Detection of Lithium in Real World using Optical Emission Spectroscopy: Caution to E-Waste Management

The exponential increase in the use of digital technology in day-to-day life has generated an excessive aggregation of electronic waste (e-waste), which is one of the major sources of environmental contamination in the twenty-first century. Amongst them, lithium (Li) is the most pronounced one due to the extensive use of Li-ion batteries in nearly every electronic device. Disposal of lithium-ion batteries in soil and water leads to various adverse effects not only on human health but also on plants and aquatic creatures. Toxic effects on cardiovascular, gastrointestinal, and endocrine systems are a few to mention. Therefore, the determination and quantification of the lithium level in the soil and water are extremely crucial. Here, we have developed a device and technique that can instantly quantify the lithium concentration in water and soil samples, at the site of sampling. The device is based on the principles of optical emission spectroscopy. To obtain the optical signals and to compute the electrolyte concentration a user-friendly software is developed. As proof of concept, we measured time-dependent Li-ion leaching in water and soil using the developed device and obtained promising results. The device is also IoT enabled for easy transfer of data from a remote place. Compared to the conventional techniques, our device is cost-effective, easily portable, requires less expertise and sample preparation, and also requires less time. As per our understanding, the current work will be pertinent in combating the adverse effects of e-waste in the environment using a non-invasive approach.