Composite Sorbent Prepared from Layered Double Hydroxide Nanoparticles to Remediate Simulated Groundwater Polluted with Lead and Cadmium Ions
Bibliographic record
Abstract
This study presents a novel composite sorbent, synthesized from industrially inexpensive and abundant materials, designed for the remediation of groundwater contaminated by lead (Pb) and cadmium (Cd) ions through a permeable reactive barrier (PRB) technique.The synthesis process innovatively employs alum, a low-cost compound, alongside plaster kiln dusta by-product waste from the gypsum industry and Cetyl trim ethyl ammonium bromide (CTAB), to produce Nano-sized layered double hydroxide (LDH) composed of aluminum (Al +3 ) and calcium (Ca +2 ) ions.The synthesized LDH gel-solution was characterized using X-ray diffraction (XRD) analysis and subsequently intercalated onto an iron-slag surface, yielding a novel sorbent termed "iron-slag coated with (Ca/Al-CTAB)-LDH".The intercalation of CTAB and the presence of LDH nanoparticles significantly increased the iron-slag surface area from 0.48802 to 10.21 m 2 /g, thereby enhancing the adsorption capacity of the sorbent for Pb and Cd ions.Optimal synthesis parameters were identified as 0.035 g/50 mL CTAB, pH 10, (Ca/Al) molar ratio of 2, and an iron-slag dosage of 1 g/50 mL.Long-term column tests, spanning a duration of at least 25 days, were conducted, revealing a marked increase in the sorbent's longevity in the packed column when a low flow rate and inlet concentration of contaminants were combined with a high mass of sorbent.The experimental data from the breakthrough curves were successfully fitted by several models, including Bohart-Adams, Thomas-BDST, Yan, Belter-Cussler-Hu, and Clark expressions, with a determination coefficient (R2) exceeding 0.99 and a sum of squared errors (SSE) less than 0.162.The hydraulic conductivity of the packed sorbent remained largely constant at 2.7×10 -2 cm/s, suggesting its suitability for PRB applications.The prepared sorbent demonstrated high efficacy in the removal of Pb and Cd ions from contaminated water, making it a promising tool for environmental remediation.
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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".