Effects of Simulated Oilfield Produced Water on Early Seedling Growth After Treatment in a Pilot-Scale Constructed Wetland System

• Published in: International journal of phytoremediation 2015-04, Vol.17 (4), p.330-340
• Main Authors: Pardue, Michael J, Castle, James W, Rodgers, John H, Huddleston, George M
• Format: Article
• Language: English
• Subjects: Abelmoschus; Bioassays; Biodegradation, Environmental; Citrullus lanatus; constructed wetlands; Construction; Corn; Crops; Crops, Agricultural - growth & development; Crops, Agricultural - metabolism; Germination; Glycine max; Guidelines; irrigation; Lactuca sativa; lettuce; Lettuces; millets; Oil fields; okra; Panicum miliaceum; phytoremediation; Phytotoxicity; Pilot Projects; Plant growth; Plants (organisms); seed germination; seedling growth; Seedlings - growth & development; Seedlings - metabolism; Sorghum; Sorghum bicolor; Soybeans; subsurface flow; Waste Water - analysis; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - metabolism; watermelons; Wetlands; Zea mays
• ISSN: 1549-7879; 1522-6514; 1549-7879
• DOI: 10.1080/15226514.2014.910168

Seed germination and early seedling growth bioassays were used to evaluate phytotoxicity of simulated oilfield produced water (OPW) before and after treatment in a subsurface-flow, pilot-scale constructed wetland treatment system (CWTS). Responses to untreated and treated OPW were compared among seven plant species, including three monocotyledons: corn (Zea mays) , millet (Panicum miliaceum) , and sorghum (Sorghum bicolor) ; and four dicotyledons: lettuce (Lactuca sativa) , okra (Abelmoschus esculents) , watermelon (Citrullus lanatus) , and soybean (Glycine max) . Phytotoxicity was greater in untreated OPW than in treated OPW. Exposures to untreated and treated OPW enhanced growth in some plant species (sorghum, millet, okra, and corn) relative to a negative control and reduced growth in other plant species (lettuce, soybean, and watermelon). Early seedling growth parameters indicated that dicotyledons were more sensitive to test waters compared to monocotyledons, suggesting that morphological differences between plant species affected phytotoxicity. Results indicated the following sensitivity scale for plant species: lettuce > soybean > watermelon > corn> okra≈millet >sorghum. Phytotoxicity of the treated OPW to lettuce and soybean, although concentrations of COCs were less than irrigation guideline concentrations, suggests that chemical characterization and comparison to guideline concentrations alone may not be sufficient to evaluate water for use in growing crops.