Constructed Treatment Wetlands: Innovative Technology for Petroleum Industry

Abstract

Constructed wetlands are innovative and inexpensive treatment approaches that have the potential of removing organic such as aromatics components [benzene, toluene, ethylbenzene and xylene (BETX)] and inorganic compounds in wastewater from a range of sources. The traditional treatment technologies used by the oil industry such as hydrocyclones, separators, etc. removes only dispersed oil but could not remove aromatics components in dissolved water phase. Despite the effectiveness, environmental friendliness and positive economics of constructed treatment wetlands, the application of this novel wastewater treatment technology is still rare in the petroleum industry. The study investigates the potential of aromatic hydrocarbon removal in constructed wetland and consequently advancing proper understanding of scientific and optimal operating conditions of constructed treatment wetlands in the petroleum industry. The research focuses on the investigation of the measures to improve the treatment efficiency of contaminants, assessment of the role of the main constructed wetland components and boundary conditions impacting on the operation and treatment performance. Twelve vertical-flow experimental wetland filters have been designed, constructed using different filter media, and were operated in batch-flow mode to reduce operating cost. The experimental filters were designed to optimize the chemical, physical and microbiological processes naturally occurring within wetlands. Six filters were located indoors, and six outdoors. The outdoor rig simulates natural weather conditions while the indoor rig operates under controlled environmental conditions such as regulated temperature, humidity and light. Findings indicate that the constructed wetlands successfully remove aromatic hydrocarbon (benzene inflow of approximately 1 g L -1 ) from simulated produced waters with better indoor treatment performances than the rig placed outdoors.This result suggests that constructed treatment wetland is very attractive, sustainable and innovative technology capable of meeting zero discharge goal in the production, storage, refining and transportation sectors of the oil and gas industry. Jun-

Green Technology for Crude Oil Processed Water Treatment: A Practical Approach for Nigeria Petroleum Industry

“…This is also supported by Azubuike et al [47] who reported that the major removal pathway for organic contaminants is by degradation, rhizoremediation, stabilization, volatilization and mineralization in the presence of plants. This is in agreement with Eke et al [48] stating that removal pathway in CWs is by volatilization, aerobic degradation and metabolic activity of microorganisms.…”