The Biosorption of Platinum and Palladium in Chloride Real Leach Solution by Modified Biomass
Bibliographic record
Abstract
Modern demands for technological goods have created a global problem of excess electronic wastes (e-wastes). Increasing demands of precious metals to supply factories around the world for these electronic goods may also pose a strain towards current global gold, platinum and palladium reserves. As e-wastes often contain prominent levels of toxic materials along with valuable metals, its recycling must be conducted on an industrial scale to ensure a steady supply of precious metals (PM) for future needs. Current conventional methods of recycling PM including pyrometallurgical and hydrometallurgical processes are often costly, environmentally unfriendly and potentially hazardous. Therefore, researchers have turned towards the study of biomass-based adsorbents, also known as biosorbents, for applications in PM recovery and recycling.\nIn the research presented in the thesis herein, wheat straw, canola meal and wood bark nuggets were used and immobilized with dithiooxamide (DTO), ethylenediamine (EN) and primary amine (PA) to create 12 novel biosorbents. These biosorbents were examined for their effectiveness in recovering platinum (Pt) and palladium (Pd) from real leach solution provided by a PM refining plant in Ontario. From these 12 biosorbents, it was determined that dithiooxamide-immobilized wood bark (DTO-WB) was the most effective. Being able to recover up to 97.4% Pt and 99.8% Pd from diluted leach solution, DTO-WB was selected as the biosorbent of focus for the rest of the research. Characterization analysis including Fourier-Transform Infrared Spectroscopy (FT-IR) and Carbon, Hydrogen, Nitrogen and Sulfur (CHNS) content analysis confirmed that DTO immobilization was successful on the structure of WB. Further experimentation and data analysis revealed that the rate of adsorption of Pt and Pd on DTO-WB progressed via the pseudo-second order rate model. Adsorption isotherm model studies indicate that the adsorption of Pt and Pd by DTO-WB followed the Freundlich and Langmuir adsorption isotherm respectively. Calculated energy levels of activation by Pt and Pd suggests that adsorption progresses due to chemisorption. Thermodynamic studies reveal that DTO-WB adsorption of Pt and Pd is endothermic in nature and that adsorption efficiencies may be improved by increasing operating temperatures. Acknowledging that a variety of dissolved metals exists in real leach solution, performed co-adsorption experiments indicated that DTO-WB was efficient in recovering other PM, namely silver and rhodium. Selenium, a potentially toxic element commonly present in drinking water was also adsorbed in significant numbers by DTO-WB, suggesting that the adsorbent may potentially be used in water-treatment research.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".