Detection of Hexavalent Chromium Concentration in Aqueous Solution Using Lab Developed Colorimeter

Abstract

The detection of hazardous carcinogenic heavy metals in aqueous solutions is important for biological health and environmental protection. There are various techniques to ascertain these oncogenic chemicals in an aqueous solution, like a potentiometric electrochemical sensor, spectrophotometer sensor, colorimeter sensor, and chemical sensors. As compared to other available methods, the colorimeter sensor has advantages such as low-cost instrument, qualitative sample detection, and higher precision. In this paper, the colorimeter is developed in the lab to detect hexavalent chromium [Cr (VI)] in the aqueous solution. Moreover, the absorbance principle is used to calibrate and measure the known sample concentration using amplified optical power light-emitting diodes (OP-LED). The estimation of Cr (VI) concentration in an aqueous solution is evaluated and programmed in a low-cost Arduino UNO development board. The concentration value is displayed on the touch screen. The readings displayed on the lab developed instrument annotates that the concentration percentage of the known sample can be used to determine the unknown concentration. The concentration of the known solution is determined and compared with commercially available colorimeters concerning the lab-developed colorimeter.