Flow Measurement
Measurement of flow of influent to a treatment plant is essential in order to calculate load and mass balance. Measurement could be performed with different methods like magnetic flow meters or open channels like Parshall flume or weirs, in which the flow is calculated as a function of liquid depth.
Immension Sensor Cerlic FLX measure flow as a function of liquid depth in open channels. Two sensors can be connected to the same BB2 central unit, so flow can be measured in two different flumes/weirs simultaneously, e.g. influent and by-pass flow.
Sampling
Reliable and representative sampling with built in cleaning – Cerlic COW
Influent water contains nutrients, both soluble and particles. To get a representative sample, the sampling device needs to be able to cope with both small and big particles. Sampling with lift head between 3 – 6 meter, requires good velocity in the inlet hose to avoid that heavier particles settles, which may jopardize the sample representativeness. Cerlic COW utilizes pre-vacuum of sample chamber to lift samples rapidly when suction height exceeds 3 meters.
The built in flushing prevents dirt and grease to build up in the sample chamber and will reduce manual maintenance.
Optimization of the pre-precipitation chemical dosing
The pre-precipitation chemical dosing is usually controlled by means of influent flow rate as it is assumed that the phosphorus load is proportional versus the flow. This is not always the case. At normal diurnal variations, or high hydraulic load in connection with storm water, etc. it is quite frequent that the dosing is too high. Normally, this is taken care of by manual adjusting of the dosing.
By measuring the influent suspended solids on-line with the Suspended Solids Meter ITX20 together with the flow, the dosing could be optimized to match the load of phosphorus. Savings of chemicals up to 20 – 25% may be achieved by this method.
