Survival and growth of the dominant salt marsh grass spartina alterniflora in an oil industry saline wastewater

Abstract

Saline oil produced water (PW) is the largest wastewater stream in the oil exploration and production processes. Although eventual disposal of PW into shallow coastal waters occurs nearby coastal wetlands, no studies regarding its toxicity to higher plants were found in our literature review. To fill this knowledge gap and evaluate the potential use of this halophyte for PW phytoremediation the salt marsh grass Spartina alterniflora was grown in five PW concentrations and no PW treatment control for seven weeks. The oil & grease, NaCl, and ammonium (N-NH4+) concentrations in the PW were 120 mg L−1, 30 g L−1, and 381 mg L−1, respectively. Plants grown in 30% PW and 10% PW achieved survival rates (75%) significantly higher than plants grown in 100% PW (35% survival). LT50 of S. alterniflora to raw PW with 120 mg L−1 of oil & grease (100% PW) was estimated at 30 days. Root and sprout biomass were significantly stimulated by PW; plants grown in 10% to 50% PW concentrations were 70–300% more productive than those in control, 80% PW and 100% PW, respectively. No significant inhibitory effects on survival or growth were detected for concentrations of PW less than 80% when compared to control. Our results pointed out that S. alterniflora grows in saline oil PW and its potential use to phytoremediate this effluent should be evaluated.