Nurhidayanti and Riyadi 2024 - Coffee-ground chitosan cadmium adsorption

Nurhidayanti and Riyadi modeled cadmium adsorption onto a combined chitosan and coffee-ground activated-carbon adsorbent. This is in-scope remediation evidence because it measures cadmium removal from industrial wastewater; it is not coffee occurrence evidence and should not be used as a food or beverage concentration source.

Key numbers

The introduction reports a preliminary cadmium concentration of 1.15 mg/L in wastewater from one Bekasi Regency textile-industry sample. The same passage gives the Indonesian wastewater quality standard for cadmium as 0.05 mg/L. The results section reports that the best tested treatment, chitosan plus 1.4 g coffee-ground activated carbon, reduced cadmium to 0.07 mg/L.

Figure 3 reports cadmium-removal efficiencies across the adsorbent-mass series:

The one-way ANOVA for cadmium concentration reported p = 8.28x10-9, F calculated = 599.17, and F table = 5.32. The ANOVA for percent removal reported p = 1.01x10-8, F count = 569.43, and F table = 5.32.

The source gives the following isotherm parameters in Table 1:

The abstract states a Langmuir correlation coefficient of 0.9970, while Table 1 and the results prose report 0.9954. The page preserves the table value in the numerical table and records the discrepancy here.

Table 2 reports the kinetic fits:

The results prose prints the Elovich constant as 149.9 mg.g-1, while Table 2 prints 194.9 mg.g-1. The table value is used above and the internal mismatch is retained as a verification caveat.

Table 3 reports thermodynamic parameters for cadmium adsorption onto the chitosan and coffee-ground adsorbent:

The table header says “Temperature (oC)” even though 298, 318, 328, and 338 are Kelvin-like values. The source unit label is not converted here.

Methods (brief)

The study was conducted at PT. Tuv Nord Indonesia and Pelita Bangsa University from June to December 2022. Materials included chitosan, cadmium solution, ZnCl2, HCl, NaOH, and spent coffee grounds from coffee shops. All treatments and measurements were carried out in triplicate.

The authors state that preliminary wastewater testing, adsorbent preparation, and the biosorbent cadmium-removal experiments were completed in 2021; this paper focuses on the isotherm, kinetic, and thermodynamic data analysis. The paper fits Langmuir, Freundlich, Dubinin-Raduskevich, and Temkin isotherms and pseudo-first-order, pseudo-second-order, Elovich, and Weber-Morris kinetic models. SEM-EDX characterization of the chitosan plus 1.4 g coffee-ground adsorbent reported 74.30% carbon, 18.29% oxygen, 0.88% sodium, 0.34% magnesium, 2.99% tin, 0.51% zirconium, 0.53% copper, 0.46% zinc, 0.46% chlorine, 0.42% potassium, 0.34% phosphorus, 0.27% calcium, 0.15% silicon, and 0.06% aluminum.

Implications

Certification: Do not use this source as coffee, coffee-ground, or drinking-water occurrence evidence. The measured endpoint is cadmium reduction in wastewater after treatment with a chitosan and coffee-ground activated-carbon adsorbent.

Courses: Useful example of why engineered adsorption capacity and removal efficiency are not the same thing as consumer-product occurrence. The source also shows internal consistency issues common in adsorption papers: the abstract, tables, and prose do not always print the same fitted constants.

App: Context only. The source can support remediation-pathway notes for cadmium wastewater control and bioadsorbent screening, not product scoring.

Wiki pages this source may touch

• remediation-evidence
• cadmium
• index

Verification notes

Recovered from skip:not-food-occurrence under the 2026-06-10 inclusion-by-default rule. The old skip treated a coffee-ground adsorbent paper as out of scope because it was not coffee occurrence. On reading, it is in-scope lane a2 mitigation/remediation because it reports cadmium-removal values from industrial wastewater.

Numbers were checked against the abstract, introduction, methods, Figure 3 prose, Tables 1-3, and conclusion in the extracted PDF text. Units are preserved as printed. The paper uses only cadmium as the primary measured heavy-metal removal target; other elements in SEM-EDX are adsorbent-characterization results and are not treated as occurrence values. Products and ingredients are intentionally empty.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.