Charcoal Residue from Cashew Nutshells as a Bioadsorbent in Fixed Bed Column for Produced Water

• Published in: Water, air, and soil pollution Vol. 235; no. 12; p. 790
• Main Authors: de Oliveira, Karine Fonseca Soares, de Deus Junior, Joemil Oliveira, dado SilvaNascimento, Talita Lorena, dos Anjos, Raoni Batista, de Araújo Melo, Dulce Maria, Braga, Renata Martins, de Freitas Melo, Marcus Antonio
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-12-2024; Springer Nature B.V
• Subjects: Activated carbon; Adsorption; Atmospheric Protection/Air Quality Control/Air Pollution; Beds (process engineering); Biodegradation; Carbonyl compounds; Carbonyl groups; Carbonyls; Charcoal; Circular economy; Climate Change/Climate Change Impacts; Columnar structure; Copper; Earth and Environmental Science; Electron microscopy; Environment; Fixed beds; Fourier transforms; Grease; Heavy metals; Heterogeneous structure; Hydrogeology; Infrared spectroscopy; Kinetics; Lead; Local economy; Metal ions; Metals; Nutshells; Operating costs; Pollution control; Production costs; Reuse; Scanning electron microscopy; Sodium hydroxide; Soil Science & Conservation; Structural analysis; Titration; Trivalent chromium; Wastewater; Water Quality/Water Pollution; Water treatment; Agro-industrial waste; Bioadsorption; Oil and grease content; Fixed-bed column; Wastewater; Heavy metal
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-024-07612-5

One of the produced water treatment methods is adsorption, however, the use of commercial activated carbon as an adsorbent, in industrial scale, makes the process expensive. An alternative for replacing commercial activated carbon is the use of bioadsorbents, which have been gaining emphasis in recent decades, high performance, and low production costs. The objective of this work is to develop an efficient and low cost bioadsorbent by reusing the charcoal from the cashew nutshell (
Anarcadium accidentale
L.) for the removal of metal ions (Cu
2+
, Pb
2+
and Cr
3+
), oil and grease content (OGC). The bioadsorbent was pretreated with NaOH and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), point of zero charge (pHpzc) and Boehm titration. The adsorption tests involved adsorption kinetics and equilibrium experiments in a batch system using metallic solution and in a fixed bed column using multi-element metallic and semi-synthetic OGC solution. The characterization results revealed the presence of hydroxyl, carboxyl and carbonyl groups, as well as an irregular and heterogeneous structure, which are favorable characteristics for the adsorption process. The bioadsorbent was able to remove 98.9; 90.9, 77.1 and 100% for Cu
2+
, Pb
2+
, Cr
3+
and OGC, respectively, in a fixed bed adsorption column. It is concluded that bioadsorbent developed has high potential for removing metals and OGC, in addition to being an abundant product in nature, renewable, biodegradable and its reuse contributes to reduce environmental pollution, waste production and improves the local circular economy through the recovery of the by-product.