Abstract
A novel bismuth (Bi)-biopolymer (chitosan) nanocomposite screen-printed carbon electrode was developed using a Bi and chitosan co-electrodepositing technique for detecting multiple heavy metal ions. The developed sensor was fabricated with environmentally benign materials and processes. In real wastewater, heavy metal detection was evaluated by the developed sensor using square wave anodic stripping voltammetry (SWASV). The nanocomposite sensor showed the detection limit of 0.1 ppb Zn2+, 0.1 ppb Cd2+ and 0.2 ppb Pb2+ in stock solutions. The improved sensitivity of the Bi-chitosan nanocomposite sensor over previously reported Bi nanocomposite sensors was attributed to the role of chitosan. When used for real wastewater samples collected from a mining site and soil leachate, similar detection limit values with 0.4 ppb Cd2+ and 0.3 ppb Pb2+ were obtained with relative standard deviations (RSD) ranging from 1.3% to 5.6% (n = 8). Temperature changes (4 and 23 °C) showed no significant impact on sensor performance. Although Zn2+ in stock solutions was well measured by the sensor, the interference observed while detecting Zn2+ in the presence of Cu2+ was possibly due to the presence of Cu-Zn intermetallic species in mining wastewater. Overall, the developed sensor has the capability of monitoring multiple heavy metals in contaminated water samples without the need for complicated sample preparation or transportation of samples to a laboratory.
Highlights
Heavy metal ions such as lead, cadmium, zinc, and copper are well-studied water and soil pollutants that pose a threat to public health and have a lingering impact on various ecosystems
We developed a nanocomposite film with Bi and chitosan to increase both mechanical stability and electrochemical sensitivity for improved heavy metal detection
The Bi 4f5/2 and Bi 4f7/2 spin orbital splitting of Bi metal are at binding energies of 157.2 eV and 162.5 eV, respectively, and these peaks and 5.3 eV of energy splitting between two orbits are in agreement with reported values elsewhere [35,36]
Summary
Heavy metal ions such as lead, cadmium, zinc, and copper are well-studied water and soil pollutants that pose a threat to public health and have a lingering impact on various ecosystems. They are non-biodegradable and have long biological half-lives, lasting longer in aquatic and terrestrial environments, negatively affecting both humans and other living organisms. Heavy metal contaminations can be found in liquid wastes of many related industries (e.g., mining operations and metal processing) [3] The traditional methods such as electrothermal atomic absorption spectrometry (EAAS), flame atomic absorption spectrometry (FAAS), and inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma (ICP)) have provided accuracy and reliability in detecting heavy metals. The sensor performance was evaluated comprehensively in terms of representativeness, repeatability, limit of detection (LOD), lifetime and temperature effect with mining wastewater and contaminated soil leachate
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
