Low Cost Wavelength Specific Water Quality Measurement Technique

Area of Science:

• Analytical Chemistry
• Environmental Science
• Optical Engineering

Background:

• Optical sensing offers advantages like high sensitivity and selectivity for chemical analysis.
• Traditional water quality monitoring methods can be expensive and complex.
• There is a need for cost-effective and portable solutions for real-time water parameter measurement.

Purpose of the Study:

• To develop a low-cost, robust, and user-friendly optical sensing technique for measuring bulk water properties.
• To quantify changes in pH, total dissolved solids (TDS), and turbidity using optical measurements.
• To demonstrate a functional prototype for rapid water quality assessment.

Main Methods:

• A multi-wavelength optical sensing mechanism utilizing three different LEDs was designed.
• The absorption of LED light passing through water samples was measured.
• Optical responses were correlated with water parameter changes (pH, TDS, turbidity) using regression analysis.

Main Results:

• Linear regression coefficients of 0.9691 for pH, 0.9729 for TDS, and 0.76 for turbidity were achieved.
• The method demonstrated good correlation between optical responses and water quality parameters.
• A low-cost prototype (~$20) was successfully developed and demonstrated.

Conclusions:

• The developed optical sensing technique provides a viable, low-cost method for water quality monitoring.
• The compact and portable device can replace expensive spectrophotometers for specific parameter measurements.
• This approach enables rapid and accessible water quality analysis, particularly in resource-limited settings.