TOC, TNb, TP and COD - combined in one unit

The control of waste water effluent and local waste water treatment plants takes a special position - from an ecological as well as economic point of view. By continuous measurements the treatment performance may be monitored. The effluent finally is discharged into river water and/ or lakes which can be better protected. The monitoring of the effluent of waste water treatment plants is regulated by local authorities. However, the aim of such legal frameworks for water management is to protect water as a meaningful part of ecosystems, as natural basis of life for human kind as well as for flora and fauna.

Generally, four different analysers are needed in order to monitor the four sum parameters. LAR's QuickTOC_NPO is the ultimate online analyser for the determination of total organic carbon (TOC), total bound nitrogen (TN_b), total phosphorus (TP) and the chemical oxygen demand (COD). All parameters are determined in accordance to international standards. LAR provide with its QuickTOC_NPO a measurement system for measuring the four parameters in a single unit.

The catalyst-free ceramic oven is the centre piece of the QuickTOC_NPO. At 1,200°C, it reliably dissolves all carbon bonds and thus enables a complete analysis of samples. Despite the high temperatures used, absolute safety is guaranteed in all settings. For this the QuickTOC_NPO can be delivered with a number of different housings, depending on the intended location.

Due to the close relation between TOC and COD it is very easy to correlate both parameters. The Total Phosphorus is determined by the photometric molybdenum blue method. First the sample is being mixed with an oxidising agent. Subsequently, the mixture is led into the reactor where ultra violet light (UV) activates the sample‘s oxidation. Finally, by adding the molybdenum blue it becomes visible how much TP is in the sample. The TN_b measurement takes place in less 3 minutes – as promt at the TOC value. Thereby, even short measurement value peaks can also be reliably shown.

Depending on the composition of the sample the sample taking may differ. Under normal circumstances the outlet/ effluent of a sewage plant is free of particles – or at least there are only a few. In this case a centrifugal separator is sufficient for the sample extraction. However, is the sample characterised by a high particle density, the sample should be taken by the filterless, patented FlowSampler.

The modular system offers the greatest flexibility, while using the parameters in any combination. The link between the four parameters in one unit reduces the investment costs, support and maintenance and enables an efficient monitoring of the plants effluent.