Potential of joyweed Alternanthera sessilis for rapid treatment of domestic sewage in SHEFROL^® bioreactor

Abstract

In a first-ever report on this subject, it is shown that a common amphibious plant joyweed (Alternanthera sessilis) can be used in rapid and efficient treatment of biodegradable wastewaters, typified by domestic sewage. The plant was effective when used indoors under artificial lighting, as well as outdoors. It enabled treatment of sewage, varying widely in strength (from 300 mg/L to 1800 mg/L in chemical oxygen demand), to the extent of 78.9–83.9%. It was also able to remove biological oxygen demand, suspended solids, phosphorous, nitrogen, and the heavy metal copper to the extent of 87%, 93%, 45%, and 43%, respectively. Over 99% of total coliforms, faecal coliforms, and faecal streptococci were also removed. The treatment was very swiftly achieved, at a hydraulic retention time of just 6 h, in the “sheet flow root level” (SHEFROL^®) bioreactor developed earlier by us and of which a patent claim has been registered. The findings indicate that A. sessilis has the potential to affect primary, secondary, and tertiary treatment of domestic sewage along with significant pathogen removal in a single process step when used in SHEFROL^® bioreactors.

Keywords:

• Alternanthera sessilis
• bioremediation
• domestic sewage treatment
• SHEFROL^®

Acknowledgments

Authors thank Dr. M. Premalatha for assisting in the experiments.

Additional information

Funding

Authors thank the Ministry of Water Resources, RD & GR, Government of India, for funding an R&D project which enabled the work and Department of Biotechnology, Government of India, for supporting the patenting of SHEFROL^®. SAA thanks the Council of Scientific and Industrial Research (CSIR), New Delhi for the Emeritus Scientist grant (21(1034)/16/EMR-II) which has enabled him to document the findings presented in the article.