SCERP Project Number: W-4
Principal Investigator: Walter H. Zachritz, II
New Mexico State University
EXECUTIVE SUMMARY
Subsurface flow constructed wetlands (SF) or artificial wetlands filter (AWF) systems have been examined for potential use in effective removal of complex halogenated and nonhalogenated organic compounds from various waste streams. While numerous studies have been conducted to examine the potential of AWF systems to treat domestic wastewater, landfill leachate, acid mine drainage, and stabilization lagoon effluent, little has been done with respect to their use for the removal of aromatic and halogenated organic compounds such as benzene, toluene, xylenes (BTXs), phenol, pentachlorophenol, and oily wastes. Our study explores the capacity of an AWF system to remove aromatic organic compounds as represented by benzoic acid and evaluate its potential for biodegradation of more recalcitrant molecules. Six small, pilot-scale AWF systems that run on a continuous flow basis were tested for effectiveness of vegetation (Scirpus validus), the microbial population, oxidation- reduction potential (ORP), and evapotranspiration on the degradation of benzoic acid by the system. Initial results indicate excellent (nearly 99 percent) removal of benzoic acid at concentrations up to 40 mg/l. Additionally, the total microbial population was fairly diverse overall, but contained a subpopulation of benzoate degraders of lower diversity.
Key Words: submerged surface constructed wetlands, hazardous waste,
biodegradation.
The FY91 SCERP-supported phase of this project:: W-4
The FY92 SCERP-supported phase of this project: W-18
The FY93 SCERP-supported phase of this project:: WQ93-10
Last updated 7/1/99