An inexpensive phytoremediation system for treating 50,000 L/day of sewage

Abstract

The paper describes the setting up and long-term continuous operation of the first real-life, pilot scale, sewage treatment plant based on the recently patented phytoremediation technology, trademarked as SHEFROL^®. The unit was about three times cheaper to install, operate and maintain than the least expensive of the other wetland-based technologies presently in vogue. Its semi-permanent version is 30 times cheaper. Monitoring of flow rates and levels of treatment intermittently over a 3 year course of continuous operation indicated the constancy and robustness of the reactor in treating total solids, suspended solids, chemical oxygen demand, biological oxygen demand, total Kjeldahl nitrogen, and soluble phosphorous to the average extents of 94, 84, 79, 70, 62 and 28% respectively. Earlier experience with bench-scale SHEFROL^® units has indicated that removal of metals like Cu, Ni, Co, Zn, and Mn also takes place to the extent of 25–45% in these systems. These primary, secondary, and tertiary treatments occurred in a single unit process with no necessity of any pumping, aeration, or recycling. Models based on artificial intelligence were developed which enable forecasting the reactor performance in terms of secondary and tertiary treatment, respectively.

NOVELTY STATEMENT

The paper describes the setting-up, long-term (3 years) performance evaluation at pilot scale, and modeling of a recently patented novel and unprecedented phytoremediation-based sewage treatment technology. The system is seen to be much more robust, versatile, space efficient, and economical, than existing macrophyte-based sewage treatment systems.

Keywords:

• Sewage
• salvinia
• SHEFROL bioreactor
• artificial neural network

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Authors thank the Ministry of Water Resources, RD & GR, Government of India (since renamed Ministry of Jal Shakti), for funding an R&D project (grant 23/30.2004-R&D/957-968) which enabled the work and Department of Biotechnology, Government of India, for supporting the patenting of SHEFROL^®.