid mine drainage, municipal wastewater-impaired waters, and agricultural runoff. This offers a sustainable and cost-effective alternative to traditional water/wastewater treatment facilities that could be applied at a broader scale, both in the United States and abroad (Regis 2022). We have developed laboratory flow-through and batch bioreactors (Vanzin 2023) that mimic existing demonstration scale treatment wetlands deployed in Southern California and enable us to challenge these systems with a variety of contaminants to learn what is possible without hurting the environment. Hired MURF students will use and maintain these laboratory algal “wetland” bioreactors for their research.

More Information:

Grand Challenge: Provide access to clean water.
  • Vega MPA, Scholes RC, Brady AR, Daly RA, Narrowe AB, Vanzin GF, Wrighton KC, Sedlak DL, Sharp JO (2023) Methane-oxidizing activity enhances sulfamethoxazole biotransformation in a benthic constructed wetland biomat. Environ. Sci. Technol. 57,18:7240 10.1021/acs.est.2c09314
  • Yang Z, Acker SM, Brady AR, Arenazas A, Morales L, Ticona J, Romero G, Vanzin GF; Ranville JF, Sharp JO (2023) Heavy metal removal by the photosynthetic microbial biomat found within shallow unit process open water constructed wetlands. Sci Total Environment. 876, (162478).
  • Vanzin GPeel H; Wang W.; Bosworth L; Yang Z; Vega MAP; Root C; Brady A; Romero GM; Rodríguez AA; Ticona J; Morales LP; Sharp JO. (2023) Scalable and customizable parallel flow-through reactors to quantify biological processes related to contaminant attenuation by photosynthetic, wetland microbial mats.  MethodsX (10), 102074.
  • Regis A, Vanneste J, Acker S, Martinez G, Quea J, Garcia V, Alejo F, Zea J, Krahenbuhl R, Vanzin G,Sharp J. (2022) Pressure-driven membrane processes for boron and arsenic removal: pH and synergistic effects. Desalination 522:115441.
  • Brady AR, Vega MA, Riddle KN, Peel HF, Lundeen EJ, Siegmund JG, Sharp JO. (2021) Biomat resilience to desiccation and flooding within a shallow, unit process open water engineered wetland. Water 13(6):815.
  • Scholes RC, Vega MA, Sharp JO, Sedlak DL (2021) Nitrate removal from reverse osmosis concentrate in pilot-scale open-water unit process wetlands. Environ Sci: Water Res Technol 7:650-61.
  • Jasper JT, Nguyen MT, Jones ZL, Ismail NS, Sedlak DL, Sharp JO, Luthy RG, Horne AJ, Nelson KL (2013). Unit process wetlands for removal of trace organic contaminants and pathogens from municipal wastewater effluent. Environ Engrg Science. 30(8): 409-420.

Primary Contacts:

<p style="font-weight: 400">Josh Sharp (<a href=""></a>)</p>

Student Preparation


We are looking for student(s) who are interested in environmental engineering research focused on nature-based solutions to water quality challenges. The student should have familiarity with environmental engineering / water treatment themes and ideally have completed coursework in this discipline. This applied research falls at the intersection of microbiology, geochemistry and engineering and is about exploring the boundaries of what is currently possible by these sustainable systems. An ideal student should have several larger (~3-hour) blocks of time available during a typical 9-5 workweek (particularly when starting as a graduate student will be in lab with them) and be interested in hands-on laboratory research and the unexplored nature (and unpredictability) that goes with those activities.




Laboratory-based experimental design and implementation. Hands-on laboratory skills. Collaborative research.


Undergraduate students are typically paired with a more senior graduate student and or faculty researcher in my laboratory for one-on-one guidance and mentorship when in the laboratory. This includes safety training, laboratory skills, etc. As the student gains proficiency, they will also gain more autonomy and “ownership” of particular experiments, but they will constantly communicate and engage with laboratory members and PI Sharp.


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