A Low-Cost Continuous Turbidity Monitor.

Area of Science:

• Environmental Science
• Water Quality Monitoring
• Sensor Technology

Background:

• Turbidity is a key indicator of water quality, reflecting suspended solids.
• Lack of affordable monitoring hinders water quality improvements, particularly in developing nations.
• Existing low-cost turbidity meters are often not suitable for continuous monitoring.

Purpose of the Study:

• To adapt and verify a low-cost turbidity monitoring technology for continuous use.
• To assess the accuracy and cost-effectiveness of the developed continuous monitor.
• To evaluate the monitor's performance in a real-world, long-term trial.

Main Methods:

• Component cost analysis for a continuous turbidity monitor.
• Laboratory calibration and accuracy testing in the 0-100 nephelometric turbidity unit (NTU) range.
• A 38-day continuous monitoring field trial with two prototype monitors.

Main Results:

• The monitor achieves approximately 1 NTU accuracy within the 0-100 NTU range.
• Component costs are around 64 USD, making it highly accessible.
• Field trials showed median errors of 0.45 and 1.40 NTU, with noise attributed to ambient light and bubbles.

Conclusions:

• The low-cost continuous turbidity monitor provides actionable water quality data at a minimal cost.
• The technology shows promise for widespread adoption, especially where cost is a major constraint.
• Further refinement to mitigate noise sources like ambient light and bubbles could enhance its utility across various applications.