Title: Assaying coliform removal in waste stabilisation ponds system through the dispersed flow regime
Authors: Jadhav Kapilesh; Jadhav Indrani
Addresses: School of Engineering and Technology, Jaipur National University, Jaipur, India ' School of Life Sciences, Jaipur National University, Jaipur, India
Abstract: This study aims to investigate total coliform (TC) and thermotolerant coliform (TTC) removal efficiency of the waste stabilisation ponds (WSPs) system in Central India through the dispersed flow regime. To accomplish this, coliform (TC and TTC) die-off coefficient (Kb) was estimated for each pond (anaerobic, facultative and maturation) by the dispersed flow regime. Maximum Kb value was observed for the maturation pond (Kb, 5.8) in comparison to the facultative (Kb, 5.6) and anaerobic ponds (Kb, 1.8) and satisfactory correlate with the pond's depth (R2, 0.99) and hydraulic detention time (HDT) (R2, 0.73). On comparing coliform (TC and TTC) removal efficiency of different ponds in different seasons (viz; post monsoon, winter and summer), it was observed that total and thermotolerant coliform load increased in the post monsoon season. This was attributed to differences in the prevalence of infection and fecal excretion levels and due to the mixing of runaway water with raw sewage during the monsoon, which increased the bacterial load. Applying the dispersed flow model to assay coliform removal efficiency of WSPs system, we concluded that shallow ponds with a higher hydraulic detention time have good removal efficiency compared to deep ponds with lower hydraulic detention time.
Keywords: total coliform; TC; thermotolerant coliform; TTC; waste stabilisation ponds system; WSPs; die-off coefficient (Kb); dispersed flow regime; hydraulic detention time; HDT; environment management.
International Journal of Environmental Technology and Management, 2018 Vol.21 No.1/2, pp.64 - 76
Received: 24 Mar 2017
Accepted: 14 Mar 2018
Published online: 14 Jun 2018 *