A web server can be integrated with a PLC to provide remote monitoring and alarming capability giving it even more functionality and value especially for small wastewater utilities which are not manned 24/7.

PLC = Programmable Logic Computer

An industrial grade computer used to control pumps, blowers and other equipment as necessary to perform specific process tasks.

A PLC can be very basic or super sophisticated... depending on the process and customer requirements.

PLC’s are a great tool for efficient process control but like they say: "garbage in garbage out".

To make a process work well everything has to be successfully integrated...

  • Programming logic
  • Sensors
  • Equipment

 

Process Sensors

An ORP (Oxidation-Reduction Potential) based online process controller (ORP-Drive) is utilized to control the aeration system so as to provide optimal nutrient removal via nitrification (BioOxydation) & denitrification (BioReduction) cycles and optimal sludge digestion with the least amount of energy consumption. Optimized process control results in a healthier and more resilient biomass; promotes better settling sludge and consequently improves clarifier performance. The ORP probes we use are fairly inexpensive and can last up to 3 years in the wastewater environment. As biomedia circulates in the bioreactor it helps to keep the ORP probe clean virtually eliminating the need for an operator to remove for cleaning.

A Dissolved Oxygen online process analyzer utilizes state of the art optical technology for measuring dissolved oxygen in the bioreactor. The DO analyzer will actually be used as the process controller during the plant startup period (1-2 months) to help reduce typical startup foaming (caused by young sludge and high DO levels). When the plant biomass matures and begins to provide effective nitrification (1-2 months) but is not able provide satisfactory overall nitrogen removal the operator can switch to ORP control and adjust ORP set points to achieve better nitrogen removal. The corrosion resistant DO sensor is inert to common interferences found in water and wastewater plants, such as hydrogen sulfide, chloride, chlorine and ammonium. There are no fragile membranes or electrolyte to replace. Just replace the sensor cap annually, and you’re back in business. Selecting the process control parameter of choice (DO or ORP) can be made by a simple flip of a selector switch.