Pilot-scale constructed wetlands for tertiary treatment of refinery effluent

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:382749

Hawkins, W B; Dunn, A W; Rodgers, Jr, J H ^[1]; Dorn, P B ^[2]

---

1. Univ. of Mississippi, University, MS (United States). Biological Field Station
2. Shell Development Co., Houston, TX (United States)

Two pilot-scale wetlands were designed and constructed for tertiary treatment of refinery effluent with the goal of removing Cu, Pb, and Zn. The wetlands were built to operate in series or in parallel, with hydraulic retention times of 24 and 48 hours, respectively. The wetlands were lined with a 76 cm layer of compacted clay which is covered with a non-porous 60-mil polyethylene liner. The hydrosoil selected for use in the constructed wetlands was an alluvial sediment consisting of 74.1% sand, 25.6% silt, and 0.3% clay. Scirpus californicus (Giant Bulrush) was planted in both wetlands with an average initial plant density of 9 plants per m{sup 2} and average initial heights of 0.3 m. After six months of wetland operation, the desired design characteristics have been achieved and have aided in metal removals. The hydrosoil developed an average redox potential of {minus}170 mV and a ph of 7.0. S. californicus increased to an average density of 42 plants per m{sup 2} and grew to an average height of 2.7 m. These wetland characteristics have resulted in removals of approximately 67% of the Cu, 89% of the Pb, and 98% of the Zn from the refinery effluent in preliminary monitoring. Additional studies to evaluate operating efficiencies under different conditions are in progress.

• OSTI ID: 382749
• Report Number(s): CONF-9511137--; ISBN 1-880611-03-1
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
BIODEGRADATION
CHEMICAL EFFLUENTS
CONSTRUCTION
COPPER
LEAD
PETROLEUM REFINERIES
WASTE MANAGEMENT
WETLANDS
ZINC