Design of pilot-scale constructed wetlands for tertiary treatment of refinery effluent

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:37459

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

---

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

Two pilot-scale constructed wetlands (4:1 length:width aspect) were designed for tertiary treatment of refinery effluent. As requirements for removal of contaminants from NPDES effluents become more stringent, cost-effective technological approaches are needed to achieve the necessary treatment levels and be efficient, effective and low maintenance. The fundamental design of these constructed wetlands was based on biogeochemical principles that regulate the fate and persistence of the targeted elements (Cu, Zn, Pb). In order to maximize opportunities to learn more about the internal function of the wetlands, they were built to operate in series or in parallel permitting hydraulic retention times of 24 to 48 hours. The wetlands were lined with {approximately}76 cm of compacted clay as well as a 30 mil polyethylene liner. The hydrosoil selected for use in the constructed wetlands is 74.1% sand, 25.6% silt, 0.3% clay. Based on laboratory studies, this hydrosoil achieves a redox of 250 to {approximately}300 mv and a pH of 7.5 in the presence of Scirpus californicus. These conditions should enhance the ability of the constructed wetlands to retain and sequester the target elements and control chronic toxicity from the effluent.

• OSTI ID: 37459
• Report Number(s): CONF-9410273--
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
CHEMICAL EFFLUENTS
CONSTRUCTION
COPPER
LEAD
PETROLEUM REFINERIES
REMOVAL
TECHNOLOGY ASSESSMENT
WASTE PROCESSING
WASTE WATER
WATER POLLUTION CONTROL
WETLANDS
ZINC