Study about the treatability of an industrial stream by means advanced BM Respirometry - Case Study
When it is needed to know whether a particular type of industrial stream can be treated biologically, either because it is expected to be incorporated into the global influent of the treatment process or because has to be individually eliminated in a new biological treatment, it is necessary to know its biodegradable character, degree of toxicity or possible inhibition that could cause in the microorganisms of the biomass responsible of its degradation as fundamental parameters.
It is quite possible that the percentage of biodegradability is not sufficient, as it might be the case that a very biodegradable discharge may contain a high percentage of very slowly biodegradable COD giving way to the well known consequences that this can entail.
Likewise, it may be about low BOD/DQO ratio, either because the BOD is really low or also due to a toxic effect that the sample has been generating during the BOD test performance.
In fact, this same toxic effect can be translated to the bCOD/DQO (Biodegradable COD / COD) where, by varying the ratio [sample volume/ sludge volume] in the respirometry tests, there is the possibility to generate different levels of apparent biodegradability degrees, when the reality is that the relatively low values of DQOb are the consequence of a certain degree of toxicity that was being generated during the respirometry tests performance.
Faced with the problem of reliable analyses to determine the treatability of an industrial stream, BM Respirometry is erected as an important tool when, for a given ratio [sample volume] / [sludge volume] as a first step to the protocol of treatability, is able to determine the degree of its biodegradability, possible toxicity to the microorganisms and the effect that toxicity could make on the specific biodegradability. This not only results in significant time saving, but also the analysis of the combined effect of biodegradability – toxicity.
Once the results of this type of tests have been obtained, when confirmed the presence of toxicity, we can optionally go to a second step in which we could determine the maximum allowed flow to be treated without any toxicity.
2. Operation modes of a BM respirometer
The BM respirometry systems from Surcis, S.L. (www.surcis.com) include three different operational modes, thus opening up an important range of possibilities to allow a wide range of applications related with the biological wastewater treatment. All operation modes also include programmable automatic temperature control. BM-Advance models also include a programmable pH control.