Assessment of selected decentralised sewage treatment systems
Student name: Ms Manpreet Kaur
Guide: Dr Arun Kansal
Year of completion: 2010
Host Organisation: The Energy and Resources Institute (TERI)
Supervisor (Host Organisation): Dr Malini Balakrishnan
Abstract: The aim of this study is to compare organics and nutrient removal in two wastewater
treatment systems and to examine reuse and upgradation options for the treated effluent.
Water quality parameters viz., suspended solids, volatile suspended solids, sulphates, chemical
oxygen demand, phosphates, and ammoniacal nitrogen were analyzed for pilot scale
membrane bioreactor (MBR) working in parallel to a full scale constructed wetland (rootzone)
treatment plant at TERI-RETREAT Gual-Pahari. The analysis was done for a period of
12 weeks, by collecting samples twice a week. In this study, performance of the root-zone and
membrane bioreactor systems were compared by calculating the efficiency of both the systems
from the average readings of the data so recorded. The results showed that COD removal
efficiency of MBR was 73% whereas that of root zone system was found to be 51%.
Ammoniacal nitrogen reduction percent in MBR was found to be almost 100% whereas that
for root zone system was found to be 53%. Sulphates reduction of MBR was 19% whereas that
of root-zone system was 18.81%. The treated wastewater of the root zone system is already
being used for horticultural purposes in Gual Pahari and that of MBR is being used for
cleaning purposes in the pilot installations. More reuse options were explored based on the
available literature.
KEY WORDS: Decentralized wastewater treatment, root zone system, membrane bioreactor, nutrient
removal, wastewater reuse.
