Turbidity Measurement of Natural Water with a Hand-made Device : Tool Development for Supporting Environmental Learning

Abstract

Water analyses of rivers, lakes, and ponds near schools have often been used as school environmental learning activities, and turbidity is one of the essential items of analysis. Low levels of turbidity in sample waters, however, are difficult to measure without an expensive turbidity meter. We developed a hand-made turbidity meter by assembling inexpensive electronic parts and examined the performance of this device by practical analysis of seawater in an estuary. The results include the following: 1. This hand-made device could measure a slight change in the level of turbidity (0-2.5) of sample waters. 2. The salinity and pH value had risen from the ebbing and flowing water, while turbidity had fallen during this period. This result shows that the turbidity of water in this region derives from river water. 3. The turbidity measured by this device is shown to have a positive correlation with suspended solids in sample water. As a result, this device can be an effective tool for environmental learning in schools.