Bioaugmentation to Improve Nitrification in Activated Sludge Treatment

Abstract

Bioaugmentation is a proposed technique to improve nutrient removal in municipal wastewater treatment. Compared with commonly used nitrification/denitrification (NDN) processes, bioaugmentation may be able to reduce tankage or land requirements. Many approaches for bioaugmentation have been developed, but few studies have compared the benefits among different approaches. This paper quantifies the effectiveness of bioaugmentation processes and investigates three major ''onsite'' bioaugmentation alternatives: 1) the parallel-plants approach, which uses acclimated biomass grown in a nitrifying ''long-SRT'' (sludge retention time) plant to augment a low-SRT treatment plant; 2) the enricher-reactor approach, which uses an offline reactor to produce the augmentation cultures; and 3) the enricher-reactor/return activated sludge (ER-RAS) approach, which grows enrichment culture in a reaeration reactor that receives a portion of the recycle activated sludge. Kinetic models were developed to simulate each approach, and the benefits of various approaches are presented on the same basis with controllable parameters, such as bioaugmentation levels, aeration tank volume, and temperatures. Examples were given to illustrate the potential benefits of bioaugmentation by upgrading a ''carbon-only'' wastewater treatment plant to nitrification. Simulation results suggested that all bioaugmentation approaches can decrease the minimum SRT for nitrification. The parallelplants approach creates the highest concentration of biomass but may fail at too low temperature. The ER-RAS approach likely would be more useful at lower temperature and required less reactor volume; enricherreactor approach would likely be more advantageous in the presence of inhibitory compound(s). Water Environ. Res., 82, 524 (2010).

Dynamic Simulation of Continuous Mixed Sugars Fermentation with Increasing Cell Retention Time for Lactic Acid Production using Enterococcus mundtii QU 25

“…Cell growth was estimated in terms of optical density at a wavelength of 562 nm (OD 562 ) with spectrophotometer (UV-1600, Shimadzu). One unit of OD 562 was equivalent to 0.218 g dry cell weight (DCW, g•L -1 ) (16). The concentrations of cellobiose, xylose, glucose, and fermentation products were analysed by a high-performance liquid chromatography (HPLC) system (US HPLC-1210, JASCO, Tokyo, Japan) equipped with a SUGAR SH-1011 column (Shodex, Tokyo, Japan).…”

“…By controlling the cell concentration, and/or the cell retention time (CRT) of the process, the robustness of the continuous process can be improved to handle different substrate combination with a higher variety of digestibilities or toxicities. The process can be operated without repeating the inoculation and may prevent significant cell decay due to sudden environmental changes [16], which might exploit potential to overcome the CCR and/or grow inhibiting effects induced by pretreatment by-products, carbon sources, and the end products.…”

In situ Groundwater Remediation Using Enricher Reactor – Permeable Reactive Biobarrier

“…Appropriate growth conditions for culture enrichment such as availability of nutrients and target compounds, and suitable environmental conditions (pH and temperature) are provided in the ERs to induce the desired degradation capability. ER has been successfully applied in wastewater treatment for the removal of naphthalene and phenanthrene (Cardinal and Stenstrom, 1991), 1-naphthylamine (Babcock et al, 1992), pentachlorophenol (Jittwattanarat et al, 2007a), nitrogen (Jittwattanarat et al, 2007b;Leu and Stenstrom, 2010), and pharmaceutical drugs such as cephalexin and cephradine (Saravanane et al, 2001a;.…”

Groundwater Remediation Using an Enricher Reactor—Permeable Reactive Biobarrier for Periodically Absent Contaminants

“…The use of the enricher reactor technique in wastewater treatment was introduced by Cardinal and Stenstrom (1991) for the removal of naphthalene and phenanthrene. Later, this concept was applied successfully for the removal of 1-naphthylamine (Babcock et al, 1992); pentachlorophenol (Jittwattanarat et al, 2007a); nitrogen (Jittwattanarat et al, 2007b;Leu and Stenstrom, 2010); and pharmaceutical drugs, such as cephalexin and cephradine (Saravanane et al, 2001a(Saravanane et al, ,2001b from wastewater.…”