The Effect of Baffle Installation on the Performance of a Single-Cell Stabilization Pond

Abstract

The effect of baffles on the performance of an ineffective, single-celled stabilization pond with theoretical retention time of 5-10 days, was investigated. The efficiency of the pond was evaluated by comparing the microbiological and chemical quality of pond's influent and effluent, as well as by hydraulic tests. Removal of indicator microorganism (1 log) and BOD5 (55%) remained unchanged, regardless of the number of baffles. Tracer study findings were characterized by the appearance of a peak of tracer within 15-20 hours after injection of the tracer, followed by a long “tail” of lower concentration. These findings, along with optical observations, indicated that the baffles succeeded in channeling influent flow to the planned routes (resulting in increased traveling distance of the wastewater). However, the actual retention time of the influent, particularly a small but important fraction of it, remained short regardless of baffle installation. The lack of mixing caused by thermal stratification of the water column resulted in rapid bottom flow in the cool hypolimnion. These findings may explain, in part, the lack of success in improving treatment efficiency.

Bioelectrochemical system as an oxidising filter for soluble and particulate organic matter removal from municipal wastewater

“…A WSP system designed to treat municipal wastewater typically consists of non-mechanically mixed anaerobic, facultative and maturation ponds [4]. Collectively, these ponds are employed to remove suspended solids (SS), organic pollutants, human pathogens and some nutrients from wastewater [5]. However, inadequate and inconsistent removal of pollutants and pathogens are not uncommon and hamper the widespread use of WSPs.…”

A bio-anodic filter facilitated entrapment, decomposition and in situ oxidation of algal biomass in wastewater effluent

“…Typically, a WSP system consists of serially-connected anaerobic, facultative and maturation ponds (Mara et al, 1992). Facultative ponds (FPs) facilitate much of the oxidation of organic matter through a mutualistic relationship between algae and bacteria, and the process relies heavily on natural factors (wind, sunlight, temperature) to fulfil the requirements of such mutualistic relationship (Pedahzur et al, 1993;Tharavathi & Hosetti, 2003). However, due to the reliance on these uncontrollable factors the removal of dissolved organic carbon (DOC) and suspended solids (SS, concentration of up to 200 mg L -1 ) are often inadequate (Ellis & Mara, 1983;Mara et al, 1998;Mara et al, 1992).…”

Enhancing sedimentation by improving flow conditions using parallel retrofit baffles

“…One of the most cost effective ways to achieve this is by means of different baffles to direct the flow of water and correct poor hydraulic conditions. An S-shape series-connected baffle configuration has been suggested and implemented by many studies and projects (Marsalek et al, 1992;Pedahzur et al, 1993;Shaw et al, 1997;Walt and Water, 2000;Khan et al, 2006;Zhang et al, 2011;Kim et al, 2013) to maximize the flow path available for settling and/or to optimize particle contact time for disinfection. However, forcing the flow to go through a relatively narrow path and change direction many times may generate strong and unwanted turbulence at the turns, potentially disturbing settled particles and energizing the carried particles, especially under high flow.…”