technology over conventional systems to recycle the domestic wastewater
with potential for decentralization facility for waste management.
They claimed removal of 5 days' BOD (BOD5) by over 90%, COD
by 80–90%, total dissolved solids (TDS) by 90–92%, and the total suspended
solids (TSS) by 90–95% from urban wastewater after the treatment
with worms. The microbes play an important role in vermibiofiltration
system and they also provide some extracellular enzymes
to facilitate the earthworms for rapid degradation of organic substances
in vermibeds [25]. Likewise, Zhao et al. [2] investigated the interactions
between microorganism and earthworm in vermi-biofiltration system.
They demonstrated that earthworm biofilm was dominated by the
members of the phylum Proteobacteria and Pseudomonas sp.
The majority of previous studies are available on either utilization
of vermi-biofiltration or only constructed wetland filtration system
for removal of nutrients/pollutants from wastewaters, but no comprehensive
report is available on utilizing potentials of both systems
to develop an effective integrated system, comprising of earthworm
and construction wetland system, for wastewater treatment. Although,
Chiarawatchai [26] has conducted an interesting study on
combining vertical sub-surface flow constructed wetlands (VSFCWs)
with earthworm. The integration of these two ecological techniques
(traditional wetlands system with vermi-biofiltration mechanism)
can be a cost effective and sustainable option for onsite wastewater
treatment.
The aim of this study was to assess the potential of an integrated
vermi-biofiltration system with VSFCWs constructed by using earthworm
Perionyx sansibaricus and a wetland weed Cyprus rotundus
(coco-grass or red nut sedge) under a small-scale laboratory experiment.
C. rotundus is one of the most invasive weeds and have been reported
from tropical and temperate regions of the world. It is a perennial
plant and mainly occurs in gardens, agriculture plots, around stagnate
water bodies etc. Few earlier studies have demonstrated the capabilities
of C. rotundus in wastewater treatment and phytoremediation [27–29].