Nivelco Process Instruments for Wastewater Treatment.
Nivelco and Aqua Technology Group can provide all your instrumentation and control needs for collection systems, liftstations and pumps, package plants and wastewater treatment plant. This diagram of the wastewater treatment process details two separate sections: wastewater treatment processes and slurry treatment processes.
COLLECTION SYSTEM / LIFTSTATIONS / SUMPS / PITS
The sewage is collected in lifstations, underground sumps or pits, also known as wetwells, and is pumped to the sewage treatment plant.
Measurement and control tasks:
Reliable level measurement is necessary to provide pump start and stop signals with fail safe switch-off points to avoid dry running.
The EasyTREK SP type non-contact ultrasonic level transmitter models with IP68 ingress protection is Nivelco’s recommendation for this measurement task.
Another popular choice for liftstations or deep sumps is the flush mounted NIVOPRESS NC type
hydrostatic borehole transmitter or the NIVOPRESS NP series with recessed membrane equipped with a sewage adaptor working on the principal of the diving bell.
A PLC or our MultiCONT process controller unit is ideal to process the analogue 4…20 mA signals and to control the switching points. For fail-safe protection, the robust NIVOFLOAT NWP float level switches are recommended.
WASTEWATER TREATMENT PLANT
The sewage pumped in from the network contains a lot of organic and non-organic materials in suspended form as well as in solution. This pollution has to be removed. The particles are filtered with a mechanical screen. The dissolved pollution can be reduced by adding coagulant materials. The reduced slurry is then separated from the water in the sedimentation tank.
The purified sewage can be streamed to any natural water after chemical inspection and yield measurement.
- Ultrasonic level transmitters for level measurement (2-wire integrated (blind) or compact versions), EchoTREK or EasyTREK
- For the control of the mechanical screen a differential system with 2 ultrasonic level transmitters is recommended
- The AnaCONT range of analytical measurement devices is ideal for the chemical analysis of the cleaned water
- Open channel flow metering can be done using our Parshall flume, and EasyTREK level transmitter.
- For the calculation and data logging a MULTICONT PEW controller can be used.
- High and low level switching will be performedwith NIVOSWITCH vibrating fork sensors
WASTEWATER TREATMENT PLANT,SLURRY TREATMENT PROCESS
The slurry separated in the sedimentation tank istransferred to the digester tank. The emitted biogas is stored in a biogas tank and then fed to a biogas generator. The biogas section of the plant is classified as a hazardous environment. The slurry retained in the digester is transported from the plant after dewatering (dehydration)
- ATEX certified ultrasonic level transmitters(EchoTREK or EasyTREK) or ATEX certified guided microwave level transmitter (Micro-TREK) can be used for level measurement.
- Nivelco’s choice for measuring the temperature of biogas is the ATEX certified temperature transmitter THERMOCONT TTJ Ex.
- Nivelco recommends an ATEX certified pressure transmitter for measuring the biogas pressure the NIVOPRESS DT Ex