Adsorption of nickel in wastewater using modified lignin : hydrogen peroxide modified lignin
Simpson, Maija Elizabeth (2025)
2025
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2025051411541
https://urn.fi/URN:NBN:fi:amk-2025051411541
Tiivistelmä
This study was conducted to further understand the way in which hydrogen peroxide modified lignin adsorbed different concentrations of nickel solution. This project was a continuation of previous studies done at Tampere University of Applied Sciences in the adsorption capabilities of modified lignin. This research worked with higher nickel concentrations: 0 mg/L to 500 mg/L.
The results using FAAS analysis concluded that hydrogen peroxide modified lignin adsorbs lower nickel concentrations the best, with the highest removal rate at 80.04% for initial concentration 10 mg/L. It was noted that the pH of the solutions was an important factor in the overall nickel removal as pH of 6-6.4 had efficient removal rate whilst pH lower than 5 resulted in much lower values. The data was also fitted into three isotherm models: Freundlich, Langmuir and Sips. Freundlich resulted in the best correlation coefficient at 0.9795 suggesting that the system was multi-layer adsorption. The nickel ions stuck to the lignin’s surface at variable strength interactions.
Using the FT-IR analysis, the procedure showed that the functional groups in the lignin did not change after modification. However, due to the larger absorbance intensity values in the modified lignin, this expressed the appearance of more functional groups, especially hydroxyl and carbonyl groups, when compared to the original lignin. This demonstrated that the modification was successful.
The data and results from this thesis will be part of an article that is not yet published.
The results using FAAS analysis concluded that hydrogen peroxide modified lignin adsorbs lower nickel concentrations the best, with the highest removal rate at 80.04% for initial concentration 10 mg/L. It was noted that the pH of the solutions was an important factor in the overall nickel removal as pH of 6-6.4 had efficient removal rate whilst pH lower than 5 resulted in much lower values. The data was also fitted into three isotherm models: Freundlich, Langmuir and Sips. Freundlich resulted in the best correlation coefficient at 0.9795 suggesting that the system was multi-layer adsorption. The nickel ions stuck to the lignin’s surface at variable strength interactions.
Using the FT-IR analysis, the procedure showed that the functional groups in the lignin did not change after modification. However, due to the larger absorbance intensity values in the modified lignin, this expressed the appearance of more functional groups, especially hydroxyl and carbonyl groups, when compared to the original lignin. This demonstrated that the modification was successful.
The data and results from this thesis will be part of an article that is not yet published.