SUNITA PUNIA, ASHA GUPTA* AND JAGDISH PARSHAD
Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology,
Hissar-125 001 (Haryana), India
*(e-mail: gupta06amit@gmail.com; Mobile : 94163 72247)
(Received: December 15, 2022; Accepted: January 28, 2023)
ABSTRACT
The primary sources of heavy metal pollution today are a variety of operations in the metal processing and electroplating industries. Inexpensive microbes can be a good substitute for heavy metal subtraction from metal-contaminated sites. The present study was focused on the isolation and screening of metaltolerant bacterial strains from the electroplating effluent. A total of eight bacterial colonies were isolated from electroplating effluent. Out of eight isolated colonies: only two were more cadmium tolerant than other isolated strains based on their growth. The two (Cd-7 and Cd-13) selected strains were optimized at various environmental conditions like pH (4 to10), temperatures (27 to 47°C) and different metal concentrations (20-300 mg/l). The ideal pH for both strains’ growth was found to be eight, the ideal temperature was found to be 37°C and the ideal metal dose was found to be 200 ppm. The biosynthesis of Cd nanoparticles was confirmed by the change in colour of media treated with metal solution. This resulted from a noticeable decrease in cadmium salts. When metal solution was added, the solution’s colour changed to a light brown for the control, and the bacteria’s growth peaked after 72 of stirring. The maximum absorbance on a UV-VIS spectrophotometer at 380 nm also gave surety of the presence of cadmium nanoparticles. The screened, heavy metal-resistant microbes could be effective and valuable for treating industrial waste water.
Key words : Cadmium nitrate, nanoparticles, heavy metals, bacterial strains