Measurement and modelling of ordinary heterotrophic organism active biomass concentrations in anoxic/aerobic activated sludge mixed liquor

Abstract

Ordinary heterotrophic organism (OHO) active biomass (ZBH) is a key parameter in models for activated sludge systems, which defines quantitatively the kinetic rates of relevant processes. However, ZBH has not been measured directly with consistent success: a simple respirometric batch test has provided varying correspondence between measured and theoretical concentrations. In this paper, the batch test is applied to mixed liquors drawn from well defined anoxic/aerobic parent systems at 10 and 20 d sludge ages, with consistent but poor correspondence between measured and theoretical values. In contrast, aerobic digestion batch tests on the same mixed liquors give good correspondences. It is concluded that the differences between theoretical and batch test measured values are due to the batch test method itself and its interpretation. It is found that the batch test conditions (particularly the substrate/ZBH ratio) influence the kinetic constants derived from the data, and hence the ZBH estimate. Two kinetic models with two competing OHO populations, a fast and a slow grower, are developed and applied to the batch tests and parent systems. The first model is based on kinetic selection only, while the second includes additional metabolic selection. Both models can account for the observations in the batch tests, but the second provides greater consistency between simulations of the parent systems and batch tests.

Experimental Methods in Wastewater Treatment

“…In fact, the challenge of the methods described in this section is to assess the part of the VSS that represents the biomass concentration. For further information on how to assess the part of the VSS that is active biomass the reader is referred to Ekama et al (1996), Still et al (1996) and Lee et al (2006).…”

Bacterial Community of Natural Dye Wastewater Treatment Facility

“…합성염색폐 수처리 공정에서 중요한 염료의 탈색을 위해 많은 경우 흡착 제를 이용한다 [13]. 최근에는 염료의 탈색과 난분해성 화합물 의 분해를 위해 생물학적 처리방법들이 적용되고 있으며 특정 미생물을 이용하여 분해 효율을 높이는 연구들이 진행되고 있다 [6,11,14,15,21,25,26]. DGGE를 위한 nested-PCR은 GC clamp가 붙어 있는 GC-341F primer (5′-CGC CCG CCG CGC GCG GCG GGC GGG GCG GGG GCA CGG GGG GCC TAC GGG AGG …”

“…The most dominant taxon retrieved by both methods was the member of the phylum Proteobacteria with Alphaproteobacteria as the predominant class. The bacterial community associated with the natural dye wastewater treatment facility is composed of parasites of animals and plants, decomposers of polysaccharides and dyes, and producers of extracellular polysaccharides.Key words : Bacterial community, denaturing gradient gel electrophoresis, natural dye wastewater *Corresponding author [6,11,14,15,21,25,26]. …”

“…Key words : Bacterial community, denaturing gradient gel electrophoresis, natural dye wastewater *Corresponding author [6,11,14,15,21,25,26]. …”

New framework for standardized notation in wastewater treatment modelling

“…With this research a specific notation was introduced (further referred to as the 'UCT system') and several research groups are still using this naming system (e.g. Barker & Dold 1997; Lee et al 2006). Petersen table, composed of a stoichiometric matrix, a rate vector and extra information as units and names) and with a new and standardized notation (in this paper referred to as the 'IWA system').…”