Bio-based 3D-printed adsorption modules for nickel recovery from aqueous solutions
Dalalbarati, Mahsa (2026)
Diplomityö
2026
School of Engineering Science, Kemiantekniikka
Kaikki oikeudet pidätetään.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe20260623101737
https://urn.fi/URN:NBN:fi-fe20260623101737
Tiivistelmä
This study focused on the development of bio-based 3D-printed adsorption modules for nickel recovery from aqueous solutions. Lignin-based and cellulose-based materials were chemically modified mainly through carboxymethylation and crosslinking to improve their interaction with Ni(II) ions. The modified materials were then mixed with polyamide 12 (PA12) as the polymer matrix and fabricated into porous adsorption structures using selective laser sintering (SLS) 3D printing technology.
A set of batch adsorption experiments was conducted to investigate how changes in pH, contact time, nickel concentration, and temperature affected the performance of the developed adsorbents. The highest adsorption performance was observed near the natural pH range of the nickel solution, around pH 5-6, and this condition was selected for the following adsorption experiments. The experimental adsorption capacity reached approximately 16.46 mg/g for the cellulose-based adsorbent and 13.58 mg/g for the lignin-based adsorbent, showing that the cellulose-based material had slightly higher nickel uptake under the studied conditions.
A rapid uptake of Ni (II) was observed during the initial stage of adsorption, followed by a slower increase until equilibrium was reached after approximately 12-24 h. Among the evaluated kinetic models, the pseudo-second-order model provided the closest agreement with the experimental data for both adsorbents, yielding R² values of 0.9940 for cellulose and 0.9955 for lignin. The equilibrium data were represented more accurately by the Langmuir model than by the Freundlich model. However, some deviation from ideal monolayer adsorption was observed, which may be related to the heterogeneous structure of the bio-based adsorbents.
Thermodynamic evaluation suggested a weak dependence of adsorption on temperature. Although the process showed slightly endothermic characteristics, increasing the temperature produced only minor changes in adsorption performance within the investigated range. SEM/EDS analysis confirmed the presence of nickel on the adsorbent surfaces after adsorption, while FTIR results suggested that hydroxyl and other oxygen-containing functional groups were involved in Ni(II) binding. TGA results also showed that the prepared adsorbents maintained relatively good thermal stability before and after nickel adsorption.
Overall, the results demonstrate that bio-based materials can be combined with SLS 3D printing to produce structured adsorption modules for nickel recovery from aqueous solutions. Among the studied materials, the cellulose-based adsorbent showed slightly better and more stable adsorption performance. This work provides a basis for further development of bio-based 3D-printed adsorbents for sustainable water treatment and resource recovery applications.
A set of batch adsorption experiments was conducted to investigate how changes in pH, contact time, nickel concentration, and temperature affected the performance of the developed adsorbents. The highest adsorption performance was observed near the natural pH range of the nickel solution, around pH 5-6, and this condition was selected for the following adsorption experiments. The experimental adsorption capacity reached approximately 16.46 mg/g for the cellulose-based adsorbent and 13.58 mg/g for the lignin-based adsorbent, showing that the cellulose-based material had slightly higher nickel uptake under the studied conditions.
A rapid uptake of Ni (II) was observed during the initial stage of adsorption, followed by a slower increase until equilibrium was reached after approximately 12-24 h. Among the evaluated kinetic models, the pseudo-second-order model provided the closest agreement with the experimental data for both adsorbents, yielding R² values of 0.9940 for cellulose and 0.9955 for lignin. The equilibrium data were represented more accurately by the Langmuir model than by the Freundlich model. However, some deviation from ideal monolayer adsorption was observed, which may be related to the heterogeneous structure of the bio-based adsorbents.
Thermodynamic evaluation suggested a weak dependence of adsorption on temperature. Although the process showed slightly endothermic characteristics, increasing the temperature produced only minor changes in adsorption performance within the investigated range. SEM/EDS analysis confirmed the presence of nickel on the adsorbent surfaces after adsorption, while FTIR results suggested that hydroxyl and other oxygen-containing functional groups were involved in Ni(II) binding. TGA results also showed that the prepared adsorbents maintained relatively good thermal stability before and after nickel adsorption.
Overall, the results demonstrate that bio-based materials can be combined with SLS 3D printing to produce structured adsorption modules for nickel recovery from aqueous solutions. Among the studied materials, the cellulose-based adsorbent showed slightly better and more stable adsorption performance. This work provides a basis for further development of bio-based 3D-printed adsorbents for sustainable water treatment and resource recovery applications.