Kinetic and biosorption isotherm studies on biosorption of nickel and cadmium by using Halobacillus trueperi isolated from factory wastewater entry into the Caspian Sea
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Salman Ahmady asbchin , Davood Siamian , Nasrolahi Omran Nasrolahi Omran  |
Islamic Azad University Tonekabon Branch, Tonekabon, Iran , davood_siyamiyan@yahoo.com |
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Abstract: (109 Views) |
Background and Objectives: : The Caspian Sea is affected by many pollutants, including toxic and heavy metals, which enter the sea through rivers contaminated with urban and industrial wastewater. Heavy metal contamination in wastewater is a significant concern for human health and the environment, prompting increased efforts to develop efficient and sustainable removal methods. Despite significant efforts in the last few decades, further research initiatives remain vital to comprehensively address the long-term performance and practical scalability of various adsorption methods and adsorbents for heavy metal biosorption
Methods: In this study, Halobacillus trueperi bacteria isolated from the waste paint factory Babol were studied molecularly from the perspective of biochemistry. The effects of parameters such as pH, temperature, concentration of metal-on-metal ions, and removal efficiency of nickel and cadmium were investigated. Using the techniques of Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM), effective bio-absorption was analyzed.
Findings: The highest adsorption rate of cadmium and nickel metal ions was observed by bacteria studied at pH of about 6 and 7, respectively, so that higher pH was observed due to metal ion deposition, and lower pH due to reduced adsorption competition. The best temperature for adsorption in both metals was about 40 degrees Celsius. Kinetics showed that the adsorption of metal ions in the opening minutes of rapid reaction kinetics has gradually reduced slope. The highest metal removal is performed in the first 15 minutes and then slowly continued adsorption and equilibrium within 90 minutes. This is especially important in an industry that in a very short time the bacteria can remove more metal from an aqueous solution. Isogram Langmuir described the adsorption of cadmium and nickel metals well by equilibrium experimental data.
Conclusion: Results showed that maximum absorption of metal uptake (maximum adsorption capacity of the adsorbent) in about 0/5 and 0/7 mmol per gram (mmol / g) dry absorbent. SEM analysis showed that the metals were absorbed by bacterial surface groups. After contact with the bacterium, the surface shape of the bacterium changed. Most of the adsorption of metals is inactive, so this adsorbent can be used dead and inactive. |
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Keywords: Caspian sea, Toxic metals, bacterial surface groups, microbial removal, role of pH |
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Type of Study: Research/ Original/ Regular Article |
Subject:
Marine Environment / Marine pollution Received: 2023/07/16 | Revised: 2025/04/28 | Accepted: 2025/03/5
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