Bioremediation and Detoxification of Electronic Waste Using Priestia aryabhattai MGP1
1. Introduction
1.1 Context and significance
Electronic waste has emerged as a major environmental concern due to the rapid technological advances and the increasing turnover of electronic devices. The accumulation of e-waste, which includes polymers such as acrylonitrile‐butadiene‐styrene (ABS), contributes to soil and water contamination as hazardous additives and metals leach into the environment. The traditional disposal methods, which often rely on physical or chemical recycling, pose risks to ecological and public health (Environmental Research, 2023). Employing biological agents for waste detoxification offers an eco‐friendly alternative by facilitating the breakdown of complex polymers through microbial enzymatic actions.
1.2 Objectives of the study
The primary objective of this study is to evaluate the bioremediation potential of Priestia aryabhattai MGP1 in degrading e-waste polymers. In doing so, the investigation focuses on (a) isolating and characterizing the bioagent from contaminated soil, (b) optimizing culture conditions for maximum degradation efficacy, and (c) assessing the detoxification performance from a structural and phytotoxicity perspective. By addressing these aims, the study seeks to establish a sustainable approach for the detoxification and reuse of electronic waste (Environmental Research, 2023).
2. Methods
2.1 Sample collection and preparation
Electronic waste granules were obtained by dismantling discarded television casings and subsequently grinding the polymer components into uniform 5 mm granules. Soil samples from e-waste dumping sites in Kichha, Uttarakhand, India, were collected at depths of 5–15 cm and used to enrich indigenous bacteria. The collected soil and e-waste granules were then prepared under sterile conditions to serve as the carbon source in further experiments (Environmental Research, 2023).
2.2 Experimental design
The enriched soil samples underwent serial dilution and isolation to select potent bacterial strains capable of utilizing ABS as a sole carbon substrate. Priestia aryabhattai MGP1 was identified as a dominant strain based on its rapid growth and ability to degrade e-waste under optimized culture conditions. Incubation parameters such as temperature, pH, and shaking speed were fine-tuned using response surface methodology (RSM) to maximize the biodegradation rate.
2.3 Data analysis techniques
Analytical techniques including optical density measurements (OD600), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and Energy-Dispersive X-ray (EDX) analyses were employed to monitor the structural and chemical changes in the polymer. Statistical analysis, incorporating ANOVA, was used to validate the significance of the optimized parameters and the degradation efficiency achieved during the experiments (Environmental Research, 2023).
3. Results
3.1 Key findings from bioremediation tests
The bacterial isolate Priestia aryabhattai MGP1 demonstrated a significant capacity for e-waste degradation. Under optimal conditions—pH 7, temperature of 30 °C, and a shaking speed of 120 rpm—the strain achieved an approximate 18.88% weight loss of ABS polymer over a 60-day period. Growth curves indicated rapid proliferation in nutrient-rich media supplemented with e-waste granules. Enzyme assays confirmed catalase and protease activities, corroborating the strain’s ability to break down complex polymeric chains.
3.2 Detoxification performance of Priestia aryabhattai MGP1
Detoxification was further validated by changes in polymer structure, as evidenced by FTIR analysis showing diminished peaks for C–H and C≡N bonds. FESEM imaging revealed notable alterations in surface morphology—such as crack formation and increased roughness—while EDX results confirmed a reduction or elimination of hazardous elements (e.g., magnesium, aluminium, chlorine). Additionally, phytotoxicity assays performed on Vigna radiata demonstrated improved seed germination and plant growth in soils treated with MGP1, indicating a decrease in environmental toxicity.
4. Conclusion
4.1 Summary of outcomes
The study successfully established that Priestia aryabhattai MGP1 is an effective agent for the bioremediation of electronic waste. Under optimized laboratory conditions, the bioagent not only degraded significant amounts of ABS polymer but also detoxified the surrounding environment, reducing harmful element residues and enhancing soil quality.
4.2 Implications and future directions
These encouraging results suggest that bioremediation using Priestia aryabhattai MGP1 could serve as a sustainable alternative to conventional waste management practices. Future work should aim at further refining the optimization protocols and expanding field trials to assess the scalability and long-term ecological benefits of this approach. Advanced molecular studies may also facilitate the genetic enhancement of this strain to increase its degradation efficiency, thereby offering a promising pathway for mitigating the global challenge of e-waste.
References
Environmental Research. (2023). [Details of article]. Environmental Research, 238, 117126.