Evidence map›Paper›PMID 42225848›Full record

ArticleScientific reports2026

Thermally activated paint-sludge as potential sustainable adsorbent for pollutant removal with insights from isotherms kinetics thermodynamics and response surface methodology.

Ali El-Rayyes, Martins Titus, Amnah Mohammed Alsuhaibani, Moamen S Refat, Ezekiel Foloronsho Sodiya, Kholoud K Alzahrani, Edwin Andrew Ofudje

Abstract read
In one paragraph

Article in Scientific reports, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Ali El-RayyesCenter for Scientific Research and Entrepreneurship, Northern Border University, Arar, 73213, Saudi Arabia.
Martins TitusDepartment of Chemical Sciences, Mountain Top University, Ibafo, Ogun State, Nigeria. martinstitus@mtu.edu.ng.
Amnah Mohammed AlsuhaibaniDepartment of Sports Health, College of Sport Sciences & Physical Activity, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh, 11671, Saudi Arabia.
Moamen S RefatDepartment of Chemistry, College of Science, Taif University, P.O. Box, 11099, Taif, 21944, Saudi Arabia.
Ezekiel Foloronsho SodiyaDepartment of Chemical Sciences, Mountain Top University, Ibafo, Ogun State, Nigeria.
Kholoud K AlzahraniDepartment of Biology, University College of Umluj, University of Tabuk, Umluj, Tabuk, Saudi Arabia.
Edwin Andrew OfudjeDepartment of Chemical Sciences, Mountain Top University, Ibafo, Ogun State, Nigeria.

Funding

Princess Nourah Bint Abdulrahman University PNURSP2026R65
6 · The paper itself

Abstract

The continuous rise the release of untreated paint industry wastewater containing dyes, organic pollutants, and heavy metals poses serious environmental and public health concerns, most especially in developing countries where treatment infrastructure remains inadequate. This study examines the potential of thermally activated sludge (TAS) derived from paint industry waste as cost-effective and sustainable adsorbent for the uptake of pollutants from industrial effluents. Comprehensive adsorption analyses through isotherm, kinetic, thermodynamic, and response surface methodology (RSM) modelling were performed to elucidate the adsorption mechanism and optimize operational parameters. Thermally activated sludge was synthesized via pyrolyzing paint sludge at 700 °C and compared with unactivated sludge to explain the effect of thermal modification on adsorption performance. Comprehensive characterization through XRD, FTIR, SEM-EDS, BET, and TGA confirmed that thermal activation enhanced the porosity, surface heterogeneity, mineral composition, and functional groups of the sludge adsorbent. Batch adsorption experiments were performed by varying contact time, pH, temperature, adsorbent dosage, and pollutant concentration. TAS displayed superior removal performance compare to US, achieving substantial reductions in BOD, COD, TSS, TDS, oil and grease, nitrate, and heavy metals including Pb, Cd, and Cr. Maximum adsorption efficiency 86.9% was attained under alkaline conditions. Equilibrium studies revealed that the Freundlich isotherm best explained the adsorption process (R² = 0.998 for TAS), signifying multilayer adsorption on heterogeneous surfaces, while the Langmuir maximum adsorption capacity increased from 58.82 mg g⁻¹ for US to 77.21 mg g⁻¹ for TAS. Kinetic assessment revealed that adsorption onto TAS followed the pseudo-second-order model (R² = 0.995), indicating chemisorption involvement, whereas intraparticle diffusion contributed to the overall adsorption mechanism. Examinations of the thermodynamic data confirmed that the adsorption process was spontaneous and endothermic, with TAS displaying stronger adsorbate-adsorbent interactions compare to US. RSM study identified pH and adsorbent dosage as the most influential operational variables and demonstrated significant interaction effects between process parameters. Thermal activation improved adsorption efficiency, adsorption capacity, and process stability, highlighting the potential of converting industrial sludge waste into a value-added material for sustainable wastewater treatment applications.

Indexed as

Activated sludgeAdsorption mechanismHeavy metalOptimizationPaint industry

Identifiers

PMID42225848
PMCPMC13462732

What Socratic holds

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LicenceCC BY-NC-ND
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.