Hybrid Wetland Living Machine^® System

The Hybrid Wetland Living Machine system, which uniquely combines horizontal and tidal flow wetlands, was developed and patented by Worrell Water Technologies. This newest generation, wetland‑based Living Machine system has superior process control and nitrogen removal compared to conventional constructed wetlands for wastewater treatment while retaining its simplicity and energy efficiency.

System Description
(Click for larger picture)

The Hybrid Wetland Living Machine system combines two complimentary wetland technologies. Horizontal subsurface flow wetlands are well‑established, simple, low‑energy systems capable of moderate to good treatment. Tidal Flow Wetlands utilize a fill‑and‑drain wetland technology with special media to increase treatment efficiency and final effluent quality of the combined wetland system. The overall treatment system consists of the horizontal flow wetland cell(s), coupled to a set of tidal flow wetland cells with a hydraulic control/pump structure and a control system.

The horizontal flow wetland receives wastewater influent and provides initial treatment and flow equalization. Water is recycled through the Tidal Wetland Cells to “turbocharge” the horizontal wetland and enhance the nitrogen removal.

There are no exposed water surfaces in any of the wetlands thus preventing mosquito breeding and potential human contact with wastewater. The wetland vegetation, especially the root zone, enhances treatment by promoting a complex and stable ecosystem. The system can be operated with simple controls or a computer–based system depending on the site requirements and interactive features desired. Either control system would have alarms for critical conditions. The computer controller can be equipped for remote monitoring and operation.

Effluent Quality and Benefits

This system is designed for nitrogen removal and advanced BOD and TSS removal. The design can be tailored to the amount of nitrogen removal required and effluent total nitrogen can be as low as 10 mg/l. The system provides excellent reliability and stability due to the long residence time and complimentary treatment processes.

The Hybrid Wetland system is beautiful, effective and requires very little operational attention. This ecologically engineered system uses very little energy and machinery to achieve high quality effluent. This system can be used in its entirety or the Tidal Flow component can be retrofitted to existing horizontal flow wetlands or lagoon systems to improve overall treatment and nitrogen removal. Layout and plant selection can be configured to meet site and aesthetic criteria.

Other benefits include:

1. The energy costs for tertiary treatment are approximately 20% of an equivalent activated sludge system.
2. The footprint is less than half that of traditional horizontal subsurface flow wetlands.
3. There is no clarifier and thus no residual sludge (waste bacterial material) to manage or dispose of.
4. Operation is automated, minimizing operator time.
5. The design utilizes plants that can be customized to provide an attractive addition to any landscape.
6. The process is virtually odor free.