Online pH measurement in Waste Water Treatment Plant in Textile Industry

Wastewater from textile plants is as diverse as the processes used in the industry. Still, one can make some general statements about the wastewater

• It contains few bacteria

• The proportion of organic nitrogen is small

• Heavy metals occur only with the use of metallic dyes

• Temperatures are high, raw water being between 20°c and 30°c, sometimes even higher

• Wastewater is generally alkaline

• The proportion of phosphates depends on the process used

An important criterion for estimating the efflux of wastewater is the extent to which dyes are diluted. The greater the dilution, the more material will enter the Wastewater The wastewater must usually be neutralized before discharge. Sometimes collecting and allowing it to mix can do this simply. Wastewater from textile mills rarely has the right proportions of organic material to act as feedstock for bacteria in a biological treatment stage. Treatment often uses liquor from communal drains. Treatment is easier if buffer tanks can store the sporadic discharge of large quantities. If further treatment is necessary for specific substances, these may have to be treated specifically by precipitation, flocculation, filtration or adsorption.

Use of DIGITIZED pH Measurement

pH measurement is a critical measurement in wastewater plant in Textile industry. In pH analysis, the connection between sensor and cable has so far been the weakest point. Until today, pH instrument had the problems such as tightness, corrosion and handling. Measurement variables with very small currents make high demands on the connection between sensor and transmitter. Leaks and corrosion impair the measurement value transfer. In this case, particularly high-resistance measurements in a dirty or damp environment quickly become a problem. In order to minimise the voltage drop as far as possible, the use of expensive MIL connectors with gold contacts, complicated special cable and complex measuring amplifier has until now been necessary. However, the systems remained prone to failure.

New Digitized pH measurement solve all these problems by their inductive, contactless plug-in connection with bayonet lock.

The new Digitized pH measurement sensors are based on an inductive plug-in connection with bi-directional signal and energy transfer. The 'built-in ‚intelligence' allows to save and evaluate process-and sensor-relevant data. The result is a revolutionary simplification of process measuring technology

The unique sensor intelligence in the form of an integrated circuit board offers many possibilities: Manufacturing data and current sensor properties as well as sensor histories can be recorded. The sensor load is logged and used as a basis for look-ahead maintenance. Another trendsetting feature is the electronic signature, a requirement from the pharmaceutical industry. The main benefit is the storage of calibration data. Digitized pH measurement sensors can be precalibrated under optimum conditions in the laboratory. After calibration, they are simply replaced in the measuring point.

With precalibrated sensors, measuring points that are difficult to access are no longer roblematic. The sensors identify themselves within the application so that each measuring point recognises its individual sensor. Measuring point down-time is dramatically reduced which is especially important for sensitive processes. Further safety aspects are obvious. A sensor cannot be crewed out of a process connection inadvertently when removing a cable for example. Digitized pH measurement sensors also offer cost saving potential. Sensors that had to be thrown away in the past can now be checked and regenerated, e.g. by suitable cleaning, under optimum conditions in the laboratory. Sensor lifetime in the process is thus considerably increased. Thanks to the comfortable precalibration in the lab, calibrations under soiled or moist conditions are no longer necessary. This reduces work time in hazardous areas to a minimum.

Thanks to the significantly increased reliability, operational safety and availability of digital sensors with Digitized pH measurement technology, improved environmental protection is ensured. This digitized measurement can also be used for conductivity, ORP and dissolved oxygen along with pH measurement.

The danger of unnecessary loads due to rejects is reduced, which safeguards resources and saves energy which is one of the most important need in the Textile industry.

- Kedar Tillu