Assessment of the capability of an optical sensor for in-line real-time wastewater quality analysis in food manufacturing

TLDR

The study evaluates a commercial optical product monitor for in‑line, real‑time water‑content analysis, aiming to link light‑attenuation measurements to turbidity and colour and to test performance at higher turbidities. Using the monitor, the authors measured light‑intensity attenuation at four wavelengths on test fluids, correlating these data with turbidity and colour parameters. The sensor resolved attenuation for turbidities up to 1700 NTU, with ≥20 NTU data fitting the Beer–Lambert model, and it distinguished filtered from unfiltered samples by higher attenuation coefficients.

Abstract

This work investigates the use of a commercial optical product monitor to achieve in-line real-time water content analysis. Test fluids were used and optical measurements of attenuation of light intensity at four colours were made. These measurements were used to identify any relationship between these and the water quality parameters of turbidity and colour. Variation in light attenuation for turbidities up to 1700 NTU was successfully resolved by the instrument, with optical data for turbidities ≥ 20 NTU fitting well the Beer-Lambert model. The sensor was also able to clearly identify the effect of filtering out suspended solids with unfiltered samples (apparent colour) exhibiting significantly higher attenuation coefficients than filtered samples (true colour). Further studies will concentrate on whether the instrument can analyse samples with turbidities higher than 1700 NTU, together with further investigating the variation in the attenuation coefficient seen with turbidity and colour of light.