Float Holders Significantly Reduce Dissolved Oxygen Sensor Maintenance Workload (at Oxidation Ditch Type Sewage Treatment Plants)

Introduction

The detectors used to perform dissolved oxygen (DO) measurement in oxidation ditch type sewage treatment plants tend to become dirty quickly and require frequent cleaning. It has been difficult to remedy this problem inexpensively. One solution that significantly reduces the sensor maintenance workload is the use of float holders. A field test using float holders on the detectors in the FLXA402 dissolved oxygen analyzer system has demonstrated that the sensors could be kept free of heavy dirt accumulation, eliminating the need for maintenance and enabling continuous measurement for long periods of time.

Expected Benefits

• Ensures stable, continuous dissolved oxygen measurement
• Reduces operating cost
• Eliminates the need for manual cleaning

Process Overview

An oxidation ditch is a large circular basin equipped with aerators that is used to remove organic matter and pollutants from sewage through the processes of adsorption, oxidation, and decomposition.

Oxidation Ditch

Solution Details

Field Data

For the onfield test, two detectors were mounted in PB350G angled float holders. One sensor received no maintenance and the other was cleaned every two weeks and calibrated ce a month. This test showed that the readings from the two sensors were nearly identical over a six month period.