Recent Topics Posters
Adhikari, Sajag , Kim, Seonyoung , Stevens, Kevin , Venables, Barney J .
Effects of triclosan on seed germination and seedling development of four wetland plant species grown in a continuous flow-through system.
Triclosan (TCS) is a widely used antimicrobial agent found in consumer products and is released to the environment at sub-ppb concentrations following incomplete removal by wastewater treatment plant (WWTP) processing. The mode of antimicrobial activity of TCS involves inhibition of lipid biosynthesis via an enzyme pathway shared by prokaryotes and plants. TCS released to the environment is acutely and chronically toxic to aquatic organisms and bioaccumulates in algae and fish. Little is known regarding bioconcentration and effects of TCS on wetland plants. As WWTPs discharge into aquatic habitats and as constructed wetlands are of increasing interest for polishing wastewater for reuse purposes, understanding the effect of TCS on wetland plants is necessary to understand impacts on wetland functions and services. We developed a continuous flow system with six treatments (de-ionized water, de-ionized water + solvent, and TCS concentrations of 0.4, 10, 100, and 1000 ppb). The system consisted of syringe and peristaltic pumps, infusion flasks, and modified seedling trays. Turnover rates in the trays were 7.5 times per day (5.7 ml min-1). Effects on seed germination and seedling growth were determined for four wetland plant species (Bidens bidentoides, Cyprerus erythrorhizos, Eclipta prostrata and Sesbania herbacea). GC/MS was utilized to monitor TCS concentrations in the seedling trays and assess bioaccumulation in shoot and root tissues. Preliminary results indicate there were no significant differences in germination (percent and rate) of plant species among treatments. Shoot fresh weight were not significantly affected by treatments, however, root fresh weight, root surface area and root length was inversely proportional to TCS concentration. Given the influence of TCS on root system morphology, TCS may impact root foraging and nutrient uptake capacity and thereby play a role in determining plant community structure in ecosystems receiving WWTP effluent.
Log in to add this item to your schedule
1 - University of North Texas, Department of Biological Sciences, Institute of Applied Sciences, Denton, TX, 76203, USA
Presentation Type: Recent Topics Poster
Location: Ball Room & Party Room/SUB
Date: Monday, July 28th, 2008
Time: 12:30 PM