Characterization of wastewater and activated sludge from European municipal wastewater treatment plants using the NUR test

Abstract

Denitrification kinetics and wastewater characterization of eight different plants in Europe are discussed. Denitrification batch tests revealed three distinct rates except in the cases of Plaisir, Rostock and Orense where 4 rates were observed. The latter three plants revealed atypical rapid initial rates which were between 7 and 21 mgN/gVSS.h. All denitrification kinetics under non-limiting carbon conditions revealed fast first rates which ranged between 3.0 and 7.3 mgN/gVSS.h. Acetate was used to simulate denitrification kinetics with readily biodegradable COD present. Two subsequent rates were observed. Rates 2 and 3 ranged between 2 and 3 mgN/gVSS.h, and 1 and 2 mgN/gVSS.h, respectively. The RBCOD fraction varied between 10 and 19%, except for one of the plants where the value determined was 7%.

The role of biodegradable particulate and colloidal organic compounds in biological nutrient removal activated sludge systems

“…1.5-1.8 mg N/(g VSS h) (Wschod) and 1.7-2.0 mg N/ (g VSS h) (Debogorze). The NUR1 and NUR2 values observed at both studied plants fit into the ranges reported by Naidoo et al (1998) for similar experiments at eight municipal WWTPs in Europe. In that study, the NURs associated with utilization of the readily biodegradable and slowly biodegradable substrates remained in the range of 3.3-5.7 and 1.6-3.6 mg N/(g VSS h), respectively.…”

Influent fractionation for the use of ASM1 to optimize urban wastewater treatment: Application to the removal of C and N in a SBR

“…a) The soluble fraction of COD (S s0 ) was also identified by physico-chemical methods described by (MAMAIS et al, 1993;NAIDOO et al, 1998).The first step consisted in the elimination of suspended solids by using a coagulant flocculant. The supernatant was then filtered at 0.45 µm.…”

“…It is necessary to conduct a thorough analysis of the respirograms, and to manage properly the nutrients to biomass ratio (SPERANDIO, 2007). Physico-chemical methods can also be used to identify some ASM1 variables and especially S S (MAMAIS et al, 1993;NAIDOO et al, 1998). The main failure of these methods is the lack of distinction between non-biodegradable and biodegradable matter.…”

Microbial electrochemical systems for nitrate removal from diluted streams

“…Although denitrification rates are shown to be higher (almost twice as fast) within a mixotrophic culture in heterotrophic conditions with methanol as electron donor than in autotrophic conditions with hydrogen as electron donor [22], as exposed previously, nitrate may still be encountered in secondary effluents from WWTP, and only limited organic compounds and/or non-biodegradable forms of COD are usually present [20], preventing the complete heterotrophic removal of nitrate. Therefore, there is still a compelling need for the development of solutions that are able to fully remove N from wastewaters before its discharge into waterways.…”

“…However, in practice, bigger ratios are required, such as the previously reported proportion of 4.5 [17], which could partly be attributed to biomass growth [18,19], or the presence of different forms of COD (i.e. nonbiodegradable organic compounds) [20]. Even if the influent C/N ratios could theoretically be enough to sustain full denitrification in a WWTP, very high aerobic-to-anoxic recirculation ratios are required to achieve high nitrogen removal efficiencies.…”